Ajna Positions NFT-V1

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity 0.8.18;

import {
    AuctionsState,
    Borrower,
    Bucket,
    DepositsState,
    LoansState,
    PoolState
}                   from '../../interfaces/pool/commons/IPoolState.sol';
import {
    DrawDebtResult,
    RepayDebtResult
}                   from '../../interfaces/pool/commons/IPoolInternals.sol';

import {
    _borrowFeeRate,
    _priceAt,
    _isCollateralized
}                           from '../helpers/PoolHelper.sol';
import { 
    _revertIfPriceDroppedBelowLimit,
    _revertOnMinDebt
}                           from '../helpers/RevertsHelper.sol';

import { Deposits } from '../internal/Deposits.sol';
import { Loans }    from '../internal/Loans.sol';
import { Maths }    from '../internal/Maths.sol';

import { SettlerActions } from './SettlerActions.sol';

/**
    @title  BorrowerActions library
    @notice External library containing logic for for pool actors:
            - `Borrowers`: pledge collateral and draw debt; repay debt and pull collateral
 */
library BorrowerActions {

    /*************************/
    /*** Local Var Structs ***/
    /*************************/

    /// @dev Struct used for `drawDebt` function local vars.
    struct DrawDebtLocalVars {
        bool    borrow;                // true if borrow action
        uint256 borrowerDebt;          // [WAD] borrower's accrued debt
        uint256 t0BorrowAmount;        // [WAD] t0 amount to borrow
        uint256 t0DebtChange;          // [WAD] additional t0 debt resulted from draw debt action
        bool    pledge;                // true if pledge action
        bool    stampNpTpRatio;        // true if loan's Np to Tp ratio should be restamped (when drawing debt or pledge settles auction)
    }

    /// @dev Struct used for `repayDebt` function local vars.
    struct RepayDebtLocalVars {
        uint256 borrowerDebt;          // [WAD] borrower's accrued debt
        bool    pull;                  // true if pull action
        bool    repay;                 // true if repay action
        bool    stampNpTpRatio;        // true if loan's Np to Tp ratio should be restamped (when repay settles auction or pull collateral)
        uint256 t0RepaidDebt;          // [WAD] t0 debt repaid
    }

    /**************/
    /*** Events ***/
    /**************/

    // See `IPoolEvents` for descriptions
    event LoanStamped(address indexed borrowerAddress);

    /**************/
    /*** Errors ***/
    /**************/

    // See `IPoolErrors` for descriptions
    error AuctionActive();
    error BorrowerNotSender();
    error BorrowerUnderCollateralized();
    error InsufficientLiquidity();
    error InsufficientCollateral();
    error InvalidAmount();
    error LimitIndexExceeded();
    error NoDebt();

    /***************************/
    /***  External Functions ***/
    /***************************/

    /**
     *  @notice See `IERC20PoolBorrowerActions` and `IERC721PoolBorrowerActions` for descriptions
     *  @dev    === Write state ===
     *  @dev    - `Loans.update` (`_upsert`):
     *  @dev      insert or update loan in loans array
     *  @dev      remove loan from loans array
     *  @dev      update borrower in `address => borrower` mapping
     *  @dev    === Reverts on ===
     *  @dev    not enough quote tokens available `InsufficientLiquidity()`
     *  @dev    borrower not sender `BorrowerNotSender()`
     *  @dev    borrower debt less than pool min debt `AmountLTMinDebt()`
     *  @dev    limit price reached `LimitIndexExceeded()`
     *  @dev    borrower cannot draw more debt `BorrowerUnderCollateralized()`
     *  @dev    borrower cannot be in auction `AuctionActive()`
     */
    function drawDebt(
        AuctionsState storage auctions_,
        DepositsState storage deposits_,
        LoansState    storage loans_,
        PoolState calldata poolState_,
        uint256 maxAvailable_,
        address borrowerAddress_,
        uint256 amountToBorrow_,
        uint256 limitIndex_,
        uint256 collateralToPledge_
    ) external returns (
        DrawDebtResult memory result_
    ) {
        // revert if not enough pool balance to borrow
        if (amountToBorrow_ > maxAvailable_) revert InsufficientLiquidity();

        // revert if borrower is in auction
        if (_inAuction(auctions_, borrowerAddress_)) revert AuctionActive();

        DrawDebtLocalVars memory vars;
        vars.pledge = collateralToPledge_ != 0;
        vars.borrow = amountToBorrow_ != 0;

        // revert if no amount to pledge or borrow
        if (!vars.pledge && !vars.borrow) revert InvalidAmount();

        Borrower memory borrower = loans_.borrowers[borrowerAddress_];

        vars.borrowerDebt = Maths.wmul(borrower.t0Debt, poolState_.inflator);

        result_.debtPreAction       = borrower.t0Debt;
        result_.collateralPreAction = borrower.collateral;
        result_.t0PoolDebt          = poolState_.t0Debt;
        result_.poolDebt            = poolState_.debt;
        result_.poolCollateral      = poolState_.collateral;
        result_.remainingCollateral = borrower.collateral;

        if (vars.pledge) {
            // add new amount of collateral to pledge to borrower balance
            borrower.collateral  += collateralToPledge_;

            result_.remainingCollateral += collateralToPledge_;
            result_.newLup              = Deposits.getLup(deposits_, result_.poolDebt);

            // add new amount of collateral to pledge to pool balance
            result_.poolCollateral += collateralToPledge_;
        }

        if (vars.borrow) {
            // only intended recipient can borrow quote
            if (borrowerAddress_ != msg.sender) revert BorrowerNotSender();

            vars.t0BorrowAmount = Maths.ceilWdiv(amountToBorrow_, poolState_.inflator);

            // t0 debt change is t0 amount to borrow plus the origination fee
            vars.t0DebtChange = Maths.wmul(vars.t0BorrowAmount, _borrowFeeRate(poolState_.rate) + Maths.WAD);

            borrower.t0Debt += vars.t0DebtChange;

            vars.borrowerDebt = Maths.wmul(borrower.t0Debt, poolState_.inflator);

            // check that drawing debt doesn't leave borrower debt under pool min debt amount
            _revertOnMinDebt(
                loans_,
                result_.poolDebt,
                vars.borrowerDebt,
                poolState_.quoteTokenScale
            );

            // add debt change to pool's debt
            result_.t0PoolDebt += vars.t0DebtChange;
            result_.poolDebt   = Maths.wmul(result_.t0PoolDebt, poolState_.inflator);
            result_.newLup     = Deposits.getLup(deposits_, result_.poolDebt);

            // revert if borrow drives LUP price under the specified price limit
            _revertIfPriceDroppedBelowLimit(result_.newLup, limitIndex_);

            // use new lup to check borrow action won't push borrower into a state of under-collateralization
            // this check also covers the scenario when loan is already auctioned
            if (!_isCollateralized(vars.borrowerDebt, borrower.collateral, result_.newLup, poolState_.poolType)) {
                revert BorrowerUnderCollateralized();
            }

            // stamp borrower Np to Tp ratio when draw debt
            vars.stampNpTpRatio = true;
        }

        // update loan state
        Loans.update(
            loans_,
            borrower,
            borrowerAddress_,
            poolState_.rate,
            false,                          // loan not in auction
            vars.stampNpTpRatio
        );

        result_.debtPostAction       = borrower.t0Debt;
        result_.collateralPostAction = borrower.collateral;
    }

    /**
     *  @notice See `IERC20PoolBorrowerActions` and `IERC721PoolBorrowerActions` for descriptions
     *  @dev    === Write state ===
     *  @dev    - `Loans.update` (`_upsert`):
     *  @dev      insert or update loan in loans array
     *  @dev      remove loan from loans array
     *  @dev      update borrower in `address => borrower` mapping
     *  @dev    === Reverts on ===
     *  @dev    no debt to repay `NoDebt()`
     *  @dev    borrower debt less than pool min debt `AmountLTMinDebt()`
     *  @dev    borrower not sender `BorrowerNotSender()`
     *  @dev    not enough collateral to pull `InsufficientCollateral()`
     *  @dev    limit price reached `LimitIndexExceeded()`
     *  @dev    borrower cannot be in auction `AuctionActive()`
     */
    function repayDebt(
        AuctionsState storage auctions_,
        DepositsState storage deposits_,
        LoansState    storage loans_,
        PoolState calldata poolState_,
        address borrowerAddress_,
        uint256 maxQuoteTokenAmountToRepay_,
        uint256 collateralAmountToPull_,
        uint256 limitIndex_
    ) external returns (
        RepayDebtResult memory result_
    ) {
        RepayDebtLocalVars memory vars;
        vars.repay = maxQuoteTokenAmountToRepay_ != 0;
        vars.pull  = collateralAmountToPull_     != 0;

        // revert if no amount to pull or repay
        if (!vars.repay && !vars.pull) revert InvalidAmount();

        if (_inAuction(auctions_, borrowerAddress_)) revert AuctionActive();

        Borrower memory borrower = loans_.borrowers[borrowerAddress_];

        vars.borrowerDebt = Maths.wmul(borrower.t0Debt, poolState_.inflator);

        result_.debtPreAction       = borrower.t0Debt;
        result_.collateralPreAction = borrower.collateral;
        result_.t0PoolDebt          = poolState_.t0Debt;
        result_.poolDebt            = poolState_.debt;
        result_.poolCollateral      = poolState_.collateral;
        result_.remainingCollateral = borrower.collateral;

        if (vars.repay) {
            if (borrower.t0Debt == 0) revert NoDebt();

            if (maxQuoteTokenAmountToRepay_ == type(uint256).max) {
                vars.t0RepaidDebt = borrower.t0Debt;
            } else {
                vars.t0RepaidDebt = Maths.min(
                    borrower.t0Debt,
                    Maths.floorWdiv(maxQuoteTokenAmountToRepay_, poolState_.inflator)
                );
            }

            result_.quoteTokenToRepay = Maths.ceilWmul(vars.t0RepaidDebt, poolState_.inflator);
            // revert if (due to roundings) calculated token amount to repay is 0
            if (result_.quoteTokenToRepay == 0) revert InvalidAmount();

            result_.t0PoolDebt -= vars.t0RepaidDebt;
            result_.poolDebt   = Maths.wmul(result_.t0PoolDebt, poolState_.inflator);

            vars.borrowerDebt = Maths.wmul(borrower.t0Debt - vars.t0RepaidDebt, poolState_.inflator);

            // check that paying the loan doesn't leave borrower debt under min debt amount
            _revertOnMinDebt(
                loans_,
                result_.poolDebt,
                vars.borrowerDebt,
                poolState_.quoteTokenScale
            );

            result_.newLup = Deposits.getLup(deposits_, result_.poolDebt);
            borrower.t0Debt -= vars.t0RepaidDebt;
        }

        if (vars.pull) {
            // only intended recipient can pull collateral
            if (borrowerAddress_ != msg.sender) revert BorrowerNotSender();

            // calculate LUP only if it wasn't calculated in repay action
            if (!vars.repay) result_.newLup = Deposits.getLup(deposits_, result_.poolDebt);

            // prevent underflow
            if (collateralAmountToPull_ > borrower.collateral) 
                revert InsufficientCollateral();

            // check collateralization
            borrower.collateral -= collateralAmountToPull_;
            if (!_isCollateralized(vars.borrowerDebt, borrower.collateral, result_.newLup, poolState_.poolType)) 
                revert InsufficientCollateral();

            // stamp borrower Np to Tp ratio when pull collateral action
            vars.stampNpTpRatio = true;

            result_.poolCollateral -= collateralAmountToPull_;
        }

        // check limit price and revert if price dropped below
        _revertIfPriceDroppedBelowLimit(result_.newLup, limitIndex_);

        // update loan state
        Loans.update(
            loans_,
            borrower,
            borrowerAddress_,
            poolState_.rate,
            false,                         // loan not in auction
            vars.stampNpTpRatio
        );

        result_.debtPostAction       = borrower.t0Debt;
        result_.collateralPostAction = borrower.collateral;
    }

    /**
     *  @notice See `IPoolBorrowerActions` for descriptions
     *  @dev    === Write state ===
     *  @dev    - `Loans.update` (`_upsert`):
     *  @dev      insert or update loan in loans array
     *  @dev      remove loan from loans array
     *  @dev      update borrower in `address => borrower` mapping
     *  @dev    === Reverts on ===
     *  @dev    auction active `AuctionActive()`
     *  @dev    loan not fully collateralized `BorrowerUnderCollateralized()`
     *  @dev    === Emit events ===
     *  @dev    - `LoanStamped`
     */
    function stampLoan(
        AuctionsState storage auctions_,
        DepositsState storage deposits_,
        LoansState    storage loans_,
        PoolState calldata poolState_
    ) external returns (
        uint256 newLup_
    ) {
        // revert if loan is in auction
        if (_inAuction(auctions_, msg.sender)) revert AuctionActive();

        Borrower memory borrower = loans_.borrowers[msg.sender];

        newLup_ = Deposits.getLup(deposits_, poolState_.debt);

        // revert if loan is not fully collateralized at current LUP
        if (
            !_isCollateralized(
                Maths.wmul(borrower.t0Debt, poolState_.inflator), // current borrower debt
                borrower.collateral,
                newLup_,
                poolState_.poolType
            )
        ) revert BorrowerUnderCollateralized();

        // update loan state to stamp Np to Tp ratio
        Loans.update(
            loans_,
            borrower,
            msg.sender,
            poolState_.rate,
            false,          // loan not in auction
            true            // stamp Np to Tp ratio of the loan
        );

        emit LoanStamped(msg.sender);
    }

    /**********************/
    /*** View Functions ***/
    /**********************/

    /**
     *  @notice Returns `true` if borrower is in auction.
     *  @dev    Used to accuratley increment and decrement `t0DebtInAuction` accumulator.
     *  @param  auctions_ Struct for pool auctions state.
     *  @param  borrower_ Borrower address to check auction status for.
     *  @return `True` if borrower is in auction.
     */
    function _inAuction(
        AuctionsState storage auctions_,
        address borrower_
    ) internal view returns (bool) {
        return auctions_.liquidations[borrower_].kickTime != 0;
    }

}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity 0.8.18;

import { Math } from '@openzeppelin/contracts/utils/math/Math.sol';

import { Bucket, Lender } from '../../interfaces/pool/commons/IPoolState.sol';

import { Maths } from './Maths.sol';

/**
    @title  Buckets library
    @notice Internal library containing common logic for buckets management.
 */
library Buckets {

    /**************/
    /*** Events ***/
    /**************/

    // See `IPoolError` for descriptions
    error BucketBankruptcyBlock();

    /***********************************/
    /*** Bucket Management Functions ***/
    /***********************************/

    /**
     *  @notice Add collateral to a bucket and updates `LP` for bucket and lender with the amount coresponding to collateral amount added.
     *  @dev    Increment `bucket.collateral` and `bucket.lps` accumulator
     *  @dev    - `addLenderLP`:
     *  @dev    increment `lender.lps` accumulator and `lender.depositTime` state
     *  @param  lender_                Address of the lender.
     *  @param  deposit_               Current bucket deposit (quote tokens). Used to calculate bucket's exchange rate / `LP`.
     *  @param  collateralAmountToAdd_ Additional collateral amount to add to bucket.
     *  @param  bucketPrice_           Bucket price.
     *  @return addedLP_               Amount of bucket `LP` for the collateral amount added.
     */
    function addCollateral(
        Bucket storage bucket_,
        address lender_,
        uint256 deposit_,
        uint256 collateralAmountToAdd_,
        uint256 bucketPrice_
    ) internal returns (uint256 addedLP_) {
        // cannot deposit in the same block when bucket becomes insolvent
        uint256 bankruptcyTime = bucket_.bankruptcyTime;
        if (bankruptcyTime == block.timestamp) revert BucketBankruptcyBlock();

        // calculate amount of LP to be added for the amount of collateral added to bucket
        addedLP_ = collateralToLP(
            bucket_.collateral,
            bucket_.lps,
            deposit_,
            collateralAmountToAdd_,
            bucketPrice_,
            Math.Rounding.Down
        );
        // update bucket LP balance and collateral

        // update bucket collateral
        bucket_.collateral += collateralAmountToAdd_;
        // update bucket and lender LP balance and deposit timestamp
        bucket_.lps += addedLP_;

        addLenderLP(bucket_, bankruptcyTime, lender_, addedLP_);
    }

    /**
     *  @notice Add amount of `LP` for a given lender in a given bucket.
     *  @dev    Increments lender lps accumulator and updates the deposit time.
     *  @param  bucket_         Bucket to record lender `LP`.
     *  @param  bankruptcyTime_ Time when bucket become insolvent.
     *  @param  lender_         Lender address to add `LP` for in the given bucket.
     *  @param  lpAmount_       Amount of `LP` to be recorded for the given lender.
     */
    function addLenderLP(
        Bucket storage bucket_,
        uint256 bankruptcyTime_,
        address lender_,
        uint256 lpAmount_
    ) internal {
        if (lpAmount_ != 0) {
            Lender storage lender = bucket_.lenders[lender_];

            if (bankruptcyTime_ >= lender.depositTime) lender.lps = lpAmount_;
            else lender.lps += lpAmount_;

            lender.depositTime = block.timestamp;
        }
    }

    /**********************/
    /*** View Functions ***/
    /**********************/

    /****************************/
    /*** Assets to LP helpers ***/
    /****************************/

