// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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
     *
     * Furthermore, `isContract` will also return true if the target contract within
     * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
     * which only has an effect at the end of a transaction.
     * ====
     *
     * [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://consensys.net/diligence/blog/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/v0.8.0/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: MIT

pragma solidity ^0.8.0;

import "./OFTCoreV2.sol";
import "./IOFTV2.sol";
import "../../../../oz/utils/introspection/ERC165.sol";

abstract contract BaseOFTV2 is OFTCoreV2, ERC165, IOFTV2 {

    constructor(uint8 _sharedDecimals) OFTCoreV2(_sharedDecimals) {
    }

    function __BaseOFTV2_init(address _lzEndpoint) internal {
        __OFTCoreV2_init(_lzEndpoint);
    }

    /************************************************************************
    * public functions
    ************************************************************************/
    function sendFrom(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, LzCallParams calldata _callParams) public payable virtual override {
        _send(_from, _dstChainId, _toAddress, _amount, _callParams.refundAddress, _callParams.zroPaymentAddress, _callParams.adapterParams);
    }

    function sendAndCall(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes calldata _payload, uint64 _dstGasForCall, LzCallParams calldata _callParams) public payable virtual override {
        _sendAndCall(_from, _dstChainId, _toAddress, _amount, _payload, _dstGasForCall, _callParams.refundAddress, _callParams.zroPaymentAddress, _callParams.adapterParams);
    }

    /************************************************************************
    * public view functions
    ************************************************************************/
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return interfaceId == type(IOFTV2).interfaceId || super.supportsInterface(interfaceId);
    }

    function estimateSendFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) public view virtual override returns (uint nativeFee, uint zroFee) {
        return _estimateSendFee(_dstChainId, _toAddress, _amount, _useZro, _adapterParams);
    }

    function estimateSendAndCallFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes calldata _payload, uint64 _dstGasForCall, bool _useZro, bytes calldata _adapterParams) public view virtual override returns (uint nativeFee, uint zroFee) {
        return _estimateSendAndCallFee(_dstChainId, _toAddress, _amount, _payload, _dstGasForCall, _useZro, _adapterParams);
    }

    function circulatingSupply() public view virtual override returns (uint);

    function token() public view virtual override returns (address);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

import {Ownable} from "./oz/access/Ownable.sol";
import {IERC20, ERC20, ERC20Permit, ERC20Votes} from "./oz/token/ERC20/extensions/ERC20Votes.sol";
import {SafeERC20} from "./oz/token/ERC20/utils/SafeERC20.sol";
import {IERC165} from "./oz/utils/introspection/IERC165.sol";
import {Address} from "./oz/utils/Address.sol";

import {OFTV2} from "./lz/token/oft/v2/OFTV2.sol";

import {IBuyTaxReceiver} from "./interfaces/IBuyTaxReceiver.sol";
import {IAntiMevStrategy} from "./interfaces/IAntiMevStrategy.sol";

/**
 * @title BenCoinV2
 * @author Ben Coin Collective
 *
 * BenCoinV2 is an ERC20 token contract with additional features such as taxing, anti-MEV protection and transfer blacklisting.
 *
 * The contract is part of the Ben Coin ecosystem.
 * The owner of this contract has control over functions such as setting taxes, managing whitelists, enabling/disabling features &
 * provides a way to recover tokens accidentally sent to the contract. It is not an upgradeable proxy contract, but can however
 * update logic for the anti-MEV strategy and buy tax receiving.
 *
 * No extra tokens can be minted after deployment, but this is a LayerZero cross chain compatible token contract, and is permitted to burn
 * on the source chain and mint on another, but the overall token count does not change.
 */
contract BenCoinV2 is OFTV2, ERC20Votes {
  using SafeERC20 for IERC20;

  event SetTax(uint buyTax, uint sellTax, bool isTaxing);
  event SetBuyTaxReceiver(address buyTaxReceiver);
  event SetTaxableContract(address taxableContract, bool isTaxable);
  event SetTaxWhitelist(address whitelist, bool isWhitelisted);
  event SetIsAntiMEV(bool isAntiMEV);
  event SetIsTransferBlacklisting(bool isBlacklisting);
  event SetTransferBlacklist(address blacklist, bool isBlacklisted);

  error OnlyMigrator();
  error MigratorSetOnInvalidChain();
  error MaxTaxExceeded();
  error BothAddressesAreContracts();
  error TransferBlacklisted(address);
  error InvalidBuyTaxReceiver();
  error InvalidArrayLength();
  error AlreadyInitialized();

  address private buyTaxReceiver;
  uint16 private buyTax;
  uint16 private sellTax;
  bool private isTaxingEnabled;
  bool private isAntiMEV;
  bool private isBlacklisting;
  bool private isInitialized;
  uint8 private taxFlag = NOT_TAXING;
  mapping(address contractAddress => bool isTaxable) private taxableAddress;
  mapping(address whitelist => bool isWhitelisted) private taxWhitelist; // For certain addresses to be exempt from tax like exchanges

  mapping(address blacklist => bool isBlacklisted) private transferBlacklist;
  IAntiMevStrategy private antiMEVStrategy;

  uint256 private constant MAX_TAX = 10; // 10%
  // Using 1 & 2 instead of 0 to save gas when resetting
  uint8 private constant NOT_TAXING = 1;
  uint8 private constant TAXING = 2;
  uint256 private constant FEE_DENOMINATOR = 10000;
  uint8 private constant SHARED_DECIMALS = 8;

  /**
   * @notice BenCoinV2 contract constructor
   */
  constructor() OFTV2("BEN", "BEN", SHARED_DECIMALS) ERC20Permit("BEN") {}

  /**
   * @notice Initializes the contract
   * @param _lzEndpoint The endpoint for Layer Zero
   * @param _buyTaxReceiver The address to send the buy tax to
   * @param _antiMEVStrategy The anti-MEV strategy to use
   * @param _migrator The migrator contract address for benV1 to benV2 (only used on Ethereum)
   * @param _migratorMintSupply The migrator contract address for benV1 to benV2 (only used on Ethereum)
   * @param _buyTax The buy tax (10000 basis points, so 300 is 3%)
   * @param _sellTax The sell tax (10000 basis points, so 100 is 1%)
   * @param _isTaxingEnabled Whether or not taxing is enabled
   * @param _isAntiMEV Whether or not anti-MEV is enabled
   * @param _isTransferBlacklisting Whether or not transfer blacklisting is enabled
   */
  function initialize(
    address _lzEndpoint,
    address _buyTaxReceiver,
    address _antiMEVStrategy,
    address _migrator,
    uint256 _migratorMintSupply,
    uint256 _buyTax,
    uint256 _sellTax,
    bool _isTaxingEnabled,
    bool _isAntiMEV,
    bool _isTransferBlacklisting
  ) external notInitialized onlyOwner {
    __OFTV2_init(_lzEndpoint);

    _setTax(_buyTax, _sellTax, _isTaxingEnabled);
    _setIsAntiMEV(_isAntiMEV);
    _setIsTransferBlacklisting(_isTransferBlacklisting);
    if (_isTaxingEnabled) {
      _setBuyTaxReceiver(_buyTaxReceiver);
    }

    antiMEVStrategy = IAntiMevStrategy(_antiMEVStrategy);
    isInitialized = true;
    if (_migrator != address(0)) {
      if (
        block.chainid != 1 && // ethereum
        block.chainid != 1337 && // ganache
        block.chainid != 31337 // hardhat
      ) {
        // Migrator can only be set on ethereum as well as local development chain ids like hardhat.
        // This is because the migrator gets minted with the whole supply to distribute during the V1 to V2 migration.
        revert MigratorSetOnInvalidChain();
      }

      // If the migrator is set then mint the total supply of BenV2 tokens to it
      _mint(_migrator, _migratorMintSupply);
    }
  }

  /**
   * @dev Modifier to check if the contract has been initialized
   */
  modifier notInitialized() {
    if (isInitialized) {
      revert AlreadyInitialized();
    }
    _;
  }

  /**
   * @dev Anti-MEV modifier
   * @param _from The sender address
   * @param _to The receiver address
   * @param _amount The amount being transferred
   */
  modifier antiMEV(
    address _from,
    address _to,
    uint256 _amount
  ) {
    if (isAntiMEV) {
      antiMEVStrategy.onTransfer(_from, _to, _amount, taxFlag == TAXING);
    }
    _;
  }

  /**
   * @notice Burns BEN coin
   * @param _amount The amount to burn
   */
  function burn(uint256 _amount) external {
    _burn(_msgSender(), _amount);
  }

  /**
   * @notice Burns BEN coin from a specific address which has given the sender an allowance
   * @param _account The account to burn from
   * @param _amount The amount to burn
   */
  function burnFrom(address _account, uint256 _amount) external {
    _spendAllowance(_account, _msgSender(), _amount);
    _burn(_account, _amount);
  }

  function _mint(address _account, uint256 _amount) internal override(ERC20, ERC20Votes) {
    ERC20Votes._mint(_account, _amount);
  }

  function _burn(address _account, uint256 _amount) internal override(ERC20, ERC20Votes) {
    ERC20Votes._burn(_account, _amount);
  }

  function _beforeTokenTransfer(
    address _from,
    address _to,
    uint256 _amount
  ) internal override(ERC20) antiMEV(_from, _to, _amount) {
    if (isBlacklisting && transferBlacklist[_from]) {
      revert TransferBlacklisted(_from);
    }

    ERC20._beforeTokenTransfer(_from, _to, _amount);

    if (isTaxingEnabled && taxFlag == NOT_TAXING && taxableAddress[_to] && !taxWhitelist[_from]) {
      taxFlag = TAXING; // Set this so no further taxing is done by other transfers
      IBuyTaxReceiver(buyTaxReceiver).swapCallback();
      taxFlag = NOT_TAXING;
    }
  }

  function _afterTokenTransfer(address _from, address _to, uint256 _amount) internal override(ERC20, ERC20Votes) {
    ERC20Votes._afterTokenTransfer(_from, _to, _amount);

    // Take a fee if it is a taxable contract
    if (isTaxingEnabled && taxFlag == NOT_TAXING) {
      // If it's a buy then we take from who-ever it is sent to and send to the contract for selling back to ETH
      if (taxableAddress[_from] && !taxWhitelist[_to]) {
        uint256 fee = _calcTax(buyTax, _amount);
        // Transfers from the receiver to the buy tax receiver for later selling
        taxFlag = TAXING;
        _transfer(_to, buyTaxReceiver, fee);
        taxFlag = NOT_TAXING;
      } else if (taxableAddress[_to] && !taxWhitelist[_from]) {
        uint256 fee = _calcTax(sellTax, _amount);
        // Transfers from taxable contracts (like LPs) to the admin directly
        taxFlag = TAXING;
        _transfer(_to, owner(), fee);
        taxFlag = NOT_TAXING;
      }
    }
  }

