// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @openzeppelin/contracts/access/Ownable2Step.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (access/Ownable2Step.sol)

pragma solidity ^0.8.0;

import "./Ownable.sol";

/**
 * @dev Contract module which provides access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership} and {acceptOwnership}.
 *
 * This module is used through inheritance. It will make available all functions
 * from parent (Ownable).
 */
abstract contract Ownable2Step is Ownable {
    address private _pendingOwner;

    event OwnershipTransferStarted(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Returns the address of the pending owner.
     */
    function pendingOwner() public view virtual returns (address) {
        return _pendingOwner;
    }

    /**
     * @dev Starts the ownership transfer of the contract to a new account. Replaces the pending transfer if there is one.
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual override onlyOwner {
        _pendingOwner = newOwner;
        emit OwnershipTransferStarted(owner(), newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`) and deletes any pending owner.
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual override {
        delete _pendingOwner;
        super._transferOwnership(newOwner);
    }

    /**
     * @dev The new owner accepts the ownership transfer.
     */
    function acceptOwnership() external {
        address sender = _msgSender();
        require(pendingOwner() == sender, "Ownable2Step: caller is not the new owner");
        _transferOwnership(sender);
    }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol



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

pragma solidity ^0.8.0;

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

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

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

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

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

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

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

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

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

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

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

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

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

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

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

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

        return true;
    }

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

        _beforeTokenTransfer(from, to, amount);

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

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// 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);
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

// File: @openzeppelin/contracts/utils/Context.sol



// 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;
    }
}

// File: @openzeppelin/contracts/utils/math/Math.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (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) {
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1);

            ///////////////////////////////////////////////
            // 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 10, 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 * 8) < value ? 1 : 0);
        }
    }
}

// File: contracts/gauges/AbsGauge.sol



// SPDX-License-Identifier: LGPL-3.0

pragma solidity 0.8.17;

import "@openzeppelin/contracts/access/Ownable2Step.sol";
import {Math} from "@openzeppelin/contracts/utils/math/Math.sol";
import "../interfaces/ILT.sol";
import "../interfaces/IGaugeController.sol";
import "../interfaces/IVotingEscrow.sol";
import "../interfaces/IMinter.sol";
import "light-lib/contracts/LibTime.sol";

abstract contract AbsGauge is Ownable2Step {
    event Deposit(address indexed provider, uint256 value);
    event Withdraw(address indexed provider, uint256 value);
    event UpdateLiquidityLimit(
        address user,
        uint256 originalBalance,
        uint256 originalSupply,
        uint256 workingBalance,
        uint256 workingSupply,
        uint256 votingBalance,
        uint256 votingTotal
    );
    event SetPermit2Address(address oldAddress, address newAddress);

    uint256 internal constant _TOKENLESS_PRODUCTION = 40;
    uint256 internal constant _DAY = 86400;
    uint256 internal constant _WEEK = _DAY * 7;

    bool public isKilled;
    // pool lp token
    address public lpToken;

    //Contracts
    IMinter public minter;
    // lt_token
    ILT public ltToken;
    //IERC20 public template;
    IGaugeController public controller;
    IVotingEscrow public votingEscrow;

    uint256 public futureEpochTime;

    mapping(address => uint256) public workingBalances;
    uint256 public workingSupply;

    // The goal is to be able to calculate ∫(rate * balance / totalSupply dt) from 0 till checkpoint
    // All values are kept in units of being multiplied by 1e18
    uint256 public period; //modified from "int256 public period" since it never be minus.

    // uint256[100000000000000000000000000000] public period_timestamp;
    mapping(uint256 => uint256) public periodTimestamp;

    //uint256[100_000_000_000_000_000_000_000_000_000] public periodTimestamp;

    // 1e18 * ∫(rate(t) / totalSupply(t) dt) from 0 till checkpoint
    // bump epoch when rate() changes
    mapping(uint256 => uint256) integrateInvSupply;

    // 1e18 * ∫(rate(t) / totalSupply(t) dt) from (last_action) till checkpoint
    mapping(address => uint256) public integrateInvSupplyOf;
    mapping(address => uint256) public integrateCheckpointOf;

    // ∫(balance * rate(t) / totalSupply(t) dt) from 0 till checkpoint
    // Units rate * t = already number of coins per address to issue
    mapping(address => uint256) public integrateFraction; //Mintable Token amount (include minted amount)

    uint256 public inflationRate;

    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;

    function _init(address _lpAddr, address _minter, address _owner) internal {
        require(_lpAddr != address(0), "CE000");
        require(_minter != address(0), "CE000");
        require(_owner != address(0), "CE000");
        require(!_initialized, "Initializable: contract is already initialized");
        _initialized = true;

        _transferOwnership(_owner);

        lpToken = _lpAddr;
        minter = IMinter(_minter);
        address _ltToken = minter.token();
        ltToken = ILT(_ltToken);
        controller = IGaugeController(minter.controller());
        votingEscrow = IVotingEscrow(controller.votingEscrow());
        periodTimestamp[0] = block.timestamp;
        inflationRate = ltToken.rate();
        futureEpochTime = ltToken.futureEpochTimeWrite();
    }

    /***
     * @notice Calculate limits which depend on the amount of lp Token per-user.
     *        Effectively it calculates working balances to apply amplification
     *        of LT production by LT
     * @param _addr User address
     * @param _l User's amount of liquidity (LP tokens)
     * @param _L Total amount of liquidity (LP tokens)
     */
    function _updateLiquidityLimit(address _addr, uint256 _l, uint256 _L) internal {
        // To be called after totalSupply is updated
        uint256 _votingBalance = votingEscrow.balanceOfAtTime(_addr, block.timestamp);
        uint256 _votingTotal = votingEscrow.totalSupplyAtTime(block.timestamp);

        uint256 _lim = (_l * _TOKENLESS_PRODUCTION) / 100;
        if (_votingTotal > 0) {
            // 0.4 * _l + 0.6 * _L * balance/total
            _lim += (_L * _votingBalance * (100 - _TOKENLESS_PRODUCTION)) / _votingTotal / 100;
        }

