/**
 *Submitted for verification at basescan.org on 2023-09-23
*/

/**
 *v3.0.0
 *0xc295f619afc2b8543d91c8970ea4c0726f197250
 *Submitted for verification at basescan.org on 2023-09-19
*/

/**
 *v1.3.11
 *0x8db550677053f2ca3d3bf677cb4e06cc10511958
 *Submitted for verification at FtmScan.com on 2023-02-21
*/

/**
 *v1.1.0
 *0xc9ab1ab21358f4fc36cbbbe27f3b3ead423ec33b
 *Submitted for verification at FtmScan.com on 2022-11-03
*/

/**
 *  EQUALIZER EXCHANGE
 *  The New Liquidity Hub of XChain Decentralized Finance!
 *  https://equalizer.exchange  (Dapp)
 *  https://discord.gg/MaMhbgHMby   (Community)
 *
 *  SPDX-License-Identifier: UNLICENSED
 *
 *
 *  Equalizer v3 Pair Factory
 *  - Equalizer Stableswap 2pool
 *  - Equalizer Classic AMM
 *
 *
 *
 *
 *  Version: v3.0.1
 *  - Introducing 3-Dimensional Fees
 *    - 0° : Constant Fees for all pools
 *    - 1° : Dual Fees - Stablepools vs Volatile pools
 *    - 2° : Fees Overrides: Custom Fees per Pool
 *    - 3° : 🆕 Dynamic Fees Overrides using EⅢ Manangerial Approach
 *              - Fully Dynamic Custom Fees per Pool
 *              - Real Time Variable/Static/Streaming
 *              - EⅢ DEX's Dynamic Fee plugins (https://eliteness.network/e3)
 *                - Volatility-derived Fees adjustment for higher Fee APR
 *                - Auto-adjusting: Low Volume --> Low Fees, attracts trades
 *              - Curve.fi's "A-factor ramp" inspired Trade Fee On/Off Ramps
 *              - Balancer's "Liquidity Bootstrapping Pool" inspired
 *                Quadratic Fees downramps for fine-grained smooth curves, for
 *                New pools/IDO/LGE/Fair Launches via Guru Network's SeedR🌱 plugin
 *
 *
 *  Version: v3.0.0
 *  - Fee Precision upto 1 atto of a token
 *  - Zero-fee Trading for amounts less than PRECISION / getRealFee)
 *    - Example: For BTC/USDT with 0.01% trade fee & decimals 8 & 6,
 *      NO FEES is charged on token amounts traded that are
 *      less than 0.001 USDC or 0.00001 BTC!
 *
 *
 *  Version: 1.3.11 (Deployed at v2.0.0)
 *  - Fees Overrides
 *    - Per Pair Customizable Fees
 *  - Introduce `getRealFees(_pool)` as a new Standard
 *
 *
 *  Version: 1.3.8
 *  - Clarify Fee-Claims are once per veNFT per 7 days per pool
 *  - Real-time Countdown
 *
 *
 *  Version: 1.0.2
 *  - Dual-fee algorithm based on pool stability (correlativity)
 *    - For lower Stableswap fees & higher Volatile pool fee
 *    - Independently adjustable `stableFee` & `volatileFee`
 *
 *
 *
 *  Contributors:
 *   -   Andre Cronje, Solidly.Exchange
 *   -   543 (Sam), ftm.guru, Eliteness.network & Equalizer.exchange
 *
 *
 *
 */

// File: contracts/interfaces/IPairFactory.sol


pragma solidity 0.8.9;

interface IPairFactory {
    function isPaused() external view returns (bool);
    function allPairsLength() external view returns (uint);
    function isPair(address pair) external view returns (bool);
    function pairCodeHash() external pure returns (bytes32);
    function getFee(bool _stable) external view returns(uint256);
    function getRealFee(address _pair) external view returns(uint256);
    function getPair(address tokenA, address token, bool stable) external view returns (address);
    function getInitializable() external view returns (address, address, bool);
    function createPair(address tokenA, address tokenB, bool stable) external returns (address pair);
}