  /**
   * @notice Calculate the tax fee
   * @param _tax The tax rate in basis points (10000 basis points = 100%)
   * @param _amount The amount to apply the tax to
   * @return fees The calculated tax fees
   * @dev Internal function used to calculate tax fees
   */
  function _calcTax(uint256 _tax, uint256 _amount) private pure returns (uint256 fees) {
    fees = (_amount * _tax) / FEE_DENOMINATOR;
  }

  function _setTax(uint256 _buyTax, uint256 _sellTax, bool _isTaxingEnabled) internal {
    // Cannot set tax higher than MAX_TAX (10%)
    if ((_buyTax * MAX_TAX > FEE_DENOMINATOR) || (_sellTax * MAX_TAX > FEE_DENOMINATOR)) {
      revert MaxTaxExceeded();
    }

    buyTax = uint16(_buyTax);
    sellTax = uint16(_sellTax);
    isTaxingEnabled = _isTaxingEnabled;

    emit SetTax(_buyTax, _sellTax, _isTaxingEnabled);
  }

  function _setIsAntiMEV(bool _isAntiMEV) private {
    isAntiMEV = _isAntiMEV;
    emit SetIsAntiMEV(_isAntiMEV);
  }

  function _setIsTransferBlacklisting(bool _isBlacklisting) private {
    isBlacklisting = _isBlacklisting;
    emit SetIsTransferBlacklisting(_isBlacklisting);
  }

  function _setBuyTaxReceiver(address _buyTaxReceiver) private {
    if (
      !Address.isContract(_buyTaxReceiver) ||
      !IERC165(_buyTaxReceiver).supportsInterface(type(IBuyTaxReceiver).interfaceId)
    ) {
      revert InvalidBuyTaxReceiver();
    }
    buyTaxReceiver = _buyTaxReceiver;
    emit SetBuyTaxReceiver(_buyTaxReceiver);
  }

  /**
   * @notice Set the tax parameters
   * @param _buyTax The buy tax rate in basis points (10000 basis points = 100%)
   * @param _sellTax The sell tax rate in basis points (10000 basis points = 100%)
   * @param _isTaxingEnabled Whether or not taxing is enabled
   * @dev Only callable by the owner
   */
  function setTax(uint256 _buyTax, uint256 _sellTax, bool _isTaxingEnabled) external onlyOwner {
    _setTax(_buyTax, _sellTax, _isTaxingEnabled);
  }

  /**
   * @notice Set whether or not a contract is taxable
   * @param _taxableContract The contract to set taxable state for
   * @param _isTaxable Whether or not the contract is taxable
   * @dev Only callable by the owner
   */
  function setTaxableContract(address _taxableContract, bool _isTaxable) external onlyOwner {
    taxableAddress[_taxableContract] = _isTaxable;
    emit SetTaxableContract(_taxableContract, _isTaxable);
  }

  /**
   * @notice Set whether or not an address is whitelisted for tax
   * @param _whitelist The address to set whitelist state for
   * @param _isWhitelisted Whether or not the address is whitelisted
   * @dev Only callable by the owner
   */
  function setTaxWhitelist(address _whitelist, bool _isWhitelisted) external onlyOwner {
    taxWhitelist[_whitelist] = _isWhitelisted;
    emit SetTaxWhitelist(_whitelist, _isWhitelisted);
  }

  /**
   * @notice Set whether an anti-MEV strategy is used
   * @param _isAntiMEV Whether or not anti-MEV is enabled
   * @dev Only callable by the owner
   */
  function setIsAntiMEV(bool _isAntiMEV) external onlyOwner {
    _setIsAntiMEV(_isAntiMEV);
  }

  /**
   * @notice Set the anti-MEV strategy
   * @param _antiMEVStrategy The anti-MEV strategy to use
   * @dev Only callable by the owner
   */
  function setAntiMevStrategy(IAntiMevStrategy _antiMEVStrategy) external onlyOwner {
    antiMEVStrategy = _antiMEVStrategy;
  }

  /**
   * @notice Set whether or not transfer blacklisting is enabled
   * @param _isBlacklisting Whether or not transfer blacklisting is enabled
   * @dev Only callable by the owner
   */
  function setIsTransferBlacklisting(bool _isBlacklisting) external onlyOwner {
    _setIsTransferBlacklisting(_isBlacklisting);
  }

  /**
   * @notice Recover tokens sent to this contract by accident
   * @param _token The token to recover
   * @param _amount The amount to recover
   * @dev Only callable by the owner
   */
  function recoverToken(IERC20 _token, uint _amount) external onlyOwner {
    _token.safeTransfer(owner(), _amount);
  }

  /**
   * @notice Set the buy tax receiver address
   * @param _buyTaxReceiver The address to send the buy tax to
   * @dev Only callable by the owner
   */
  function setBuyTaxReceiver(address _buyTaxReceiver) external onlyOwner {
    _setBuyTaxReceiver(_buyTaxReceiver);
  }

  /**
   * @notice Set whether or not an address is blacklisted from transferring
   * @param _blacklist The address to set blacklist state for
   * @param _isBlacklisted Whether or not the address is blacklisted
   * @dev Only callable by the owner
   */
  function setTransferBlacklist(address _blacklist, bool _isBlacklisted) external onlyOwner {
    transferBlacklist[_blacklist] = _isBlacklisted;
    emit SetTransferBlacklist(_blacklist, _isBlacklisted);
  }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

import {IERC20} from "./oz/token/ERC20/IERC20.sol";
import {BenCoinV2} from "./BenCoinV2.sol";
import {SafeERC20} from "./oz/token/ERC20/utils/SafeERC20.sol";

/**
 * @title BenV1ToV2Migration
 * @author Ben Coin Collective
 * @dev BenV1ToV2Migration allows users to migrate their BenV1 tokens to BenV2 tokens.
 * This contract facilitates the migration process.
 * The treasury is responsible for initiating the final migration process.
 *
 * BenV1 tokens are exchanged for BenV2 tokens at a specified rate (from 420.69 trillion BenV1 to 888 billion BenV2 supply).
 * and any remaining BenV2 tokens after the migration are sent to the treasury.
 */
contract BenV1ToV2Migration {
  using SafeERC20 for IERC20;
  using SafeERC20 for BenCoinV2;

  event Claimed(address user, uint256 v2Amount);

  error AlreadyInitializedStep1();
  error AlreadyInitializedStep2();
  error NotInitializedStep1();
  error NotInitializedStep2OrTreasury();
  error CannotUseZeroAddress();
  error CannotUseZero();
  error CannotUseDeadlineInPast();
  error NoTokensToClaim();
  error DeadlinePassed();
  error DeadlineNotPassed();
  error OnlyTreasury();

  BenCoinV2 public benV2;
  uint8 public initializedStep;
  IERC20 public immutable benV1;
  uint40 public immutable deadlineForMigration;
  address public immutable treasury;
  uint104 public immutable maxV2Supply;
  uint128 public immutable maxV1Supply;

  uint256 private constant previouslyBurntV1Supply = 14_000_000_000_000 ether;

  modifier initializedStep1() {
    if (initializedStep < 1) {
      revert NotInitializedStep1();
    }
    _;
  }

  modifier notInitializedStep1() {
    if (initializedStep > 0) {
      revert AlreadyInitializedStep1();
    }
    _;
  }

  modifier initializedStep2OrTreasury() {
    if (initializedStep < 2 && msg.sender != treasury) {
      revert NotInitializedStep2OrTreasury();
    }
    _;
  }

  modifier notInitializedStep2() {
    if (initializedStep > 1) {
      revert AlreadyInitializedStep2();
    }
    _;
  }

  modifier onlyTreasury() {
    if (msg.sender != treasury) {
      revert OnlyTreasury();
    }
    _;
  }

  /**
   * @param _benV1 BEN Coin V1 contract address
   * @param _maxV2Supply The maximum supply of BEN Coin V2
   * @param _deadlineForMigration The deadline for the migration of Ben V1 to V2
   * @param _treasury The treasury address
   *
   * Constructor initializes key parameters for the migration process.
   *
   * It also performs validation checks to ensure the provided addresses and values are valid.
   */
  constructor(address _benV1, uint104 _maxV2Supply, uint40 _deadlineForMigration, address _treasury) {
    if (_benV1 == address(0) || _treasury == address(0)) {
      revert CannotUseZeroAddress();
    }

    if (_maxV2Supply == 0) {
      revert CannotUseZero();
    }

    if (_deadlineForMigration < block.timestamp) {
      revert CannotUseDeadlineInPast();
    }

    benV1 = IERC20(_benV1);
    deadlineForMigration = _deadlineForMigration;
    treasury = _treasury;
    maxV1Supply = uint128(benV1.totalSupply());
    maxV2Supply = _maxV2Supply;
  }

  /**
   * @notice Convert Ben V1 to BEN Coin V2, requires Ben V1 approval
   * @dev This function is only callable by the treasury or after flood gates are open
   *
   * Users can convert their BenV1 tokens to BenV2 tokens at the specified rate.
   * To do this, users must approve this contract to spend their BenV1 tokens.
   * After successful conversion, BenV2 tokens are transferred to the user.
   */
  function claim() external initializedStep2OrTreasury {
    if (deadlineForMigration < block.timestamp) {
      revert DeadlinePassed();
    }

    uint256 balance = benV1.balanceOf(msg.sender);
    if (balance == 0) {
      revert NoTokensToClaim();
    }

    // Transfer benV1 to this contract and mint benV2 to the user at the appropriate rate
    benV1.safeTransferFrom(msg.sender, address(this), balance);
    uint256 amountOfBenV2 = conversionRate(balance);
    benV2.safeTransfer(msg.sender, amountOfBenV2);
    emit Claimed(msg.sender, amountOfBenV2);
  }

  /**
   * @notice Finish the migration and send the remainder of the V2 tokens to the treasury
   * @dev This function can be called by anyone after the deadline has passed
   *
   * After the migration deadline has passed, this function can be called by anyone to
   * send any remaining BenV2 tokens to the treasury.
   */
  function finishMigration() external {
    if (deadlineForMigration > block.timestamp) {
      revert DeadlineNotPassed();
    }

    // Send the remainder of the V2 tokens to the treasury
    uint balance = benV2.balanceOf(address(this));
    if (balance > 0) {
      benV2.safeTransfer(treasury, balance);
    }
  }

  /**
   * @notice Calculate the conversion rate from Ben V1 to Ben V2
   * @param _amountOfBenV1 The amount of Ben V1 to convert
   * @return amountOfBenV2 The amount of Ben V2 that would be received after conversion
   *
   * This function calculates the conversion rate for exchanging BenV1 tokens to BenV2 tokens.
   * It helps users determine the number of BenV2 tokens they will receive for a given amount of BenV1 tokens.
   */
  function conversionRate(uint _amountOfBenV1) public view returns (uint amountOfBenV2) {
    return (_amountOfBenV1 * maxV2Supply) / maxV1Supply;
  }

  /**
   * @notice Can only be called once to initialize the migration process
   * @param _benV2 BEN Coin V2 contract address
   * @dev This function can be called by anyone
   *
   * This function initializes the first step of the migration process. The previously
   * burnt BenV1 tokens are minted to the treasury.
   */
  function initializeStep1(BenCoinV2 _benV2) external notInitializedStep1 {
    initializedStep = 1;

    if (address(_benV2) == address(0)) {
      revert CannotUseZeroAddress();
    }

    benV2 = _benV2;

    // Transfer the previously burnt V1 tokens to the treasury
    uint previouslyBurntV1SupplyAsV2 = conversionRate(previouslyBurntV1Supply);
    _benV2.transfer(treasury, previouslyBurntV1SupplyAsV2);
  }

  /**
   * @notice This opens the flood gates to allow all other users to start the migration process
   * @dev This function is only callable by the treasury after initializeStep1 is completed
   *
   * After step 1 is completed, the treasury can call this function to allow all other users to
   * start the migration process, converting their BenV1 tokens to BenV2 tokens.
   */
  function initializeStep2() external initializedStep1 notInitializedStep2 onlyTreasury {
    initializedStep = 2;
  }
}