    /**
     *  @notice Returns the amount of bucket `LP` calculated for the given amount of collateral.
     *  @param  bucketCollateral_ Amount of collateral in bucket.
     *  @param  bucketLP_         Amount of `LP` in bucket.
     *  @param  deposit_          Current bucket deposit (quote tokens). Used to calculate bucket's exchange rate / `LP`.
     *  @param  collateral_       The amount of collateral to calculate bucket LP for.
     *  @param  bucketPrice_      Bucket's price.
     *  @param  rounding_         The direction of rounding when calculating LP (down when adding, up when removing collateral from pool).
     *  @return Amount of `LP` calculated for the amount of collateral.
     */
    function collateralToLP(
        uint256 bucketCollateral_,
        uint256 bucketLP_,
        uint256 deposit_,
        uint256 collateral_,
        uint256 bucketPrice_,
        Math.Rounding rounding_
    ) internal pure returns (uint256) {
        // case when there's no deposit nor collateral in bucket
        if (deposit_ == 0 && bucketCollateral_ == 0) return Maths.wmul(collateral_, bucketPrice_);

        // case when there's deposit or collateral in bucket but no LP to cover
        if (bucketLP_ == 0) return Maths.wmul(collateral_, bucketPrice_);

        // case when there's deposit or collateral and bucket has LP balance
        return Math.mulDiv(
            bucketLP_,
            collateral_ * bucketPrice_,
            deposit_ * Maths.WAD + bucketCollateral_ * bucketPrice_,
            rounding_
        );
    }

    /**
     *  @notice Returns the amount of `LP` calculated for the given amount of quote tokens.
     *  @param  bucketCollateral_ Amount of collateral in bucket.
     *  @param  bucketLP_         Amount of `LP` in bucket.
     *  @param  deposit_          Current bucket deposit (quote tokens). Used to calculate bucket's exchange rate / `LP`.
     *  @param  quoteTokens_      The amount of quote tokens to calculate `LP` amount for.
     *  @param  bucketPrice_      Bucket's price.
     *  @param  rounding_         The direction of rounding when calculating LP (down when adding, up when removing quote tokens from pool).
     *  @return The amount of `LP` coresponding to the given quote tokens in current bucket.
     */
    function quoteTokensToLP(
        uint256 bucketCollateral_,
        uint256 bucketLP_,
        uint256 deposit_,
        uint256 quoteTokens_,
        uint256 bucketPrice_,
        Math.Rounding rounding_
    ) internal pure returns (uint256) {
        // case when there's no deposit nor collateral in bucket
        if (deposit_ == 0 && bucketCollateral_ == 0) return quoteTokens_;

        // case when there's deposit or collateral in bucket but no LP to cover
        if (bucketLP_ == 0) return quoteTokens_;

        // case when there's deposit or collateral and bucket has LP balance
        return Math.mulDiv(
            bucketLP_,
            quoteTokens_ * Maths.WAD,
            deposit_ * Maths.WAD + bucketCollateral_ * bucketPrice_,
            rounding_
        );
    }

    /****************************/
    /*** LP to Assets helpers ***/
    /****************************/

    /**
     *  @notice Returns the amount of collateral calculated for the given amount of lp
     *  @dev    The value returned is not capped at collateral amount available in bucket.
     *  @param  bucketCollateral_ Amount of collateral in bucket.
     *  @param  bucketLP_         Amount of `LP` in bucket.
     *  @param  deposit_          Current bucket deposit (quote tokens). Used to calculate bucket's exchange rate / `LP`.
     *  @param  lp_               The amount of LP to calculate collateral amount for.
     *  @param  bucketPrice_      Bucket's price.
     *  @return The amount of collateral coresponding to the given `LP` in current bucket.
     */
    function lpToCollateral(
        uint256 bucketCollateral_,
        uint256 bucketLP_,
        uint256 deposit_,
        uint256 lp_,
        uint256 bucketPrice_,
        Math.Rounding rounding_
    ) internal pure returns (uint256) {
        // case when there's no deposit nor collateral in bucket
        if (deposit_ == 0 && bucketCollateral_ == 0) return Maths.wdiv(lp_, bucketPrice_);

        // case when there's deposit or collateral in bucket but no LP to cover
        if (bucketLP_ == 0) return Maths.wdiv(lp_, bucketPrice_);

        // case when there's deposit or collateral and bucket has LP balance
        return Math.mulDiv(
            deposit_ * Maths.WAD + bucketCollateral_ * bucketPrice_,
            lp_,
            bucketLP_ * bucketPrice_,
            rounding_
        );
    }

    /**
     *  @notice Returns the amount of quote token (in value) calculated for the given amount of `LP`.
     *  @dev    The value returned is not capped at available bucket deposit.
     *  @param  bucketCollateral_ Amount of collateral in bucket.
     *  @param  bucketLP_         Amount of `LP` in bucket.
     *  @param  deposit_          Current bucket deposit (quote tokens). Used to calculate bucket's exchange rate / `LP`.
     *  @param  lp_               The amount of LP to calculate quote tokens amount for.
     *  @param  bucketPrice_      Bucket's price.
     *  @return The amount coresponding to the given quote tokens in current bucket.
     */
    function lpToQuoteTokens(
        uint256 bucketCollateral_,
        uint256 bucketLP_,
        uint256 deposit_,
        uint256 lp_,
        uint256 bucketPrice_,
        Math.Rounding rounding_
    ) internal pure returns (uint256) {
        // case when there's no deposit nor collateral in bucket
        if (deposit_ == 0 && bucketCollateral_ == 0) return lp_;

        // case when there's deposit or collateral in bucket but no LP to cover
        if (bucketLP_ == 0) return lp_;

        // case when there's deposit or collateral and bucket has LP balance
        return Math.mulDiv(
            deposit_ * Maths.WAD + bucketCollateral_ * bucketPrice_,
            lp_,
            bucketLP_ * Maths.WAD,
            rounding_
        );
    }

    /****************************/
    /*** Exchange Rate helper ***/
    /****************************/

    /**
     *  @notice Returns the exchange rate for a given bucket (conversion of 1 lp to quote token).
     *  @param  bucketCollateral_ Amount of collateral in bucket.
     *  @param  bucketLP_         Amount of `LP` in bucket.
     *  @param  bucketDeposit_    The amount of quote tokens deposited in the given bucket.
     *  @param  bucketPrice_      Bucket's price.
     */
    function getExchangeRate(
        uint256 bucketCollateral_,
        uint256 bucketLP_,
        uint256 bucketDeposit_,
        uint256 bucketPrice_
    ) internal pure returns (uint256) {
        return lpToQuoteTokens(
            bucketCollateral_,
            bucketLP_,
            bucketDeposit_,
            Maths.WAD,
            bucketPrice_,
            Math.Rounding.Up
        );
    }
}

// SPDX-License-Identifier: BSD
pragma solidity ^0.8.4;

/// @title Clone
/// @author zefram.eth
/// @notice Provides helper functions for reading immutable args from calldata
contract Clone {
    /// @notice Reads an immutable arg with type address
    /// @param argOffset The offset of the arg in the packed data
    /// @return arg The arg value
    function _getArgAddress(uint256 argOffset)
        internal
        pure
        returns (address arg)
    {
        uint256 offset = _getImmutableArgsOffset();
        // solhint-disable-next-line no-inline-assembly
        assembly {
            arg := shr(0x60, calldataload(add(offset, argOffset)))
        }
    }

    /// @notice Reads an immutable arg with type uint256
    /// @param argOffset The offset of the arg in the packed data
    /// @return arg The arg value
    function _getArgUint256(uint256 argOffset)
        internal
        pure
        returns (uint256 arg)
    {
        uint256 offset = _getImmutableArgsOffset();
        // solhint-disable-next-line no-inline-assembly
        assembly {
            arg := calldataload(add(offset, argOffset))
        }
    }

    /// @notice Reads a uint256 array stored in the immutable args.
    /// @param argOffset The offset of the arg in the packed data
    /// @param arrLen Number of elements in the array
    /// @return arr The array
    function _getArgUint256Array(uint256 argOffset, uint64 arrLen)
        internal
        pure
      returns (uint256[] memory arr)
    {
      uint256 offset = _getImmutableArgsOffset();
      uint256 el;
      arr = new uint256[](arrLen);
      for (uint64 i = 0; i < arrLen; i++) {
        assembly {
          // solhint-disable-next-line no-inline-assembly
          el := calldataload(add(add(offset, argOffset), mul(i, 32)))
        }
        arr[i] = el;
      }
      return arr;
    }

    /// @notice Reads an immutable arg with type uint64
    /// @param argOffset The offset of the arg in the packed data
    /// @return arg The arg value
    function _getArgUint64(uint256 argOffset)
        internal
        pure
        returns (uint64 arg)
    {
        uint256 offset = _getImmutableArgsOffset();
        // solhint-disable-next-line no-inline-assembly
        assembly {
            arg := shr(0xc0, calldataload(add(offset, argOffset)))
        }
    }

    /// @notice Reads an immutable arg with type uint8
    /// @param argOffset The offset of the arg in the packed data
    /// @return arg The arg value
    function _getArgUint8(uint256 argOffset) internal pure returns (uint8 arg) {
        uint256 offset = _getImmutableArgsOffset();
        // solhint-disable-next-line no-inline-assembly
        assembly {
            arg := shr(0xf8, calldataload(add(offset, argOffset)))
        }
    }

    /// @return offset The offset of the packed immutable args in calldata
    function _getImmutableArgsOffset() internal pure returns (uint256 offset) {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            offset := sub(
                calldatasize(),
                add(shr(240, calldataload(sub(calldatasize(), 2))), 2)
            )
        }
    }
}

// SPDX-License-Identifier: BSD

pragma solidity ^0.8.4;

/// @title ClonesWithImmutableArgs
/// @author wighawag, zefram.eth
/// @notice Enables creating clone contracts with immutable args
library ClonesWithImmutableArgs {
    error CreateFail();

    /// @notice Creates a clone proxy of the implementation contract, with immutable args
    /// @dev data cannot exceed 65535 bytes, since 2 bytes are used to store the data length
    /// @param implementation The implementation contract to clone
    /// @param data Encoded immutable args
    /// @return instance The address of the created clone
    function clone(address implementation, bytes memory data)
        internal
        returns (address payable instance)
    {
        // unrealistic for memory ptr or data length to exceed 256 bits
        unchecked {
            uint256 extraLength = data.length + 2; // +2 bytes for telling how much data there is appended to the call
            uint256 creationSize = 0x41 + extraLength;
            uint256 runSize = creationSize - 10;
            uint256 dataPtr;
            uint256 ptr;
            // solhint-disable-next-line no-inline-assembly
            assembly {
                ptr := mload(0x40)

                // -------------------------------------------------------------------------------------------------------------
                // CREATION (10 bytes)
                // -------------------------------------------------------------------------------------------------------------

                // 61 runtime  | PUSH2 runtime (r)     | r                       | –
                mstore(
                    ptr,
                    0x6100000000000000000000000000000000000000000000000000000000000000
                )
                mstore(add(ptr, 0x01), shl(240, runSize)) // size of the contract running bytecode (16 bits)

                // creation size = 0a
                // 3d          | RETURNDATASIZE        | 0 r                     | –
                // 81          | DUP2                  | r 0 r                   | –
                // 60 creation | PUSH1 creation (c)    | c r 0 r                 | –
                // 3d          | RETURNDATASIZE        | 0 c r 0 r               | –
                // 39          | CODECOPY              | 0 r                     | [0-runSize): runtime code
                // f3          | RETURN                |                         | [0-runSize): runtime code

                // -------------------------------------------------------------------------------------------------------------
                // RUNTIME (55 bytes + extraLength)
                // -------------------------------------------------------------------------------------------------------------

                // 3d          | RETURNDATASIZE        | 0                       | –
                // 3d          | RETURNDATASIZE        | 0 0                     | –
                // 3d          | RETURNDATASIZE        | 0 0 0                   | –
                // 3d          | RETURNDATASIZE        | 0 0 0 0                 | –
                // 36          | CALLDATASIZE          | cds 0 0 0 0             | –
                // 3d          | RETURNDATASIZE        | 0 cds 0 0 0 0           | –
                // 3d          | RETURNDATASIZE        | 0 0 cds 0 0 0 0         | –
                // 37          | CALLDATACOPY          | 0 0 0 0                 | [0, cds) = calldata
                // 61          | PUSH2 extra           | extra 0 0 0 0           | [0, cds) = calldata
                mstore(
                    add(ptr, 0x03),
                    0x3d81600a3d39f33d3d3d3d363d3d376100000000000000000000000000000000
                )
                mstore(add(ptr, 0x13), shl(240, extraLength))

                // 60 0x37     | PUSH1 0x37            | 0x37 extra 0 0 0 0      | [0, cds) = calldata // 0x37 (55) is runtime size - data
                // 36          | CALLDATASIZE          | cds 0x37 extra 0 0 0 0  | [0, cds) = calldata
                // 39          | CODECOPY              | 0 0 0 0                 | [0, cds) = calldata, [cds, cds+0x37) = extraData
                // 36          | CALLDATASIZE          | cds 0 0 0 0             | [0, cds) = calldata, [cds, cds+0x37) = extraData
                // 61 extra    | PUSH2 extra           | extra cds 0 0 0 0       | [0, cds) = calldata, [cds, cds+0x37) = extraData
                mstore(
                    add(ptr, 0x15),
                    0x6037363936610000000000000000000000000000000000000000000000000000
                )
                mstore(add(ptr, 0x1b), shl(240, extraLength))

                // 01          | ADD                   | cds+extra 0 0 0 0       | [0, cds) = calldata, [cds, cds+0x37) = extraData
                // 3d          | RETURNDATASIZE        | 0 cds 0 0 0 0           | [0, cds) = calldata, [cds, cds+0x37) = extraData
                // 73 addr     | PUSH20 0x123…         | addr 0 cds 0 0 0 0      | [0, cds) = calldata, [cds, cds+0x37) = extraData
                mstore(
                    add(ptr, 0x1d),
                    0x013d730000000000000000000000000000000000000000000000000000000000
                )
                mstore(add(ptr, 0x20), shl(0x60, implementation))

                // 5a          | GAS                   | gas addr 0 cds 0 0 0 0  | [0, cds) = calldata, [cds, cds+0x37) = extraData
                // f4          | DELEGATECALL          | success 0 0             | [0, cds) = calldata, [cds, cds+0x37) = extraData
                // 3d          | RETURNDATASIZE        | rds success 0 0         | [0, cds) = calldata, [cds, cds+0x37) = extraData
                // 3d          | RETURNDATASIZE        | rds rds success 0 0     | [0, cds) = calldata, [cds, cds+0x37) = extraData
                // 93          | SWAP4                 | 0 rds success 0 rds     | [0, cds) = calldata, [cds, cds+0x37) = extraData
                // 80          | DUP1                  | 0 0 rds success 0 rds   | [0, cds) = calldata, [cds, cds+0x37) = extraData
                // 3e          | RETURNDATACOPY        | success 0 rds           | [0, rds) = return data (there might be some irrelevant leftovers in memory [rds, cds+0x37) when rds < cds+0x37)
                // 60 0x35     | PUSH1 0x35            | 0x35 sucess 0 rds       | [0, rds) = return data
                // 57          | JUMPI                 | 0 rds                   | [0, rds) = return data
                // fd          | REVERT                | –                       | [0, rds) = return data
                // 5b          | JUMPDEST              | 0 rds                   | [0, rds) = return data
                // f3          | RETURN                | –                       | [0, rds) = return data
                mstore(
                    add(ptr, 0x34),
                    0x5af43d3d93803e603557fd5bf300000000000000000000000000000000000000
                )
            }

            // -------------------------------------------------------------------------------------------------------------
            // APPENDED DATA (Accessible from extcodecopy)
            // (but also send as appended data to the delegatecall)
            // -------------------------------------------------------------------------------------------------------------

            extraLength -= 2;
            uint256 counter = extraLength;
            uint256 copyPtr = ptr + 0x41;
            // solhint-disable-next-line no-inline-assembly
            assembly {
                dataPtr := add(data, 32)
            }
            for (; counter >= 32; counter -= 32) {
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    mstore(copyPtr, mload(dataPtr))
                }

                copyPtr += 32;
                dataPtr += 32;
            }
            uint256 mask = ~(256**(32 - counter) - 1);
            // solhint-disable-next-line no-inline-assembly
            assembly {
                mstore(copyPtr, and(mload(dataPtr), mask))
            }
            copyPtr += counter;
            // solhint-disable-next-line no-inline-assembly
            assembly {
                mstore(copyPtr, shl(240, extraLength))
            }
            // solhint-disable-next-line no-inline-assembly
            assembly {
                instance := create(0, ptr, creationSize)
            }
            if (instance == address(0)) {
                revert CreateFail();
            }
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity 0.8.18;

import { Math } from '@openzeppelin/contracts/utils/math/Math.sol';

import { DepositsState } from '../../interfaces/pool/commons/IPoolState.sol';

import { _priceAt, MAX_FENWICK_INDEX } from '../helpers/PoolHelper.sol';

import { Maths } from './Maths.sol';

/**
    @title  Deposits library
    @notice Internal library containing common logic for deposits management.
    @dev    Implemented as `Fenwick Tree` data structure.
 */
library Deposits {

    /// @dev Max index supported in the `Fenwick` tree
    uint256 internal constant SIZE = 8192;

    /**************/
    /*** Errors ***/
    /**************/

    // See `IPoolErrors` for descriptions
    error InvalidAmount();

    /**
     *  @notice Increase a value in the FenwickTree at an index.
     *  @dev    Starts at leaf/target and moved up towards root
     *  @dev    === Reverts on ===
     *  @dev    unscaled amount to add is 0 `InvalidAmount()`
     *  @param  deposits_          Deposits state struct.
     *  @param  index_             The deposit index.
     *  @param  unscaledAddAmount_ The unscaled amount to increase deposit by.
     */
    function unscaledAdd(
        DepositsState storage deposits_,
        uint256 index_,
        uint256 unscaledAddAmount_
    ) internal {