        _lim = Math.min(_l, _lim);
        uint256 _oldBal = workingBalances[_addr];
        workingBalances[_addr] = _lim;
        uint256 _workingSupply = workingSupply + _lim - _oldBal;
        workingSupply = _workingSupply;

        emit UpdateLiquidityLimit(_addr, _l, _L, _lim, _workingSupply, _votingBalance, _votingTotal);
    }

    //to avoid "stack too deep"
    struct CheckPointParameters {
        uint256 _period;
        uint256 _periodTime;
        uint256 _integrateInvSupply;
        uint256 rate;
        uint256 newRate;
        uint256 prevFutureEpoch;
    }

    /***
     * @notice Checkpoint for a user
     * @param _addr User address
     *
     *This function does,
     *1. Calculate Iis for All: Calc and add Iis for every week. Iis only increses over time.
     *2. Calculate Iu for _addr: Calc by (defferece between Iis(last time) and Iis(this time))* LP deposit amount of _addr(include  locking boost)
     *
     * working_supply & working_balance = total_supply & total_balance with  locking boost。
     * Check whitepaper about Iis and Iu.
     */
    function _checkpoint(address _addr) internal {
        CheckPointParameters memory _st;

        _st._period = period;
        _st._periodTime = periodTimestamp[_st._period];
        _st._integrateInvSupply = integrateInvSupply[_st._period];
        _st.rate = inflationRate;
        _st.newRate = _st.rate;
        _st.prevFutureEpoch = futureEpochTime;
        if (_st.prevFutureEpoch >= _st._periodTime) {
            //update future_epoch_time & inflation_rate
            futureEpochTime = ltToken.futureEpochTimeWrite();
            _st.newRate = ltToken.rate();
            inflationRate = _st.newRate;
        }
        controller.checkpointGauge(address(this));

        if (isKilled) {
            // Stop distributing inflation as soon as killed
            _st.rate = 0;
        }

        // Update integral of 1/supply
        if (block.timestamp > _st._periodTime) {
            uint256 _workingSupply = workingSupply;
            uint256 _prevWeekTime = _st._periodTime;
            uint256 _weekTime = Math.min(LibTime.timesRoundedByWeek(_st._periodTime + _WEEK), block.timestamp);
            for (uint256 i; i < 500; i++) {
                uint256 _dt = _weekTime - _prevWeekTime;
                uint256 _w = controller.gaugeRelativeWeight(address(this), LibTime.timesRoundedByWeek(_prevWeekTime));

                if (_workingSupply > 0) {
                    if (_st.prevFutureEpoch >= _prevWeekTime && _st.prevFutureEpoch < _weekTime) {
                        // If we went across one or multiple epochs, apply the rate
                        // of the first epoch until it ends, and then the rate of
                        // the last epoch.
                        // If more than one epoch is crossed - the gauge gets less,
                        // but that'd meen it wasn't called for more than 1 year
                        _st._integrateInvSupply += (_st.rate * _w * (_st.prevFutureEpoch - _prevWeekTime)) / _workingSupply;
                        _st.rate = _st.newRate;
                        _st._integrateInvSupply += (_st.rate * _w * (_weekTime - _st.prevFutureEpoch)) / _workingSupply;
                    } else {
                        _st._integrateInvSupply += (_st.rate * _w * _dt) / _workingSupply;
                    }
                    // On precisions of the calculation
                    // rate ~= 10e18
                    // last_weight > 0.01 * 1e18 = 1e16 (if pool weight is 1%)
                    // _working_supply ~= TVL * 1e18 ~= 1e26 ($100M for example)
                    // The largest loss is at dt = 1
                    // Loss is 1e-9 - acceptable
                }
                if (_weekTime == block.timestamp) {
                    break;
                }
                _prevWeekTime = _weekTime;
                _weekTime = Math.min(_weekTime + _WEEK, block.timestamp);
            }
        }

        _st._period += 1;
        period = _st._period;
        periodTimestamp[_st._period] = block.timestamp;
        integrateInvSupply[_st._period] = _st._integrateInvSupply;

        uint256 _workingBalance = workingBalances[_addr];
        // Update user-specific integrals
        // Calc the ΔIu of _addr and add it to Iu.
        integrateFraction[_addr] += (_workingBalance * (_st._integrateInvSupply - integrateInvSupplyOf[_addr])) / 10 ** 18;
        integrateInvSupplyOf[_addr] = _st._integrateInvSupply;
        integrateCheckpointOf[_addr] = block.timestamp;
    }

    /***
     * @notice Record a checkpoint for `_addr`
     * @param _addr User address
     * @return bool success
     */
    function userCheckpoint(address _addr) external returns (bool) {
        require((msg.sender == _addr) || (msg.sender == address(minter)), "GP000");
        _checkpoint(_addr);
        _updateLiquidityLimit(_addr, lpBalanceOf(_addr), lpTotalSupply());
        return true;
    }

    /***
     * @notice Get the number of claimable tokens per user
     * @dev This function should be manually changed to "view" in the ABI
     * @return uint256 number of claimable tokens per user
     */
    function claimableTokens(address _addr) external returns (uint256) {
        _checkpoint(_addr);
        return (integrateFraction[_addr] - minter.minted(_addr, address(this)));
    }