// SPDX-License-Identifier: Unlicense
/*
 * @title Solidity Bytes Arrays Utils
 * @author Gonçalo Sá <goncalo.sa@consensys.net>
 *
 * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
 *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
 */
pragma solidity >=0.8.0 <0.9.0;


library BytesLib {
    function concat(
        bytes memory _preBytes,
        bytes memory _postBytes
    )
    internal
    pure
    returns (bytes memory)
    {
        bytes memory tempBytes;

        assembly {
        // Get a location of some free memory and store it in tempBytes as
        // Solidity does for memory variables.
            tempBytes := mload(0x40)

        // Store the length of the first bytes array at the beginning of
        // the memory for tempBytes.
            let length := mload(_preBytes)
            mstore(tempBytes, length)

        // Maintain a memory counter for the current write location in the
        // temp bytes array by adding the 32 bytes for the array length to
        // the starting location.
            let mc := add(tempBytes, 0x20)
        // Stop copying when the memory counter reaches the length of the
        // first bytes array.
            let end := add(mc, length)

            for {
            // Initialize a copy counter to the start of the _preBytes data,
            // 32 bytes into its memory.
                let cc := add(_preBytes, 0x20)
            } lt(mc, end) {
            // Increase both counters by 32 bytes each iteration.
                mc := add(mc, 0x20)
                cc := add(cc, 0x20)
            } {
            // Write the _preBytes data into the tempBytes memory 32 bytes
            // at a time.
                mstore(mc, mload(cc))
            }

        // Add the length of _postBytes to the current length of tempBytes
        // and store it as the new length in the first 32 bytes of the
        // tempBytes memory.
            length := mload(_postBytes)
            mstore(tempBytes, add(length, mload(tempBytes)))

        // Move the memory counter back from a multiple of 0x20 to the
        // actual end of the _preBytes data.
            mc := end
        // Stop copying when the memory counter reaches the new combined
        // length of the arrays.
            end := add(mc, length)

            for {
                let cc := add(_postBytes, 0x20)
            } lt(mc, end) {
                mc := add(mc, 0x20)
                cc := add(cc, 0x20)
            } {
                mstore(mc, mload(cc))
            }

        // Update the free-memory pointer by padding our last write location
        // to 32 bytes: add 31 bytes to the end of tempBytes to move to the
        // next 32 byte block, then round down to the nearest multiple of
        // 32. If the sum of the length of the two arrays is zero then add
        // one before rounding down to leave a blank 32 bytes (the length block with 0).
            mstore(0x40, and(
            add(add(end, iszero(add(length, mload(_preBytes)))), 31),
            not(31) // Round down to the nearest 32 bytes.
            ))
        }

        return tempBytes;
    }

    function concatStorage(bytes storage _preBytes, bytes memory _postBytes) internal {
        assembly {
        // Read the first 32 bytes of _preBytes storage, which is the length
        // of the array. (We don't need to use the offset into the slot
        // because arrays use the entire slot.)
            let fslot := sload(_preBytes.slot)
        // Arrays of 31 bytes or less have an even value in their slot,
        // while longer arrays have an odd value. The actual length is
        // the slot divided by two for odd values, and the lowest order
        // byte divided by two for even values.
        // If the slot is even, bitwise and the slot with 255 and divide by
        // two to get the length. If the slot is odd, bitwise and the slot
        // with -1 and divide by two.
            let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
            let mlength := mload(_postBytes)
            let newlength := add(slength, mlength)
        // slength can contain both the length and contents of the array
        // if length < 32 bytes so let's prepare for that
        // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
            switch add(lt(slength, 32), lt(newlength, 32))
            case 2 {
            // Since the new array still fits in the slot, we just need to
            // update the contents of the slot.
            // uint256(bytes_storage) = uint256(bytes_storage) + uint256(bytes_memory) + new_length
                sstore(
                _preBytes.slot,
                // all the modifications to the slot are inside this
                // next block
                add(
                // we can just add to the slot contents because the
                // bytes we want to change are the LSBs
                fslot,
                add(
                mul(
                div(
                // load the bytes from memory
                mload(add(_postBytes, 0x20)),
                // zero all bytes to the right
                exp(0x100, sub(32, mlength))
                ),
                // and now shift left the number of bytes to
                // leave space for the length in the slot
                exp(0x100, sub(32, newlength))
                ),
                // increase length by the double of the memory
                // bytes length
                mul(mlength, 2)
                )
                )
                )
            }
            case 1 {
            // The stored value fits in the slot, but the combined value
            // will exceed it.
            // get the keccak hash to get the contents of the array
                mstore(0x0, _preBytes.slot)
                let sc := add(keccak256(0x0, 0x20), div(slength, 32))

            // save new length
                sstore(_preBytes.slot, add(mul(newlength, 2), 1))

            // The contents of the _postBytes array start 32 bytes into
            // the structure. Our first read should obtain the `submod`
            // bytes that can fit into the unused space in the last word
            // of the stored array. To get this, we read 32 bytes starting
            // from `submod`, so the data we read overlaps with the array
            // contents by `submod` bytes. Masking the lowest-order
            // `submod` bytes allows us to add that value directly to the
            // stored value.

                let submod := sub(32, slength)
                let mc := add(_postBytes, submod)
                let end := add(_postBytes, mlength)
                let mask := sub(exp(0x100, submod), 1)

                sstore(
                sc,
                add(
                and(
                fslot,
                0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00
                ),
                and(mload(mc), mask)
                )
                )

                for {
                    mc := add(mc, 0x20)
                    sc := add(sc, 1)
                } lt(mc, end) {
                    sc := add(sc, 1)
                    mc := add(mc, 0x20)
                } {
                    sstore(sc, mload(mc))
                }

                mask := exp(0x100, sub(mc, end))

                sstore(sc, mul(div(mload(mc), mask), mask))
            }
            default {
            // get the keccak hash to get the contents of the array
                mstore(0x0, _preBytes.slot)
            // Start copying to the last used word of the stored array.
                let sc := add(keccak256(0x0, 0x20), div(slength, 32))

            // save new length
                sstore(_preBytes.slot, add(mul(newlength, 2), 1))

            // Copy over the first `submod` bytes of the new data as in
            // case 1 above.
                let slengthmod := mod(slength, 32)
                let mlengthmod := mod(mlength, 32)
                let submod := sub(32, slengthmod)
                let mc := add(_postBytes, submod)
                let end := add(_postBytes, mlength)
                let mask := sub(exp(0x100, submod), 1)

                sstore(sc, add(sload(sc), and(mload(mc), mask)))

                for {
                    sc := add(sc, 1)
                    mc := add(mc, 0x20)
                } lt(mc, end) {
                    sc := add(sc, 1)
                    mc := add(mc, 0x20)
                } {
                    sstore(sc, mload(mc))
                }

                mask := exp(0x100, sub(mc, end))

                sstore(sc, mul(div(mload(mc), mask), mask))
            }
        }
    }

    function slice(
        bytes memory _bytes,
        uint256 _start,
        uint256 _length
    )
    internal
    pure
    returns (bytes memory)
    {
        require(_length + 31 >= _length, "slice_overflow");
        require(_bytes.length >= _start + _length, "slice_outOfBounds");

        bytes memory tempBytes;

        assembly {
            switch iszero(_length)
            case 0 {
            // Get a location of some free memory and store it in tempBytes as
            // Solidity does for memory variables.
                tempBytes := mload(0x40)

            // The first word of the slice result is potentially a partial
            // word read from the original array. To read it, we calculate
            // the length of that partial word and start copying that many
            // bytes into the array. The first word we copy will start with
            // data we don't care about, but the last `lengthmod` bytes will
            // land at the beginning of the contents of the new array. When
            // we're done copying, we overwrite the full first word with
            // the actual length of the slice.
                let lengthmod := and(_length, 31)

            // The multiplication in the next line is necessary
            // because when slicing multiples of 32 bytes (lengthmod == 0)
            // the following copy loop was copying the origin's length
            // and then ending prematurely not copying everything it should.
                let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                let end := add(mc, _length)

                for {
                // The multiplication in the next line has the same exact purpose
                // as the one above.
                    let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                } lt(mc, end) {
                    mc := add(mc, 0x20)
                    cc := add(cc, 0x20)
                } {
                    mstore(mc, mload(cc))
                }

                mstore(tempBytes, _length)

            //update free-memory pointer
            //allocating the array padded to 32 bytes like the compiler does now
                mstore(0x40, and(add(mc, 31), not(31)))
            }
            //if we want a zero-length slice let's just return a zero-length array
            default {
                tempBytes := mload(0x40)
            //zero out the 32 bytes slice we are about to return
            //we need to do it because Solidity does not garbage collect
                mstore(tempBytes, 0)

                mstore(0x40, add(tempBytes, 0x20))
            }
        }

        return tempBytes;
    }

    function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
        require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
        address tempAddress;

        assembly {
            tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
        }

        return tempAddress;
    }

    function toUint8(bytes memory _bytes, uint256 _start) internal pure returns (uint8) {
        require(_bytes.length >= _start + 1 , "toUint8_outOfBounds");
        uint8 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x1), _start))
        }

        return tempUint;
    }

    function toUint16(bytes memory _bytes, uint256 _start) internal pure returns (uint16) {
        require(_bytes.length >= _start + 2, "toUint16_outOfBounds");
        uint16 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x2), _start))
        }

        return tempUint;
    }

    function toUint32(bytes memory _bytes, uint256 _start) internal pure returns (uint32) {
        require(_bytes.length >= _start + 4, "toUint32_outOfBounds");
        uint32 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x4), _start))
        }

        return tempUint;
    }

    function toUint64(bytes memory _bytes, uint256 _start) internal pure returns (uint64) {
        require(_bytes.length >= _start + 8, "toUint64_outOfBounds");
        uint64 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x8), _start))
        }

        return tempUint;
    }

    function toUint96(bytes memory _bytes, uint256 _start) internal pure returns (uint96) {
        require(_bytes.length >= _start + 12, "toUint96_outOfBounds");
        uint96 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0xc), _start))
        }

        return tempUint;
    }

    function toUint128(bytes memory _bytes, uint256 _start) internal pure returns (uint128) {
        require(_bytes.length >= _start + 16, "toUint128_outOfBounds");
        uint128 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x10), _start))
        }

        return tempUint;
    }

    function toUint256(bytes memory _bytes, uint256 _start) internal pure returns (uint256) {
        require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
        uint256 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x20), _start))
        }

        return tempUint;
    }

    function toBytes32(bytes memory _bytes, uint256 _start) internal pure returns (bytes32) {
        require(_bytes.length >= _start + 32, "toBytes32_outOfBounds");
        bytes32 tempBytes32;

        assembly {
            tempBytes32 := mload(add(add(_bytes, 0x20), _start))
        }

        return tempBytes32;
    }

    function equal(bytes memory _preBytes, bytes memory _postBytes) internal pure returns (bool) {
        bool success = true;

        assembly {
            let length := mload(_preBytes)

        // if lengths don't match the arrays are not equal
            switch eq(length, mload(_postBytes))
            case 1 {
            // cb is a circuit breaker in the for loop since there's
            //  no said feature for inline assembly loops
            // cb = 1 - don't breaker
            // cb = 0 - break
                let cb := 1

                let mc := add(_preBytes, 0x20)
                let end := add(mc, length)

                for {
                    let cc := add(_postBytes, 0x20)
                // the next line is the loop condition:
                // while(uint256(mc < end) + cb == 2)
                } eq(add(lt(mc, end), cb), 2) {
                    mc := add(mc, 0x20)
                    cc := add(cc, 0x20)
                } {
                // if any of these checks fails then arrays are not equal
                    if iszero(eq(mload(mc), mload(cc))) {
                    // unsuccess:
                        success := 0
                        cb := 0
                    }
                }
            }
            default {
            // unsuccess:
                success := 0
            }
        }

        return success;
    }

    function equalStorage(
        bytes storage _preBytes,
        bytes memory _postBytes
    )
    internal
    view
    returns (bool)
    {
        bool success = true;

        assembly {
        // we know _preBytes_offset is 0
            let fslot := sload(_preBytes.slot)
        // Decode the length of the stored array like in concatStorage().
            let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
            let mlength := mload(_postBytes)