        // revert if 0 amount is added.
        if (unscaledAddAmount_ == 0) revert InvalidAmount();

        // price buckets are indexed starting at 0, Fenwick bit logic is more elegant starting at 1
        ++index_;

        // unscaledAddAmount_ is the raw amount to add directly to the value at index_, unaffected by the scale array
        // For example, to denote an amount of deposit added to the array, we would need to call unscaledAdd with
        // (deposit amount) / scale(index).  There are two reasons for this:
        // 1- scale(index) is often already known in the context of where unscaledAdd(..) is called, and we want to avoid
        //    redundant iterations through the Fenwick tree.
        // 2- We often need to precisely change the value in the tree, avoiding the rounding that dividing by scale(index).
        //    This is more relevant to unscaledRemove(...), where we need to ensure the value is precisely set to 0, but we
        //    also prefer it here for consistency.

        uint256 value;
        uint256 scaling;
        uint256 newValue;

        while (index_ <= SIZE) {
            value    = deposits_.values[index_];
            scaling  = deposits_.scaling[index_];

            // Compute the new value to be put in location index_
            newValue = value + unscaledAddAmount_;

            // Update unscaledAddAmount to propogate up the Fenwick tree
            // Note: we can't just multiply addAmount_ by scaling[i_] due to rounding
            // We need to track the precice change in values[i_] in order to ensure
            // obliterated indices remain zero after subsequent adding to related indices
            // if scaling==0, the actual scale value is 1, otherwise it is scaling
            if (scaling != 0) unscaledAddAmount_ = Maths.wmul(newValue, scaling) - Maths.wmul(value, scaling);

            deposits_.values[index_] = newValue;

            // traverse upwards through tree via "update" route
            index_ += lsb(index_);
        }
    }

    /**
     *  @notice Finds index and sum of first bucket that EXCEEDS the given sum
     *  @dev    Used in `LUP` calculation
     *  @param  deposits_      Struct for deposits state.
     *  @param  targetSum_     The sum to find index for.
     *  @return sumIndex_      Smallest index where prefixsum greater than the sum.
     *  @return sumIndexSum_   Sum at index PRECEDING `sumIndex_`.
     *  @return sumIndexScale_ Scale of bucket PRECEDING `sumIndex_`.
     */
    function findIndexAndSumOfSum(
        DepositsState storage deposits_,
        uint256 targetSum_
    ) internal view returns (uint256 sumIndex_, uint256 sumIndexSum_, uint256 sumIndexScale_) {
        // i iterates over bits from MSB to LSB.  We check at each stage if the target sum is to the left or right of sumIndex_+i
        uint256 i  = 4096; // 1 << (_numBits - 1) = 1 << (13 - 1) = 4096
        uint256 runningScale = Maths.WAD;

        // We construct the target sumIndex_ bit by bit, from MSB to LSB.  lowerIndexSum_ always maintains the sum
        // up to the current value of sumIndex_
        uint256 lowerIndexSum;
        uint256 curIndex;
        uint256 value;
        uint256 scaling;
        uint256 scaledValue;

        while (i > 0) {
            // Consider if the target index is less than or greater than sumIndex_ + i
            curIndex = sumIndex_ + i;
            value    = deposits_.values[curIndex];
            scaling  = deposits_.scaling[curIndex];

            // Compute sum up to sumIndex_ + i
            scaledValue =
                lowerIndexSum +
                (
                    scaling != 0 ? Math.mulDiv(
                        runningScale * scaling,
                        value,
                        1e36
                    ) : Maths.wmul(runningScale, value)
                );

            if (scaledValue  < targetSum_) {
                // Target value is too small, need to consider increasing sumIndex_ still
                if (curIndex <= MAX_FENWICK_INDEX) {
                    // sumIndex_+i is in range of Fenwick prices.  Target index has this bit set to 1.  
                    sumIndex_ = curIndex;
                    lowerIndexSum = scaledValue;
                }
            } else {
                // Target index has this bit set to 0
                // scaling == 0 means scale factor == 1, otherwise scale factor == scaling
                if (scaling != 0) runningScale = Maths.floorWmul(runningScale, scaling);

                // Current scaledValue is <= targetSum_, it's a candidate value for sumIndexSum_
                sumIndexSum_   = scaledValue;
                sumIndexScale_ = runningScale;
            }
            // Shift i to next less significant bit
            i = i >> 1;
        }
    }

    /**
     *  @notice Finds index of passed sum. Helper function for `findIndexAndSumOfSum`.
     *  @dev    Used in `LUP` calculation
     *  @param  deposits_ Deposits state struct.
     *  @param  sum_      The sum to find index for.
     *  @return sumIndex_ Smallest index where prefixsum greater than the sum.
     */
    function findIndexOfSum(
        DepositsState storage deposits_,
        uint256 sum_
    ) internal view returns (uint256 sumIndex_) {
        (sumIndex_,,) = findIndexAndSumOfSum(deposits_, sum_);
    }

    /**
     *  @notice Get least significant bit (`LSB`) of integer `i_`.
     *  @dev    Used primarily to decrement the binary index in loops, iterating over range parents.
     *  @param  i_  The integer with which to return the `LSB`.
     */
    function lsb(
        uint256 i_
    ) internal pure returns (uint256 lsb_) {
        if (i_ != 0) {
            // "i & (-i)"
            lsb_ = i_ & ((i_ ^ 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff) + 1);
        }
    }

    /**
     *  @notice Scale values in the tree from the index provided, upwards.
     *  @dev    Starts at passed in node and increments through range parent nodes, and ends at `8192`.
     *  @param  deposits_ Deposits state struct.
     *  @param  index_    The index to start scaling from.
     *  @param  factor_   The factor to scale the values by.
     */
    function mult(
        DepositsState storage deposits_,
        uint256 index_,
        uint256 factor_
    ) internal {
        // price buckets are indexed starting at 0, Fenwick bit logic is more elegant starting at 1
        ++index_;

        uint256 sum;
        uint256 value;
        uint256 scaling;
        uint256 bit = lsb(index_);

        // Starting with the LSB of index, we iteratively move up towards the MSB of SIZE
        // Case 1:     the bit of index_ is set to 1.  In this case, the entire subtree below index_
        //             is scaled.  So, we include factor_ into scaling[index_], and remember in sum how much
        //             we increased the subtree by, so that we can use it in case we encounter 0 bits (below).
        // Case 2:     The bit of index_ is set to 0.  In this case, consider the subtree below the node
        //             index_+bit. The subtree below that is not entirely scaled, but it does contain the
        //             subtree what was scaled earlier.  Therefore: we need to increment it's stored value
        //             (in sum) which was set in a prior interation in case 1.
        while (bit <= SIZE) {
            if ((bit & index_) != 0) {
                // Case 1 as described above
                value   = deposits_.values[index_];
                scaling = deposits_.scaling[index_];

                // Calc sum, will only be stored in range parents of starting node, index_
                if (scaling != 0) {
                    // Note: we can't just multiply by factor_ - 1 in the following line, as rounding will
                    // cause obliterated indices to have nonzero values.  Need to track the actual
                    // precise delta in the value array
                    uint256 scaledFactor = Maths.wmul(factor_, scaling);

                    sum += Maths.wmul(scaledFactor, value) - Maths.wmul(scaling, value);

                    // Apply scaling to all range parents less then starting node, index_
                    deposits_.scaling[index_] = scaledFactor;
                } else {
                    // this node's scale factor is 1
                    sum += Maths.wmul(factor_, value) - value;
                    deposits_.scaling[index_] = factor_;
                }
                // Unset the bit in index to continue traversing up the Fenwick tree
                index_ -= bit;
            } else {
                // Case 2 above.  superRangeIndex is the index of the node to consider that
                //                contains the sub range that was already scaled in prior iteration
                uint256 superRangeIndex = index_ + bit;

                value   = (deposits_.values[superRangeIndex] += sum);
                scaling = deposits_.scaling[superRangeIndex];

                // Need to be careful due to rounding to propagate actual changes upwards in tree.
                // sum is always equal to the actual value we changed deposits_.values[] by
                if (scaling != 0) sum = Maths.wmul(value, scaling) - Maths.wmul(value - sum, scaling);
            }
            // consider next most significant bit
            bit = bit << 1;
        }
    }

    /**
     *  @notice Get prefix sum of all indexes from provided index downwards.
     *  @dev    Starts at tree root and decrements through range parent nodes summing from index `sumIndex_`'s range to index `0`.
     *  @param  deposits_  Deposits state struct.
     *  @param  sumIndex_  The index to receive the prefix sum.
     *  @param  sum_       The prefix sum from current index downwards.
     */
    function prefixSum(
        DepositsState storage deposits_,
        uint256 sumIndex_
    ) internal view returns (uint256 sum_) {
        // price buckets are indexed starting at 0, Fenwick bit logic is more elegant starting at 1
        ++sumIndex_;

        uint256 runningScale = Maths.WAD; // Tracks scale(index_) as we move down Fenwick tree
        uint256 j            = SIZE;      // bit that iterates from MSB to LSB
        uint256 index        = 0;         // build up sumIndex bit by bit

        // Used to terminate loop.  We don't need to consider final 0 bits of sumIndex_
        uint256 indexLSB = lsb(sumIndex_);
        uint256 curIndex;

        while (j >= indexLSB) {
            curIndex = index + j;

            // Skip considering indices outside bounds of Fenwick tree
            if (curIndex > SIZE) continue;

            // We are considering whether to include node index + j in the sum or not.  Either way, we need to scaling[index + j],
            // either to increment sum_ or to accumulate in runningScale
            uint256 scaled = deposits_.scaling[curIndex];

            if (sumIndex_ & j != 0) {
                // node index + j of tree is included in sum
                uint256 value = deposits_.values[curIndex];

                // Accumulate in sum_, recall that scaled==0 means that the scale factor is actually 1
                sum_  += scaled != 0 ? Math.mulDiv(
                    runningScale * scaled,
                    value,
                    1e36
                ) : Maths.wmul(runningScale, value);

                // Build up index bit by bit
                index = curIndex;

                // terminate if we've already matched sumIndex_
                if (index == sumIndex_) break;
            } else {
                // node is not included in sum, but its scale needs to be included for subsequent sums
                if (scaled != 0) runningScale = Maths.floorWmul(runningScale, scaled);
            }
            // shift j to consider next less signficant bit
            j = j >> 1;
        }
    }

    /**
     *  @notice Decrease a node in the `FenwickTree` at an index.
     *  @dev    Starts at leaf/target and moved up towards root.
     *  @dev    === Reverts on ===
     *  @dev    unscaled amount to remove is 0 `InvalidAmount()`
     *  @param  deposits_             Deposits state struct.
     *  @param  index_                The deposit index.
     *  @param  unscaledRemoveAmount_ Unscaled amount to decrease deposit by.
     */
    function unscaledRemove(
        DepositsState storage deposits_,
        uint256 index_,
        uint256 unscaledRemoveAmount_
    ) internal {

        // revert if 0 amount is removed.
        if (unscaledRemoveAmount_ == 0) revert InvalidAmount();

        // price buckets are indexed starting at 0, Fenwick bit logic is more elegant starting at 1
        ++index_;

        // We operate with unscaledRemoveAmount_ here instead of a scaled quantity to avoid duplicate computation of scale factor
        // (thus redundant iterations through the Fenwick tree), and ALSO so that we can set the value of a given deposit exactly
        // to 0.
        
        while (index_ <= SIZE) {
            // Decrement deposits_ at index_ for removeAmount, storing new value in value
            uint256 value   = (deposits_.values[index_] -= unscaledRemoveAmount_);
            uint256 scaling = deposits_.scaling[index_];

            // If scale factor != 1, we need to adjust unscaledRemoveAmount by scale factor to adjust values further up in tree
            // On the line below, it would be tempting to replace this with:
            // unscaledRemoveAmount_ = Maths.wmul(unscaledRemoveAmount, scaling).  This will introduce nonzero values up
            // the tree due to rounding.  It's important to compute the actual change in deposits_.values[index_]
            // and propogate that upwards.
            if (scaling != 0) unscaledRemoveAmount_ = Maths.wmul(value + unscaledRemoveAmount_, scaling) - Maths.wmul(value,  scaling);

            // Traverse upward through the "update" path of the Fenwick tree
            index_ += lsb(index_);
        }
    }

    /**
     *  @notice Scale tree starting from given index.
     *  @dev    Starts at leaf/target and moved up towards root.
     *  @param  deposits_ Deposits state struct.
     *  @param  index_    The deposit index.
     *  @return scaled_   Scaled value.
     */
    function scale(
        DepositsState storage deposits_,
        uint256 index_
    ) internal view returns (uint256 scaled_) {
        // price buckets are indexed starting at 0, Fenwick bit logic is more elegant starting at 1
        ++index_;

        // start with scaled_1 = 1
        scaled_ = Maths.WAD;
        while (index_ <= SIZE) {
            // Traverse up through Fenwick tree via "update" path, accumulating scale factors as we go
            uint256 scaling = deposits_.scaling[index_];
            // scaling==0 means actual scale factor is 1
            if (scaling != 0) scaled_ = Maths.wmul(scaled_, scaling);
            index_ += lsb(index_);
        }
    }

    /**
     *  @notice Returns sum of all deposits.
     *  @param  deposits_ Deposits state struct.
     *  @return Sum of all deposits in tree.
     */
    function treeSum(
        DepositsState storage deposits_
    ) internal view returns (uint256) {
        // In a scaled Fenwick tree, sum is at the root node and never scaled
        return deposits_.values[SIZE];
    }

    /**
     *  @notice Returns deposit value for a given deposit index.
     *  @param  deposits_     Deposits state struct.
     *  @param  index_        The deposit index.
     *  @return depositValue_ Value of the deposit.
     */
    function valueAt(
        DepositsState storage deposits_,
        uint256 index_
    ) internal view returns (uint256 depositValue_) {
        // Get unscaled value at index and multiply by scale
        depositValue_ = Maths.wmul(unscaledValueAt(deposits_, index_), scale(deposits_,index_));
    }

    /**
     *  @notice Returns unscaled (deposit without interest) deposit value for a given deposit index.
     *  @param  deposits_             Deposits state struct.
     *  @param  index_                The deposit index.
     *  @return unscaledDepositValue_ Value of unscaled deposit.
     */
    function unscaledValueAt(
        DepositsState storage deposits_,
        uint256 index_
    ) internal view returns (uint256 unscaledDepositValue_) {
        // In a scaled Fenwick tree, sum is at the root node, but needs to be scaled
        ++index_;

        uint256 j = 1;

        // Returns the unscaled value at the node.  We consider the unscaled value for two reasons:
        // 1- If we want to zero out deposit in bucket, we need to subtract the exact unscaled value
        // 2- We may already have computed the scale factor, so we can avoid duplicate traversal

        unscaledDepositValue_ = deposits_.values[index_];
        uint256 curIndex;
        uint256 value;
        uint256 scaling;

        while (j & index_ == 0) {
            curIndex = index_ - j;

            value   = deposits_.values[curIndex];
            scaling = deposits_.scaling[curIndex];

            unscaledDepositValue_ -= scaling != 0 ? Maths.wmul(scaling, value) : value;
            j = j << 1;
        }
    }

    /**
     *  @notice Returns `LUP` for a given debt value (capped at min bucket price).
     *  @param  deposits_ Deposits state struct.
     *  @param  debt_     The debt amount to calculate `LUP` for.
     *  @return `LUP` for given debt.
     */
    function getLup(
        DepositsState storage deposits_,
        uint256 debt_
    ) internal view returns (uint256) {
        return _priceAt(findIndexOfSum(deposits_, debt_));
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/cryptography/ECDSA.sol)

pragma solidity ^0.8.0;

import "../Strings.sol";

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    enum RecoverError {
        NoError,
        InvalidSignature,
        InvalidSignatureLength,
        InvalidSignatureS,
        InvalidSignatureV // Deprecated in v4.8
    }

    function _throwError(RecoverError error) private pure {
        if (error == RecoverError.NoError) {
            return; // no error: do nothing
        } else if (error == RecoverError.InvalidSignature) {
            revert("ECDSA: invalid signature");
        } else if (error == RecoverError.InvalidSignatureLength) {
            revert("ECDSA: invalid signature length");
        } else if (error == RecoverError.InvalidSignatureS) {
            revert("ECDSA: invalid signature 's' value");
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature` or error string. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     *
     * Documentation for signature generation:
     * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
     * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
        if (signature.length == 65) {
            bytes32 r;
            bytes32 s;
            uint8 v;
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            /// @solidity memory-safe-assembly
            assembly {
                r := mload(add(signature, 0x20))
                s := mload(add(signature, 0x40))
                v := byte(0, mload(add(signature, 0x60)))
            }
            return tryRecover(hash, v, r, s);
        } else {
            return (address(0), RecoverError.InvalidSignatureLength);
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, signature);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
     *
     * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
     *
     * _Available since v4.3._
     */
    function tryRecover(
        bytes32 hash,
        bytes32 r,
        bytes32 vs
    ) internal pure returns (address, RecoverError) {
        bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
        uint8 v = uint8((uint256(vs) >> 255) + 27);
        return tryRecover(hash, v, r, s);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
     *
     * _Available since v4.2._
     */
    function recover(
        bytes32 hash,
        bytes32 r,
        bytes32 vs
    ) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, r, vs);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
     * `r` and `s` signature fields separately.
     *
     * _Available since v4.3._
     */
    function tryRecover(
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address, RecoverError) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
            return (address(0), RecoverError.InvalidSignatureS);
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(hash, v, r, s);
        if (signer == address(0)) {
            return (address(0), RecoverError.InvalidSignature);
        }

        return (signer, RecoverError.NoError);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function recover(
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from a `hash`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
        // 32 is the length in bytes of hash,
        // enforced by the type signature above
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from `s`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
    }