// File: contracts/interfaces/IPairCallee.sol


pragma solidity 0.8.9;

interface IPairCallee {
    function hook(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/interfaces/IFeeManager.sol


pragma solidity 0.8.9;

interface IFeeManager {
    function getFee(address pool) external view returns(uint256);
}

// File: contracts/interfaces/IPairCallee.sol


pragma solidity 0.8.9;

interface IPair {
    function stable() external view returns (bool _s);
}

// File: contracts/interfaces/IERC20.sol


pragma solidity 0.8.9;

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function transfer(address recipient, uint amount) external returns (bool);
    function decimals() external view returns (uint8);
    function symbol() external view returns (string memory);
    function name() external view returns (string memory);
    function balanceOf(address) external view returns (uint);
    function transferFrom(address sender, address recipient, uint amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint);
    function approve(address spender, uint value) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint value);
    event Approval(address indexed owner, address indexed spender, uint value);
}

// File: contracts/libraries/Math.sol


pragma solidity 0.8.9;

library Math {
    function max(uint a, uint b) internal pure returns (uint) {
        return a >= b ? a : b;
    }
    function min(uint a, uint b) internal pure returns (uint) {
        return a < b ? a : b;
    }
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
    function cbrt(uint256 n) internal pure returns (uint256) { unchecked {
        uint256 x = 0;
        for (uint256 y = 1 << 255; y > 0; y >>= 3) {
            x <<= 1;
            uint256 z = 3 * x * (x + 1) + 1;
            if (n / y >= z) {
                n -= y * z;
                x += 1;
            }
        }
        return x;
    }}
}

// File: @openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol


// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

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

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

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

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(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) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason 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 {
            // 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);
            }
        }
    }
}

// File: @openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol


// OpenZeppelin Contracts (last updated v4.7.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;


/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
     * initialization step. This is essential to configure modules that are added through upgrades and that require
     * initialization.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized < type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }
}

// File: contracts/PairFees.sol


pragma solidity 0.8.9;



/**
* @title Pair Fees
* @notice used as a 1:1 pair relationship to split out fees, this ensures
* that the curve does not need to be modified for LP shares
*/

contract PairFees is Initializable {

    address internal pair; // The pair it is bonded to
    address internal token0; // token0 of pair, saved localy and statically for gas optimization
    address internal token1; // Token1 of pair, saved localy and statically for gas optimization

    function initialize(address _token0, address _token1) public initializer {
        pair = msg.sender;
        token0 = _token0;
        token1 = _token1;
    }

    function _safeTransfer(address token,address to,uint256 value) internal {
        require(token.code.length > 0, "PairFees: invalid token");
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.transfer.selector, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), "PairFees: transfer failed");
    }

    // Allow the pair to transfer fees to users
    function claimFeesFor(address recipient, uint amount0, uint amount1) external {
        require(msg.sender == pair, "Only pair contract can call");
        if (amount0 > 0) _safeTransfer(token0, recipient, amount0);
        if (amount1 > 0) _safeTransfer(token1, recipient, amount1);
    }
}

// File: contracts/Pair.sol


pragma solidity 0.8.9;







contract Pair is Initializable {

    string public name;
    string public symbol;
    uint8 public constant decimals = 18;

    /// @notice Used to denote stable or volatile pair, not immutable since construction happens in the initialize method for CREATE2 deterministic addresses
    bool public stable;

    uint256 public totalSupply;

    mapping(address => mapping (address => uint)) public allowance;
    mapping(address => uint) public balanceOf;

    bytes32 internal DOMAIN_SEPARATOR;
    /// @dev keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 internal constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    uint256 internal constant MINIMUM_LIQUIDITY = 10**3;

    address public token0;
    address public token1;
    address public fees;
    address public factory;

    // Structure to capture time period obervations every 30 minutes, used for local oracles
    struct Observation {
        uint timestamp;
        uint reserve0Cumulative;
        uint reserve1Cumulative;
    }

    // Capture oracle reading every 30 minutes
    uint constant periodSize = 1800;

    Observation[] public observations;

    uint internal decimals0;
    uint internal decimals1;

    uint public reserve0;
    uint public reserve1;
    uint public blockTimestampLast;

    uint public reserve0CumulativeLast;
    uint public reserve1CumulativeLast;