        // if lengths don't match the arrays are not equal
            switch eq(slength, mlength)
            case 1 {
            // slength can contain both the length and contents of the array
            // if length < 32 bytes so let's prepare for that
            // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                if iszero(iszero(slength)) {
                    switch lt(slength, 32)
                    case 1 {
                    // blank the last byte which is the length
                        fslot := mul(div(fslot, 0x100), 0x100)

                        if iszero(eq(fslot, mload(add(_postBytes, 0x20)))) {
                        // unsuccess:
                            success := 0
                        }
                    }
                    default {
                    // cb is a circuit breaker in the for loop since there's
                    //  no said feature for inline assembly loops
                    // cb = 1 - don't breaker
                    // cb = 0 - break
                        let cb := 1

                    // get the keccak hash to get the contents of the array
                        mstore(0x0, _preBytes.slot)
                        let sc := keccak256(0x0, 0x20)

                        let mc := add(_postBytes, 0x20)
                        let end := add(mc, mlength)

                    // the next line is the loop condition:
                    // while(uint256(mc < end) + cb == 2)
                        for {} eq(add(lt(mc, end), cb), 2) {
                            sc := add(sc, 1)
                            mc := add(mc, 0x20)
                        } {
                            if iszero(eq(sload(sc), mload(mc))) {
                            // unsuccess:
                                success := 0
                                cb := 0
                            }
                        }
                    }
                }
            }
            default {
            // unsuccess:
                success := 0
            }
        }

        return success;
    }
}

// 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: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Counters.sol)

pragma solidity ^0.8.0;

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 */
library Counters {
    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }

    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }

    function increment(Counter storage counter) internal {
        unchecked {
            counter._value += 1;
        }
    }

    function decrement(Counter storage counter) internal {
        uint256 value = counter._value;
        require(value > 0, "Counter: decrement overflow");
        unchecked {
            counter._value = value - 1;
        }
    }

    function reset(Counter storage counter) internal {
        counter._value = 0;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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 message) {
        // 32 is the length in bytes of hash,
        // enforced by the type signature above
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, "\x19Ethereum Signed Message:\n32")
            mstore(0x1c, hash)
            message := keccak256(0x00, 0x3c)
        }
    }

    /**
     * @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 data) {
        /// @solidity memory-safe-assembly
        assembly {
            let ptr := mload(0x40)
            mstore(ptr, "\x19\x01")
            mstore(add(ptr, 0x02), domainSeparator)
            mstore(add(ptr, 0x22), structHash)
            data := keccak256(ptr, 0x42)
        }
    }

    /**
     * @dev Returns an Ethereum Signed Data with intended validator, created from a
     * `validator` and `data` according to the version 0 of EIP-191.
     *
     * See {recover}.
     */
    function toDataWithIntendedValidatorHash(address validator, bytes memory data) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19\x00", validator, data));
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/cryptography/EIP712.sol)

pragma solidity ^0.8.8;

import "./ECDSA.sol";
import "../ShortStrings.sol";
import "../../interfaces/IERC5267.sol";

/**
 * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
 *
 * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
 * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
 * they need in their contracts using a combination of `abi.encode` and `keccak256`.
 *
 * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
 * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
 * ({_hashTypedDataV4}).
 *
 * The implementation of the domain separator was designed to be as efficient as possible while still properly updating
 * the chain id to protect against replay attacks on an eventual fork of the chain.
 *
 * NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
 * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
 *
 * NOTE: In the upgradeable version of this contract, the cached values will correspond to the address, and the domain
 * separator of the implementation contract. This will cause the `_domainSeparatorV4` function to always rebuild the
 * separator from the immutable values, which is cheaper than accessing a cached version in cold storage.
 *
 * _Available since v3.4._
 *
 * @custom:oz-upgrades-unsafe-allow state-variable-immutable state-variable-assignment
 */
abstract contract EIP712 is IERC5267 {
    using ShortStrings for *;

    bytes32 private constant _TYPE_HASH =
        keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");

    // Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to
    // invalidate the cached domain separator if the chain id changes.
    bytes32 private immutable _cachedDomainSeparator;
    uint256 private immutable _cachedChainId;
    address private immutable _cachedThis;

    bytes32 private immutable _hashedName;
    bytes32 private immutable _hashedVersion;

    ShortString private immutable _name;
    ShortString private immutable _version;
    string private _nameFallback;
    string private _versionFallback;

    /**
     * @dev Initializes the domain separator and parameter caches.
     *
     * The meaning of `name` and `version` is specified in
     * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
     *
     * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
     * - `version`: the current major version of the signing domain.
     *
     * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
     * contract upgrade].
     */
    constructor(string memory name, string memory version) {
        _name = name.toShortStringWithFallback(_nameFallback);
        _version = version.toShortStringWithFallback(_versionFallback);
        _hashedName = keccak256(bytes(name));
        _hashedVersion = keccak256(bytes(version));

        _cachedChainId = block.chainid;
        _cachedDomainSeparator = _buildDomainSeparator();
        _cachedThis = address(this);
    }

    /**
     * @dev Returns the domain separator for the current chain.
     */
    function _domainSeparatorV4() internal view returns (bytes32) {
        if (address(this) == _cachedThis && block.chainid == _cachedChainId) {
            return _cachedDomainSeparator;
        } else {
            return _buildDomainSeparator();
        }
    }

    function _buildDomainSeparator() private view returns (bytes32) {
        return keccak256(abi.encode(_TYPE_HASH, _hashedName, _hashedVersion, block.chainid, address(this)));
    }

    /**
     * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
     * function returns the hash of the fully encoded EIP712 message for this domain.
     *
     * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
     *
     * ```solidity
     * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
     *     keccak256("Mail(address to,string contents)"),
     *     mailTo,
     *     keccak256(bytes(mailContents))
     * )));
     * address signer = ECDSA.recover(digest, signature);
     * ```
     */
    function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
        return ECDSA.toTypedDataHash(_domainSeparatorV4(), structHash);
    }

    /**
     * @dev See {EIP-5267}.
     *
     * _Available since v4.9._
     */
    function eip712Domain()
        public
        view
        virtual
        override
        returns (
            bytes1 fields,
            string memory name,
            string memory version,
            uint256 chainId,
            address verifyingContract,
            bytes32 salt,
            uint256[] memory extensions
        )
    {
        return (
            hex"0f", // 01111
            _name.toStringWithFallback(_nameFallback),
            _version.toStringWithFallback(_versionFallback),
            block.chainid,
            address(this),
            bytes32(0),
            new uint256[](0)
        );
    }
}

// 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 v4.9.0) (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].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * 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 {

    error ERC20DecreasedAllowanceBelowZero();
    error ERC20TransferToZeroAddress();
    error ERC20TransferFromZeroAddress();
    error ERC20TransferExceedsBalance();
    error ERC20MintToZeroAddress();
    error ERC20ApproveFromZeroAddress();
    error ERC20ApproveToZeroAddress();
    error ERC20TransferExceedsAllowance();

    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}.
     *
     * 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 default value returned by this function, unless
     * it's 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);
        if (currentAllowance < subtractedValue) {
            revert ERC20DecreasedAllowanceBelowZero();
        }
        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 {
        if (from == address(0)) {
            revert ERC20TransferFromZeroAddress();
        }
        if (to == address(0)) {
            revert ERC20TransferToZeroAddress();
        }

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        if (fromBalance < amount) {
            revert ERC20TransferExceedsBalance();
        }
        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 {
        if (account == address(0)) {
            revert ERC20MintToZeroAddress();
        }

        _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 {
        if (owner == address(0)) {
            revert ERC20ApproveFromZeroAddress();
        }
        if (spender == address(0)) {
            revert ERC20ApproveToZeroAddress();
        }

        _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) {
            if (currentAllowance < amount) {
                revert ERC20TransferExceedsAllowance();
            }
            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: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/ERC20Permit.sol)

pragma solidity ^0.8.0;

import "./IERC20Permit.sol";
import "../ERC20.sol";
import "../../../utils/cryptography/ECDSA.sol";
import "../../../utils/cryptography/EIP712.sol";
import "../../../utils/Counters.sol";

/**
 * @dev Implementation of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 *
 * _Available since v3.4._
 */
abstract contract ERC20Permit is ERC20, IERC20Permit, EIP712 {
    using Counters for Counters.Counter;

    error ERC20PermitExpired();
    error ERC20PermitInvalidSignature();

    mapping(address => Counters.Counter) private _nonces;

    // solhint-disable-next-line var-name-mixedcase
    bytes32 private constant _PERMIT_TYPEHASH =
        keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    /**
     * @dev In previous versions `_PERMIT_TYPEHASH` was declared as `immutable`.
     * However, to ensure consistency with the upgradeable transpiler, we will continue
     * to reserve a slot.
     * @custom:oz-renamed-from _PERMIT_TYPEHASH
     */
    // solhint-disable-next-line var-name-mixedcase
    bytes32 private _PERMIT_TYPEHASH_DEPRECATED_SLOT;

    /**
     * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `"1"`.
     *
     * It's a good idea to use the same `name` that is defined as the ERC20 token name.
     */
    constructor(string memory name) EIP712(name, "1") {}

    /**
     * @dev See {IERC20Permit-permit}.
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual override {
        if (block.timestamp > deadline) {
            revert ERC20PermitExpired();
        }

        bytes32 structHash = keccak256(abi.encode(_PERMIT_TYPEHASH, owner, spender, value, _useNonce(owner), deadline));

        bytes32 hash = _hashTypedDataV4(structHash);

        address signer = ECDSA.recover(hash, v, r, s);
        if (signer != owner) {
            revert ERC20PermitInvalidSignature();
        }

        _approve(owner, spender, value);
    }

    /**
     * @dev See {IERC20Permit-nonces}.
     */
    function nonces(address owner) public view virtual override returns (uint256) {
        return _nonces[owner].current();
    }

    /**
     * @dev See {IERC20Permit-DOMAIN_SEPARATOR}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view override returns (bytes32) {
        return _domainSeparatorV4();
    }

    /**
     * @dev "Consume a nonce": return the current value and increment.
     *
     * _Available since v4.1._
     */
    function _useNonce(address owner) internal virtual returns (uint256 current) {
        Counters.Counter storage nonce = _nonces[owner];
        current = nonce.current();
        nonce.increment();
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/ERC20Votes.sol)

pragma solidity ^0.8.0;

import "./ERC20Permit.sol";
import "../../../interfaces/IERC5805.sol";
import "../../../utils/math/Math.sol";
import "../../../utils/math/SafeCast.sol";
import "../../../utils/cryptography/ECDSA.sol";