    /***
     * @notice Kick `_addr` for abusing their boost
     * @dev Only if either they had another voting event, or their voting escrow lock expired
     * @param _addr Address to kick
     */
    function kick(address _addr) external {
        uint256 _tLast = integrateCheckpointOf[_addr];
        uint256 _tVe = votingEscrow.userPointHistoryTs(_addr, votingEscrow.userPointEpoch(_addr));
        uint256 _balance = lpBalanceOf(_addr);

        require(votingEscrow.balanceOfAtTime(_addr, block.timestamp) == 0 || _tVe > _tLast, "GP001");
        require(workingBalances[_addr] > (_balance * _TOKENLESS_PRODUCTION) / 100, "GP001");

        _checkpoint(_addr);
        _updateLiquidityLimit(_addr, lpBalanceOf(_addr), lpTotalSupply());
    }

    function integrateCheckpoint() external view returns (uint256) {
        return periodTimestamp[period];
    }

    /***
     * @notice Set the killed status for this contract
     * @dev When killed, the gauge always yields a rate of 0 and so cannot mint LT
     * @param _is_killed Killed status to set
     */
    function setKilled(bool _isKilled) external onlyOwner {
        isKilled = _isKilled;
    }

    /***
     * @notice The total amount of LP tokens that are currently deposited into the Gauge.
     */
    function lpBalanceOf(address _addr) public view virtual returns (uint256);

    /***
     * @notice The total amount of LP tokens that are currently deposited into the Gauge.
     */
    function lpTotalSupply() public view virtual returns (uint256);
}

// File: contracts/interfaces/IGaugeController.sol



// SPDX-License-Identifier: LGPL-3.0

pragma solidity 0.8.17;

interface IGaugeController {
    struct Point {
        uint256 bias;
        uint256 slope;
    }

    struct VotedSlope {
        uint256 slope;
        uint256 power;
        uint256 end;
    }

    struct UserPoint {
        uint256 bias;
        uint256 slope;
        uint256 ts;
        uint256 blk;
    }

    event AddType(string name, int128 type_id);

    event NewTypeWeight(int128 indexed type_id, uint256 time, uint256 weight, uint256 total_weight);

    event NewGaugeWeight(address indexed gauge_address, uint256 time, uint256 weight, uint256 total_weight);

    event VoteForGauge(address indexed user, address indexed gauge_address, uint256 time, uint256 weight);

    event NewGauge(address indexed gauge_address, int128 gauge_type, uint256 weight);

    /**
     * @notice Get gauge type for address
     *  @param _addr Gauge address
     * @return Gauge type id
     */
    function gaugeTypes(address _addr) external view returns (int128);

    /**
     * @notice Add gauge `addr` of type `gauge_type` with weight `weight`
     * @param addr Gauge address
     * @param gaugeType Gauge type
     * @param weight Gauge weight
     */
    function addGauge(address addr, int128 gaugeType, uint256 weight) external;

    /**
     * @notice Checkpoint to fill data common for all gauges
     */
    function checkpoint() external;

    /**
     * @notice Checkpoint to fill data for both a specific gauge and common for all gauge
     * @param addr Gauge address
     */
    function checkpointGauge(address addr) external;

    /**
     * @notice Get Gauge relative weight (not more than 1.0) normalized to 1e18(e.g. 1.0 == 1e18). Inflation which will be received by
     * it is inflation_rate * relative_weight / 1e18
     * @param gaugeAddress Gauge address
     * @param time Relative weight at the specified timestamp in the past or present
     * @return Value of relative weight normalized to 1e18
     */
    function gaugeRelativeWeight(address gaugeAddress, uint256 time) external view returns (uint256);

    /**
     *  @notice Get gauge weight normalized to 1e18 and also fill all the unfilled values for type and gauge records
     * @dev Any address can call, however nothing is recorded if the values are filled already
     * @param gaugeAddress Gauge address
     * @param time Relative weight at the specified timestamp in the past or present
     * @return Value of relative weight normalized to 1e18
     */
    function gaugeRelativeWeightWrite(address gaugeAddress, uint256 time) external returns (uint256);

    /**
     * @notice Add gauge type with name `_name` and weight `weight`
     * @dev only owner call
     * @param _name Name of gauge type
     * @param weight Weight of gauge type
     */
    function addType(string memory _name, uint256 weight) external;

    /**
     * @notice Change gauge type `type_id` weight to `weight`
     * @dev only owner call
     * @param type_id Gauge type id
     * @param weight New Gauge weight
     */
    function changeTypeWeight(int128 type_id, uint256 weight) external;

    /**
     * @notice Change weight of gauge `addr` to `weight`
     * @param gaugeAddress `Gauge` contract address
     * @param weight New Gauge weight
     */
    function changeGaugeWeight(address gaugeAddress, uint256 weight) external;

    /**
     * @notice Allocate voting power for changing pool weights
     * @param gaugeAddress Gauge which `msg.sender` votes for
     * @param userWeight Weight for a gauge in bps (units of 0.01%). Minimal is 0.01%. Ignored if 0.
     *        example: 10%=1000,3%=300,0.01%=1,100%=10000
     */
    function voteForGaugeWeights(address gaugeAddress, uint256 userWeight) external;

    /**
     * @notice Get current gauge weight
     * @param addr Gauge address
     * @return Gauge weight
     */

    function getGaugeWeight(address addr) external view returns (uint256);

    /**
     * @notice Get current type weight
     * @param type_id Type id
     * @return Type weight
     */
    function getTypeWeight(int128 type_id) external view returns (uint256);

    /**
     * @notice Get current total (type-weighted) weight
     * @return Total weight
     */
    function getTotalWeight() external view returns (uint256);