    // index0 and index1 are used to accumulate fees, this is split out from normal trades to keep the swap "clean"
    // this further allows LP holders to easily claim fees for tokens they have/staked
    uint public index0;
    uint public index1;

    // position assigned to each LP to track their current index0 & index1 vs the global position
    mapping(address => uint) public supplyIndex0;
    mapping(address => uint) public supplyIndex1;

    // tracks the amount of unclaimed, but claimable tokens off of fees for token0 and token1
    mapping(address => uint) public claimable0;
    mapping(address => uint) public claimable1;

    /// @dev simple re-entrancy check
    bool internal _locked;

    event Fees(address indexed sender, uint amount0, uint amount1);
    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint reserve0, uint reserve1);
    event Claim(address indexed sender, address indexed recipient, uint amount0, uint amount1);

    event Transfer(address indexed from, address indexed to, uint amount);
    event Approval(address indexed owner, address indexed spender, uint amount);

    modifier lock() {
        require(!_locked, "No re-entrancy");
        _locked = true;
        _;
        _locked = false;
    }

    function initialize() public initializer {
        factory = msg.sender;
        (address _token0, address _token1, bool _stable) = IPairFactory(msg.sender).getInitializable();
        (token0, token1, stable) = (_token0, _token1, _stable);
        PairFees pairFees = new PairFees();
        pairFees.initialize(_token0, _token1);
        fees = address(pairFees);

        if (_stable) {
            name = string(abi.encodePacked("Equalizer Stableswap 2pool - ", IERC20(_token0).name(), " paired with ", IERC20(_token1).name()));
            symbol = string(abi.encodePacked("s-", IERC20(_token0).symbol(), "/", IERC20(_token1).symbol()));
        } else {
            name = string(abi.encodePacked("Equalizer Classic AMM - ", IERC20(_token0).name(), " paired with ", IERC20(_token1).name()));
            symbol = string(abi.encodePacked("v-", IERC20(_token0).symbol(), "/", IERC20(_token1).symbol()));
        }

        decimals0 = 10**IERC20(_token0).decimals();
        decimals1 = 10**IERC20(_token1).decimals();

        observations.push(Observation(block.timestamp, 0, 0));
    }

    function observationLength() external view returns (uint) {
        return observations.length;
    }

    function lastObservation() public view returns (Observation memory) {
        return observations[observations.length-1];
    }

    function metadata() external view returns (uint dec0, uint dec1, uint r0, uint r1, bool st, address t0, address t1) {
        return (decimals0, decimals1, reserve0, reserve1, stable, token0, token1);
    }

    function tokens() external view returns (address, address) {
        return (token0, token1);
    }

    /// @dev claim accumulated but unclaimed fees (viewable via claimable0 and claimable1)
    function claimFees() external returns (uint claimed0, uint claimed1) {
        _updateFor(msg.sender);

        claimed0 = claimable0[msg.sender];
        claimed1 = claimable1[msg.sender];

        if (claimed0 > 0 || claimed1 > 0) {
            claimable0[msg.sender] = 0;
            claimable1[msg.sender] = 0;

            PairFees(fees).claimFeesFor(msg.sender, claimed0, claimed1);

            emit Claim(msg.sender, msg.sender, claimed0, claimed1);
        }
    }

    /// @dev Accrue fees on token0
    function _update0(uint amount) internal {
        _safeTransfer(token0, fees, amount); // transfer the fees out to PairFees
        uint256 _ratio = amount * 1e18 / totalSupply; // 1e18 adjustment is removed during claim
        if (_ratio > 0) {
            index0 += _ratio;
        }
        emit Fees(msg.sender, amount, 0);
    }

    /// @dev Accrue fees on token1
    function _update1(uint amount) internal {
        _safeTransfer(token1, fees, amount);
        uint256 _ratio = amount * 1e18 / totalSupply;
        if (_ratio > 0) {
            index1 += _ratio;
        }
        emit Fees(msg.sender, 0, amount);
    }