/**
 * @dev Extension of ERC20 to support Compound-like voting and delegation. This version is more generic than Compound's,
 * and supports token supply up to 2^224^ - 1, while COMP is limited to 2^96^ - 1.
 *
 * NOTE: If exact COMP compatibility is required, use the {ERC20VotesComp} variant of this module.
 *
 * This extension keeps a history (checkpoints) of each account's vote power. Vote power can be delegated either
 * by calling the {delegate} function directly, or by providing a signature to be used with {delegateBySig}. Voting
 * power can be queried through the public accessors {getVotes} and {getPastVotes}.
 *
 * By default, token balance does not account for voting power. This makes transfers cheaper. The downside is that it
 * requires users to delegate to themselves in order to activate checkpoints and have their voting power tracked.
 *
 * _Available since v4.2._
 */
abstract contract ERC20Votes is ERC20Permit, IERC5805 {
    struct Checkpoint {
        uint32 fromBlock;
        uint224 votes;
    }

    error ERC20VotesBrokenClock();
    error ERC20VotesSupplyOverflow();
    error ERC20VotesFutureLookup();
    error ERC20VotesSignatureExpired();
    error ERC20VotesInvalidNonce();

    bytes32 private constant _DELEGATION_TYPEHASH =
        keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)");

    mapping(address => address) private _delegates;
    mapping(address => Checkpoint[]) private _checkpoints;
    Checkpoint[] private _totalSupplyCheckpoints;

    /**
     * @dev Clock used for flagging checkpoints. Can be overridden to implement timestamp based checkpoints (and voting).
     */
    function clock() public view virtual override returns (uint48) {
        return SafeCast.toUint48(block.number);
    }

    /**
     * @dev Description of the clock
     */
    // solhint-disable-next-line func-name-mixedcase
    function CLOCK_MODE() public view virtual override returns (string memory) {
        // Check that the clock was not modified
        if (clock() != block.number) {
            revert ERC20VotesBrokenClock();
        }
        return "mode=blocknumber&from=default";
    }

    /**
     * @dev Get the `pos`-th checkpoint for `account`.
     */
    function checkpoints(address account, uint32 pos) public view virtual returns (Checkpoint memory) {
        return _checkpoints[account][pos];
    }

    /**
     * @dev Get number of checkpoints for `account`.
     */
    function numCheckpoints(address account) public view virtual returns (uint32) {
        return SafeCast.toUint32(_checkpoints[account].length);
    }

    /**
     * @dev Get the address `account` is currently delegating to.
     */
    function delegates(address account) public view virtual override returns (address) {
        return _delegates[account];
    }

    /**
     * @dev Gets the current votes balance for `account`
     */
    function getVotes(address account) public view virtual override returns (uint256) {
        uint256 pos = _checkpoints[account].length;
        unchecked {
            return pos == 0 ? 0 : _checkpoints[account][pos - 1].votes;
        }
    }

    /**
     * @dev Retrieve the number of votes for `account` at the end of `timepoint`.
     *
     * Requirements:
     *
     * - `timepoint` must be in the past
     */
    function getPastVotes(address account, uint256 timepoint) public view virtual override returns (uint256) {
        if (timepoint >= clock()) {
            revert ERC20VotesFutureLookup();
        }
        return _checkpointsLookup(_checkpoints[account], timepoint);
    }

    /**
     * @dev Retrieve the `totalSupply` at the end of `timepoint`. Note, this value is the sum of all balances.
     * It is NOT the sum of all the delegated votes!
     *
     * Requirements:
     *
     * - `timepoint` must be in the past
     */
    function getPastTotalSupply(uint256 timepoint) public view virtual override returns (uint256) {
        if (timepoint >= clock()) {
            revert ERC20VotesFutureLookup();
        }
        return _checkpointsLookup(_totalSupplyCheckpoints, timepoint);
    }

    /**
     * @dev Lookup a value in a list of (sorted) checkpoints.
     */
    function _checkpointsLookup(Checkpoint[] storage ckpts, uint256 timepoint) private view returns (uint256) {
        // We run a binary search to look for the last (most recent) checkpoint taken before (or at) `timepoint`.
        //
        // Initially we check if the block is recent to narrow the search range.
        // During the loop, the index of the wanted checkpoint remains in the range [low-1, high).
        // With each iteration, either `low` or `high` is moved towards the middle of the range to maintain the invariant.
        // - If the middle checkpoint is after `timepoint`, we look in [low, mid)
        // - If the middle checkpoint is before or equal to `timepoint`, we look in [mid+1, high)
        // Once we reach a single value (when low == high), we've found the right checkpoint at the index high-1, if not
        // out of bounds (in which case we're looking too far in the past and the result is 0).
        // Note that if the latest checkpoint available is exactly for `timepoint`, we end up with an index that is
        // past the end of the array, so we technically don't find a checkpoint after `timepoint`, but it works out
        // the same.
        uint256 length = ckpts.length;

        uint256 low = 0;
        uint256 high = length;

        if (length > 5) {
            uint256 mid = length - Math.sqrt(length);
            if (_unsafeAccess(ckpts, mid).fromBlock > timepoint) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }

        while (low < high) {
            uint256 mid = Math.average(low, high);
            if (_unsafeAccess(ckpts, mid).fromBlock > timepoint) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }

        unchecked {
            return high == 0 ? 0 : _unsafeAccess(ckpts, high - 1).votes;
        }
    }

    /**
     * @dev Delegate votes from the sender to `delegatee`.
     */
    function delegate(address delegatee) public virtual override {
        _delegate(_msgSender(), delegatee);
    }

    /**
     * @dev Delegates votes from signer to `delegatee`
     */
    function delegateBySig(
        address delegatee,
        uint256 nonce,
        uint256 expiry,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual override {
        if (block.timestamp > expiry) {
            revert ERC20VotesSignatureExpired();
        }
        address signer = ECDSA.recover(
            _hashTypedDataV4(keccak256(abi.encode(_DELEGATION_TYPEHASH, delegatee, nonce, expiry))),
            v,
            r,
            s
        );
        if (nonce != _useNonce(signer)) {
            revert ERC20VotesInvalidNonce();
        }
        _delegate(signer, delegatee);
    }

    /**
     * @dev Maximum token supply. Defaults to `type(uint224).max` (2^224^ - 1).
     */
    function _maxSupply() internal view virtual returns (uint224) {
        return type(uint224).max;
    }

    /**
     * @dev Snapshots the totalSupply after it has been increased.
     */
    function _mint(address account, uint256 amount) internal virtual override {
        super._mint(account, amount);
        if (totalSupply() > _maxSupply()) {
            revert ERC20VotesSupplyOverflow();
        }

        _writeCheckpoint(_totalSupplyCheckpoints, _add, amount);
    }

    /**
     * @dev Snapshots the totalSupply after it has been decreased.
     */
    function _burn(address account, uint256 amount) internal virtual override {
        super._burn(account, amount);

        _writeCheckpoint(_totalSupplyCheckpoints, _subtract, amount);
    }

    /**
     * @dev Move voting power when tokens are transferred.
     *
     * Emits a {IVotes-DelegateVotesChanged} event.
     */
    function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual override {
        super._afterTokenTransfer(from, to, amount);

        _moveVotingPower(delegates(from), delegates(to), amount);
    }

    /**
     * @dev Change delegation for `delegator` to `delegatee`.
     *
     * Emits events {IVotes-DelegateChanged} and {IVotes-DelegateVotesChanged}.
     */
    function _delegate(address delegator, address delegatee) internal virtual {
        address currentDelegate = delegates(delegator);
        uint256 delegatorBalance = balanceOf(delegator);
        _delegates[delegator] = delegatee;

        emit DelegateChanged(delegator, currentDelegate, delegatee);

        _moveVotingPower(currentDelegate, delegatee, delegatorBalance);
    }

    function _moveVotingPower(address src, address dst, uint256 amount) private {
        if (src != dst && amount > 0) {
            if (src != address(0)) {
                (uint256 oldWeight, uint256 newWeight) = _writeCheckpoint(_checkpoints[src], _subtract, amount);
                emit DelegateVotesChanged(src, oldWeight, newWeight);
            }

            if (dst != address(0)) {
                (uint256 oldWeight, uint256 newWeight) = _writeCheckpoint(_checkpoints[dst], _add, amount);
                emit DelegateVotesChanged(dst, oldWeight, newWeight);
            }
        }
    }

    function _writeCheckpoint(
        Checkpoint[] storage ckpts,
        function(uint256, uint256) view returns (uint256) op,
        uint256 delta
    ) private returns (uint256 oldWeight, uint256 newWeight) {
        uint256 pos = ckpts.length;

        unchecked {
            Checkpoint memory oldCkpt = pos == 0 ? Checkpoint(0, 0) : _unsafeAccess(ckpts, pos - 1);

            oldWeight = oldCkpt.votes;
            newWeight = op(oldWeight, delta);

            if (pos > 0 && oldCkpt.fromBlock == clock()) {
                _unsafeAccess(ckpts, pos - 1).votes = SafeCast.toUint224(newWeight);
            } else {
                ckpts.push(Checkpoint({fromBlock: SafeCast.toUint32(clock()), votes: SafeCast.toUint224(newWeight)}));
            }
        }
    }

    function _add(uint256 a, uint256 b) private pure returns (uint256) {
        return a + b;
    }

    function _subtract(uint256 a, uint256 b) private pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Access an element of the array without performing bounds check. The position is assumed to be within bounds.
     */
    function _unsafeAccess(Checkpoint[] storage ckpts, uint256 pos) private pure returns (Checkpoint storage result) {
        assembly {
            mstore(0, ckpts.slot)
            result.slot := add(keccak256(0, 0x20), pos)
        }
    }
}

// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity >=0.7.6;

library ExcessivelySafeCall {
    uint256 constant LOW_28_MASK =
    0x00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff;

    /// @notice Use when you _really_ really _really_ don't trust the called
    /// contract. This prevents the called contract from causing reversion of
    /// the caller in as many ways as we can.
    /// @dev The main difference between this and a solidity low-level call is
    /// that we limit the number of bytes that the callee can cause to be
    /// copied to caller memory. This prevents stupid things like malicious
    /// contracts returning 10,000,000 bytes causing a local OOG when copying
    /// to memory.
    /// @param _target The address to call
    /// @param _gas The amount of gas to forward to the remote contract
    /// @param _maxCopy The maximum number of bytes of returndata to copy
    /// to memory.
    /// @param _calldata The data to send to the remote contract
    /// @return success and returndata, as `.call()`. Returndata is capped to
    /// `_maxCopy` bytes.
    function excessivelySafeCall(
        address _target,
        uint256 _gas,
        uint16 _maxCopy,
        bytes memory _calldata
    ) internal returns (bool, bytes memory) {
        // set up for assembly call
        uint256 _toCopy;
        bool _success;
        bytes memory _returnData = new bytes(_maxCopy);
        // dispatch message to recipient
        // by assembly calling "handle" function
        // we call via assembly to avoid memcopying a very large returndata
        // returned by a malicious contract
        assembly {
            _success := call(
            _gas, // gas
            _target, // recipient
            0, // ether value
            add(_calldata, 0x20), // inloc
            mload(_calldata), // inlen
            0, // outloc
            0 // outlen
            )
        // limit our copy to 256 bytes
            _toCopy := returndatasize()
            if gt(_toCopy, _maxCopy) {
                _toCopy := _maxCopy
            }
        // Store the length of the copied bytes
            mstore(_returnData, _toCopy)
        // copy the bytes from returndata[0:_toCopy]
            returndatacopy(add(_returnData, 0x20), 0, _toCopy)
        }
        return (_success, _returnData);
    }

