// File: src/StakingFactory.sol



// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity =0.8.18;

import {IERC20} from "openzeppelin/token/ERC20/IERC20.sol";
import {Ownable} from "openzeppelin/access/Ownable.sol";
import {Staking} from "./Staking.sol";

contract StakingFactory is Ownable {
    error ZeroAddress();
    error TimeIsZero();
    error AmountIsZero();
    error StartIsMoreOrEqualThanFinish(uint _startAt, uint _finishAt);
    error FeeNotPayed();
    error TransferFailed();
    error PercentageOutOfRange(uint _percentage);

    struct StakingContract {
        address addr;
        address stakingToken;
        address rewardsToken;
        uint maxAmountUserCanStake;
        uint startAt;
        uint finishAt;
    }

    address public feeReceiver;
    uint public creatorFee;

    StakingContract[] public stakingContracts;

    constructor(address _feeReceiver, uint _creatorFee) {
        if (_feeReceiver == address(0)) {
            revert ZeroAddress();
        }
        feeReceiver = _feeReceiver;
        creatorFee = _creatorFee;
    }

    function createStakePool(
        address _stakingToken,
        address _rewardsToken,
        address _emergencyWithdrawAddress,
        uint _amountToFund,
        uint _emergencyWithdrawPercentage,
        uint _maxAmountUserCanStake,
        uint _start,
        uint _finish
    ) public payable returns (address) {
        if (
            _stakingToken == address(0) ||
            _rewardsToken == address(0) ||
            _emergencyWithdrawAddress == address(0)
        ) {
            revert ZeroAddress();
        }

        if (_emergencyWithdrawPercentage > 10000) {
            revert PercentageOutOfRange(_emergencyWithdrawPercentage);
        }

        if (msg.value < creatorFee) {
            revert FeeNotPayed();
        }

        (bool success, ) = feeReceiver.call{value: msg.value}("");
        if (!success) {
            revert TransferFailed();
        }

        if (_amountToFund == 0) {
            revert AmountIsZero();
        }

        if (_start == 0 || _finish == 0) {
            revert TimeIsZero();
        }

        if (_start >= _finish) {
            revert StartIsMoreOrEqualThanFinish(_start, _finish);
        }

        Staking staking = new Staking(
            _stakingToken,
            _rewardsToken,
            _emergencyWithdrawAddress,
            _emergencyWithdrawPercentage,
            _maxAmountUserCanStake,
            _start,
            _finish
        );

        StakingContract memory stakingContract = StakingContract({
            addr: address(staking),
            stakingToken: _stakingToken,
            rewardsToken: _rewardsToken,
            maxAmountUserCanStake: _maxAmountUserCanStake,
            startAt: _start,
            finishAt: _finish
        });

        stakingContracts.push(stakingContract);
        IERC20(_rewardsToken).transferFrom(
            msg.sender,
            address(staking),
            _amountToFund
        );

        staking.notifyRewardAmount(_amountToFund);
        staking.transferOwnership(msg.sender);

        return address(staking);
    }

    function setFee(uint _newFee) external onlyOwner {
        creatorFee = _newFee;
    }

    function setFeeReceiver(address _newReceiver) external onlyOwner {
        if (_newReceiver == address(0)) {
            revert ZeroAddress();
        }

        feeReceiver = _newReceiver;
    }

    function getStakePools() public view returns (StakingContract[] memory) {
        return stakingContracts;
    }

    function getStakePoolsWithTotalSupply()
        public
        view
        returns (StakingContract[] memory, uint[] memory)
    {
        uint[] memory totalSupplies = new uint[](stakingContracts.length);
        for (uint i; i < stakingContracts.length; ) {
            totalSupplies[i] = Staking(stakingContracts[i].addr).totalSupply();
            unchecked {
                ++i;
            }
        }

        return (stakingContracts, totalSupplies);
    }
}

// File: lib/openzeppelin-contracts/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

// File: lib/openzeppelin-contracts/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling 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: src/Staking.sol



// SPDX-License-Identifier: MIT
pragma solidity =0.8.18;

import {IERC20} from "openzeppelin/token/ERC20/IERC20.sol";
import {SafeERC20} from "openzeppelin/token/ERC20/utils/SafeERC20.sol";
import {Ownable} from "openzeppelin/access/Ownable.sol";
import {IStaking} from "./IStaking.sol";

contract Staking is Ownable, IStaking {
    using SafeERC20 for IERC20;