    /**
     * @notice This function must be called on any balance changes, otherwise can be used to infinitely claim fees
     * Fees are segregated from core funds, so fees can never put liquidity at risk
     */
    function _updateFor(address recipient) internal {
        uint _supplied = balanceOf[recipient]; // get LP balance of `recipient`
        if (_supplied > 0) {
            uint _supplyIndex0 = supplyIndex0[recipient]; // get last adjusted index0 for recipient
            uint _supplyIndex1 = supplyIndex1[recipient];
            uint _index0 = index0; // get global index0 for accumulated fees
            uint _index1 = index1;
            supplyIndex0[recipient] = _index0; // update user current position to global position
            supplyIndex1[recipient] = _index1;
            uint _delta0 = _index0 - _supplyIndex0; // see if there is any difference that need to be accrued
            uint _delta1 = _index1 - _supplyIndex1;
            if (_delta0 > 0) {
                uint _share = _supplied * _delta0 / 1e18; // add accrued difference for each supplied token
                claimable0[recipient] += _share;
            }
            if (_delta1 > 0) {
                uint _share = _supplied * _delta1 / 1e18;
                claimable1[recipient] += _share;
            }
        } else {
            supplyIndex0[recipient] = index0; // new users are set to the default global state
            supplyIndex1[recipient] = index1;
        }
    }

    function getReserves() public view returns (uint _reserve0, uint _reserve1, uint _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    /// @dev update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint _reserve0, uint _reserve1) internal {
        uint blockTimestamp = block.timestamp;
        uint timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            reserve0CumulativeLast += _reserve0 * timeElapsed;
            reserve1CumulativeLast += _reserve1 * timeElapsed;
        }

        Observation memory _point = lastObservation();
        timeElapsed = blockTimestamp - _point.timestamp; // compare the last observation with current timestamp, if greater than 30 minutes, record a new event
        if (timeElapsed > periodSize) {
            observations.push(Observation(blockTimestamp, reserve0CumulativeLast, reserve1CumulativeLast));
        }
        reserve0 = balance0;
        reserve1 = balance1;
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    /// @dev produces the cumulative price using counterfactuals to save gas and avoid a call to sync.
    function currentCumulativePrices() public view returns (uint reserve0Cumulative, uint reserve1Cumulative, uint blockTimestamp) {
        blockTimestamp = block.timestamp;
        reserve0Cumulative = reserve0CumulativeLast;
        reserve1Cumulative = reserve1CumulativeLast;

        // if time has elapsed since the last update on the pair, mock the accumulated price values
        (uint _reserve0, uint _reserve1, uint _blockTimestampLast) = getReserves();
        if (_blockTimestampLast != blockTimestamp) {
            // subtraction overflow is desired
            uint timeElapsed = blockTimestamp - _blockTimestampLast;
            reserve0Cumulative += _reserve0 * timeElapsed;
            reserve1Cumulative += _reserve1 * timeElapsed;
        }
    }

    /// @dev gives the current twap price measured from amountIn * tokenIn gives amountOut
    function current(address tokenIn, uint amountIn) external view returns (uint amountOut) {
        Observation memory _observation = lastObservation();
        (uint reserve0Cumulative, uint reserve1Cumulative,) = currentCumulativePrices();
        if (block.timestamp == _observation.timestamp) {
            _observation = observations[observations.length-2];
        }

        uint timeElapsed = block.timestamp - _observation.timestamp;
        uint _reserve0 = (reserve0Cumulative - _observation.reserve0Cumulative) / timeElapsed;
        uint _reserve1 = (reserve1Cumulative - _observation.reserve1Cumulative) / timeElapsed;
        amountOut = _getAmountOut(amountIn, tokenIn, _reserve0, _reserve1);
    }

    /// @dev as per `current`, however allows user configured granularity, up to the full window size
    function quote(address tokenIn, uint amountIn, uint granularity) external view returns (uint amountOut) {
        uint [] memory _prices = sample(tokenIn, amountIn, granularity, 1);
        uint priceAverageCumulative;
        for (uint i = 0; i < _prices.length; i++) {
            priceAverageCumulative += _prices[i];
        }
        return priceAverageCumulative / granularity;
    }