    /// @notice Use when you _really_ really _really_ don't trust the called
    /// contract. This prevents the called contract from causing reversion of
    /// the caller in as many ways as we can.
    /// @dev The main difference between this and a solidity low-level call is
    /// that we limit the number of bytes that the callee can cause to be
    /// copied to caller memory. This prevents stupid things like malicious
    /// contracts returning 10,000,000 bytes causing a local OOG when copying
    /// to memory.
    /// @param _target The address to call
    /// @param _gas The amount of gas to forward to the remote contract
    /// @param _maxCopy The maximum number of bytes of returndata to copy
    /// to memory.
    /// @param _calldata The data to send to the remote contract
    /// @return success and returndata, as `.call()`. Returndata is capped to
    /// `_maxCopy` bytes.
    function excessivelySafeStaticCall(
        address _target,
        uint256 _gas,
        uint16 _maxCopy,
        bytes memory _calldata
    ) internal view returns (bool, bytes memory) {
        // set up for assembly call
        uint256 _toCopy;
        bool _success;
        bytes memory _returnData = new bytes(_maxCopy);
        // dispatch message to recipient
        // by assembly calling "handle" function
        // we call via assembly to avoid memcopying a very large returndata
        // returned by a malicious contract
        assembly {
            _success := staticcall(
            _gas, // gas
            _target, // recipient
            add(_calldata, 0x20), // inloc
            mload(_calldata), // inlen
            0, // outloc
            0 // outlen
            )
        // limit our copy to 256 bytes
            _toCopy := returndatasize()
            if gt(_toCopy, _maxCopy) {
                _toCopy := _maxCopy
            }
        // Store the length of the copied bytes
            mstore(_returnData, _toCopy)
        // copy the bytes from returndata[0:_toCopy]
            returndatacopy(add(_returnData, 0x20), 0, _toCopy)
        }
        return (_success, _returnData);
    }

    /**
     * @notice Swaps function selectors in encoded contract calls
     * @dev Allows reuse of encoded calldata for functions with identical
     * argument types but different names. It simply swaps out the first 4 bytes
     * for the new selector. This function modifies memory in place, and should
     * only be used with caution.
     * @param _newSelector The new 4-byte selector
     * @param _buf The encoded contract args
     */
    function swapSelector(bytes4 _newSelector, bytes memory _buf)
    internal
    pure
    {
        require(_buf.length >= 4);
        uint256 _mask = LOW_28_MASK;
        assembly {
        // load the first word of
            let _word := mload(add(_buf, 0x20))
        // mask out the top 4 bytes
        // /x
            _word := and(_word, _mask)
            _word := or(_newSelector, _word)
            mstore(add(_buf, 0x20), _word)
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

interface IAntiMevStrategy {
  function onTransfer(address from, address to, uint256 amount, bool isTaxingInProgress) external;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

interface IBuyTaxReceiver {
  function swapCallback() external;
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

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

/**
 * @dev Interface of the IOFT core standard
 */
interface ICommonOFT is IERC165 {

    struct LzCallParams {
        address payable refundAddress;
        address zroPaymentAddress;
        bytes adapterParams;
    }

    /**
     * @dev estimate send token `_tokenId` to (`_dstChainId`, `_toAddress`)
     * _dstChainId - L0 defined chain id to send tokens too
     * _toAddress - dynamic bytes array which contains the address to whom you are sending tokens to on the dstChain
     * _amount - amount of the tokens to transfer
     * _useZro - indicates to use zro to pay L0 fees
     * _adapterParam - flexible bytes array to indicate messaging adapter services in L0
     */
    function estimateSendFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);

    function estimateSendAndCallFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes calldata _payload, uint64 _dstGasForCall, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);

    /**
     * @dev returns the circulating amount of tokens on current chain
     */
    function circulatingSupply() external view returns (uint);

    /**
     * @dev returns the address of the ERC20 token
     */
    function token() external view returns (address);
}

// 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 v4.9.0) (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
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC5267.sol)

pragma solidity ^0.8.0;

interface IERC5267 {
    /**
     * @dev MAY be emitted to signal that the domain could have changed.
     */
    event EIP712DomainChanged();

    /**
     * @dev returns the fields and values that describe the domain separator used by this contract for EIP-712
     * signature.
     */
    function eip712Domain()
        external
        view
        returns (
            bytes1 fields,
            string memory name,
            string memory version,
            uint256 chainId,
            address verifyingContract,
            bytes32 salt,
            uint256[] memory extensions
        );
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC5805.sol)

pragma solidity ^0.8.0;

import "../governance/utils/IVotes.sol";
import "./IERC6372.sol";

interface IERC5805 is IERC6372, IVotes {}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC6372.sol)

pragma solidity ^0.8.0;

interface IERC6372 {
    /**
     * @dev Clock used for flagging checkpoints. Can be overridden to implement timestamp based checkpoints (and voting).
     */
    function clock() external view returns (uint48);

    /**
     * @dev Description of the clock
     */
    // solhint-disable-next-line func-name-mixedcase
    function CLOCK_MODE() external view returns (string memory);
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

import "./ILayerZeroUserApplicationConfig.sol";

interface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {
    // @notice send a LayerZero message to the specified address at a LayerZero endpoint.
    // @param _dstChainId - the destination chain identifier
    // @param _destination - the address on destination chain (in bytes). address length/format may vary by chains
    // @param _payload - a custom bytes payload to send to the destination contract
    // @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
    // @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction
    // @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
    function send(uint16 _dstChainId, bytes calldata _destination, bytes calldata _payload, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;

    // @notice used by the messaging library to publish verified payload
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source contract (as bytes) at the source chain
    // @param _dstAddress - the address on destination chain
    // @param _nonce - the unbound message ordering nonce
    // @param _gasLimit - the gas limit for external contract execution
    // @param _payload - verified payload to send to the destination contract
    function receivePayload(uint16 _srcChainId, bytes calldata _srcAddress, address _dstAddress, uint64 _nonce, uint _gasLimit, bytes calldata _payload) external;

    // @notice get the inboundNonce of a lzApp from a source chain which could be EVM or non-EVM chain
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source chain contract address
    function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (uint64);

    // @notice get the outboundNonce from this source chain which, consequently, is always an EVM
    // @param _srcAddress - the source chain contract address
    function getOutboundNonce(uint16 _dstChainId, address _srcAddress) external view returns (uint64);

    // @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery
    // @param _dstChainId - the destination chain identifier
    // @param _userApplication - the user app address on this EVM chain
    // @param _payload - the custom message to send over LayerZero
    // @param _payInZRO - if false, user app pays the protocol fee in native token
    // @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChain
    function estimateFees(uint16 _dstChainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParam) external view returns (uint nativeFee, uint zroFee);

    // @notice get this Endpoint's immutable source identifier
    function getChainId() external view returns (uint16);

    // @notice the interface to retry failed message on this Endpoint destination
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source chain contract address
    // @param _payload - the payload to be retried
    function retryPayload(uint16 _srcChainId, bytes calldata _srcAddress, bytes calldata _payload) external;

    // @notice query if any STORED payload (message blocking) at the endpoint.
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source chain contract address
    function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool);

    // @notice query if the _libraryAddress is valid for sending msgs.
    // @param _userApplication - the user app address on this EVM chain
    function getSendLibraryAddress(address _userApplication) external view returns (address);

    // @notice query if the _libraryAddress is valid for receiving msgs.
    // @param _userApplication - the user app address on this EVM chain
    function getReceiveLibraryAddress(address _userApplication) external view returns (address);

    // @notice query if the non-reentrancy guard for send() is on
    // @return true if the guard is on. false otherwise
    function isSendingPayload() external view returns (bool);

    // @notice query if the non-reentrancy guard for receive() is on
    // @return true if the guard is on. false otherwise
    function isReceivingPayload() external view returns (bool);

    // @notice get the configuration of the LayerZero messaging library of the specified version
    // @param _version - messaging library version
    // @param _chainId - the chainId for the pending config change
    // @param _userApplication - the contract address of the user application
    // @param _configType - type of configuration. every messaging library has its own convention.
    function getConfig(uint16 _version, uint16 _chainId, address _userApplication, uint _configType) external view returns (bytes memory);

    // @notice get the send() LayerZero messaging library version
    // @param _userApplication - the contract address of the user application
    function getSendVersion(address _userApplication) external view returns (uint16);

    // @notice get the lzReceive() LayerZero messaging library version
    // @param _userApplication - the contract address of the user application
    function getReceiveVersion(address _userApplication) external view returns (uint16);
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

interface ILayerZeroReceiver {
    // @notice LayerZero endpoint will invoke this function to deliver the message on the destination
    // @param _srcChainId - the source endpoint identifier
    // @param _srcAddress - the source sending contract address from the source chain
    // @param _nonce - the ordered message nonce
    // @param _payload - the signed payload is the UA bytes has encoded to be sent
    function lzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) external;
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

interface ILayerZeroUserApplicationConfig {
    // @notice set the configuration of the LayerZero messaging library of the specified version
    // @param _version - messaging library version
    // @param _chainId - the chainId for the pending config change
    // @param _configType - type of configuration. every messaging library has its own convention.
    // @param _config - configuration in the bytes. can encode arbitrary content.
    function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external;

    // @notice set the send() LayerZero messaging library version to _version
    // @param _version - new messaging library version
    function setSendVersion(uint16 _version) external;

    // @notice set the lzReceive() LayerZero messaging library version to _version
    // @param _version - new messaging library version
    function setReceiveVersion(uint16 _version) external;

    // @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload
    // @param _srcChainId - the chainId of the source chain
    // @param _srcAddress - the contract address of the source contract at the source chain
    function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external;
}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity >=0.5.0;

interface IOFTReceiverV2 {
    /**
     * @dev Called by the OFT contract when tokens are received from source chain.
     * @param _srcChainId The chain id of the source chain.
     * @param _srcAddress The address of the OFT token contract on the source chain.
     * @param _nonce The nonce of the transaction on the source chain.
     * @param _from The address of the account who calls the sendAndCall() on the source chain.
     * @param _amount The amount of tokens to transfer.
     * @param _payload Additional data with no specified format.
     */
    function onOFTReceived(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes32 _from, uint _amount, bytes calldata _payload) external;
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

import "./ICommonOFT.sol";

/**
 * @dev Interface of the IOFT core standard
 */
interface IOFTV2 is ICommonOFT {

    /**
     * @dev send `_amount` amount of token to (`_dstChainId`, `_toAddress`) from `_from`
     * `_from` the owner of token
     * `_dstChainId` the destination chain identifier
     * `_toAddress` can be any size depending on the `dstChainId`.
     * `_amount` the quantity of tokens in wei
     * `_refundAddress` the address LayerZero refunds if too much message fee is sent
     * `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
     * `_adapterParams` is a flexible bytes array to indicate messaging adapter services
     */
    function sendFrom(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, LzCallParams calldata _callParams) external payable;

    function sendAndCall(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes calldata _payload, uint64 _dstGasForCall, LzCallParams calldata _callParams) external payable;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (governance/utils/IVotes.sol)
pragma solidity ^0.8.0;

/**
 * @dev Common interface for {ERC20Votes}, {ERC721Votes}, and other {Votes}-enabled contracts.
 *
 * _Available since v4.5._
 */
interface IVotes {
    /**
     * @dev Emitted when an account changes their delegate.
     */
    event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);

    /**
     * @dev Emitted when a token transfer or delegate change results in changes to a delegate's number of votes.
     */
    event DelegateVotesChanged(address indexed delegate, uint256 previousBalance, uint256 newBalance);

    /**
     * @dev Returns the current amount of votes that `account` has.
     */
    function getVotes(address account) external view returns (uint256);

    /**
     * @dev Returns the amount of votes that `account` had at a specific moment in the past. If the `clock()` is
     * configured to use block numbers, this will return the value at the end of the corresponding block.
     */
    function getPastVotes(address account, uint256 timepoint) external view returns (uint256);