    /**
     * @notice Get sum of gauge weights per type
     * @param type_id Type id
     * @return Sum of gauge weights
     */
    function getWeightsSumPreType(int128 type_id) external view returns (uint256);

    function votingEscrow() external view returns (address);
}

// File: contracts/interfaces/ILT.sol



// SPDX-License-Identifier: LGPL-3.0

pragma solidity 0.8.17;

interface ILT {
    /**
     * @dev Emitted when LT inflation rate update
     *
     * Note once a year
     */
    event UpdateMiningParameters(uint256 time, uint256 rate, uint256 supply);

    /**
     * @dev Emitted when set LT minter,can set the minter only once, at creation
     */
    event SetMinter(address indexed minter);

    function rate() external view returns (uint256);

    /**
     * @notice Update mining rate and supply at the start of the epoch
     * @dev   Callable by any address, but only once per epoch
     *        Total supply becomes slightly larger if this function is called late
     */
    function updateMiningParameters() external;

    /**
     * @notice Get timestamp of the next mining epoch start while simultaneously updating mining parameters
     * @return Timestamp of the next epoch
     */
    function futureEpochTimeWrite() external returns (uint256);

    /**
     * @notice Current number of tokens in existence (claimed or unclaimed)
     */
    function availableSupply() external view returns (uint256);

    /**
     * @notice How much supply is mintable from start timestamp till end timestamp
     * @param start Start of the time interval (timestamp)
     * @param end End of the time interval (timestamp)
     * @return Tokens mintable from `start` till `end`
     */
    function mintableInTimeframe(uint256 start, uint256 end) external view returns (uint256);

    /**
     *  @notice Set the minter address
     *  @dev Only callable once, when minter has not yet been set
     *  @param _minter Address of the minter
     */
    function setMinter(address _minter) external;

    /**
     *  @notice Mint `value` tokens and assign them to `to`
     *   @dev Emits a Transfer event originating from 0x00
     *   @param to The account that will receive the created tokens
     *   @param value The amount that will be created
     *   @return bool success
     */
    function mint(address to, uint256 value) external returns (bool);

    /**
     * @notice Burn `value` tokens belonging to `msg.sender`
     * @dev Emits a Transfer event with a destination of 0x00
     * @param value The amount that will be burned
     * @return bool success
     */
    function burn(uint256 value) external returns (bool);
}

// File: contracts/interfaces/IMinter.sol



// SPDX-License-Identifier: LGPL-3.0
pragma solidity 0.8.17;

interface IMinter {
    function token() external view returns (address);

    function controller() external view returns (address);

    function minted(address user, address gauge) external view returns (uint256);

    function mint(address gaugeAddress) external;
}

// File: contracts/interfaces/IStaking.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

interface IStaking {
    event Staking(address indexed user, uint256 amount);
    event Unstaking(address indexed user, uint256 amount);
    event Redeem(address indexed user, uint256 amount);
    event RewardsAccrued(address user, uint256 amount);
    event RewardsClaimed(address indexed user, uint256 amount);

    function staking(uint256 amount, uint256 nonce, uint256 deadline, bytes memory signature) external returns (bool);

    function redeemAll() external returns (uint256);
}

// File: contracts/interfaces/IVotingEscrow.sol



// SPDX-License-Identifier: LGPL-3.0
pragma solidity 0.8.17;

interface IVotingEscrow {
    struct Point {
        int256 bias;
        int256 slope;
        uint256 ts;
        uint256 blk;
    }

    struct LockedBalance {
        int256 amount;
        uint256 end;
    }

    event Deposit(
        address indexed provider,
        address indexed beneficiary,
        uint256 value,
        uint256 afterAmount,
        uint256 indexed locktime,
        uint256 _type,
        uint256 ts
    );
    event Withdraw(address indexed provider, uint256 value, uint256 ts);

    event Supply(uint256 prevSupply, uint256 supply);

    event SetSmartWalletChecker(address sender, address indexed newChecker, address oldChecker);

    event SetPermit2Address(address oldAddress, address newAddress);

    /***
     * @dev Get the most recently recorded rate of voting power decrease for `_addr`
     * @param _addr Address of the user wallet
     * @return Value of the slope
     */
    function getLastUserSlope(address _addr) external view returns (int256);

    /***
     * @dev Get the timestamp for checkpoint `_idx` for `_addr`
     * @param _addr User wallet address
     * @param _idx User epoch number
     * @return Epoch time of the checkpoint
     */
    function userPointHistoryTs(address _addr, uint256 _idx) external view returns (uint256);

    /***
     * @dev Get timestamp when `_addr`'s lock finishes
     * @param _addr User wallet
     * @return Epoch time of the lock end
     */
    function lockedEnd(address _addr) external view returns (uint256);

    function createLock(uint256 _value, uint256 _unlockTime, uint256 nonce, uint256 deadline, bytes memory signature) external;

    function createLockFor(
        address _beneficiary,
        uint256 _value,
        uint256 _unlockTime,
        uint256 nonce,
        uint256 deadline,
        bytes memory signature
    ) external;

    function increaseAmount(uint256 _value, uint256 nonce, uint256 deadline, bytes memory signature) external;

    function increaseAmountFor(address _beneficiary, uint256 _value, uint256 nonce, uint256 deadline, bytes memory signature) external;

    function increaseUnlockTime(uint256 _unlockTime) external;

    function checkpointSupply() external;

    function withdraw() external;

    function epoch() external view returns (uint256);

    function getUserPointHistory(address _userAddress, uint256 _index) external view returns (Point memory);

    function supplyPointHistory(uint256 _index) external view returns (int256 bias, int256 slope, uint256 ts, uint256 blk);