    /// @dev returns a memory set of twap prices
    function prices(address tokenIn, uint amountIn, uint points) external view returns (uint[] memory) {
        return sample(tokenIn, amountIn, points, 1);
    }

    function sample(address tokenIn, uint amountIn, uint points, uint window) public view returns (uint[] memory) {
        uint[] memory _prices = new uint[](points);

        uint length = observations.length-1;
        uint i = length - (points * window);
        uint nextIndex = 0;
        uint index = 0;

        for (; i < length; i+=window) {
            nextIndex = i + window;
            uint timeElapsed = observations[nextIndex].timestamp - observations[i].timestamp;
            uint _reserve0 = (observations[nextIndex].reserve0Cumulative - observations[i].reserve0Cumulative) / timeElapsed;
            uint _reserve1 = (observations[nextIndex].reserve1Cumulative - observations[i].reserve1Cumulative) / timeElapsed;
            _prices[index] = _getAmountOut(amountIn, tokenIn, _reserve0, _reserve1);
            // index < length; length cannot overflow
            unchecked {
                index = index + 1;
            }
        }
        return _prices;
    }

    /**
     * @notice this low-level function should be called by addLiquidity functions in Router.sol, which performs important safety checks
     * standard uniswap v2 implementation
     */
    function mint(address to) external lock returns (uint liquidity) {
        (uint _reserve0, uint _reserve1) = (reserve0, reserve1);
        uint _balance0 = IERC20(token0).balanceOf(address(this));
        uint _balance1 = IERC20(token1).balanceOf(address(this));
        uint _amount0 = _balance0 - _reserve0;
        uint _amount1 = _balance1 - _reserve1;

        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(_amount0 * _amount1) - MINIMUM_LIQUIDITY;
            _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(_amount0 * _totalSupply / _reserve0, _amount1 * _totalSupply / _reserve1);
        }
        require(liquidity > 0, "ILM"); // Pair: INSUFFICIENT_LIQUIDITY_MINTED
        _mint(to, liquidity);

        _update(_balance0, _balance1, _reserve0, _reserve1);
        emit Mint(msg.sender, _amount0, _amount1);
    }

    /**
     * @notice this low-level function should be called from a contract which performs important safety checks
     * standard uniswap v2 implementation
     */
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint _reserve0, uint _reserve1) = (reserve0, reserve1);
        (address _token0, address _token1) = (token0, token1);
        uint _balance0 = IERC20(_token0).balanceOf(address(this));
        uint _balance1 = IERC20(_token1).balanceOf(address(this));
        uint _liquidity = balanceOf[address(this)];

        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = _liquidity * _balance0 / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = _liquidity * _balance1 / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, "ILB"); // Pair: INSUFFICIENT_LIQUIDITY_BURNED
        _burn(address(this), _liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        _balance0 = IERC20(_token0).balanceOf(address(this));
        _balance1 = IERC20(_token1).balanceOf(address(this));

        _update(_balance0, _balance1, _reserve0, _reserve1);
        emit Burn(msg.sender, amount0, amount1, to);
    }

    /// @dev this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(!IPairFactory(factory).isPaused());
        require(amount0Out > 0 || amount1Out > 0, "IOA"); // Pair: INSUFFICIENT_OUTPUT_AMOUNT
        (uint _reserve0, uint _reserve1) =  (reserve0, reserve1);
        require(amount0Out < _reserve0 && amount1Out < _reserve1, "IL"); // Pair: INSUFFICIENT_LIQUIDITY

        uint _balance0;
        uint _balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        (address _token0, address _token1) = (token0, token1);
        require(to != _token0 && to != _token1, "IT"); // Pair: INVALID_TO
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IPairCallee(to).hook(msg.sender, amount0Out, amount1Out, data); // callback, used for flash loans
        _balance0 = IERC20(_token0).balanceOf(address(this));
        _balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = _balance0 > _reserve0 - amount0Out ? _balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = _balance1 > _reserve1 - amount1Out ? _balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, "IIA"); // Pair: INSUFFICIENT_INPUT_AMOUNT
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        (address _token0, address _token1) = (token0, token1);
        if (amount0In > 0) _update0(amount0In * IPairFactory(factory).getRealFee(address(this)) / 1e18); // accrue fees for token0 and move them out of pool
        if (amount1In > 0) _update1(amount1In * IPairFactory(factory).getRealFee(address(this)) / 1e18); // accrue fees for token1 and move them out of pool
        _balance0 = IERC20(_token0).balanceOf(address(this)); // since we removed tokens, we need to reconfirm balances, can also simply use previous balance - amountIn/ 10000 (1e18 in V3), but doing balanceOf again as safety check
        _balance1 = IERC20(_token1).balanceOf(address(this));
        // The curve, either x3y+y3x for stable pools, or x*y for volatile pools
        require(_k(_balance0, _balance1) >= _k(_reserve0, _reserve1), "K"); // Pair: K
        }