    /**
     * @dev Returns the total supply of votes available at a specific moment in the past. If the `clock()` is
     * configured to use block numbers, this will return the value at the end of the corresponding block.
     *
     * NOTE: This value is the sum of all available votes, which is not necessarily the sum of all delegated votes.
     * Votes that have not been delegated are still part of total supply, even though they would not participate in a
     * vote.
     */
    function getPastTotalSupply(uint256 timepoint) external view returns (uint256);

    /**
     * @dev Returns the delegate that `account` has chosen.
     */
    function delegates(address account) external view returns (address);

    /**
     * @dev Delegates votes from the sender to `delegatee`.
     */
    function delegate(address delegatee) external;

    /**
     * @dev Delegates votes from signer to `delegatee`.
     */
    function delegateBySig(address delegatee, uint256 nonce, uint256 expiry, uint8 v, bytes32 r, bytes32 s) external;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../../oz/access/Ownable.sol";
import "../interfaces/ILayerZeroReceiver.sol";
import "../interfaces/ILayerZeroUserApplicationConfig.sol";
import "../interfaces/ILayerZeroEndpoint.sol";
import "../util/BytesLib.sol";

/*
 * a generic LzReceiver implementation
 */
abstract contract LzApp is Ownable, ILayerZeroReceiver, ILayerZeroUserApplicationConfig {
    using BytesLib for bytes;

    error LZAPPInvalidEndpointCaller();
    error LZAPPInvalidSourceSendingContract();
    error LZAPPInvalidDestinationChain();
    error LZAPPInvalidMinGasLimit();
    error LZAPPInvalidGasLimit();
    error LZAPPInvalidAdapterParams();
    error LZAPPInvalidPayloadSize();
    error LZAPPNoTrustedPathRecord();
    error LZAPPInvalidMinGas();

    // ua can not send payload larger than this by default, but it can be changed by the ua owner
    uint constant public DEFAULT_PAYLOAD_SIZE_LIMIT = 10000;

    ILayerZeroEndpoint public lzEndpoint;
    mapping(uint16 => bytes) public trustedRemoteLookup;
    mapping(uint16 => mapping(uint16 => uint)) public minDstGasLookup;
    mapping(uint16 => uint) public payloadSizeLimitLookup;
    address public precrime;

    event SetPrecrime(address precrime);
    event SetTrustedRemote(uint16 _remoteChainId, bytes _path);
    event SetTrustedRemoteAddress(uint16 _remoteChainId, bytes _remoteAddress);
    event SetMinDstGas(uint16 _dstChainId, uint16 _type, uint _minDstGas);

    function __LzApp_init(address _endpoint) internal {
        lzEndpoint = ILayerZeroEndpoint(_endpoint);
    }

    function lzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) public virtual override {
        // lzReceive must be called by the endpoint for security
        if (_msgSender() != address(lzEndpoint)) {
            revert LZAPPInvalidEndpointCaller();
        }

        bytes memory trustedRemote = trustedRemoteLookup[_srcChainId];
        // if will still block the message pathway from (srcChainId, srcAddress). should not receive message from untrusted remote.
        if ((_srcAddress.length != trustedRemote.length) || trustedRemote.length == 0 || keccak256(_srcAddress) != keccak256(trustedRemote)) {
            revert LZAPPInvalidSourceSendingContract();
        }

        _blockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
    }

    // abstract function - the default behaviour of LayerZero is blocking. See: NonblockingLzApp if you dont need to enforce ordered messaging
    function _blockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual;

    function _lzSend(uint16 _dstChainId, bytes memory _payload, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParams, uint _nativeFee) internal virtual {
        bytes memory trustedRemote = trustedRemoteLookup[_dstChainId];
        if (trustedRemote.length == 0) {
            revert LZAPPInvalidDestinationChain();
        }
        _checkPayloadSize(_dstChainId, _payload.length);
        lzEndpoint.send{value: _nativeFee}(_dstChainId, trustedRemote, _payload, _refundAddress, _zroPaymentAddress, _adapterParams);
    }

    function _checkGasLimit(uint16 _dstChainId, uint16 _type, bytes memory _adapterParams, uint _extraGas) internal view virtual {
        uint providedGasLimit = _getGasLimit(_adapterParams);
        uint minGasLimit = minDstGasLookup[_dstChainId][_type] + _extraGas;
        if (minGasLimit == 0) {
            revert LZAPPInvalidMinGasLimit();
        }
        if (providedGasLimit < minGasLimit) {
            revert LZAPPInvalidGasLimit();
        }
    }

    function _getGasLimit(bytes memory _adapterParams) internal pure virtual returns (uint gasLimit) {
        if (_adapterParams.length < 34) {
            revert LZAPPInvalidAdapterParams();
        }
        assembly {
            gasLimit := mload(add(_adapterParams, 34))
        }
    }

    function _checkPayloadSize(uint16 _dstChainId, uint _payloadSize) internal view virtual {
        uint payloadSizeLimit = payloadSizeLimitLookup[_dstChainId];
        if (payloadSizeLimit == 0) { // use default if not set
            payloadSizeLimit = DEFAULT_PAYLOAD_SIZE_LIMIT;
        }
        if (_payloadSize > payloadSizeLimit) {
            revert LZAPPInvalidPayloadSize();
        }
    }

    //---------------------------UserApplication config----------------------------------------
    function getConfig(uint16 _version, uint16 _chainId, address, uint _configType) external view returns (bytes memory) {
        return lzEndpoint.getConfig(_version, _chainId, address(this), _configType);
    }

    // generic config for LayerZero user Application
    function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external override onlyOwner {
        lzEndpoint.setConfig(_version, _chainId, _configType, _config);
    }

    function setSendVersion(uint16 _version) external override onlyOwner {
        lzEndpoint.setSendVersion(_version);
    }

    function setReceiveVersion(uint16 _version) external override onlyOwner {
        lzEndpoint.setReceiveVersion(_version);
    }

    function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external override onlyOwner {
        lzEndpoint.forceResumeReceive(_srcChainId, _srcAddress);
    }

    // _path = abi.encodePacked(remoteAddress, localAddress)
    // this function set the trusted path for the cross-chain communication
    function setTrustedRemote(uint16 _remoteChainId, bytes calldata _path) external onlyOwner {
        trustedRemoteLookup[_remoteChainId] = _path;
        emit SetTrustedRemote(_remoteChainId, _path);
    }

    function setTrustedRemoteAddress(uint16 _remoteChainId, bytes calldata _remoteAddress) external onlyOwner {
        trustedRemoteLookup[_remoteChainId] = abi.encodePacked(_remoteAddress, address(this));
        emit SetTrustedRemoteAddress(_remoteChainId, _remoteAddress);
    }

    function getTrustedRemoteAddress(uint16 _remoteChainId) external view returns (bytes memory) {
        bytes memory path = trustedRemoteLookup[_remoteChainId];
        if (path.length == 0) {
            revert LZAPPNoTrustedPathRecord();
        }
        return path.slice(0, path.length - 20); // the last 20 bytes should be address(this)
    }

    function setPrecrime(address _precrime) external onlyOwner {
        precrime = _precrime;
        emit SetPrecrime(_precrime);
    }

    function setMinDstGas(uint16 _dstChainId, uint16 _packetType, uint _minGas) external onlyOwner {
        if (_minGas == 0) {
            revert LZAPPInvalidMinGas();
        }
        minDstGasLookup[_dstChainId][_packetType] = _minGas;
        emit SetMinDstGas(_dstChainId, _packetType, _minGas);
    }

    // if the size is 0, it means default size limit
    function setPayloadSizeLimit(uint16 _dstChainId, uint _size) external onlyOwner {
        payloadSizeLimitLookup[_dstChainId] = _size;
    }

    //--------------------------- VIEW FUNCTION ----------------------------------------
    function isTrustedRemote(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool) {
        bytes memory trustedSource = trustedRemoteLookup[_srcChainId];
        return keccak256(trustedSource) == keccak256(_srcAddress);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }

    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }

    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
     * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
     * with further edits by Uniswap Labs also under MIT license.
     */
    function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                // The surrounding unchecked block does not change this fact.
                // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1, "Math: mulDiv overflow");

            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////

            // Make division exact by subtracting the remainder from [prod1 prod0].
            uint256 remainder;
            assembly {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)

                // Subtract 256 bit number from 512 bit number.
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }

            // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
            // See https://cs.stackexchange.com/q/138556/92363.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;

            // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            uint256 inverse = (3 * denominator) ^ 2;

            // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
            // in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256

            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }

    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        //
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
        //
        // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
        // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
        // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
        //
        // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1 << (log2(a) >> 1);

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = sqrt(a);
            return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 2, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 10, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10 ** 64) {
                value /= 10 ** 64;
                result += 64;
            }
            if (value >= 10 ** 32) {
                value /= 10 ** 32;
                result += 32;
            }
            if (value >= 10 ** 16) {
                value /= 10 ** 16;
                result += 16;
            }
            if (value >= 10 ** 8) {
                value /= 10 ** 8;
                result += 8;
            }
            if (value >= 10 ** 4) {
                value /= 10 ** 4;
                result += 4;
            }
            if (value >= 10 ** 2) {
                value /= 10 ** 2;
                result += 2;
            }
            if (value >= 10 ** 1) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 256, rounded down, of a positive value.
     * Returns 0 if given 0.
     *
     * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
     */
    function log256(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
        }
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./LzApp.sol";
import "../util/ExcessivelySafeCall.sol";

/*
 * the default LayerZero messaging behaviour is blocking, i.e. any failed message will block the channel
 * this abstract class try-catch all fail messages and store locally for future retry. hence, non-blocking
 * NOTE: if the srcAddress is not configured properly, it will still block the message pathway from (srcChainId, srcAddress)
 */
abstract contract NonblockingLzApp is LzApp {
    using ExcessivelySafeCall for address;

    error LZAPPInvalidPayload();

    function __NonblockingLzApp_init(address _endpoint) internal {
        __LzApp_init(_endpoint);
    }

    mapping(uint16 => mapping(bytes => mapping(uint64 => bytes32))) public failedMessages;

    event MessageFailed(uint16 _srcChainId, bytes _srcAddress, uint64 _nonce, bytes _payload, bytes _reason);
    event RetryMessageSuccess(uint16 _srcChainId, bytes _srcAddress, uint64 _nonce, bytes32 _payloadHash);

    // overriding the virtual function in LzReceiver
    function _blockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual override {
        (bool success, bytes memory reason) = address(this).excessivelySafeCall(gasleft(), 150, abi.encodeWithSelector(this.nonblockingLzReceive.selector, _srcChainId, _srcAddress, _nonce, _payload));
        // try-catch all errors/exceptions
        if (!success) {
            _storeFailedMessage(_srcChainId, _srcAddress, _nonce, _payload, reason);
        }
    }

    function _storeFailedMessage(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload, bytes memory _reason) internal virtual {
        failedMessages[_srcChainId][_srcAddress][_nonce] = keccak256(_payload);
        emit MessageFailed(_srcChainId, _srcAddress, _nonce, _payload, _reason);
    }

    function nonblockingLzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) public virtual {
        // only internal transaction
        if (_msgSender() != address(this)) {
            revert LZAPPInvalidEndpointCaller();
        }
        _nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
    }