    /***
     * @notice Get the current voting power for `msg.sender`
     * @dev Adheres to the ERC20 `balanceOf` interface for Aragon compatibility
     * @param _addr User wallet address
     * @param _t Epoch time to return voting power at
     * @return User voting power
     * @dev return the present voting power if _t is 0
     */
    function balanceOfAtTime(address _addr, uint256 _t) external view returns (uint256);

    function totalSupply() external view returns (uint256);

    function totalSupplyAtTime(uint256 _t) external view returns (uint256);

    function userPointEpoch(address _user) external view returns (uint256);
}

// File: contracts/StakingHOPE.sol



// SPDX-License-Identifier: LGPL-3.0

pragma solidity 0.8.17;

import "./interfaces/IStaking.sol";
import "./gauges/AbsGauge.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import {TransferHelper} from "light-lib/contracts/TransferHelper.sol";

contract StakingHOPE is IStaking, ERC20, AbsGauge {
    uint256 internal constant _LOCK_TIME = 28;

    // permit2 contract
    address public permit2Address;

    struct UnstakingOrderDetail {
        uint256 amount;
        uint256 redeemTime;
        bool redeemExecuted;
    }

    struct UnstakingOrderSummary {
        uint256 notRedeemAmount;
        uint256 index;
        mapping(uint256 => UnstakingOrderDetail) orderMap;
    }

    uint256 public totalNotRedeemAmount;
    mapping(address => UnstakingOrderSummary) public unstakingMap;
    mapping(uint256 => uint256) public unstakingDayHistory;
    uint256 private _unstakeTotal;

    constructor(address _stakedToken, address _minter, address _permit2Address) ERC20("staked HOPE", "stHOPE") {
        require(_stakedToken != address(0), "CE000");
        require(_permit2Address != address(0), "CE000");

        _init(_stakedToken, _minter, _msgSender());

        permit2Address = _permit2Address;
    }

    /***
     * @notice Stake HOPE to get stHOPE
     *
     * @param amount
     * @param nonce
     * @param deadline
     * @param signature
     */
    function staking(uint256 amount, uint256 nonce, uint256 deadline, bytes memory signature) external override returns (bool) {
        require(amount != 0, "CE002");

        address staker = _msgSender();
        // checking amount
        uint256 balanceOfUser = IERC20(lpToken).balanceOf(staker);
        require(balanceOfUser >= amount, "CE002");
        TransferHelper.doTransferIn(permit2Address, lpToken, amount, staker, nonce, deadline, signature);

        _checkpoint(staker);

        _mint(staker, amount);

        _updateLiquidityLimit(staker, lpBalanceOf(staker), lpTotalSupply());

        emit Staking(staker, amount);
        return true;
    }

    /***
     * @notice unstaking the staked amount
     * The unstaking process takes 28 days to complete. During this period,
     *  the unstaked $HOPE cannot be traded, and no staking rewards are accrued.
     *
     * @param
     * @return
     */
    function unstaking(uint256 amount) external {
        require(amount != 0, "CE002");

        address staker = _msgSender();
        // checking amount
        uint256 balanceOfUser = lpBalanceOf(staker);
        require(balanceOfUser >= amount, "CE002");

        _checkpoint(staker);

        uint256 nextDayTime = ((block.timestamp + _DAY) / _DAY) * _DAY;
        // lock 28 days
        uint256 redeemTime = nextDayTime + _DAY * _LOCK_TIME;

        unstakingDayHistory[nextDayTime] = unstakingDayHistory[nextDayTime] + amount;
        _unstakeTotal = _unstakeTotal + amount;

        UnstakingOrderSummary storage summaryMap = unstakingMap[staker];

        summaryMap.notRedeemAmount = summaryMap.notRedeemAmount + amount;
        summaryMap.index = summaryMap.index + 1;
        summaryMap.orderMap[summaryMap.index] = UnstakingOrderDetail(amount, redeemTime, false);
        totalNotRedeemAmount += amount;

        _updateLiquidityLimit(staker, lpBalanceOf(staker), lpTotalSupply());
        emit Unstaking(staker, amount);
    }

    /***
     * @notice get unstaking amount
     *
     * @return
     */
    function unstakingBalanceOf(address _addr) public view returns (uint256) {
        uint256 _unstakingAmount = 0;
        UnstakingOrderSummary storage summaryMap = unstakingMap[_addr];
        for (uint256 _index = summaryMap.index; _index > 0; _index--) {
            if (summaryMap.orderMap[_index].redeemExecuted) {
                break;
            }
            if (block.timestamp < summaryMap.orderMap[_index].redeemTime) {
                _unstakingAmount += summaryMap.orderMap[_index].amount;
            }
        }
        return _unstakingAmount;
    }

    function unstakingTotal() public view returns (uint256) {
        uint256 _unstakingTotal = 0;

        uint256 nextDayTime = ((block.timestamp + _DAY) / _DAY) * _DAY;
        for (uint256 i = 0; i < _LOCK_TIME; i++) {
            _unstakingTotal += unstakingDayHistory[nextDayTime - _DAY * i];
        }
        return _unstakingTotal;
    }

    /***
     * @notice get can redeem amount
     *
     * @param
     * @return
     */
    function unstakedBalanceOf(address _addr) public view returns (uint256) {
        uint256 amountToRedeem = 0;
        UnstakingOrderSummary storage summaryMap = unstakingMap[_addr];
        for (uint256 _index = summaryMap.index; _index > 0; _index--) {
            if (summaryMap.orderMap[_index].redeemExecuted) {
                break;
            }
            if (block.timestamp >= summaryMap.orderMap[_index].redeemTime) {
                amountToRedeem += summaryMap.orderMap[_index].amount;
            }
        }
        return amountToRedeem;
    }

    function unstakedTotal() external view returns (uint256) {
        return _unstakeTotal - unstakingTotal();
    }

    /***
     * @notice Redeem all amounts to your account
     *
     * @param
     * @return
     */
    function redeemAll() external override returns (uint256) {
        address redeemer = _msgSender();
        uint256 amountToRedeem = unstakedBalanceOf(redeemer);
        require(amountToRedeem != 0, "CE002");