    IERC20 public immutable stakingToken;
    IERC20 public immutable rewardsToken;
    uint public immutable emergencyWithdrawPercentage;
    address public immutable emergencyWithdrawAddress;

    bool public rewardsNotified;
    // Duration of rewards to be paid out (in seconds)
    uint public immutable duration;
    // Timestamp of when the staking starts
    uint public immutable startAt;
    // Timestamp of when the rewards finish
    uint public immutable finishAt;
    // Minimum of last updated time and reward finish time
    uint public updatedAt;
    // Reward to be paid out per second
    uint public rewardRate;
    // Sum of (reward rate * dt * 1e18 / total supply)
    uint public rewardPerTokenStored;
    // Maximum amount a single user can stake;
    uint public immutable maxAmountUserCanStake;
    // Total rewrads that will be distributed.
    uint public totalRewards;

    // User address => rewardPerTokenStored
    mapping(address => uint) public userRewardPerTokenPaid;
    // User address => rewards to be claimed
    mapping(address => uint) public rewards;

    // Total staked
    uint public totalSupply;
    // User address => staked amount
    mapping(address => uint) public balanceOf;

    constructor(
        address _stakingToken,
        address _rewardToken,
        address _emergencyWithdrawAddress,
        uint _emergencyWithdrawPercentage,
        uint _maxAmountUserCanStake,
        uint _startAt,
        uint _finishAt
    ) {
        if (_startAt >= _finishAt) {
            revert StartIsGreaterThanFinish(_startAt, _finishAt);
        }

        if (_emergencyWithdrawPercentage > 10000) {
            revert PercentageOutOfRange(_emergencyWithdrawPercentage);
        }

        if (_maxAmountUserCanStake == 0) {
            revert AmountIsZero();
        }

        stakingToken = IERC20(_stakingToken);
        rewardsToken = IERC20(_rewardToken);
        maxAmountUserCanStake = _maxAmountUserCanStake;
        startAt = _startAt;
        finishAt = _finishAt;
        duration = _finishAt - _startAt;
        emergencyWithdrawPercentage = _emergencyWithdrawPercentage;
        emergencyWithdrawAddress = _emergencyWithdrawAddress;
    }

    modifier updateReward(address _account) {
        rewardPerTokenStored = rewardPerToken();
        updatedAt = lastTimeRewardApplicable();

        if (_account != address(0)) {
            rewards[_account] = earned(_account);
            userRewardPerTokenPaid[_account] = rewardPerTokenStored;
        }

        _;
    }

    modifier isOpen() {
        if (block.timestamp < startAt || block.timestamp > finishAt) {
            revert StakePoolClosed();
        }
        _;
    }

    function lastTimeRewardApplicable() public view returns (uint) {
        uint minFinishStart = _min(finishAt, block.timestamp);
        return startAt > minFinishStart ? 0 : minFinishStart;
    }

    function rewardPerToken() public view returns (uint) {
        if (totalSupply == 0) {
            return rewardPerTokenStored;
        }

        uint res = rewardPerTokenStored +
            (rewardRate * (lastTimeRewardApplicable() - updatedAt) * 1e18) /
            totalSupply;

        return res;
    }

    function stake(uint _amount) external isOpen updateReward(msg.sender) {
        _stake(_amount);
    }

    function _stake(uint _amount) internal {
        if (_amount == 0) {
            revert AmountIsZero();
        }

        uint amount = _amount + balanceOf[msg.sender];

        if (amount > maxAmountUserCanStake) {
            revert MaxAmountSuperceeded(amount);
        }

        uint balanceBefore = stakingToken.balanceOf(address(this));

        stakingToken.safeTransferFrom(msg.sender, address(this), _amount);

        uint balanceAfter = stakingToken.balanceOf(address(this));

        uint amountAfterTransfer = balanceAfter - balanceBefore;

        balanceOf[msg.sender] += amountAfterTransfer;
        totalSupply += amountAfterTransfer;
        emit TokensStaked(msg.sender, amountAfterTransfer);
    }

    function withdraw(uint _amount) external {
        _withdraw(_amount);
    }

    function _withdraw(uint _amount) internal updateReward(msg.sender) {
        if (_amount == 0) {
            revert AmountIsZero();
        }
        if (block.timestamp < finishAt) {
            revert TokensAreLockedUntilFinish(finishAt);
        }

        balanceOf[msg.sender] -= _amount;
        totalSupply -= _amount;
        stakingToken.safeTransfer(msg.sender, _amount);
        emit TokensWithdrawn(msg.sender, _amount);
    }

    function emergencyWithdraw(uint _amount) public updateReward(msg.sender) {
        if (_amount == 0) {
            revert AmountIsZero();
        }