    /**
     * @dev Returns an Ethereum Signed Typed Data, created from a
     * `domainSeparator` and a `structHash`. This produces hash corresponding
     * to the one signed with the
     * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
     * JSON-RPC method as part of EIP-712.
     *
     * See {recover}.
     */
    function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _balances[to] += amount;
        }

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity 0.8.18;

import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { IERC20 }    from "@openzeppelin/contracts/token/ERC20/IERC20.sol";

import { 
    IERC20Pool,
    IERC20PoolBorrowerActions,
    IERC20PoolImmutables,
    IERC20PoolLenderActions
}                              from './interfaces/pool/erc20/IERC20Pool.sol';
import { IERC20Taker }         from './interfaces/pool/erc20/IERC20Taker.sol';

import {
    IPoolLenderActions,
    IPoolKickerActions,
    IPoolTakerActions,
    IPoolSettlerActions
}                            from './interfaces/pool/IPool.sol';
import {
    IERC3156FlashBorrower,
    IERC3156FlashLender
}                            from './interfaces/pool/IERC3156FlashLender.sol';

import {
    DrawDebtResult,
    RepayDebtResult,
    SettleParams,
    SettleResult,
    TakeResult
}                    from './interfaces/pool/commons/IPoolInternals.sol';
import { PoolState } from './interfaces/pool/commons/IPoolState.sol';

import { FlashloanablePool } from './base/FlashloanablePool.sol';

import {
    _getCollateralDustPricePrecisionAdjustment,
    _roundToScale,
    _roundUpToScale
}                                               from './libraries/helpers/PoolHelper.sol';
import { 
    _revertIfAuctionClearable,
    _revertAfterExpiry 
}                               from './libraries/helpers/RevertsHelper.sol';

import { Loans }    from './libraries/internal/Loans.sol';
import { Deposits } from './libraries/internal/Deposits.sol';
import { Maths }    from './libraries/internal/Maths.sol';

import { BorrowerActions } from './libraries/external/BorrowerActions.sol';
import { LenderActions }   from './libraries/external/LenderActions.sol';
import { SettlerActions }  from './libraries/external/SettlerActions.sol';
import { TakerActions }    from './libraries/external/TakerActions.sol';

/**
 *  @title  ERC20 Pool contract
 *  @notice Entrypoint of `ERC20` Pool actions for pool actors:
 *          - `Lenders`: add, remove and move quote tokens; transfer `LP`
 *          - `Borrowers`: draw and repay debt
 *          - `Traders`: add, remove and move quote tokens; add and remove collateral
 *          - `Kickers`: kick undercollateralized loans; settle auctions; claim bond rewards
 *          - `Bidders`: take auctioned collateral
 *          - `Reserve purchasers`: start auctions; take reserves
 *          - `Flash borrowers`: initiate flash loans on quote tokens and collateral
 *  @dev    Contract is `FlashloanablePool` with flash loan logic.
 *  @dev    Contract is base `Pool` with logic to handle `ERC20` collateral.
 *  @dev    Calls logic from external `PoolCommons`, `LenderActions`, `BorrowerActions` and `Auction` actions libraries.
 */
contract ERC20Pool is FlashloanablePool, IERC20Pool {
    using SafeERC20 for IERC20;

    /*****************/
    /*** Constants ***/
    /*****************/

    /// @dev Immutable collateral scale arg offset.
    uint256 internal constant COLLATERAL_SCALE = 93;

    /****************************/
    /*** Initialize Functions ***/
    /****************************/

    /// @inheritdoc IERC20Pool
    function initialize(
        uint256 rate_
    ) external override {
        if (isPoolInitialized) revert AlreadyInitialized();

        inflatorState.inflator       = uint208(1e18);
        inflatorState.inflatorUpdate = uint48(block.timestamp);

        interestState.interestRate       = uint208(rate_);
        interestState.interestRateUpdate = uint48(block.timestamp);

        Loans.init(loans);

        // increment initializations count to ensure these values can't be updated
        isPoolInitialized = true;
    }

    /******************/
    /*** Immutables ***/
    /******************/

    /// @inheritdoc IERC20PoolImmutables
    function collateralScale() external pure override returns (uint256) {
        return _getArgUint256(COLLATERAL_SCALE);
    }

    /// @inheritdoc IERC20Pool
    function bucketCollateralDust(uint256 bucketIndex_) external pure override returns (uint256) {
        return _bucketCollateralDust(bucketIndex_);
    }

    /***********************************/
    /*** Borrower External Functions ***/
    /***********************************/

    /**
     *  @inheritdoc IERC20PoolBorrowerActions
     *  @dev    === Write state ===
     *  @dev    - increment `poolBalances.pledgedCollateral` accumulator
     *  @dev    - increment `poolBalances.t0Debt` accumulator
     *  @dev    - update `t0Debt2ToCollateral` ratio
     *  @dev    === Emit events ===
     *  @dev    - `DrawDebt`
     */
    function drawDebt(
        address borrowerAddress_,
        uint256 amountToBorrow_,
        uint256 limitIndex_,
        uint256 collateralToPledge_
    ) external nonReentrant {
        PoolState memory poolState = _accruePoolInterest();

        // ensure the borrower is not charged for additional debt that they did not receive
        amountToBorrow_     = _roundToScale(amountToBorrow_, poolState.quoteTokenScale);
        // ensure the borrower is not credited with a fractional amount of collateral smaller than the token scale
        collateralToPledge_ = _roundToScale(collateralToPledge_, _getArgUint256(COLLATERAL_SCALE));

        DrawDebtResult memory result = BorrowerActions.drawDebt(
            auctions,
            deposits,
            loans,
            poolState,
            _availableQuoteToken(),
            borrowerAddress_,
            amountToBorrow_,
            limitIndex_,
            collateralToPledge_
        );

        emit DrawDebt(borrowerAddress_, amountToBorrow_, collateralToPledge_, result.newLup);

        // update in memory pool state struct
        poolState.debt       = result.poolDebt;
        poolState.t0Debt     = result.t0PoolDebt;
        poolState.collateral = result.poolCollateral;

        // adjust t0Debt2ToCollateral ratio
        _updateT0Debt2ToCollateral(
            result.debtPreAction,
            result.debtPostAction,
            result.collateralPreAction,
            result.collateralPostAction
        );

        // update pool interest rate state
        _updateInterestState(poolState, result.newLup);

        if (collateralToPledge_ != 0) {
            // update pool balances pledged collateral state
            poolBalances.pledgedCollateral = poolState.collateral;

            // move collateral from sender to pool
            _transferCollateralFrom(msg.sender, collateralToPledge_);
        }

        if (amountToBorrow_ != 0) {
            // update pool balances t0 debt state
            poolBalances.t0Debt = poolState.t0Debt;

            // move borrowed amount from pool to sender
            _transferQuoteToken(msg.sender, amountToBorrow_);
        }
    }

    /**
     *  @inheritdoc IERC20PoolBorrowerActions
     *  @dev    === Write state ===
     *  @dev    - decrement `poolBalances.t0Debt accumulator`
     *  @dev    - decrement `poolBalances.pledgedCollateral accumulator`
     *  @dev    - update `t0Debt2ToCollateral` ratio
     *  @dev    === Emit events ===
     *  @dev    - `RepayDebt`
     */
    function repayDebt(
        address borrowerAddress_,
        uint256 maxQuoteTokenAmountToRepay_,
        uint256 collateralAmountToPull_,
        address collateralReceiver_,
        uint256 limitIndex_
    ) external nonReentrant returns (uint256 amountRepaid_) {
        PoolState memory poolState = _accruePoolInterest();

        // ensure accounting is performed using the appropriate token scale
        if (maxQuoteTokenAmountToRepay_ != type(uint256).max)
            maxQuoteTokenAmountToRepay_ = _roundToScale(maxQuoteTokenAmountToRepay_, poolState.quoteTokenScale);
        collateralAmountToPull_         = _roundToScale(collateralAmountToPull_,     _getArgUint256(COLLATERAL_SCALE));

        RepayDebtResult memory result = BorrowerActions.repayDebt(
            auctions,
            deposits,
            loans,
            poolState,
            borrowerAddress_,
            maxQuoteTokenAmountToRepay_,
            collateralAmountToPull_,
            limitIndex_
        );

        amountRepaid_        = result.quoteTokenToRepay;
        // update in memory pool state struct
        poolState.debt       = result.poolDebt;
        poolState.t0Debt     = result.t0PoolDebt;
        poolState.collateral = result.poolCollateral;

        emit RepayDebt(borrowerAddress_, amountRepaid_, collateralAmountToPull_, result.newLup);

        // adjust t0Debt2ToCollateral ratio
        _updateT0Debt2ToCollateral(
            result.debtPreAction,
            result.debtPostAction,
            result.collateralPreAction,
            result.collateralPostAction
        );

        // update pool interest rate state
        _updateInterestState(poolState, result.newLup);

        if (amountRepaid_ != 0) {
            // update pool balances t0 debt state
            poolBalances.t0Debt = poolState.t0Debt;

            // move amount to repay from sender to pool
            _transferQuoteTokenFrom(msg.sender, amountRepaid_);
        }
        if (collateralAmountToPull_ != 0) {
            // update pool balances pledged collateral state
            poolBalances.pledgedCollateral = poolState.collateral;

            // move collateral from pool to address specified as collateral receiver
            _transferCollateral(collateralReceiver_, collateralAmountToPull_);
        }
    }

    /*********************************/
    /*** Lender External Functions ***/
    /*********************************/

    /**
     *  @inheritdoc IERC20PoolLenderActions
     *  @dev    === Reverts on ===
     *  @dev    - `DustAmountNotExceeded()`
     *  @dev    === Emit events ===
     *  @dev    - `AddCollateral`
     */
    function addCollateral(
        uint256 amountToAdd_,
        uint256 index_,
        uint256 expiry_
    ) external override nonReentrant returns (uint256 bucketLP_) {
        _revertAfterExpiry(expiry_);
        PoolState memory poolState = _accruePoolInterest();

        // revert if the dust amount was not exceeded, but round on the scale amount
        if (amountToAdd_ != 0 && amountToAdd_ < _bucketCollateralDust(index_)) revert DustAmountNotExceeded();
        amountToAdd_ = _roundToScale(amountToAdd_, _getArgUint256(COLLATERAL_SCALE));

        bucketLP_ = LenderActions.addCollateral(
            buckets,
            deposits,
            amountToAdd_,
            index_
        );

        emit AddCollateral(msg.sender, index_, amountToAdd_, bucketLP_);

        // update pool interest rate state
        _updateInterestState(poolState, Deposits.getLup(deposits, poolState.debt));

        // move required collateral from sender to pool
        _transferCollateralFrom(msg.sender, amountToAdd_);
    }

    /**
     *  @inheritdoc IPoolLenderActions
     *  @dev    === Emit events ===
     *  @dev    - `RemoveCollateral`
     */
    function removeCollateral(
        uint256 maxAmount_,
        uint256 index_
    ) external override nonReentrant returns (uint256 removedAmount_, uint256 redeemedLP_) {
        _revertIfAuctionClearable(auctions, loans);

        PoolState memory poolState = _accruePoolInterest();

        // round the collateral amount appropriately based on token precision
        maxAmount_ = _roundToScale(maxAmount_, _getArgUint256(COLLATERAL_SCALE));

        (removedAmount_, redeemedLP_) = LenderActions.removeMaxCollateral(
            buckets,
            deposits,
            _bucketCollateralDust(index_),
            maxAmount_,
            index_
        );

        emit RemoveCollateral(msg.sender, index_, removedAmount_, redeemedLP_);

        // update pool interest rate state
        _updateInterestState(poolState, Deposits.getLup(deposits, poolState.debt));

        // move collateral from pool to lender
        _transferCollateral(msg.sender, removedAmount_);
    }

    /*******************************/
    /*** Pool Auctions Functions ***/
    /*******************************/

    /**
     *  @inheritdoc IPoolSettlerActions
     *  @dev    === Write state ===
     *  @dev    - decrement `poolBalances.t0Debt` accumulator
     *  @dev    - decrement `poolBalances.t0DebtInAuction` accumulator
     *  @dev    - decrement `poolBalances.pledgedCollateral` accumulator
     *  @dev    - no update of `t0Debt2ToCollateral` ratio as debt and collateral pre settle are not taken into account (pre debt and pre collateral = 0)
     *  @dev     and loan is removed from auction queue only when there's no more debt (post debt = 0)
     */
    function settle(
        address borrowerAddress_,
        uint256 maxDepth_
    ) external override nonReentrant returns (uint256 collateralSettled_, bool isBorrowerSettled_) {
        PoolState memory poolState = _accruePoolInterest();

        SettleResult memory result = SettlerActions.settlePoolDebt(
            auctions,
            buckets,
            deposits,
            loans,
            reserveAuction,
            poolState,
            SettleParams({
                borrower:    borrowerAddress_,
                poolBalance: _getNormalizedPoolQuoteTokenBalance(),
                bucketDepth: maxDepth_
            })
        );

        _updatePostSettleState(result, poolState);

        collateralSettled_ = result.collateralSettled;
        isBorrowerSettled_ = (result.debtPostAction == 0);
    }

    /**
     *  @inheritdoc IPoolTakerActions
     *  @dev    === Write state ===
     *  @dev    - decrement `poolBalances.t0Debt` accumulator
     *  @dev    - decrement `poolBalances.t0DebtInAuction` accumulator
     *  @dev    - decrement `poolBalances.pledgedCollateral` accumulator
     *  @dev    - update `t0Debt2ToCollateral` ratio only if auction settled, debt and collateral pre action are considered 0
     */
    function take(
        address        borrowerAddress_,
        uint256        maxAmount_,
        address        callee_,
        bytes calldata data_
    ) external override nonReentrant returns (uint256 collateralTaken_) {
        PoolState memory poolState = _accruePoolInterest();

        uint256 collateralTokenScale = _getArgUint256(COLLATERAL_SCALE);

        // round requested collateral to an amount which can actually be transferred
        maxAmount_ = _roundToScale(maxAmount_, collateralTokenScale);

        TakeResult memory result = TakerActions.take(
            auctions,
            buckets,
            deposits,
            loans,
            poolState,
            borrowerAddress_,
            maxAmount_,
            collateralTokenScale
        );
        // round quote token up to cover the cost of purchasing the collateral
        result.quoteTokenAmount = _roundUpToScale(result.quoteTokenAmount, poolState.quoteTokenScale);

        _updatePostTakeState(result, poolState);

        collateralTaken_ = result.collateralAmount;

        _transferCollateral(callee_, collateralTaken_);

        if (data_.length != 0) {
            IERC20Taker(callee_).atomicSwapCallback(
                collateralTaken_ / collateralTokenScale,
                result.quoteTokenAmount / poolState.quoteTokenScale,
                data_
            );
        }

        _transferQuoteTokenFrom(msg.sender, result.quoteTokenAmount);
    }

    /**
     *  @inheritdoc IPoolTakerActions
     *  @dev    === Write state ===
     *  @dev    - decrement `poolBalances.t0Debt` accumulator
     *  @dev    - decrement `poolBalances.t0DebtInAuction` accumulator
     *  @dev    - decrement `poolBalances.pledgedCollateral` accumulator
     *  @dev    - update `t0Debt2ToCollateral` ratio only if auction settled, debt and collateral pre action are considered 0
     */
    function bucketTake(
        address borrowerAddress_,
        bool    depositTake_,
        uint256 index_
    ) external override nonReentrant {

        PoolState memory poolState = _accruePoolInterest();

        TakeResult memory result = TakerActions.bucketTake(
            auctions,
            buckets,
            deposits,
            loans,
            poolState,
            borrowerAddress_,
            depositTake_,
            index_,
            _getArgUint256(COLLATERAL_SCALE)
        );

        _updatePostTakeState(result, poolState);
    }

    /***************************/
    /*** Flashloan Functions ***/
    /***************************/

    /**
     *  @inheritdoc FlashloanablePool
     *  @dev Override default implementation and allows flashloans for both quote and collateral token.
     */
    function _isFlashloanSupported(
        address token_
    ) internal virtual view override returns (bool) {
        return token_ == _getArgAddress(QUOTE_ADDRESS) || token_ == _getArgAddress(COLLATERAL_ADDRESS);
    }

    /************************/
    /*** Helper Functions ***/
    /************************/

    /**
     *  @notice Helper function to transfer amount of collateral tokens from sender to pool contract.
     *  @param  from_    Sender address.
     *  @param  amount_  Amount to transfer from sender (`WAD` precision). Scaled to collateral precision before transfer.
     */
    function _transferCollateralFrom(address from_, uint256 amount_) internal {
        // Transfer amount in favour of the pool
        uint256 transferAmount = Maths.ceilDiv(amount_, _getArgUint256(COLLATERAL_SCALE));
        IERC20(_getArgAddress(COLLATERAL_ADDRESS)).safeTransferFrom(from_, address(this), transferAmount);
    }

    /**
     *  @notice Helper function to transfer amount of collateral tokens from pool contract.
     *  @param  to_     Receiver address.
     *  @param  amount_ Amount to transfer to receiver (`WAD` precision). Scaled to collateral precision before transfer.
     */
    function _transferCollateral(address to_, uint256 amount_) internal {
        IERC20(_getArgAddress(COLLATERAL_ADDRESS)).safeTransfer(to_, amount_ / _getArgUint256(COLLATERAL_SCALE));
    }