        _checkpoint(redeemer);

        UnstakingOrderSummary storage summaryMap = unstakingMap[redeemer];
        for (uint256 _index = summaryMap.index; _index > 0; _index--) {
            if (summaryMap.orderMap[_index].redeemExecuted) {
                break;
            }
            if (block.timestamp >= summaryMap.orderMap[_index].redeemTime) {
                uint256 amount = summaryMap.orderMap[_index].amount;
                summaryMap.orderMap[_index].redeemExecuted = true;
                summaryMap.notRedeemAmount = summaryMap.notRedeemAmount - amount;
                totalNotRedeemAmount -= amount;
            }
        }

        _burn(redeemer, amountToRedeem);
        TransferHelper.doTransferOut(lpToken, redeemer, amountToRedeem);
        _updateLiquidityLimit(redeemer, lpBalanceOf(redeemer), lpTotalSupply());

        _unstakeTotal = _unstakeTotal - amountToRedeem;

        emit Redeem(redeemer, amountToRedeem);
        return amountToRedeem;
    }

    /***
     * @notice redeem amount by index(Prevent the number of unstaking too much to redeem)
     *
     * @param maxIndex
     * @return
     */
    function redeemByMaxIndex(uint256 maxIndex) external returns (uint256) {
        address redeemer = _msgSender();

        uint256 allToRedeemAmount = unstakedBalanceOf(redeemer);
        require(allToRedeemAmount != 0, "CE002");

        uint256 amountToRedeem = 0;
        _checkpoint(redeemer);

        UnstakingOrderSummary storage summaryMap = unstakingMap[redeemer];
        uint256 indexCount = 0;
        for (uint256 _index = 1; _index <= summaryMap.index; _index++) {
            if (indexCount >= maxIndex) {
                break;
            }
            if (block.timestamp >= summaryMap.orderMap[_index].redeemTime && !summaryMap.orderMap[_index].redeemExecuted) {
                uint256 amount = summaryMap.orderMap[_index].amount;
                amountToRedeem += amount;
                summaryMap.orderMap[_index].redeemExecuted = true;
                summaryMap.notRedeemAmount = summaryMap.notRedeemAmount - amount;
                totalNotRedeemAmount -= amount;
                indexCount++;
            }
        }

        if (amountToRedeem > 0) {
            _burn(redeemer, amountToRedeem);
            TransferHelper.doTransferOut(lpToken, redeemer, amountToRedeem);
            _updateLiquidityLimit(redeemer, lpBalanceOf(redeemer), lpTotalSupply());

            _unstakeTotal = _unstakeTotal - amountToRedeem;
            emit Redeem(redeemer, amountToRedeem);
        }
        return amountToRedeem;
    }

    /**
     * @dev Set permit2 address, onlyOwner
     * @param newAddress New permit2 address
     */
    function setPermit2Address(address newAddress) external onlyOwner {
        require(newAddress != address(0), "CE000");
        address oldAddress = permit2Address;
        permit2Address = newAddress;
        emit SetPermit2Address(oldAddress, newAddress);
    }

    function lpBalanceOf(address _addr) public view override returns (uint256) {
        return super.balanceOf(_addr) - unstakingMap[_addr].notRedeemAmount;
    }

    function lpTotalSupply() public view override returns (uint256) {
        return super.totalSupply() - totalNotRedeemAmount;
    }

    /***
     * @notice Transfers Gauge deposit (stHOPE) from the caller to _to.
     *
     * @param to
     * @param amount
     * @return bool
     */
    function transfer(address _to, uint256 _amount) public virtual override returns (bool) {
        address owner = _msgSender();
        uint256 fromBalance = lpBalanceOf(owner);
        require(fromBalance >= _amount, "CE002");

        _checkpoint(owner);
        _checkpoint(_to);

        bool result = super.transfer(_to, _amount);

        _updateLiquidityLimit(owner, lpBalanceOf(owner), lpTotalSupply());
        _updateLiquidityLimit(_to, lpBalanceOf(_to), lpTotalSupply());
        return result;
    }

    /***
     * @notice Tansfers a Gauge deposit between _from and _to.
     *
     * @param from
     * @param to
     * @param amount
     * @return bool
     */
    function transferFrom(address _from, address _to, uint256 _amount) public override returns (bool) {
        uint256 fromBalance = lpBalanceOf(_from);
        require(fromBalance >= _amount, "CE002");

        _checkpoint(_from);
        _checkpoint(_to);

        bool result = super.transferFrom(_from, _to, _amount);

        _updateLiquidityLimit(_from, lpBalanceOf(_from), lpTotalSupply());
        _updateLiquidityLimit(_to, lpBalanceOf(_to), lpTotalSupply());
        return result;
    }
}

// File: light-lib/contracts/IERC20.sol



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

pragma solidity 0.8.17;

/**
 * @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);
}

// File: light-lib/contracts/IPermit2.sol



// SPDX-License-Identifier: LGPL-3.0

pragma solidity 0.8.17;

interface IPermit2 {
    /// @notice The token and amount details for a transfer signed in the permit transfer signature
    struct TokenPermissions {
        // ERC20 token address
        address token;
        // the maximum amount that can be spent
        uint256 amount;
    }

    /// @notice The signed permit message for a single token transfer
    struct PermitTransferFrom {
        TokenPermissions permitted;
        // a unique value for every token owner's signature to prevent signature replays
        uint256 nonce;
        // deadline on the permit signature
        uint256 deadline;
    }

    /// @notice Specifies the recipient address and amount for batched transfers.
    /// @dev Recipients and amounts correspond to the index of the signed token permissions array.
    /// @dev Reverts if the requested amount is greater than the permitted signed amount.
    struct SignatureTransferDetails {
        // recipient address
        address to;
        // spender requested amount
        uint256 requestedAmount;
    }