        uint balance = balanceOf[msg.sender];
        if (balance == 0) {
            revert BalanceIsZero();
        }

        if (balance < _amount) {
            revert AmountIsMoreThanBalance(balance, _amount);
        }

        uint amount = 0;
        uint fee = 0;
        if (block.timestamp < finishAt) {
            fee = (_amount * emergencyWithdrawPercentage) / 10_000;
            amount = _amount - fee;
        } else {
            amount = _amount;
        }

        balanceOf[msg.sender] -= amount + fee;
        totalSupply -= amount + fee;
        stakingToken.safeTransfer(msg.sender, amount);
        if (fee > 0) {
            stakingToken.transfer(emergencyWithdrawAddress, fee);
        }

        emit EmergencyWithdraw(msg.sender, amount, fee);
    }

    function earned(address _account) public view returns (uint) {
        return
            ((balanceOf[_account] *
                (rewardPerToken() - userRewardPerTokenPaid[_account])) / 1e18) +
            rewards[_account];
    }

    function getReward() public updateReward(msg.sender) {
        address user = msg.sender;
        uint reward = rewards[user];
        if (reward > 0) {
            rewards[user] = 0;
            rewardsToken.safeTransfer(user, reward);
        }

        emit RewardsWithdrawn(user, reward);
    }

    function exit() external {
        if (block.timestamp < finishAt) {
            emergencyWithdraw(balanceOf[msg.sender]);
        } else {
            _withdraw(balanceOf[msg.sender]);
        }
        getReward();
    }

    function withdrawLeftover() external onlyOwner {
        // Can't withdraw leftovers until 7 days have passed since the end
        if (block.timestamp < finishAt + 604800) {
            revert RewardPeriodNotFinished(startAt, finishAt);
        }
        uint leftover = rewardsToken.balanceOf(address(this));
        if (leftover > 0) {
            rewardsToken.safeTransfer(owner(), leftover);
        }
    }

    function notifyRewardAmount(
        uint _amount
    ) external onlyOwner updateReward(address(0)) {
        if (_amount == 0) {
            revert AmountIsZero();
        }

        if (block.timestamp > finishAt) {
            revert RewardPeriodFinished(startAt, finishAt);
        }
        if (rewardsNotified) {
            revert RewardsAlreadyNotified();
        }

        rewardsNotified = true;

        uint currentTime = block.timestamp > startAt
            ? block.timestamp
            : startAt;
        rewardRate = _amount / duration;

        if (rewardRate == 0) {
            revert RewardRateIsZero();
        }

        uint balance = rewardsToken.balanceOf(address(this));

        if (rewardRate * duration > balance) {
            revert RewardRateIsMoreThanBalance(balance, rewardRate);
        }

        updatedAt = currentTime;
        totalRewards = _amount;

        emit NotifiedRewards(_amount);
    }

    function _min(uint x, uint y) private pure returns (uint) {
        return x <= y ? x : y;
    }
}

// File: lib/openzeppelin-contracts/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: lib/openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/IERC20Permit.sol";
import "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to
     * 0 before setting it to a non-zero value.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
     * Revert on invalid signature.
     */
    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

        (bool success, bytes memory returndata) = address(token).call(data);
        return
            success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
    }
}

// File: src/IStaking.sol



// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.18;

interface IStaking {
    error StartIsGreaterThanFinish(uint _startAt, uint _finishAt);
    error AmountIsZero();
    error BalanceIsZero();
    error StakePoolClosed();
    error RewardPeriodNotFinished(uint _startAt, uint _finishAt);
    error RewardRateIsZero();
    error RewardRateIsMoreThanBalance(uint _balance, uint _rewardRate);
    error RewardsAlreadyNotified();
    error RewardPeriodFinished(uint _startAt, uint _finishAt);
    error TokensAreLockedUntilFinish(uint _finishAt);
    error MaxAmountSuperceeded(uint _amount);
    error AmountIsMoreThanBalance(uint _balance, uint _amount);
    error PercentageOutOfRange(uint _percentage);

    event TokensStaked(address _staker, uint _amount);
    event TokensWithdrawn(address _staker, uint _amount);
    event RewardsWithdrawn(address _staker, uint _amount);
    event EmergencyWithdraw(address _staker, uint _amount, uint _fee);
    event NotifiedRewards(uint _amount);
}

// File: lib/openzeppelin-contracts/contracts/token/ERC20/extensions/IERC20Permit.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.0;

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

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

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

// File: lib/openzeppelin-contracts/contracts/utils/Address.sol



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

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

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

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

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

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

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

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

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

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

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

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

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

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