    //@notice override this function
    function _nonblockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual;

    function retryMessage(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) public payable virtual {
        // assert there is message to retry
        bytes32 payloadHash = failedMessages[_srcChainId][_srcAddress][_nonce];
        if (payloadHash == bytes32(0)) {
            revert LZAPPInvalidSourceSendingContract();
        }
        if (keccak256(_payload) != payloadHash) {
            revert LZAPPInvalidPayload();
        }
        // clear the stored message
        failedMessages[_srcChainId][_srcAddress][_nonce] = bytes32(0);
        // execute the message. revert if it fails again
        _nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
        emit RetryMessageSuccess(_srcChainId, _srcAddress, _nonce, payloadHash);
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../../../lzApp/NonblockingLzApp.sol";
import "../../../util/ExcessivelySafeCall.sol";
import "./ICommonOFT.sol";
import "./IOFTReceiverV2.sol";

abstract contract OFTCoreV2 is NonblockingLzApp {
    using BytesLib for bytes;
    using ExcessivelySafeCall for address;

    error OFTCoreCallerMustBeOFTCore();
    error OFTCoreUnknownPacketType();
    error OFTCoreAmountZero();
    error OFTCoreAdapterParamsNotAllowed();
    error OFTCoreAmountSDOverflow();
    error OFTCoreInvalidPayload();

    uint public constant NO_EXTRA_GAS = 0;

    // packet type
    uint8 public constant PT_SEND = 0;
    uint8 public constant PT_SEND_AND_CALL = 1;

    uint8 public immutable sharedDecimals;

    bool public useCustomAdapterParams;
    mapping(uint16 => mapping(bytes => mapping(uint64 => bool))) public creditedPackets;

    /**
     * @dev Emitted when `_amount` tokens are moved from the `_sender` to (`_dstChainId`, `_toAddress`)
     * `_nonce` is the outbound nonce
     */
    event SendToChain(uint16 indexed _dstChainId, address indexed _from, bytes32 indexed _toAddress, uint _amount);

    /**
     * @dev Emitted when `_amount` tokens are received from `_srcChainId` into the `_toAddress` on the local chain.
     * `_nonce` is the inbound nonce.
     */
    event ReceiveFromChain(uint16 indexed _srcChainId, address indexed _to, uint _amount);

    event SetUseCustomAdapterParams(bool _useCustomAdapterParams);

    event CallOFTReceivedSuccess(uint16 indexed _srcChainId, bytes _srcAddress, uint64 _nonce, bytes32 _hash);

    event NonContractAddress(address _address);

    // _sharedDecimals should be the minimum decimals on all chains
    constructor(uint8 _sharedDecimals) {
        sharedDecimals = _sharedDecimals;
    }

    function __OFTCoreV2_init(address _lzEndpoint) internal {
        __NonblockingLzApp_init(_lzEndpoint);
    }

    /************************************************************************
    * public functions
    ************************************************************************/
    function callOnOFTReceived(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes32 _from, address _to, uint _amount, bytes calldata _payload, uint _gasForCall) public virtual {
        if (_msgSender() != address(this)) {
            revert OFTCoreCallerMustBeOFTCore();  
        }

        // send
        _amount = _transferFrom(address(this), _to, _amount);
        emit ReceiveFromChain(_srcChainId, _to, _amount);

        // call
        IOFTReceiverV2(_to).onOFTReceived{gas: _gasForCall}(_srcChainId, _srcAddress, _nonce, _from, _amount, _payload);
    }

    function setUseCustomAdapterParams(bool _useCustomAdapterParams) public virtual onlyOwner {
        useCustomAdapterParams = _useCustomAdapterParams;
        emit SetUseCustomAdapterParams(_useCustomAdapterParams);
    }

    /************************************************************************
    * internal functions
    ************************************************************************/
    function _estimateSendFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bool _useZro, bytes memory _adapterParams) internal view virtual returns (uint nativeFee, uint zroFee) {
        // mock the payload for sendFrom()
        bytes memory payload = _encodeSendPayload(_toAddress, _ld2sd(_amount));
        return lzEndpoint.estimateFees(_dstChainId, address(this), payload, _useZro, _adapterParams);
    }

    function _estimateSendAndCallFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes memory _payload, uint64 _dstGasForCall, bool _useZro, bytes memory _adapterParams) internal view virtual returns (uint nativeFee, uint zroFee) {
        // mock the payload for sendAndCall()
        bytes memory payload = _encodeSendAndCallPayload(msg.sender, _toAddress, _ld2sd(_amount), _payload, _dstGasForCall);
        return lzEndpoint.estimateFees(_dstChainId, address(this), payload, _useZro, _adapterParams);
    }

    function _nonblockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual override {
        uint8 packetType = _payload.toUint8(0);

        if (packetType == PT_SEND) {
            _sendAck(_srcChainId, _srcAddress, _nonce, _payload);
        } else if (packetType == PT_SEND_AND_CALL) {
            _sendAndCallAck(_srcChainId, _srcAddress, _nonce, _payload);
        } else {
            revert OFTCoreUnknownPacketType();
        }
    }

    function _send(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParams) internal virtual returns (uint amount) {
        _checkAdapterParams(_dstChainId, PT_SEND, _adapterParams, NO_EXTRA_GAS);

        (amount,) = _removeDust(_amount);
        amount = _debitFrom(_from, _dstChainId, _toAddress, amount); // amount returned should not have dust
        if (amount == 0) {
            revert OFTCoreAmountZero();
        }

        bytes memory lzPayload = _encodeSendPayload(_toAddress, _ld2sd(amount));
        _lzSend(_dstChainId, lzPayload, _refundAddress, _zroPaymentAddress, _adapterParams, msg.value);

        emit SendToChain(_dstChainId, _from, _toAddress, amount);
    }

    function _sendAck(uint16 _srcChainId, bytes memory, uint64, bytes memory _payload) internal virtual {
        (address to, uint64 amountSD) = _decodeSendPayload(_payload);
        if (to == address(0)) {
            to = address(0xdead);
        }

        uint amount = _sd2ld(amountSD);
        amount = _creditTo(_srcChainId, to, amount);

        emit ReceiveFromChain(_srcChainId, to, amount);
    }

    function _sendAndCall(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes memory _payload, uint64 _dstGasForCall, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParams) internal virtual returns (uint amount) {
        _checkAdapterParams(_dstChainId, PT_SEND_AND_CALL, _adapterParams, _dstGasForCall);

        (amount,) = _removeDust(_amount);
        amount = _debitFrom(_from, _dstChainId, _toAddress, amount);
        if (amount == 0) {
            revert OFTCoreAmountZero();
        }

        // encode the msg.sender into the payload instead of _from
        bytes memory lzPayload = _encodeSendAndCallPayload(msg.sender, _toAddress, _ld2sd(amount), _payload, _dstGasForCall);
        _lzSend(_dstChainId, lzPayload, _refundAddress, _zroPaymentAddress, _adapterParams, msg.value);

        emit SendToChain(_dstChainId, _from, _toAddress, amount);
    }

    function _sendAndCallAck(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual {
        (bytes32 from, address to, uint64 amountSD, bytes memory payloadForCall, uint64 gasForCall) = _decodeSendAndCallPayload(_payload);

        bool credited = creditedPackets[_srcChainId][_srcAddress][_nonce];
        uint amount = _sd2ld(amountSD);

        // credit to this contract first, and then transfer to receiver only if callOnOFTReceived() succeeds
        if (!credited) {
            amount = _creditTo(_srcChainId, address(this), amount);
            creditedPackets[_srcChainId][_srcAddress][_nonce] = true;
        }

        if (!_isContract(to)) {
            emit NonContractAddress(to);
            return;
        }

        // workaround for stack too deep
        uint16 srcChainId = _srcChainId;
        bytes memory srcAddress = _srcAddress;
        uint64 nonce = _nonce;
        bytes memory payload = _payload;
        bytes32 from_ = from;
        address to_ = to;
        uint amount_ = amount;
        bytes memory payloadForCall_ = payloadForCall;

        // no gas limit for the call if retry
        uint gas = credited ? gasleft() : gasForCall;
        (bool success, bytes memory reason) = address(this).excessivelySafeCall(gasleft(), 150, abi.encodeWithSelector(this.callOnOFTReceived.selector, srcChainId, srcAddress, nonce, from_, to_, amount_, payloadForCall_, gas));

        if (success) {
            bytes32 hash = keccak256(payload);
            emit CallOFTReceivedSuccess(srcChainId, srcAddress, nonce, hash);
        } else {
            // store the failed message into the nonblockingLzApp
            _storeFailedMessage(srcChainId, srcAddress, nonce, payload, reason);
        }
    }

    function _isContract(address _account) internal view returns (bool) {
        return _account.code.length > 0;
    }

    function _checkAdapterParams(uint16 _dstChainId, uint16 _pkType, bytes memory _adapterParams, uint _extraGas) internal virtual {
        if (useCustomAdapterParams) {
            _checkGasLimit(_dstChainId, _pkType, _adapterParams, _extraGas);
        } else if (_adapterParams.length != 0) {
            revert OFTCoreAdapterParamsNotAllowed();
        }
    }

    function _ld2sd(uint _amount) internal virtual view returns (uint64) {
        uint amountSD = _amount / _ld2sdRate();
        if (amountSD > type(uint64).max) {
            revert OFTCoreAmountSDOverflow();
        }
        return uint64(amountSD);
    }

    function _sd2ld(uint64 _amountSD) internal virtual view returns (uint) {
        return _amountSD * _ld2sdRate();
    }

    function _removeDust(uint _amount) internal virtual view returns (uint amountAfter, uint dust) {
        dust = _amount % _ld2sdRate();
        amountAfter = _amount - dust;
    }

    function _encodeSendPayload(bytes32 _toAddress, uint64 _amountSD) internal virtual view returns (bytes memory) {
        return abi.encodePacked(PT_SEND, _toAddress, _amountSD);
    }

    function _decodeSendPayload(bytes memory _payload) internal virtual view returns (address to, uint64 amountSD) {
        if (_payload.toUint8(0) != PT_SEND || _payload.length != 41) {
            revert OFTCoreInvalidPayload();
        }

        to = _payload.toAddress(13); // drop the first 12 bytes of bytes32
        amountSD = _payload.toUint64(33);
    }

    function _encodeSendAndCallPayload(address _from, bytes32 _toAddress, uint64 _amountSD, bytes memory _payload, uint64 _dstGasForCall) internal virtual view returns (bytes memory) {
        return abi.encodePacked(
            PT_SEND_AND_CALL,
            _toAddress,
            _amountSD,
            _addressToBytes32(_from),
            _dstGasForCall,
            _payload
        );
    }

    function _decodeSendAndCallPayload(bytes memory _payload) internal virtual view returns (bytes32 from, address to, uint64 amountSD, bytes memory payload, uint64 dstGasForCall) {
        if (_payload.toUint8(0) != PT_SEND_AND_CALL) {
            revert OFTCoreInvalidPayload();
        }

        to = _payload.toAddress(13); // drop the first 12 bytes of bytes32
        amountSD = _payload.toUint64(33);
        from = _payload.toBytes32(41);
        dstGasForCall = _payload.toUint64(73);
        payload = _payload.slice(81, _payload.length - 81);
    }

    function _addressToBytes32(address _address) internal pure virtual returns (bytes32) {
        return bytes32(uint(uint160(_address)));
    }

    function _debitFrom(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount) internal virtual returns (uint);

    function _creditTo(uint16 _srcChainId, address _toAddress, uint _amount) internal virtual returns (uint);

    function _transferFrom(address _from, address _to, uint _amount) internal virtual returns (uint);

    function _ld2sdRate() internal view virtual returns (uint);
}