    /**
     *  @notice Helper function to calculate the minimum amount of collateral an actor may have in a bucket.
     *  @param  bucketIndex_  Bucket index.
     *  @return Amount of collateral dust amount of the bucket.
     */
    function _bucketCollateralDust(uint256 bucketIndex_) internal pure returns (uint256) {
        // price precision adjustment will always be 0 for encumbered collateral
        uint256 pricePrecisionAdjustment = _getCollateralDustPricePrecisionAdjustment(bucketIndex_);
        // difference between the normalized scale and the collateral token's scale
        return Maths.max(_getArgUint256(COLLATERAL_SCALE), 10 ** pricePrecisionAdjustment);
    } 
}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity 0.8.18;

import { ClonesWithImmutableArgs } from '@clones/ClonesWithImmutableArgs.sol';

import { IERC20PoolFactory } from './interfaces/pool/erc20/IERC20PoolFactory.sol';
import { IPoolFactory }      from './interfaces/pool/IPoolFactory.sol';
import { PoolType }          from './interfaces/pool/IPool.sol';

import { ERC20Pool }    from './ERC20Pool.sol';
import { PoolDeployer } from './base/PoolDeployer.sol';

/**
 *  @title  ERC20 Pool Factory
 *  @notice Pool factory contract for creating `ERC20` pools. Actors actions:
 *          - `Pool creators`: create pool by providing a fungible token for quote and collateral and an interest rate between `1%-10%`
 *  @dev    Reverts if pool is already created or if params to deploy new pool are invalid.
 */
contract ERC20PoolFactory is PoolDeployer, IERC20PoolFactory {

    using ClonesWithImmutableArgs for address;

    /// @dev `ERC20` clonable pool contract used to deploy the new pool.
    ERC20Pool public implementation;

    /// @dev Default `bytes32` hash used by `ERC20` `Non-NFTSubset` pool types
    bytes32 public constant ERC20_NON_SUBSET_HASH = keccak256("ERC20_NON_SUBSET_HASH");

    constructor(address ajna_) {
        if (ajna_ == address(0)) revert DeployWithZeroAddress();

        ajna = ajna_;

        implementation = new ERC20Pool();
    }

    /**
     *  @inheritdoc IERC20PoolFactory
     *  @dev  immutable args: pool type; ajna, collateral and quote address; quote and collateral scale
     *  @dev    === Write state ===
     *  @dev    - `deployedPools` mapping
     *  @dev    - `deployedPoolsList` array
     *  @dev    === Reverts on ===
     *  @dev    - `0x` address provided as quote or collateral `DeployWithZeroAddress()`
     *  @dev    - quote or collateral lacks `decimals()` method `DecimalsNotCompliant()`
     *  @dev    - pool with provided quote / collateral pair already exists `PoolAlreadyExists()`
     *  @dev    - invalid interest rate provided `PoolInterestRateInvalid()`
     *  @dev    === Emit events ===
     *  @dev    - `PoolCreated`
     */
    function deployPool(
        address collateral_, address quote_, uint256 interestRate_
    ) external canDeploy(collateral_, quote_, interestRate_) returns (address pool_) {
        address existingPool = deployedPools[ERC20_NON_SUBSET_HASH][collateral_][quote_];
        if (existingPool != address(0)) revert IPoolFactory.PoolAlreadyExists(existingPool);

        uint256 quoteTokenScale = _getTokenScale(quote_);
        uint256 collateralScale = _getTokenScale(collateral_);

        bytes memory data = abi.encodePacked(
            PoolType.ERC20,
            ajna,
            collateral_,
            quote_,
            quoteTokenScale,
            collateralScale
        );

        ERC20Pool pool = ERC20Pool(address(implementation).clone(data));

        pool_ = address(pool);

        // Track the newly deployed pool
        deployedPools[ERC20_NON_SUBSET_HASH][collateral_][quote_] = pool_;
        deployedPoolsList.push(pool_);

        emit PoolCreated(pool_, ERC20_NON_SUBSET_HASH);

        pool.initialize(interestRate_);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.2) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to owner address
    mapping(uint256 => address) private _owners;

    // Mapping owner address to token count
    mapping(address => uint256) private _balances;

    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return
            interfaceId == type(IERC721).interfaceId ||
            interfaceId == type(IERC721Metadata).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: address zero is not a valid owner");
        return _balances[owner];
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _ownerOf(tokenId);
        require(owner != address(0), "ERC721: invalid token ID");
        return owner;
    }

    /**
     * @dev See {IERC721Metadata-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev See {IERC721Metadata-symbol}.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        _requireMinted(tokenId);

        string memory baseURI = _baseURI();
        return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
    }

    /**
     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
     * by default, can be overridden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return "";
    }

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            "ERC721: approve caller is not token owner or approved for all"
        );

        _approve(to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        _requireMinted(tokenId);

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        _setApprovalForAll(_msgSender(), operator, approved);
    }

    /**
     * @dev See {IERC721-isApprovedForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved");

        _transfer(from, to, tokenId);
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, "");
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) public virtual override {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved");
        _safeTransfer(from, to, tokenId, data);
    }

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * `data` is additional data, it has no specified format and it is sent in call to `to`.
     *
     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
     * implement alternative mechanisms to perform token transfer, such as signature-based.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeTransfer(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, data), "ERC721: transfer to non ERC721Receiver implementer");
    }

    /**
     * @dev Returns the owner of the `tokenId`. Does NOT revert if token doesn't exist
     */
    function _ownerOf(uint256 tokenId) internal view virtual returns (address) {
        return _owners[tokenId];
    }

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     * and stop existing when they are burned (`_burn`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _ownerOf(tokenId) != address(0);
    }

    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
    }

    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, "");
    }

    /**
     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
     */
    function _safeMint(
        address to,
        uint256 tokenId,
        bytes memory data
    ) internal virtual {
        _mint(to, tokenId);
        require(
            _checkOnERC721Received(address(0), to, tokenId, data),
            "ERC721: transfer to non ERC721Receiver implementer"
        );
    }

    /**
     * @dev Mints `tokenId` and transfers it to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - `to` cannot be the zero address.
     *
     * Emits a {Transfer} event.
     */
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "ERC721: mint to the zero address");
        require(!_exists(tokenId), "ERC721: token already minted");

        _beforeTokenTransfer(address(0), to, tokenId, 1);

        // Check that tokenId was not minted by `_beforeTokenTransfer` hook
        require(!_exists(tokenId), "ERC721: token already minted");

        unchecked {
            // Will not overflow unless all 2**256 token ids are minted to the same owner.
            // Given that tokens are minted one by one, it is impossible in practice that
            // this ever happens. Might change if we allow batch minting.
            // The ERC fails to describe this case.
            _balances[to] += 1;
        }

        _owners[tokenId] = to;

        emit Transfer(address(0), to, tokenId);

        _afterTokenTransfer(address(0), to, tokenId, 1);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     * This is an internal function that does not check if the sender is authorized to operate on the token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);

        _beforeTokenTransfer(owner, address(0), tokenId, 1);

        // Update ownership in case tokenId was transferred by `_beforeTokenTransfer` hook
        owner = ERC721.ownerOf(tokenId);

        // Clear approvals
        delete _tokenApprovals[tokenId];

        unchecked {
            // Cannot overflow, as that would require more tokens to be burned/transferred
            // out than the owner initially received through minting and transferring in.
            _balances[owner] -= 1;
        }
        delete _owners[tokenId];

        emit Transfer(owner, address(0), tokenId);

        _afterTokenTransfer(owner, address(0), tokenId, 1);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
        require(to != address(0), "ERC721: transfer to the zero address");

        _beforeTokenTransfer(from, to, tokenId, 1);

        // Check that tokenId was not transferred by `_beforeTokenTransfer` hook
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");

        // Clear approvals from the previous owner
        delete _tokenApprovals[tokenId];

        unchecked {
            // `_balances[from]` cannot overflow for the same reason as described in `_burn`:
            // `from`'s balance is the number of token held, which is at least one before the current
            // transfer.
            // `_balances[to]` could overflow in the conditions described in `_mint`. That would require
            // all 2**256 token ids to be minted, which in practice is impossible.
            _balances[from] -= 1;
            _balances[to] += 1;
        }
        _owners[tokenId] = to;

        emit Transfer(from, to, tokenId);

        _afterTokenTransfer(from, to, tokenId, 1);
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits an {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
    }

    /**
     * @dev Approve `operator` to operate on all of `owner` tokens
     *
     * Emits an {ApprovalForAll} event.
     */
    function _setApprovalForAll(
        address owner,
        address operator,
        bool approved
    ) internal virtual {
        require(owner != operator, "ERC721: approve to caller");
        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

    /**
     * @dev Reverts if the `tokenId` has not been minted yet.
     */
    function _requireMinted(uint256 tokenId) internal view virtual {
        require(_exists(tokenId), "ERC721: invalid token ID");
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) private returns (bool) {
        if (to.isContract()) {
            try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, data) returns (bytes4 retval) {
                return retval == IERC721Receiver.onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert("ERC721: transfer to non ERC721Receiver implementer");
                } else {
                    /// @solidity memory-safe-assembly
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting and burning. If {ERC721Consecutive} is
     * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s tokens will be transferred to `to`.
     * - When `from` is zero, the tokens will be minted for `to`.
     * - When `to` is zero, ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     * - `batchSize` is non-zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 firstTokenId,
        uint256 batchSize
    ) internal virtual {}

    /**
     * @dev Hook that is called after any token transfer. This includes minting and burning. If {ERC721Consecutive} is
     * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s tokens were transferred to `to`.
     * - When `from` is zero, the tokens were minted for `to`.
     * - When `to` is zero, ``from``'s tokens were burned.
     * - `from` and `to` are never both zero.
     * - `batchSize` is non-zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 firstTokenId,
        uint256 batchSize
    ) internal virtual {}

    /**
     * @dev Unsafe write access to the balances, used by extensions that "mint" tokens using an {ownerOf} override.
     *
     * WARNING: Anyone calling this MUST ensure that the balances remain consistent with the ownership. The invariant
     * being that for any address `a` the value returned by `balanceOf(a)` must be equal to the number of tokens such
     * that `ownerOf(tokenId)` is `a`.
     */
    // solhint-disable-next-line func-name-mixedcase
    function __unsafe_increaseBalance(address account, uint256 amount) internal {
        _balances[account] += amount;
    }
}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity 0.8.18;

import {
    IERC721Token,
    IPoolErrors,
    IPoolLenderActions,
    IPoolKickerActions,
    IPoolTakerActions,
    IPoolSettlerActions
}                           from './interfaces/pool/IPool.sol';
import {
    DrawDebtResult,
    RepayDebtResult,
    SettleParams,
    SettleResult,
    TakeResult
}                           from './interfaces/pool/commons/IPoolInternals.sol';
import { PoolState }        from './interfaces/pool/commons/IPoolState.sol';

import {
    IERC721Pool,
    IERC721PoolBorrowerActions,
    IERC721PoolImmutables,
    IERC721PoolLenderActions
}                               from './interfaces/pool/erc721/IERC721Pool.sol';
import { IERC721Taker }         from './interfaces/pool/erc721/IERC721Taker.sol';
import { IERC721PoolState }     from './interfaces/pool/erc721/IERC721PoolState.sol';

import { FlashloanablePool } from './base/FlashloanablePool.sol';
import { _roundToScale }     from './libraries/helpers/PoolHelper.sol';

import {
    _revertIfAuctionClearable,
    _revertAfterExpiry
}                               from './libraries/helpers/RevertsHelper.sol';

import { Maths }    from './libraries/internal/Maths.sol';
import { Deposits } from './libraries/internal/Deposits.sol';
import { Loans }    from './libraries/internal/Loans.sol';

import { LenderActions }   from './libraries/external/LenderActions.sol';
import { BorrowerActions } from './libraries/external/BorrowerActions.sol';
import { SettlerActions }  from './libraries/external/SettlerActions.sol';
import { TakerActions }    from './libraries/external/TakerActions.sol';

/**
 *  @title  ERC721 Pool contract
 *  @notice Entrypoint of `ERC721` Pool actions for pool actors:
 *          - `Lenders`: add, remove and move quote tokens; transfer `LP`
 *          - `Borrowers`: draw and repay debt
 *          - `Traders`: add, remove and move quote tokens; add and remove collateral
 *          - `Kickers`: auction undercollateralized loans; settle auctions; claim bond rewards
 *          - `Bidders`: take auctioned collateral
 *          - `Reserve purchasers`: start auctions; take reserves
 *          - `Flash borrowers`: initiate flash loans on ERC20 quote tokens
 *  @dev    Contract is `FlashloanablePool` with flashloan logic.
 *  @dev    Contract is base `Pool` with logic to handle `ERC721` collateral.
 *  @dev    Calls logic from external `PoolCommons`, `LenderActions`, `BorrowerActions` and `Auction` actions libraries.
 */
contract ERC721Pool is FlashloanablePool, IERC721Pool {

    /*****************/
    /*** Constants ***/
    /*****************/

    /// @dev Immutable NFT subset pool arg offset.
    uint256 internal constant SUBSET = 93;

    /***********************/
    /*** State Variables ***/
    /***********************/

    /// @dev Borrower `address => array` of tokenIds pledged by borrower mapping.
    mapping(address => uint256[]) public borrowerTokenIds;
    /// @dev Array of `tokenIds` in pool buckets (claimable from pool).
    uint256[]                     public bucketTokenIds;

    /// @dev Mapping of `tokenIds` allowed in `NFT` Subset type pool.
    mapping(uint256 => bool)      internal tokenIdsAllowed_;

    /****************************/
    /*** Initialize Functions ***/
    /****************************/

    /// @inheritdoc IERC721Pool
    function initialize(
        uint256[] memory tokenIds_,
        uint256 rate_
    ) external override {
        if (isPoolInitialized) revert AlreadyInitialized();

        inflatorState.inflator       = uint208(1e18);
        inflatorState.inflatorUpdate = uint48(block.timestamp);

        interestState.interestRate       = uint208(rate_);
        interestState.interestRateUpdate = uint48(block.timestamp);

        uint256 noOfTokens = tokenIds_.length;

        if (noOfTokens != 0) {
            // add subset of tokenIds allowed in the pool
            for (uint256 id = 0; id < noOfTokens;) {
                tokenIdsAllowed_[tokenIds_[id]] = true;

                unchecked { ++id; }
            }
        }

        Loans.init(loans);

        // increment initializations count to ensure these values can't be updated
        isPoolInitialized = true;
    }

    /******************/
    /*** Immutables ***/
    /******************/

    /// @inheritdoc IERC721PoolImmutables
    function isSubset() external pure override returns (bool) {
        return _getArgUint256(SUBSET) != 0;
    }

    /***********************************/
    /*** Borrower External Functions ***/
    /***********************************/

    function tokenIdsAllowed(uint256 tokenId_) public view returns (bool) {
        return (_getArgUint256(SUBSET) == 0 || tokenIdsAllowed_[tokenId_]);
    }

    /**
     *  @inheritdoc IERC721PoolBorrowerActions
     *  @dev    === Write state ===
     *  @dev    - decrement `poolBalances.t0DebtInAuction` accumulator
     *  @dev    - increment `poolBalances.pledgedCollateral` accumulator
     *  @dev    - increment `poolBalances.t0Debt` accumulator
     *  @dev    - update `t0Debt2ToCollateral` ratio only if loan not in auction, debt and collateral pre action are considered 0 if auction settled
     *  @dev    - update `borrowerTokenIds` and `bucketTokenIds` arrays
     *  @dev    === Emit events ===
     *  @dev    - `DrawDebtNFT`
     */
    function drawDebt(
        address borrowerAddress_,
        uint256 amountToBorrow_,
        uint256 limitIndex_,
        uint256[] calldata tokenIdsToPledge_
    ) external nonReentrant {
        PoolState memory poolState = _accruePoolInterest();

        // ensure the borrower is not charged for additional debt that they did not receive
        amountToBorrow_ = _roundToScale(amountToBorrow_, poolState.quoteTokenScale);

        DrawDebtResult memory result = BorrowerActions.drawDebt(
            auctions,
            deposits,
            loans,
            poolState,
            _availableQuoteToken(),
            borrowerAddress_,
            amountToBorrow_,
            limitIndex_,
            Maths.wad(tokenIdsToPledge_.length)
        );

        emit DrawDebtNFT(borrowerAddress_, amountToBorrow_, tokenIdsToPledge_, result.newLup);

        // update in memory pool state struct
        poolState.debt       = result.poolDebt;
        poolState.t0Debt     = result.t0PoolDebt;
        poolState.collateral = result.poolCollateral;

        // adjust t0Debt2ToCollateral ratio
        _updateT0Debt2ToCollateral(
            result.debtPreAction,
            result.debtPostAction,
            result.collateralPreAction,
            result.collateralPostAction
        );

        // update pool interest rate state
        _updateInterestState(poolState, result.newLup);

        if (tokenIdsToPledge_.length != 0) {
            // update pool balances pledged collateral state
            poolBalances.pledgedCollateral = poolState.collateral;

            // move collateral from sender to pool
            _transferFromSenderToPool(borrowerTokenIds[borrowerAddress_], tokenIdsToPledge_);
        }

        // move borrowed amount from pool to sender
        if (amountToBorrow_ != 0) {
            // update pool balances t0 debt state
            poolBalances.t0Debt = poolState.t0Debt;

            // move borrowed amount from pool to sender
            _transferQuoteToken(msg.sender, amountToBorrow_);
        }
    }

    /**
     *  @inheritdoc IERC721PoolBorrowerActions
     *  @dev    === Write state ===
     *  @dev    - decrement `poolBalances.t0Debt accumulator`
     *  @dev    - decrement `poolBalances.t0DebtInAuction accumulator`
     *  @dev    - decrement `poolBalances.pledgedCollateral accumulator`
     *  @dev    - update `t0Debt2ToCollateral` ratio only if loan not in auction, debt and collateral pre action are considered 0 if auction settled
     *  @dev    - update `borrowerTokenIds` and `bucketTokenIds` arrays
     *  @dev    === Emit events ===
     *  @dev    - `RepayDebt`
     */
    function repayDebt(
        address borrowerAddress_,
        uint256 maxQuoteTokenAmountToRepay_,
        uint256 noOfNFTsToPull_,
        address collateralReceiver_,
        uint256 limitIndex_
    ) external nonReentrant returns (uint256 amountRepaid_) {
        PoolState memory poolState = _accruePoolInterest();