        _update(_balance0, _balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    /// @dev force balances to match reserves
    function skim(address to) external lock {
        (address _token0, address _token1) = (token0, token1);
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)) - (reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)) - (reserve1));
    }

    /// @dev force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }

    function _f(uint x0, uint y) internal pure returns (uint) {
        return x0*(y*y/1e18*y/1e18)/1e18+(x0*x0/1e18*x0/1e18)*y/1e18;
    }

    function _d(uint x0, uint y) internal pure returns (uint) {
        return 3*x0*(y*y/1e18)/1e18+(x0*x0/1e18*x0/1e18);
    }

    function _get_y(uint x0, uint xy, uint y) internal pure returns (uint) {
        for (uint i = 0; i < 255; i++) {
            uint y_prev = y;
            uint k = _f(x0, y);
            if (k < xy) {
                uint dy = (xy - k)*1e18/_d(x0, y);
                y = y + dy;
            } else {
                uint dy = (k - xy)*1e18/_d(x0, y);
                y = y - dy;
            }
            if (y > y_prev) {
                if (y - y_prev <= 1) {
                    return y;
                }
            } else {
                if (y_prev - y <= 1) {
                    return y;
                }
            }
        }
        return y;
    }

    function getAmountOut(uint amountIn, address tokenIn) external view returns (uint) {
        (uint _reserve0, uint _reserve1) = (reserve0, reserve1);
        amountIn -= amountIn * IPairFactory(factory).getRealFee(address(this)) / 1e18; // remove fee from amount received
        return _getAmountOut(amountIn, tokenIn, _reserve0, _reserve1);
    }

    function _getAmountOut(uint amountIn, address tokenIn, uint _reserve0, uint _reserve1) internal view returns (uint) {
        if (stable) {
            uint xy =  _k(_reserve0, _reserve1);
            _reserve0 = _reserve0 * 1e18 / decimals0;
            _reserve1 = _reserve1 * 1e18 / decimals1;
            (uint reserveA, uint reserveB) = tokenIn == token0 ? (_reserve0, _reserve1) : (_reserve1, _reserve0);
            amountIn = tokenIn == token0 ? amountIn * 1e18 / decimals0 : amountIn * 1e18 / decimals1;
            uint y = reserveB - _get_y(amountIn+reserveA, xy, reserveB);
            return y * (tokenIn == token0 ? decimals1 : decimals0) / 1e18;
        } else {
            (uint reserveA, uint reserveB) = tokenIn == token0 ? (_reserve0, _reserve1) : (_reserve1, _reserve0);
            return amountIn * reserveB / (reserveA + amountIn);
        }
    }

    function _k(uint x, uint y) internal view returns (uint) {
        if (stable) {
            uint _x = x * 1e18 / decimals0;
            uint _y = y * 1e18 / decimals1;
            uint _a = (_x * _y) / 1e18;
            uint _b = ((_x * _x) / 1e18 + (_y * _y) / 1e18);
            return _a * _b / 1e18;  // x3y+y3x >= k
        } else {
            return x * y; // xy >= k
        }
    }

    function _mint(address dst, uint amount) internal {
        _updateFor(dst); // balances must be updated on mint/burn/transfer
        totalSupply += amount;
        balanceOf[dst] += amount;
        emit Transfer(address(0), dst, amount);
    }

    function _burn(address dst, uint amount) internal {
        _updateFor(dst);
        totalSupply -= amount;
        balanceOf[dst] -= amount;
        emit Transfer(dst, address(0), amount);
    }

    function approve(address spender, uint amount) external returns (bool) {
        allowance[msg.sender][spender] = amount;