    /// @notice Used to reconstruct the signed permit message for multiple token transfers
    /// @dev Do not need to pass in spender address as it is required that it is msg.sender
    /// @dev Note that a user still signs over a spender address
    struct PermitBatchTransferFrom {
        // the tokens and corresponding amounts permitted for a transfer
        TokenPermissions[] permitted;
        // a unique value for every token owner's signature to prevent signature replays
        uint256 nonce;
        // deadline on the permit signature
        uint256 deadline;
    }

    /// @notice A map from token owner address and a caller specified word index to a bitmap. Used to set bits in the bitmap to prevent against signature replay protection
    /// @dev Uses unordered nonces so that permit messages do not need to be spent in a certain order
    /// @dev The mapping is indexed first by the token owner, then by an index specified in the nonce
    /// @dev It returns a uint256 bitmap
    /// @dev The index, or wordPosition is capped at type(uint248).max
    function nonceBitmap(address, uint256) external view returns (uint256);

    /// @notice Transfers a token using a signed permit message
    /// @dev Reverts if the requested amount is greater than the permitted signed amount
    /// @param permit The permit data signed over by the owner
    /// @param owner The owner of the tokens to transfer
    /// @param transferDetails The spender's requested transfer details for the permitted token
    /// @param signature The signature to verify
    function permitTransferFrom(
        PermitTransferFrom memory permit,
        SignatureTransferDetails calldata transferDetails,
        address owner,
        bytes calldata signature
    ) external;

    /// @notice Transfers a token using a signed permit message
    /// @notice Includes extra data provided by the caller to verify signature over
    /// @dev The witness type string must follow EIP712 ordering of nested structs and must include the TokenPermissions type definition
    /// @dev Reverts if the requested amount is greater than the permitted signed amount
    /// @param permit The permit data signed over by the owner
    /// @param owner The owner of the tokens to transfer
    /// @param transferDetails The spender's requested transfer details for the permitted token
    /// @param witness Extra data to include when checking the user signature
    /// @param witnessTypeString The EIP-712 type definition for remaining string stub of the typehash
    /// @param signature The signature to verify
    function permitWitnessTransferFrom(
        PermitTransferFrom memory permit,
        SignatureTransferDetails calldata transferDetails,
        address owner,
        bytes32 witness,
        string calldata witnessTypeString,
        bytes calldata signature
    ) external;

    /// @notice Transfers multiple tokens using a signed permit message
    /// @param permit The permit data signed over by the owner
    /// @param owner The owner of the tokens to transfer
    /// @param transferDetails Specifies the recipient and requested amount for the token transfer
    /// @param signature The signature to verify
    function permitTransferFrom(
        PermitBatchTransferFrom memory permit,
        SignatureTransferDetails[] calldata transferDetails,
        address owner,
        bytes calldata signature
    ) external;

    /// @notice Transfers multiple tokens using a signed permit message
    /// @dev The witness type string must follow EIP712 ordering of nested structs and must include the TokenPermissions type definition
    /// @notice Includes extra data provided by the caller to verify signature over
    /// @param permit The permit data signed over by the owner
    /// @param owner The owner of the tokens to transfer
    /// @param transferDetails Specifies the recipient and requested amount for the token transfer
    /// @param witness Extra data to include when checking the user signature
    /// @param witnessTypeString The EIP-712 type definition for remaining string stub of the typehash
    /// @param signature The signature to verify
    function permitWitnessTransferFrom(
        PermitBatchTransferFrom memory permit,
        SignatureTransferDetails[] calldata transferDetails,
        address owner,
        bytes32 witness,
        string calldata witnessTypeString,
        bytes calldata signature
    ) external;

    /// @notice Invalidates the bits specified in mask for the bitmap at the word position
    /// @dev The wordPos is maxed at type(uint248).max
    /// @param wordPos A number to index the nonceBitmap at
    /// @param mask A bitmap masked against msg.sender's current bitmap at the word position
    function invalidateUnorderedNonces(uint256 wordPos, uint256 mask) external;
}

// File: light-lib/contracts/LibTime.sol



// SPDX-License-Identifier: GPL-3.0

pragma solidity 0.8.17;

library LibTime {

    // 7 * 86400 seconds - all future times are rounded by week
    uint256 public constant DAY = 86400;
    uint256 public constant WEEK = DAY * 7;

    /**
     * @dev times are rounded by week
     * @param time time
     */
    function timesRoundedByWeek(uint256 time) internal pure returns (uint256) {
        return (time / WEEK) * WEEK;
    }
}
// File: light-lib/contracts/TransferHelper.sol



// SPDX-License-Identifier: LGPL-3.0

pragma solidity 0.8.17;

import "./IERC20.sol";
import "./IPermit2.sol";

library TransferHelper {
    
    /**
     * @dev Similar to EIP20 transfer, except it handles a False result from `transferFrom` and reverts in that case.
     *      This will revert due to insufficient balance or insufficient allowance.
     *      This function returns the actual amount received,
     *      which may be less than `amount` if there is a fee attached to the transfer.
     *
     *      Note: This wrapper safely handles non-standard ERC-20 tokens that do not return a value.
     */
    function doTransferFrom(address tokenAddress, address from, address to, uint256 amount) internal returns(uint256) {
        IERC20 token = IERC20(tokenAddress);
        uint256 balanceBefore = token.balanceOf(to);
        safeTransferFrom(token, from, to, amount);
        uint256 balanceAfter = token.balanceOf(to);
        uint256 actualAmount = balanceAfter - balanceBefore;
        assert(actualAmount <= amount);
        return actualAmount;
    }