        // ensure accounting is performed using the appropriate token scale
        if (maxQuoteTokenAmountToRepay_ != type(uint256).max)
            maxQuoteTokenAmountToRepay_ = _roundToScale(maxQuoteTokenAmountToRepay_, poolState.quoteTokenScale);

        RepayDebtResult memory result = BorrowerActions.repayDebt(
            auctions,
            deposits,
            loans,
            poolState,
            borrowerAddress_,
            maxQuoteTokenAmountToRepay_,
            Maths.wad(noOfNFTsToPull_),
            limitIndex_
        );

        amountRepaid_        = result.quoteTokenToRepay;
        // update in memory pool state struct
        poolState.debt       = result.poolDebt;
        poolState.t0Debt     = result.t0PoolDebt;
        poolState.collateral = result.poolCollateral;

        emit RepayDebt(borrowerAddress_, amountRepaid_, noOfNFTsToPull_, result.newLup);

        // adjust t0Debt2ToCollateral ratio
        _updateT0Debt2ToCollateral(
            result.debtPreAction,
            result.debtPostAction,
            result.collateralPreAction,
            result.collateralPostAction
        );

        // update pool interest rate state
        _updateInterestState(poolState, result.newLup);

        // update pool balances pledged collateral state
        poolBalances.pledgedCollateral = poolState.collateral;

        if (amountRepaid_ != 0) {
            // update pool balances t0 debt state
            poolBalances.t0Debt = poolState.t0Debt;

            // move amount to repay from sender to pool
            _transferQuoteTokenFrom(msg.sender, amountRepaid_);
        }
        if (noOfNFTsToPull_ != 0) {
            // move collateral from pool to address specified as collateral receiver
            _transferFromPoolToAddress(collateralReceiver_, borrowerTokenIds[msg.sender], noOfNFTsToPull_);
        }
    }

    /*********************************/
    /*** Lender External Functions ***/
    /*********************************/

    /**
     *  @inheritdoc IERC721PoolLenderActions
     *  @dev    === Write state ===
     *  @dev    - update `bucketTokenIds` arrays
     *  @dev    === Emit events ===
     *  @dev    - `AddCollateralNFT`
     */
    function addCollateral(
        uint256[] calldata tokenIds_,
        uint256 index_,
        uint256 expiry_
    ) external override nonReentrant returns (uint256 bucketLP_) {
        _revertAfterExpiry(expiry_);
        PoolState memory poolState = _accruePoolInterest();

        bucketLP_ = LenderActions.addCollateral(
            buckets,
            deposits,
            Maths.wad(tokenIds_.length),
            index_
        );

        emit AddCollateralNFT(msg.sender, index_, tokenIds_, bucketLP_);

        // update pool interest rate state
        _updateInterestState(poolState, Deposits.getLup(deposits, poolState.debt));

        // move required collateral from sender to pool
        _transferFromSenderToPool(bucketTokenIds, tokenIds_);
    }

    /**
     *  @inheritdoc IERC721PoolLenderActions
     *  @dev    === Write state ===
     *  @dev    - update `bucketTokenIds` arrays
     *  @dev    === Emit events ===
     *  @dev    - `MergeOrRemoveCollateralNFT`
     */
    function mergeOrRemoveCollateral(
        uint256[] calldata removalIndexes_,
        uint256 noOfNFTsToRemove_,
        uint256 toIndex_
    ) external override nonReentrant returns (uint256 collateralMerged_, uint256 bucketLP_) {
        _revertIfAuctionClearable(auctions, loans);

        PoolState memory poolState = _accruePoolInterest();
        uint256 collateralAmount = Maths.wad(noOfNFTsToRemove_);

        (
            collateralMerged_,
            bucketLP_
        ) = LenderActions.mergeOrRemoveCollateral(
            buckets,
            deposits,
            removalIndexes_,
            collateralAmount,
            toIndex_
        );

        emit MergeOrRemoveCollateralNFT(msg.sender, collateralMerged_, bucketLP_);

        // update pool interest rate state
        _updateInterestState(poolState, Deposits.getLup(deposits, poolState.debt));

        if (collateralMerged_ == collateralAmount) {
            // Total collateral in buckets meets the requested removal amount, noOfNFTsToRemove_
            _transferFromPoolToAddress(msg.sender, bucketTokenIds, noOfNFTsToRemove_);
        }
    }

    /**
     *  @inheritdoc IPoolLenderActions
     *  @dev    === Write state ===
     *  @dev    - update `bucketTokenIds` arrays
     *  @dev    === Emit events ===
     *  @dev    - `RemoveCollateral`
     *  @param noOfNFTsToRemove_ Number of `NFT` tokens to remove.
     */
    function removeCollateral(
        uint256 noOfNFTsToRemove_,
        uint256 index_
    ) external override nonReentrant returns (uint256 removedAmount_, uint256 redeemedLP_) {
        _revertIfAuctionClearable(auctions, loans);

        PoolState memory poolState = _accruePoolInterest();

        removedAmount_ = Maths.wad(noOfNFTsToRemove_);
        redeemedLP_ = LenderActions.removeCollateral(
            buckets,
            deposits,
            removedAmount_,
            index_
        );

        emit RemoveCollateral(msg.sender, index_, noOfNFTsToRemove_, redeemedLP_);

        // update pool interest rate state
        _updateInterestState(poolState, Deposits.getLup(deposits, poolState.debt));

        _transferFromPoolToAddress(msg.sender, bucketTokenIds, noOfNFTsToRemove_);
    }

    /*******************************/
    /*** Pool Auctions Functions ***/
    /*******************************/

    /**
     *  @inheritdoc IPoolSettlerActions
     *  @dev    === Write state ===
     *  @dev    - decrement `poolBalances.t0Debt` accumulator
     *  @dev    - decrement `poolBalances.t0DebtInAuction` accumulator
     *  @dev    - decrement `poolBalances.pledgedCollateral` accumulator
     *  @dev    - no update of `t0Debt2ToCollateral` ratio as debt and collateral pre settle are not taken into account (pre debt and pre collateral = 0)
     */
    function settle(
        address borrowerAddress_,
        uint256 maxDepth_
    ) external nonReentrant override returns (uint256 collateralSettled_, bool isBorrowerSettled_) {
        PoolState memory poolState = _accruePoolInterest();

        SettleParams memory params = SettleParams({
            borrower:    borrowerAddress_,
            poolBalance: _getNormalizedPoolQuoteTokenBalance(),
            bucketDepth: maxDepth_
        });

        SettleResult memory result = SettlerActions.settlePoolDebt(
            auctions,
            buckets,
            deposits,
            loans,
            reserveAuction,
            poolState,
            params
        );

        _updatePostSettleState(result, poolState);

        // move token ids from borrower array to pool claimable array if any collateral used to settle bad debt
        _rebalanceTokens(params.borrower, result.collateralRemaining);

        collateralSettled_ = result.collateralSettled;
        isBorrowerSettled_ = (result.debtPostAction == 0);
    }

    /**
     *  @inheritdoc IPoolTakerActions
     *  @dev    === Write state ===
     *  @dev    - decrement `poolBalances.t0Debt` accumulator
     *  @dev    - decrement `poolBalances.t0DebtInAuction` accumulator
     *  @dev    - decrement `poolBalances.pledgedCollateral` accumulator
     *  @dev    - update `t0Debt2ToCollateral` ratio only if auction settled, debt and collateral pre action are considered 0
     */
    function take(
        address        borrowerAddress_,
        uint256        collateral_,
        address        callee_,
        bytes calldata data_
    ) external override nonReentrant returns (uint256 collateralTaken_) {
        PoolState memory poolState = _accruePoolInterest();

        TakeResult memory result = TakerActions.take(
            auctions,
            buckets,
            deposits,
            loans,
            poolState,
            borrowerAddress_,
            Maths.wad(collateral_),
            1
        );

        _updatePostTakeState(result, poolState);

        // transfer rounded collateral from pool to taker
        collateralTaken_ = result.collateralAmount / 1e18;
        uint256[] memory tokensTaken = _transferFromPoolToAddress(
            callee_,
            borrowerTokenIds[borrowerAddress_],
            collateralTaken_
        );

        uint256 totalQuoteTokenAmount = result.quoteTokenAmount + result.excessQuoteToken;

        if (data_.length != 0) {
            IERC721Taker(callee_).atomicSwapCallback(
                tokensTaken,
                totalQuoteTokenAmount  / poolState.quoteTokenScale,
                data_
            );
        }

        // move borrower token ids to bucket claimable token ids after taking / reducing borrower collateral
        _rebalanceTokens(borrowerAddress_, result.remainingCollateral);

        // transfer from taker to pool the amount of quote tokens needed to cover collateral auctioned (including excess for rounded collateral)
        _transferQuoteTokenFrom(msg.sender, totalQuoteTokenAmount);

        // transfer from pool to borrower the excess of quote tokens after rounding collateral auctioned
        if (result.excessQuoteToken != 0) _transferQuoteToken(borrowerAddress_, result.excessQuoteToken);
    }

    /**
     *  @inheritdoc IPoolTakerActions
     *  @dev    === Write state ===
     *  @dev    - decrement `poolBalances.t0Debt` accumulator
     *  @dev    - decrement `poolBalances.t0DebtInAuction` accumulator
     *  @dev    - decrement `poolBalances.pledgedCollateral` accumulator
     *  @dev    - update `t0Debt2ToCollateral` ratio only if auction settled, debt and collateral pre action are considered 0
     */
    function bucketTake(
        address borrowerAddress_,
        bool    depositTake_,
        uint256 index_
    ) external override nonReentrant {

        PoolState memory poolState = _accruePoolInterest();

        TakeResult memory result = TakerActions.bucketTake(
            auctions,
            buckets,
            deposits,
            loans,
            poolState,
            borrowerAddress_,
            depositTake_,
            index_,
            1
        );

        _updatePostTakeState(result, poolState);

        // move borrower token ids to bucket claimable token ids after taking / reducing borrower collateral
        _rebalanceTokens(borrowerAddress_, result.remainingCollateral);
    }

    /**************************/
    /*** Internal Functions ***/
    /**************************/

    /**
     *  @notice Rebalance `NFT` token and transfer difference to floor collateral from borrower to pool claimable array.
     *  @dev    === Write state ===
     *  @dev    - update `borrowerTokens` and `bucketTokenIds` arrays
     *  @param  borrowerAddress_    Address of borrower.
     *  @param  borrowerCollateral_ Current borrower collateral to be rebalanced.
     */
    function _rebalanceTokens(
        address borrowerAddress_,
        uint256 borrowerCollateral_
    ) internal {
        // rebalance borrower's collateral, transfer difference to floor collateral from borrower to pool claimable array
        uint256[] storage borrowerTokens = borrowerTokenIds[borrowerAddress_];

        uint256 noOfTokensPledged    = borrowerTokens.length;
        /*
            eg1. borrowerCollateral_ = 4.1, noOfTokensPledged = 6; noOfTokensToTransfer = 1
            eg2. borrowerCollateral_ = 4, noOfTokensPledged = 6; noOfTokensToTransfer = 2
        */
        uint256 borrowerCollateralRoundedUp = (borrowerCollateral_ + 1e18 - 1) / 1e18;
        uint256 noOfTokensToTransfer = noOfTokensPledged - borrowerCollateralRoundedUp;

        for (uint256 i = 0; i < noOfTokensToTransfer;) {
            uint256 tokenId = borrowerTokens[--noOfTokensPledged]; // start with moving the last token pledged by borrower
            borrowerTokens.pop();                                  // remove token id from borrower
            bucketTokenIds.push(tokenId);                          // add token id to pool claimable tokens

            unchecked { ++i; }
        }
    }

    /**
     *  @notice Helper function for transferring multiple `NFT` tokens from msg.sender to pool.
     *  @dev    Reverts in case token id is not supported by subset pool.
     *  @param  poolTokens_ Array in pool that tracks `NFT` ids (could be tracking `NFT`s pledged by borrower or `NFT`s added by a lender in a specific bucket).
     *  @param  tokenIds_   Array of `NFT` token ids to transfer from `msg.sender` to pool.
     */
    function _transferFromSenderToPool(
        uint256[] storage poolTokens_,
        uint256[] calldata tokenIds_
    ) internal {
        for (uint256 i = 0; i < tokenIds_.length;) {
            uint256 tokenId = tokenIds_[i];
            if (!tokenIdsAllowed(tokenId)) revert OnlySubset();
            poolTokens_.push(tokenId);

            _transferNFT(msg.sender, address(this), tokenId);

            unchecked { ++i; }
        }
    }

    /**
     *  @notice Helper function for transferring multiple `NFT` tokens from pool to given address.
     *  @dev    It transfers `NFT`s from the most recent one added into the pool (pop from array tracking `NFT`s in pool).
     *  @param  toAddress_      Address where pool should transfer tokens to.
     *  @param  poolTokens_     Array in pool that tracks `NFT` ids (could be tracking `NFT`s pledged by borrower or `NFT`s added by a lender in a specific bucket).
     *  @param  amountToRemove_ Number of `NFT` tokens to transfer from pool to given address.
     *  @return Array containing token ids that were transferred from pool to address.
     */
    function _transferFromPoolToAddress(
        address toAddress_,
        uint256[] storage poolTokens_,
        uint256 amountToRemove_
    ) internal returns (uint256[] memory) {
        uint256[] memory tokensTransferred = new uint256[](amountToRemove_);

        uint256 noOfNFTsInPool = poolTokens_.length;

        for (uint256 i = 0; i < amountToRemove_;) {
            uint256 tokenId = poolTokens_[--noOfNFTsInPool]; // start with transferring the last token added in bucket
            poolTokens_.pop();

            _transferNFT(address(this), toAddress_, tokenId);

            tokensTransferred[i] = tokenId;

            unchecked { ++i; }
        }

        return tokensTransferred;
    }

    /**
     *  @notice Helper function to transfer an `NFT` from owner to target address (reused in code to reduce contract deployment bytecode size).
     *  @dev    Since `transferFrom` is used instead of `safeTransferFrom`, calling smart contracts must be careful to check that they support any received `NFT`s.
     *  @param  from_    `NFT` owner address.
     *  @param  to_      New `NFT` owner address.
     *  @param  tokenId_ `NFT` token id to be transferred.
     */
    function _transferNFT(address from_, address to_, uint256 tokenId_) internal {
        // slither-disable-next-line calls-loop
        IERC721Token(_getArgAddress(COLLATERAL_ADDRESS)).transferFrom(from_, to_, tokenId_);
    }

    /*******************************/
    /*** External View Functions ***/
    /*******************************/

    /// @inheritdoc IERC721PoolState
    function getBorrowerTokenIds(address borrower_) external view override returns(uint256[] memory) {
        return borrowerTokenIds[borrower_];
    }

    /// @inheritdoc IERC721PoolState
    function getBucketTokenIds() external view override returns(uint256[] memory) {
        return bucketTokenIds;
    }

}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity 0.8.18;

import { ClonesWithImmutableArgs } from '@clones/ClonesWithImmutableArgs.sol';
import { IERC165 }                 from '@openzeppelin/contracts/utils/introspection/IERC165.sol';

import { IERC721PoolFactory } from './interfaces/pool/erc721/IERC721PoolFactory.sol';
import { IPoolFactory }       from './interfaces/pool/IPoolFactory.sol';
import { PoolType }           from './interfaces/pool/IPool.sol';

import { ERC721Pool }   from './ERC721Pool.sol';
import { PoolDeployer } from './base/PoolDeployer.sol';

/**
 *  @title  ERC721 Pool Factory
 *  @notice Pool factory contract for creating `ERC721` pools. If a list with token ids is provided then a subset `ERC721` pool is created for the `NFT`.
 *  @notice Pool factory contract for creating `ERC20` pools.  If a list with token ids is provided then a subset `ERC721` pool is created for the `NFT`. Actors actions:
 *          - `Pool creators`: create pool by providing a fungible token for quote, a non fungible token for collateral and an interest rate between `1%-10%`.
 *  @dev    Reverts if pool is already created or if params to deploy new pool are invalid.
 */
contract ERC721PoolFactory is PoolDeployer, IERC721PoolFactory {

    using ClonesWithImmutableArgs for address;

    /// @dev `ERC721` clonable pool contract used to deploy the new pool.
    ERC721Pool public implementation;