        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, "Pair: EXPIRED");
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
                keccak256(bytes(name)),
                keccak256(bytes("1")),
                block.chainid,
                address(this)
            )
        );
        bytes32 digest = keccak256(
            abi.encodePacked(
                "\x19\x01",
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, "Pair: INVALID_SIGNATURE");
        allowance[owner][spender] = value;

        emit Approval(owner, spender, value);
    }

    function transfer(address dst, uint amount) external returns (bool) {
        _transferTokens(msg.sender, dst, amount);
        return true;
    }

    function transferFrom(address src, address dst, uint amount) external returns (bool) {
        address spender = msg.sender;
        uint spenderAllowance = allowance[src][spender];

        if (spender != src && spenderAllowance != type(uint).max) {
            uint newAllowance = spenderAllowance - amount;
            allowance[src][spender] = newAllowance;

            emit Approval(src, spender, newAllowance);
        }

        _transferTokens(src, dst, amount);
        return true;
    }

    function _transferTokens(address src, address dst, uint amount) internal {
        _updateFor(src); // update fee position for src
        _updateFor(dst); // update fee position for dst

        balanceOf[src] -= amount;
        balanceOf[dst] += amount;

        emit Transfer(src, dst, amount);
    }

    function _safeTransfer(address token,address to,uint256 value) internal {
        require(token.code.length > 0, "Pair: invalid token");
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.transfer.selector, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), "Pair: transfer failed");
    }

}

// File: contracts/factories/PairFactory.sol


pragma solidity 0.8.9;



contract PairFactory is Initializable {

    bool public isPaused;
    address public pauser;
    address public pendingPauser;

    uint256 public stableFee;
    uint256 public volatileFee;
    address public feeManager;
    address public pendingFeeManager;

    mapping(address => mapping(address => mapping(bool => address))) public getPair;
    address[] public allPairs;
    mapping(address => bool) public isPair; // simplified check if its a pair, given that `stable` flag might not be available in peripherals

    address internal _temp0;
    address internal _temp1;
    bool internal _temp;

	/// VARIBALES ARE STATEFUL !  DONT MESS WITH THEM SLOTS !!
	/// ADDITIONAL SLOTS ATTACHED TO TAIL -- DONT DELETE ANY VARIABLES, ONLY ADD NEW ONES TO THE TAIL!!!
	/// (There are a limited number of slots! (almost infinte, dont worry;))
	/// v1.3.11
	//(Using a new variable instead at Tail to not cause slot collision, as this contract will be used as Equalizer's PairFactory implementation)
	uint256 public constant MAX_FEE = 1 ether;
    mapping(address => uint256) public feesOverrideStatic;
    mapping(address => address) public feesOverrideDynamic;



    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * Such events, much eventful
     * @notice Events are stateless, ordering doesn't matter.
     */
    event PairCreated(address indexed token0, address indexed token1, bool stable, address pair, uint);


    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * wow functions, very fun
     * @notice Functions are stateless, ordering doesn't matter.
     */

    function initialize() public initializer {
        pauser = msg.sender;
        isPaused = false;
        feeManager = msg.sender;
        stableFee = 0.0002 ether;
        volatileFee = 0.01 ether;
    }

    function allPairsLength() external view returns (uint) {
        return allPairs.length;
    }

    function setPauser(address _pauser) external {
        require(msg.sender == pauser, "PairFactory: not a pauser");
        pendingPauser = _pauser;
    }

    function acceptPauser() external {
        require(msg.sender == pendingPauser, "PairFactory: not a pendingPauser");
        pauser = pendingPauser;
    }

    function setPause(bool _state) external {
        require(msg.sender == pauser, "PairFactory: not a pauser");
        isPaused = _state;
    }

    function setFeeManager(address _feeManager) external {
        require(msg.sender == feeManager, "not fee manager");
        pendingFeeManager = _feeManager;
    }

    function acceptFeeManager() external {
        require(msg.sender == pendingFeeManager, "not pending fee manager");
        feeManager = pendingFeeManager;
    }