    /**
     * @dev transfer with permit2
     */
    function doTransferIn(
        address permit2Address,
        address tokenAddress,
        uint256 _value,
        address from,
        uint256 nonce,
        uint256 deadline,
        bytes memory signature
    ) internal returns (uint256) {
        IPermit2.PermitTransferFrom memory permit = IPermit2.PermitTransferFrom({
            permitted: IPermit2.TokenPermissions({token: tokenAddress, amount: _value}),
            nonce: nonce,
            deadline: deadline
        });
        IPermit2.SignatureTransferDetails memory transferDetails = IPermit2.SignatureTransferDetails({
            to: address(this),
            requestedAmount: _value
        });
        // Read from storage once
        IERC20 token = IERC20(permit.permitted.token);
        uint256 balanceBefore = token.balanceOf(transferDetails.to);
        if (nonce == 0 && deadline == 0) {
            safeTransferFrom(token, from, transferDetails.to, transferDetails.requestedAmount);
        } else {
            IPermit2(permit2Address).permitTransferFrom(permit, transferDetails, from, signature);
        }
        // Calculate the amount that was *actually* transferred
        uint256 balanceAfter = IERC20(permit.permitted.token).balanceOf(address(this));
        uint256 actualAmount = balanceAfter - balanceBefore;
        assert(actualAmount <= transferDetails.requestedAmount);
        
        return actualAmount;
    }

    /**
     * @dev Similar to EIP20 transfer, except it handles a False success from `transfer` and returns an explanatory
     *      error code rather than reverting. If caller has not called checked protocol's balance, this may revert due to
     *      insufficient cash held in this contract. If caller has checked protocol's balance prior to this call, and verified
     *      it is >= amount, this should not revert in normal conditions.
     *
     *      Note: This wrapper safely handles non-standard ERC-20 tokens that do not return a value.
     */
    function doTransferOut(address tokenAddress, address to, uint256 amount) internal returns(uint256) {
        IERC20 token = IERC20(tokenAddress);
        uint256 balanceBefore = token.balanceOf(to);
        safeTransfer(token, to, amount);
        uint256 balanceAfter = token.balanceOf(to);
        uint256 actualAmount = balanceAfter - balanceBefore;
        assert(actualAmount <= amount);
        return actualAmount;
    }

    function doApprove(address tokenAddress, address to, uint256 amount) internal {
        IERC20 token = IERC20(tokenAddress);
        safeApprove(token, to, amount);
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 amount
    ) internal {
        bool success;

        /// @solidity memory-safe-assembly
        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata into memory, beginning with the function selector.
            mstore(freeMemoryPointer, 0x23b872dd00000000000000000000000000000000000000000000000000000000)
            mstore(add(freeMemoryPointer, 4), from) // Append the "from" argument.
            mstore(add(freeMemoryPointer, 36), to) // Append the "to" argument.
            mstore(add(freeMemoryPointer, 68), amount) // Append the "amount" argument.

            success := and(
                // Set success to whether the call reverted, if not we check it either
                // returned exactly 1 (can't just be non-zero data), or had no return data.
                or(and(eq(mload(0), 1), gt(returndatasize(), 31)), iszero(returndatasize())),
                // We use 100 because the length of our calldata totals up like so: 4 + 32 * 3.
                // We use 0 and 32 to copy up to 32 bytes of return data into the scratch space.
                // Counterintuitively, this call must be positioned second to the or() call in the
                // surrounding and() call or else returndatasize() will be zero during the computation.
                call(gas(), token, 0, freeMemoryPointer, 100, 0, 32)
            )
        }

        require(success, "TRANSFER_FROM_FAILED");
    }

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 amount
    ) internal {
        bool success;

        /// @solidity memory-safe-assembly
        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata into memory, beginning with the function selector.
            mstore(freeMemoryPointer, 0xa9059cbb00000000000000000000000000000000000000000000000000000000)
            mstore(add(freeMemoryPointer, 4), to) // Append the "to" argument.
            mstore(add(freeMemoryPointer, 36), amount) // Append the "amount" argument.

            success := and(
                // Set success to whether the call reverted, if not we check it either
                // returned exactly 1 (can't just be non-zero data), or had no return data.
                or(and(eq(mload(0), 1), gt(returndatasize(), 31)), iszero(returndatasize())),
                // We use 68 because the length of our calldata totals up like so: 4 + 32 * 2.
                // We use 0 and 32 to copy up to 32 bytes of return data into the scratch space.
                // Counterintuitively, this call must be positioned second to the or() call in the
                // surrounding and() call or else returndatasize() will be zero during the computation.
                call(gas(), token, 0, freeMemoryPointer, 68, 0, 32)
            )
        }

        require(success, "TRANSFER_FAILED");
    }

    function safeApprove(
        IERC20 token,
        address to,
        uint256 amount
    ) internal {
        bool success;

        /// @solidity memory-safe-assembly
        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata into memory, beginning with the function selector.
            mstore(freeMemoryPointer, 0x095ea7b300000000000000000000000000000000000000000000000000000000)
            mstore(add(freeMemoryPointer, 4), to) // Append the "to" argument.
            mstore(add(freeMemoryPointer, 36), amount) // Append the "amount" argument.

            success := and(
                // Set success to whether the call reverted, if not we check it either
                // returned exactly 1 (can't just be non-zero data), or had no return data.
                or(and(eq(mload(0), 1), gt(returndatasize(), 31)), iszero(returndatasize())),
                // We use 68 because the length of our calldata totals up like so: 4 + 32 * 2.
                // We use 0 and 32 to copy up to 32 bytes of return data into the scratch space.
                // Counterintuitively, this call must be positioned second to the or() call in the
                // surrounding and() call or else returndatasize() will be zero during the computation.
                call(gas(), token, 0, freeMemoryPointer, 68, 0, 32)
            )
        }

        require(success, "APPROVE_FAILED");
    }
}