    /// @dev Default `bytes32` hash used by `ERC721` `Non-NFTSubset` pool types
    bytes32 public constant ERC721_NON_SUBSET_HASH = keccak256("ERC721_NON_SUBSET_HASH");

    constructor(address ajna_) {
        if (ajna_ == address(0)) revert DeployWithZeroAddress();

        ajna = ajna_;

        implementation = new ERC721Pool();
    }

    /**
     *  @inheritdoc IERC721PoolFactory
     *  @dev  immutable args: pool type; ajna, collateral and quote address; quote scale; number of token ids in subset
     *  @dev    === Write state ===
     *  @dev    - `deployedPools` mapping
     *  @dev    - `deployedPoolsList` array
     *  @dev    === Reverts on ===
     *  @dev    - `0x` address provided as quote or collateral `DeployWithZeroAddress()`
     *  @dev    - quote lacks `decimals()` method `DecimalsNotCompliant()`
     *  @dev    - pool with provided quote / collateral pair already exists `PoolAlreadyExists()`
     *  @dev    - invalid interest rate provided `PoolInterestRateInvalid()`
     *  @dev    - not supported `NFT` provided `NFTNotSupported()`
     *  @dev    === Emit events ===
     *  @dev    - `PoolCreated`
     */
    function deployPool(
        address collateral_, address quote_, uint256[] memory tokenIds_, uint256 interestRate_
    ) external canDeploy(collateral_, quote_, interestRate_) returns (address pool_) {
        bytes32 subsetHash = getNFTSubsetHash(tokenIds_);

        address existingPool = deployedPools[subsetHash][collateral_][quote_];
        if (existingPool != address(0)) revert IPoolFactory.PoolAlreadyExists(existingPool);

        uint256 quoteTokenScale = _getTokenScale(quote_);

        try IERC165(collateral_).supportsInterface(0x80ac58cd) returns (bool supportsERC721Interface) {
            if (!supportsERC721Interface) revert NFTNotSupported();
        } catch {
            revert NFTNotSupported();
        }

        bytes memory data = abi.encodePacked(
            PoolType.ERC721,
            ajna,
            collateral_,
            quote_,
            quoteTokenScale,
            tokenIds_.length
        );

        ERC721Pool pool = ERC721Pool(address(implementation).clone(data));

        pool_ = address(pool);

        // Track the newly deployed pool
        deployedPools[subsetHash][collateral_][quote_] = pool_;
        deployedPoolsList.push(pool_);

        emit PoolCreated(pool_, subsetHash);

        pool.initialize(tokenIds_, interestRate_);
    }

    /**
     *  @dev                Create a new pool that accepts any token in a NFT collection
     *  @param collateral_  The NFT collateral token address
     *  @param quote_       The borrower quote token address
     *  @return pool_       The address of the new pool
     */
    function deployPool(address collateral_, address quote_, uint256 interestRate_) public returns (address pool_) {
        pool_ = this.deployPool(collateral_, quote_, new uint256[](0), interestRate_);
    }

    /*******************************/
    /*** Pool Creation Functions ***/
    /*******************************/

    /**
     *  @notice Get the hash of the subset of `NFT`s that will be used to create the pool.
     *  @dev    If no `tokenIds` are provided, the default `ERC721_NON_SUBSET_HASH` is returned.
     *  @param  tokenIds_ The array of token ids that will be used to create the pool.
     *  @return The hash of the subset of `NFT`s that will be used to create the pool.
     */
    function getNFTSubsetHash(uint256[] memory tokenIds_) public pure returns (bytes32) {
        if (tokenIds_.length == 0) return ERC721_NON_SUBSET_HASH;
        else {
            // check the array of token ids is sorted in ascending order
            // revert if not sorted
            _checkTokenIdSortOrder(tokenIds_);

            // hash the sorted array of tokenIds
            return keccak256(abi.encode(tokenIds_));
        }
    }

    /**
     *  @notice Check that the array of token ids is sorted in ascending order, else revert.
     *  @dev    The counters are modified in unchecked blocks due to being bounded by array length.
     *  @param  tokenIds_ The array of token ids to check for sorting.
     */
    function _checkTokenIdSortOrder(uint256[] memory tokenIds_) internal pure {
        for (uint256 i = 0; i < tokenIds_.length - 1; ) {
            if (tokenIds_[i] >= tokenIds_[i + 1]) revert TokenIdSubsetInvalid();
            unchecked {
                ++i;
            }
        }
    }

}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/structs/EnumerableSet.sol)
// This file was procedurally generated from scripts/generate/templates/EnumerableSet.js.

pragma solidity ^0.8.0;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 *
 * [WARNING]
 * ====
 * Trying to delete such a structure from storage will likely result in data corruption, rendering the structure
 * unusable.
 * See https://github.com/ethereum/solidity/pull/11843[ethereum/solidity#11843] for more info.
 *
 * In order to clean an EnumerableSet, you can either remove all elements one by one or create a fresh instance using an
 * array of EnumerableSet.
 * ====
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping(bytes32 => uint256) _indexes;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];

        if (valueIndex != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.

            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;

            if (lastIndex != toDeleteIndex) {
                bytes32 lastValue = set._values[lastIndex];

                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastValue;
                // Update the index for the moved value
                set._indexes[lastValue] = valueIndex; // Replace lastValue's index to valueIndex
            }

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the index for the deleted slot
            delete set._indexes[value];

            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }

    // Bytes32Set

    struct Bytes32Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        bytes32[] memory store = _values(set._inner);
        bytes32[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }
}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity 0.8.18;

import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { IERC20 }    from "@openzeppelin/contracts/token/ERC20/IERC20.sol";

import { Pool }                  from './Pool.sol';
import { PoolCommons }           from '../libraries/external/PoolCommons.sol';
import { IERC3156FlashBorrower } from '../interfaces/pool/IERC3156FlashBorrower.sol';

/**
 *  @title  Flashloanable Pool Contract
 *  @notice Pool contract with `IERC3156` flashloans capabilities.
 *  @notice No fee is charged for taking flashloans from pool.
 *  @notice Flashloans can be taking in `ERC20` quote and `ERC20` collateral tokens.
 */
abstract contract FlashloanablePool is Pool {
    using SafeERC20 for IERC20;

    /**
     *  @notice Called by flashloan borrowers to borrow liquidity which must be repaid in the same transaction.
     *  @param  receiver_ Address of the contract which implements the appropriate interface to receive tokens.
     *  @param  token_    Address of the `ERC20` token caller wants to borrow.
     *  @param  amount_   The denormalized amount (dependent upon token precision) of tokens to borrow.
     *  @param  data_     User-defined calldata passed to the receiver.
     *  @return `True` if flashloan was successful.
     */
    function flashLoan(
        IERC3156FlashBorrower receiver_,
        address token_,
        uint256 amount_,
        bytes calldata data_
    ) external virtual override nonReentrant returns (bool) {
        if (!_isFlashloanSupported(token_)) revert FlashloanUnavailableForToken();
        PoolCommons.flashLoan(receiver_, token_, amount_, data_);
        // if flashLoan call didn't revert then flashloan was successful
        return true;
    }

    /**
     *  @notice Returns `0`, as no fee is charged for flashloans.
     */
    function flashFee(
        address token_,
        uint256
    ) external virtual view override returns (uint256) {
        if (!_isFlashloanSupported(token_)) revert FlashloanUnavailableForToken();
        return 0;
    }

    /**
     *  @notice Returns the amount of tokens available to be lent.
     *  @param  token_   Address of the `ERC20` token to be lent.
     *  @return maxLoan_ The amount of `token_` that can be lent.
     */
     function maxFlashLoan(
        address token_
    ) external virtual view override returns (uint256 maxLoan_) {
        if (_isFlashloanSupported(token_)) maxLoan_ = IERC20(token_).balanceOf(address(this));
    }

    /**
     *  @notice Returns `true` if pool allows flashloans for given token address, `false` otherwise.
     *  @dev    Allows flashloans for quote token, overriden in pool implementation to allow flashloans for other tokens.
     *  @param  token_   Address of the `ERC20` token to be lent.
     *  @return `True` if token can be flashloaned, `false` otherwise.
     */
    function _isFlashloanSupported(
        address token_
    ) internal virtual view returns (bool) {
        return token_ == _getArgAddress(QUOTE_ADDRESS);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (interfaces/IERC1271.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC1271 standard signature validation method for
 * contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
 *
 * _Available since v4.1._
 */
interface IERC1271 {
    /**
     * @dev Should return whether the signature provided is valid for the provided data
     * @param hash      Hash of the data to be signed
     * @param signature Signature byte array associated with _data
     */
    function isValidSignature(bytes32 hash, bytes memory signature) external view returns (bytes4 magicValue);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

import { IPool }                     from '../IPool.sol';
import { IERC20PoolBorrowerActions } from './IERC20PoolBorrowerActions.sol';
import { IERC20PoolLenderActions }   from './IERC20PoolLenderActions.sol';
import { IERC20PoolImmutables }      from './IERC20PoolImmutables.sol';
import { IERC20PoolEvents }          from './IERC20PoolEvents.sol';

/**
 * @title ERC20 Pool
 */
interface IERC20Pool is
    IPool,
    IERC20PoolLenderActions,
    IERC20PoolBorrowerActions,
    IERC20PoolImmutables,
    IERC20PoolEvents
{

    /**
     *  @notice Initializes a new pool, setting initial state variables.
     *  @param  rate_ Initial interest rate of the pool (min accepted value 1%, max accepted value 10%).
     */
    function initialize(uint256 rate_) external;

    /**
     *  @notice Returns the minimum amount of collateral an actor may have in a bucket.
     *  @param  bucketIndex_ The bucket index for which the dust limit is desired, or `0` for pledged collateral.
     *  @return The dust limit for `bucketIndex_`.
     */
    function bucketCollateralDust(
        uint256 bucketIndex_
    ) external pure returns (uint256);

}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title ERC20 Pool Borrower Actions
 */
interface IERC20PoolBorrowerActions {

    /**
     *  @notice Called by borrowers to add collateral to the pool and/or borrow quote from the pool.
     *  @dev    Can be called by borrowers with either `0` `amountToBorrow_` or `0` `collateralToPledge_`, if borrower only wants to take a single action. 
     *  @param  borrowerAddress_    The borrower to whom collateral was pledged, and/or debt was drawn for.
     *  @param  amountToBorrow_     The amount of quote tokens to borrow (`WAD` precision).
     *  @param  limitIndex_         Lower bound of `LUP` change (if any) that the borrower will tolerate from a creating or modifying position.
     *  @param  collateralToPledge_ The amount of collateral to be added to the pool (`WAD` precision).
     */
    function drawDebt(
        address borrowerAddress_,
        uint256 amountToBorrow_,
        uint256 limitIndex_,
        uint256 collateralToPledge_
    ) external;

    /**
     *  @notice Called by borrowers to repay borrowed quote to the pool, and/or pull collateral form the pool.
     *  @dev    Can be called by borrowers with either `0` `maxQuoteTokenAmountToRepay_` or `0` `collateralAmountToPull_`, if borrower only wants to take a single action. 
     *  @param  borrowerAddress_            The borrower whose loan is being interacted with.
     *  @param  maxQuoteTokenAmountToRepay_ The max amount of quote tokens to repay (`WAD` precision).
     *  @param  collateralAmountToPull_     The max amount of collateral to be puled from the pool (`WAD` precision).
     *  @param  recipient_                  The address to receive amount of pulled collateral.
     *  @param  limitIndex_                 Ensures `LUP` has not moved far from state when borrower pulls collateral.
     *  @return amountRepaid_               The amount of quote token repaid (`WAD` precision).
     */
    function repayDebt(
        address borrowerAddress_,
        uint256 maxQuoteTokenAmountToRepay_,
        uint256 collateralAmountToPull_,
        address recipient_,
        uint256 limitIndex_
    ) external returns (uint256 amountRepaid_);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title ERC20 Pool Events
 */
interface IERC20PoolEvents {

    /**
     *  @notice Emitted when actor adds claimable collateral to a bucket.
     *  @param  actor     Recipient that added collateral.
     *  @param  index     Index at which collateral were added.
     *  @param  amount    Amount of collateral added to the pool (`WAD` precision).
     *  @param  lpAwarded Amount of `LP` awarded for the deposit (`WAD` precision).
     */
    event AddCollateral(
        address indexed actor,
        uint256 indexed index,
        uint256 amount,
        uint256 lpAwarded
    );

    /**
     *  @notice Emitted when borrower draws debt from the pool, or adds collateral to the pool.
     *  @param  borrower          The borrower to whom collateral was pledged, and/or debt was drawn for.
     *  @param  amountBorrowed    Amount of quote tokens borrowed from the pool (`WAD` precision).
     *  @param  collateralPledged Amount of collateral locked in the pool (`WAD` precision).
     *  @param  lup               `LUP` after borrow.
     */
    event DrawDebt(
        address indexed borrower,
        uint256 amountBorrowed,
        uint256 collateralPledged,
        uint256 lup
    );
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

import { IPoolFactory } from '../IPoolFactory.sol';

/**
 *  @title ERC20 Pool Factory
 *  @dev   Used to deploy `ERC20` pools.
 */
interface IERC20PoolFactory is IPoolFactory {

    /**************************/
    /*** External Functions ***/
    /**************************/

    /**
     *  @notice Deploys a cloned pool for the given collateral and quote token.
     *  @dev    Pool must not already exist, and must use `WETH` instead of `ETH`.
     *  @param  collateral_   Address of `ERC20` collateral token.
     *  @param  quote_        Address of `ERC20` quote token.
     *  @param  interestRate_ Initial interest rate of the pool.
     *  @return pool_         Address of the newly created pool.
     */
    function deployPool(
        address collateral_,
        address quote_,
        uint256 interestRate_
    ) external returns (address pool_);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title ERC20 Pool Immutables
 */
interface IERC20PoolImmutables {

    /**
     *  @notice Returns the `collateralScale` immutable.
     *  @return The precision of the collateral `ERC20` token based on decimals.
     */
    function collateralScale() external view returns (uint256);

}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title ERC20 Pool Lender Actions
 */
interface IERC20PoolLenderActions {

    /**
     *  @notice Deposit claimable collateral into a specified bucket.
     *  @param  amountToAdd_ Amount of collateral to deposit (`WAD` precision).
     *  @param  index_       The bucket index to which collateral will be deposited.
     *  @param  expiry_      Timestamp after which this transaction will revert, preventing inclusion in a block with unfavorable price.
     *  @return bucketLP_    The amount of `LP` awarded for the added collateral (`WAD` precision).
     */
    function addCollateral(
        uint256 amountToAdd_,
        uint256 index_,
        uint256 expiry_
    ) external returns (uint256 bucketLP_);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

interface IERC20Taker {
    /**
     *  @notice Called by `Pool.take` allowing a taker to externally swap collateral for quote token.
     *  @param  collateralAmount The denormalized amount of collateral being taken (`WAD` precision).
     *  @param  quoteAmountDue   Denormalized amount of quote token required to purchase `collateralAmount` at the 
     *                           current auction price (`WAD` precision).
     *  @param  data             Taker-provided calldata passed from taker's invocation to their callback.
     */
    function atomicSwapCallback(
        uint256        collateralAmount, 
        uint256        quoteAmountDue,
        bytes calldata data
    ) external;
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

interface IERC3156FlashBorrower {

    /**
     * @dev    Receive a flash loan.
     * @param  initiator The initiator of the loan.
     * @param  token     The loan currency.
     * @param  amount    The amount of tokens lent (token precision).
     * @param  fee       The additional amount of tokens to repay.
     * @param  data      Arbitrary data structure, intended to contain user-defined parameters.
     * @return The `keccak256` hash of `ERC3156FlashBorrower.onFlashLoan`
     */
    function onFlashLoan(
        address initiator,
        address token,
        uint256 amount,
        uint256 fee,
        bytes   calldata data
    ) external returns (bytes32);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;
import { IERC3156FlashBorrower } from "./IERC3156FlashBorrower.sol";


interface IERC3156FlashLender {

    /**
     * @dev    The amount of currency available to be lent.
     * @param  token_ The loan currency.
     * @return The amount of `token` that can be borrowed (token precision).
     */
    function maxFlashLoan(
        address token_
    ) external view returns (uint256);

    /**
     * @dev    The fee to be charged for a given loan.
     * @param  token_    The loan currency.
     * @param  amount_   The amount of tokens lent (token precision).
     * @return The amount of `token` to be charged for the loan (token precision), on top of the returned principal .
     */
    function flashFee(
        address token_,
        uint256 amount_
    ) external view returns (uint256);

    /**
     * @dev    Initiate a flash loan.
     * @param  receiver_ The receiver of the tokens in the loan, and the receiver of the callback.
     * @param  token_    The loan currency.
     * @param  amount_   The amount of tokens lent (token precision).
     * @param  data_     Arbitrary data structure, intended to contain user-defined parameters.
     * @return `True` when successful flashloan, `false` otherwise.
     */
    function flashLoan(
        IERC3156FlashBorrower receiver_,
        address token_,
        uint256 amount_,
        bytes   calldata data_
    ) external returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
     * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
     * understand this adds an external call which potentially creates a reentrancy vulnerability.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Metadata is IERC721 {
    /**
     * @dev Returns the token collection name.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the token collection symbol.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    function tokenURI(uint256 tokenId) external view returns (string memory);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

import { IPool } from '../IPool.sol';

import { IERC721PoolBorrowerActions } from './IERC721PoolBorrowerActions.sol';
import { IERC721PoolLenderActions }   from './IERC721PoolLenderActions.sol';
import { IERC721PoolImmutables }      from './IERC721PoolImmutables.sol';
import { IERC721PoolState }           from './IERC721PoolState.sol';
import { IERC721PoolEvents }          from './IERC721PoolEvents.sol';
import { IERC721PoolErrors }          from './IERC721PoolErrors.sol';

/**
 * @title ERC721 Pool
 */
interface IERC721Pool is
    IPool,
    IERC721PoolLenderActions,
    IERC721PoolBorrowerActions,
    IERC721PoolState,
    IERC721PoolImmutables,
    IERC721PoolEvents,
    IERC721PoolErrors
{

    /**
     *  @notice Initializes a new pool, setting initial state variables.
     *  @param  tokenIds_  Enumerates `tokenIds_` to be allowed in the pool.
     *  @param  rate_      Initial interest rate of the pool.
     */
    function initialize(
        uint256[] memory tokenIds_,
        uint256 rate_
    ) external;

}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title ERC721 Pool Borrower Actions
 */
interface IERC721PoolBorrowerActions {