    function setFeeDefaults(uint256 _stable, uint256 _volatile) external {
        require(msg.sender == feeManager, "not fee manager");
        require(_stable < MAX_FEE, "fee too high");
        require(_volatile < MAX_FEE, "fee too high");
        require(_volatile * _stable != 0, "fee must be nonzero");
        stableFee = _stable;
        volatileFee = _volatile;
    }

    function setFeesOverrideStatic(address _pair, uint256 _fee) external {
        require(msg.sender == feeManager, "not fee manager");
        require(_fee < MAX_FEE, "fee too high");
        require(_fee != 0, "fee must be nonzero");
        feesOverrideStatic[_pair] = _fee;
    }

    function setFeesOverrideDynamic(address _pair, address _feeManager) external {
        require(msg.sender == feeManager, "not fee manager");
        require(AddressUpgradeable.isContract(_feeManager), "invalid fee manager");
        uint _fee = IFeeManager(_feeManager).getFee(_pair);
        require(_fee < MAX_FEE, "fee too high");
        require(_fee != 0, "fee must be nonzero");
        feesOverrideDynamic[_pair] = _feeManager;
    }

    function getRealFee(address _pair) public view returns(uint256) {
    	/// to get base fees, call `stableFee()` or `volatileFee()`
    	uint _fos = feesOverrideStatic[ _pair ];
    	if( _fos > 0 ) {
    		return _fos;
    	}
    	address _fod = feesOverrideDynamic[_pair];
    	if( _fod != address(0) ) {
    		return Math.min(
    			Math.max(
    				1,
    				IFeeManager(_fod).getFee(_pair)
    			),
    			1 ether - 1
    		);
    	}
    	return IPair(_pair).stable()
    		? stableFee
    		: volatileFee
    	;
    }

    /// This method was retired in v3.0.1
    /// This method was added in v1.3.11
    /// This method, when called by an actual Pair contract itself, would return the real fees.
    /// If simply read, it will show basic fees: stableFee, or the volatileFee.
    /// Please use the `getRealFee` method instead for your Analytics / Dapps / Usecases!
    /// If you want to request a flashloan from any Pair, please query `getRealFee` instead.
    /*
    function getFee(bool _stable) public view returns(uint256) {
    	address _c = msg.sender;
    	if(isPair[ _c ]) {
    		uint _fo = feesOverrides[ _c ];
    		if( _fo > 0 ) {
    			return _fo;
    		}
    		else return _stable ? stableFee : volatileFee;	//non-overridden fee is base fee.
    	}
        else return _stable ? stableFee : volatileFee;	//non-pair callers (_c) see base fee.
    }
    */

    // Past implementaion of `getFee() for 2° Fees reference
    function getFee(bool _stable) public view returns(uint256) {
        return _stable ? stableFee : volatileFee;
    }

    function pairCodeHash() external pure returns (bytes32) {
        return keccak256(type(Pair).creationCode);
    }

    function getInitializable() external view returns (address, address, bool) {
        return (_temp0, _temp1, _temp);
    }

    function createPair(address tokenA, address tokenB, bool stable) external returns (address pair) {
        require(tokenA != tokenB, "IA"); // Pair: IDENTICAL_ADDRESSES
        (address token0, address token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
        require(token0 != address(0), "ZA"); // Pair: ZERO_ADDRESS
        require(getPair[token0][token1][stable] == address(0), "PE"); // Pair: PAIR_EXISTS - single check is sufficient
        bytes32 salt = keccak256(abi.encodePacked(token0, token1, stable)); // notice salt includes stable as well, 3 parameters
        (_temp0, _temp1, _temp) = (token0, token1, stable);
        Pair newPair = new Pair{salt:salt}();
        newPair.initialize();
        pair = address(newPair);
        getPair[token0][token1][stable] = pair;
        getPair[token1][token0][stable] = pair; // populate mapping in the reverse direction
        allPairs.push(pair);
        isPair[pair] = true;
        emit PairCreated(token0, token1, stable, pair, allPairs.length);
    }

}

{
  "compilationTarget": {
    "Pair.sol": "Pair"
  },
  "evmVersion": "london",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}