    /**
     *  @notice Called by borrowers to add collateral to the pool and/or borrow quote from the pool.
     *  @dev    Can be called by borrowers with either `0` `amountToBorrow_` or `0` `collateralToPledge`_, if borrower only wants to take a single action. 
     *  @param  borrower_         The address of borrower to drawDebt for.
     *  @param  amountToBorrow_   The amount of quote tokens to borrow (`WAD` precision).
     *  @param  limitIndex_       Lower bound of `LUP` change (if any) that the borrower will tolerate from a creating or modifying position.
     *  @param  tokenIdsToPledge_ Array of token ids to be pledged to the pool.
     */
    function drawDebt(
        address borrower_,
        uint256 amountToBorrow_,
        uint256 limitIndex_,
        uint256[] calldata tokenIdsToPledge_
    ) external;

    /**
     *  @notice Called by borrowers to repay borrowed quote to the pool, and/or pull collateral form the pool.
     *  @dev    Can be called by borrowers with either `0` `maxQuoteTokenAmountToRepay_` or `0` `collateralAmountToPull_`, if borrower only wants to take a single action. 
     *  @param  borrowerAddress_            The borrower whose loan is being interacted with.
     *  @param  maxQuoteTokenAmountToRepay_ The max amount of quote tokens to repay (`WAD` precision).
     *  @param  noOfNFTsToPull_             The integer number of `NFT` collateral to be puled from the pool.
     *  @param  recipient_                  The address to receive amount of pulled collateral.
     *  @param  limitIndex_                 Ensures `LUP` has not moved far from state when borrower pulls collateral.
     *  @return amountRepaid_               The amount of quote token repaid (`WAD` precision).
     */
    function repayDebt(
        address borrowerAddress_,
        uint256 maxQuoteTokenAmountToRepay_,
        uint256 noOfNFTsToPull_,
        address recipient_,
        uint256 limitIndex_
    ) external returns (uint256 amountRepaid_);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title ERC721 Pool Errors
 */
interface IERC721PoolErrors {

    /**
     *  @notice User attempted to add an `NFT` to the pool with a `tokenId` outside of the allowed subset.
     */
    error OnlySubset();
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title ERC721 Pool Events
 */
interface IERC721PoolEvents {

    /**
     *  @notice Emitted when actor adds claimable collateral to a bucket.
     *  @param  actor     Recipient that added collateral.
     *  @param  index     Index at which collateral were added.
     *  @param  tokenIds  Array of tokenIds to be added to the pool.
     *  @param  lpAwarded Amount of LP awarded for the deposit (`WAD` precision).
     */
    event AddCollateralNFT(
        address indexed actor,
        uint256 indexed index,
        uint256[] tokenIds,
        uint256   lpAwarded
    );

    /**
     *  @notice Emitted when actor adds claimable collateral to a bucket.
     *  @param  actor            Recipient that added collateral.
     *  @param  collateralMerged Amount of collateral merged (`WAD` precision).
     *  @param  toIndexLps       If non-zero, amount of LP in toIndex when collateral is merged into bucket (`WAD` precision). If 0, no collateral is merged.
     */
    event MergeOrRemoveCollateralNFT(
        address indexed actor,
        uint256 collateralMerged,
        uint256 toIndexLps
    );

    /**
     *  @notice Emitted when borrower draws debt from the pool or adds collateral to the pool.
     *  @param  borrower          `msg.sender`.
     *  @param  amountBorrowed    Amount of quote tokens borrowed from the pool (`WAD` precision).
     *  @param  tokenIdsPledged   Array of tokenIds to be added to the pool.
     *  @param  lup               LUP after borrow.
     */
    event DrawDebtNFT(
        address indexed borrower,
        uint256   amountBorrowed,
        uint256[] tokenIdsPledged,
        uint256   lup
    );
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

import { IPoolFactory } from '../IPoolFactory.sol';

/**
 *  @title ERC721 Pool Factory
 *  @dev   Used to deploy non fungible pools.
 */
interface IERC721PoolFactory is IPoolFactory {

    /**************/
    /*** Errors ***/
    /**************/

    /**
     *  @notice User tried to deploy a pool with an array of `tokenIds` that weren't sorted, or contained duplicates.
     */
    error TokenIdSubsetInvalid();

    /**************************/
    /*** External Functions ***/
    /**************************/

    /**
     *  @notice Deploys a cloned pool for the given collateral and quote token.
     *  @dev    Pool must not already exist, and must use `WETH` instead of `ETH`.
     *  @param  collateral_   Address of `NFT` collateral token.
     *  @param  quote_        Address of `NFT` quote token.
     *  @param  tokenIds_     Ids of subset `NFT` tokens.
     *  @param  interestRate_ Initial interest rate of the pool.
     *  @return pool_         Address of the newly created pool.
     */
    function deployPool(
        address collateral_,
        address quote_,
        uint256[] memory tokenIds_,
        uint256 interestRate_
    ) external returns (address pool_);

    /**
     *  @notice User attempted to make pool with non supported `NFT` contract as collateral.
     */
    error NFTNotSupported();
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title ERC721 Pool Immutables
 */
interface IERC721PoolImmutables{

    /**
     *  @notice Returns the type of `NFT` pool.
     *  @return `True` if `NTF` pool is a subset pool.
     */
    function isSubset() external view returns (bool);

}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title ERC721 Pool Lender Actions
 */
interface IERC721PoolLenderActions {

    /**
     *  @notice Deposit claimable collateral into a specified bucket.
     *  @param  tokenIds_ Array of token ids to deposit.
     *  @param  index_    The bucket index to which collateral will be deposited.
     *  @param  expiry_   Timestamp after which this transaction will revert, preventing inclusion in a block with unfavorable price.
     *  @return bucketLP_ The amount of `LP `changed for the added collateral.
     */
    function addCollateral(
        uint256[] calldata tokenIds_,
        uint256 index_,
        uint256 expiry_
    ) external returns (uint256 bucketLP_);

    /**
     *  @notice Merge collateral accross a number of buckets, `removalIndexes_` reconstitute an `NFT`.
     *  @param  removalIndexes_   Array of bucket indexes to remove all collateral that the caller has ownership over.
     *  @param  noOfNFTsToRemove_ Intergral number of `NFT`s to remove if collateral amount is met `noOfNFTsToRemove_`, else merge at bucket index, `toIndex_`.
     *  @param  toIndex_          The bucket index to which merge collateral into.
     *  @return collateralMerged_ Amount of collateral merged into `toIndex_` (`WAD` precision).
     *  @return bucketLP_         If non-zero, amount of `LP` in `toIndex_` when collateral is merged into bucket (`WAD` precision). If `0`, no collateral is merged.
     */
    function mergeOrRemoveCollateral(
        uint256[] calldata removalIndexes_,
        uint256 noOfNFTsToRemove_,
        uint256 toIndex_
    ) external returns (uint256 collateralMerged_, uint256 bucketLP_);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title ERC721 Pool State
 */
interface IERC721PoolState {

    /**
     *  @notice Check if a token id is allowed as collateral in pool.
     *  @param  tokenId The token id to check.
     *  @return allowed `True` if token id is allowed in pool.
     */
    function tokenIdsAllowed(
        uint256 tokenId
    ) external view returns (bool allowed);

    /**
     *  @notice Returns the token id of an `NFT` pledged by a borrower with a given index.
     *  @param  borrower The address of borrower that pledged the `NFT`.
     *  @param  nftIndex `NFT` index in borrower's pledged token ids array.
     *  @return tokenId  Token id of the `NFT`.
     */
    function borrowerTokenIds(
        address borrower,
        uint256 nftIndex
    ) external view returns (uint256 tokenId);

    /**
     *  @notice Returns the token id of an `NFT` added in pool bucket (claimable from pool).
     *  @param  nftIndex `NFT` index in bucket's token ids array.
     *  @return tokenId  Token id of the `NFT`.
     */
    function bucketTokenIds(
        uint256 nftIndex
    ) external view returns (uint256 tokenId);

    /**
     *  @notice Returns the list of `NFT` tokenIds pledged by a borrower in a pool.
     *  @param  borrower_ The address of borrower that pledged the `NFT`s.
     *  @return List of `NFT`s pledged by borrower.
     */
    function getBorrowerTokenIds(address borrower_) external view returns(uint256[] memory);

    /**
     *  @notice Returns the list of `NFT` tokenIds added to pool buckets.
     *  @return List of `NFT`s that are claimable from the pool.
     */
    function getBucketTokenIds() external view returns(uint256[] memory);

}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
     *
     * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

interface IERC721Taker {
    /**
     *  @notice Called by `Pool.take` allowing a taker to externally swap collateral for quote token.
     *  @param  tokenIds       Identifies the `NFT`s being taken.
     *  @param  quoteAmountDue Denormalized amount of quote token required to purchase `collateralAmount` at the 
     *                         current auction price (`WAD` precision).
     *  @param  data           Taker-provided calldata passed from taker's invocation to their callback.
     */
    function atomicSwapCallback(
        uint256[] memory tokenIds, 
        uint256          quoteAmountDue,
        bytes calldata   data
    ) external;
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

import { IPoolBorrowerActions } from './commons/IPoolBorrowerActions.sol';
import { IPoolLPActions }       from './commons/IPoolLPActions.sol';
import { IPoolLenderActions }   from './commons/IPoolLenderActions.sol';
import { IPoolKickerActions }   from './commons/IPoolKickerActions.sol';
import { IPoolTakerActions }    from './commons/IPoolTakerActions.sol';
import { IPoolSettlerActions }  from './commons/IPoolSettlerActions.sol';

import { IPoolImmutables }      from './commons/IPoolImmutables.sol';
import { IPoolState }           from './commons/IPoolState.sol';
import { IPoolDerivedState }    from './commons/IPoolDerivedState.sol';
import { IPoolEvents }          from './commons/IPoolEvents.sol';
import { IPoolErrors }          from './commons/IPoolErrors.sol';
import { IERC3156FlashLender }  from './IERC3156FlashLender.sol';

/**
 * @title Base Pool Interface
 */
interface IPool is
    IPoolBorrowerActions,
    IPoolLPActions,
    IPoolLenderActions,
    IPoolKickerActions,
    IPoolTakerActions,
    IPoolSettlerActions,
    IPoolImmutables,
    IPoolState,
    IPoolDerivedState,
    IPoolEvents,
    IPoolErrors,
    IERC3156FlashLender
{

}

/// @dev Pool type enum - `ERC20` and `ERC721`
enum PoolType { ERC20, ERC721 }

/// @dev `ERC20` token interface.
interface IERC20Token {
    function balanceOf(address account) external view returns (uint256);
    function burn(uint256 amount) external;
    function decimals() external view returns (uint8);
}

/// @dev `ERC721` token interface.
interface IERC721Token {
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title Pool Borrower Actions
 */
interface IPoolBorrowerActions {

    /**
     *  @notice Called by fully collateralized borrowers to restamp the `Np to Tp ratio` of the loan (only if loan is fully collateralized and not in auction).
     *          The reason for stamping the `Np to Tp ratio` on the loan is to provide some certainty to the borrower as to at what price they can expect to be liquidated.
     *          This action can restamp only the loan of `msg.sender`.
     */
    function stampLoan() external;

}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title Pool Derived State
 */
interface IPoolDerivedState {

    /**
     *  @notice Returns the exchange rate for a given bucket index.
     *  @param  index_        The bucket index.
     *  @return exchangeRate_ Exchange rate of the bucket (`WAD` precision).
     */
    function bucketExchangeRate(
        uint256 index_
    ) external view returns (uint256 exchangeRate_);

    /**
     *  @notice Returns the prefix sum of a given bucket.
     *  @param  index_   The bucket index.
     *  @return The deposit up to given index (`WAD` precision).
     */
    function depositUpToIndex(
        uint256 index_
    ) external view returns (uint256);

    /**
     *  @notice Returns the bucket index for a given debt amount.
     *  @param  debt_  The debt amount to calculate bucket index for (`WAD` precision).
     *  @return Bucket index.
     */
    function depositIndex(
        uint256 debt_
    ) external view returns (uint256);

    /**
     *  @notice Returns the total amount of quote tokens deposited in pool.
     *  @return Total amount of deposited quote tokens (`WAD` precision).
     */
    function depositSize() external view returns (uint256);

    /**
     *  @notice Returns the meaningful actual utilization of the pool.
     *  @return Deposit utilization (`WAD` precision).
     */
    function depositUtilization() external view returns (uint256);

    /**
     *  @notice Returns the scaling value of deposit at given index.
     *  @param  index_  Deposit index.
     *  @return Deposit scaling (`WAD` precision).
     */
    function depositScale(
        uint256 index_
    ) external view returns (uint256);

}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.18;

/**
 * @title Pool Errors.
 */
interface IPoolErrors {
    /**************************/
    /*** Common Pool Errors ***/
    /**************************/

    /**
     *  @notice Adding liquidity above current auction price.
     */
    error AddAboveAuctionPrice();

    /**
     *  @notice The action cannot be executed on an active auction.
     */
    error AuctionActive();

    /**
     *  @notice Attempted auction to clear doesn't meet conditions.
     */
    error AuctionNotClearable();

    /**
     *  @notice Auction does not meet requirements to take liquidity.
     */
    error AuctionNotTakeable();

    /**
     *  @notice Head auction should be cleared prior of executing this action.
     */
    error AuctionNotCleared();

    /**
     *  @notice The auction price is greater than the arbed bucket price.
     */
    error AuctionPriceGtBucketPrice();

    /**
     *  @notice Pool already initialized.
     */
    error AlreadyInitialized();

    /**
     *  @notice Borrower is attempting to create or modify a loan such that their loan's quote token would be less than the pool's minimum debt amount.
     */
    error AmountLTMinDebt();

    /**
     *  @notice Recipient of borrowed quote tokens doesn't match the caller of the `drawDebt` function.
     */
    error BorrowerNotSender();

    /**
     *  @notice Borrower has a healthy over-collateralized position.
     */
    error BorrowerOk();

    /**
     *  @notice Borrower is attempting to borrow more quote token than they have collateral for.
     */
    error BorrowerUnderCollateralized();

    /**
     *  @notice Operation cannot be executed in the same block when bucket becomes insolvent.
     */
    error BucketBankruptcyBlock();

    /**
     *  @notice User attempted to merge collateral from a lower price bucket into a higher price bucket.
     */
    error CannotMergeToHigherPrice();

    /**
     *  @notice User attempted an operation which does not exceed the dust amount, or leaves behind less than the dust amount.
     */
    error DustAmountNotExceeded();

    /**
     *  @notice Callback invoked by `flashLoan` function did not return the expected hash (see `ERC-3156` spec).
     */
    error FlashloanCallbackFailed();

    /**
     *  @notice Balance of pool contract before flashloan is different than the balance after flashloan.
     */
    error FlashloanIncorrectBalance();

    /**
     *  @notice Pool cannot facilitate a flashloan for the specified token address.
     */
    error FlashloanUnavailableForToken();

    /**
     *  @notice User is attempting to move or pull more collateral than is available.
     */
    error InsufficientCollateral();

    /**
     *  @notice Lender is attempting to move or remove more collateral they have claim to in the bucket.
     *  @notice Lender is attempting to remove more collateral they have claim to in the bucket.
     *  @notice Lender must have enough `LP` to claim the desired amount of quote from the bucket.
     */
    error InsufficientLP();

    /**
     *  @notice Bucket must have more quote available in the bucket than the lender is attempting to claim.
     */
    error InsufficientLiquidity();

    /**
     *  @notice When increasing / decreasing `LP` allowances indexes and amounts arrays parameters should have same length.
     */
    error InvalidAllowancesInput();

    /**
     *  @notice When transferring `LP` between indices, the new index must be a valid index.
     */
    error InvalidIndex();

    /**
     *  @notice The amount used for performed action should be greater than `0`.
     */
    error InvalidAmount();

    /**
     *  @notice Borrower is attempting to borrow more quote token than is available before the supplied `limitIndex`.
     */
    error LimitIndexExceeded();

    /**
     *  @notice When moving quote token `HTP` must stay below `LUP`.
     *  @notice When removing quote token `HTP` must stay below `LUP`.
     */
    error LUPBelowHTP();

    /**
     *  @notice From index and to index arguments to move are the same.
     */
    error MoveToSameIndex();

    /**
     *  @notice Owner of the `LP` must have approved the new owner prior to transfer.
     */
    error NoAllowance();

    /**
     *  @notice Actor is attempting to take or clear an inactive auction.
     */
    error NoAuction();

    /**
     *  @notice No pool reserves are claimable.
     */
    error NoReserves();

    /**
     *  @notice Actor is attempting to take or clear an inactive reserves auction.
     */
    error NoReservesAuction();

    /**
     *  @notice Lender must have non-zero `LP` when attemptign to remove quote token from the pool.
     */
    error NoClaim();

    /**
     *  @notice Borrower has no debt to liquidate.
     *  @notice Borrower is attempting to repay when they have no outstanding debt.
     */
    error NoDebt();

    /**
     *  @notice Actor is attempting to kick with bucket price below the `LUP`.
     */
    error PriceBelowLUP();

    /**
     *  @notice Lender is attempting to remove quote tokens from a bucket that exists above active auction debt from top-of-book downward.
     */
    error RemoveDepositLockedByAuctionDebt();

    /**
     * @notice User attempted to kick off a new auction less than `2` weeks since the last auction completed.
     */
    error ReserveAuctionTooSoon();

    /**
     *  @notice Current block timestamp has reached or exceeded a user-provided expiration.
     */
    error TransactionExpired();

    /**
     *  @notice The address that transfer `LP` is not approved by the `LP` receiving address.
     */
    error TransferorNotApproved();

    /**
     *  @notice Owner of the `LP` attemps to transfer `LP` to same address.
     */
    error TransferToSameOwner();

    /**
     *  @notice The DebtToCollateral of the loan to be inserted in loans heap is zero.
     */
    error ZeroDebtToCollateral();

}