// File: lib/BokkyPooBahsDateTimeLibrary/contracts/BokkyPooBahsDateTimeLibrary.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.9.0;

// ----------------------------------------------------------------------------
// BokkyPooBah's DateTime Library v1.01
//
// A gas-efficient Solidity date and time library
//
// https://github.com/bokkypoobah/BokkyPooBahsDateTimeLibrary
//
// Tested date range 1970/01/01 to 2345/12/31
//
// Conventions:
// Unit      | Range         | Notes
// :-------- |:-------------:|:-----
// timestamp | >= 0          | Unix timestamp, number of seconds since 1970/01/01 00:00:00 UTC
// year      | 1970 ... 2345 |
// month     | 1 ... 12      |
// day       | 1 ... 31      |
// hour      | 0 ... 23      |
// minute    | 0 ... 59      |
// second    | 0 ... 59      |
// dayOfWeek | 1 ... 7       | 1 = Monday, ..., 7 = Sunday
//
//
// Enjoy. (c) BokkyPooBah / Bok Consulting Pty Ltd 2018-2019. The MIT Licence.
// ----------------------------------------------------------------------------

library BokkyPooBahsDateTimeLibrary {

    uint constant SECONDS_PER_DAY = 24 * 60 * 60;
    uint constant SECONDS_PER_HOUR = 60 * 60;
    uint constant SECONDS_PER_MINUTE = 60;
    int constant OFFSET19700101 = 2440588;

    uint constant DOW_MON = 1;
    uint constant DOW_TUE = 2;
    uint constant DOW_WED = 3;
    uint constant DOW_THU = 4;
    uint constant DOW_FRI = 5;
    uint constant DOW_SAT = 6;
    uint constant DOW_SUN = 7;

    // ------------------------------------------------------------------------
    // Calculate the number of days from 1970/01/01 to year/month/day using
    // the date conversion algorithm from
    //   https://aa.usno.navy.mil/faq/JD_formula.html
    // and subtracting the offset 2440588 so that 1970/01/01 is day 0
    //
    // days = day
    //      - 32075
    //      + 1461 * (year + 4800 + (month - 14) / 12) / 4
    //      + 367 * (month - 2 - (month - 14) / 12 * 12) / 12
    //      - 3 * ((year + 4900 + (month - 14) / 12) / 100) / 4
    //      - offset
    // ------------------------------------------------------------------------
    function _daysFromDate(uint year, uint month, uint day) internal pure returns (uint _days) {
        require(year >= 1970);
        int _year = int(year);
        int _month = int(month);
        int _day = int(day);

        int __days = _day
          - 32075
          + 1461 * (_year + 4800 + (_month - 14) / 12) / 4
          + 367 * (_month - 2 - (_month - 14) / 12 * 12) / 12
          - 3 * ((_year + 4900 + (_month - 14) / 12) / 100) / 4
          - OFFSET19700101;

        _days = uint(__days);
    }

    // ------------------------------------------------------------------------
    // Calculate year/month/day from the number of days since 1970/01/01 using
    // the date conversion algorithm from
    //   http://aa.usno.navy.mil/faq/docs/JD_Formula.php
    // and adding the offset 2440588 so that 1970/01/01 is day 0
    //
    // int L = days + 68569 + offset
    // int N = 4 * L / 146097
    // L = L - (146097 * N + 3) / 4
    // year = 4000 * (L + 1) / 1461001
    // L = L - 1461 * year / 4 + 31
    // month = 80 * L / 2447
    // dd = L - 2447 * month / 80
    // L = month / 11
    // month = month + 2 - 12 * L
    // year = 100 * (N - 49) + year + L
    // ------------------------------------------------------------------------
    function _daysToDate(uint _days) internal pure returns (uint year, uint month, uint day) {
        int __days = int(_days);

        int L = __days + 68569 + OFFSET19700101;
        int N = 4 * L / 146097;
        L = L - (146097 * N + 3) / 4;
        int _year = 4000 * (L + 1) / 1461001;
        L = L - 1461 * _year / 4 + 31;
        int _month = 80 * L / 2447;
        int _day = L - 2447 * _month / 80;
        L = _month / 11;
        _month = _month + 2 - 12 * L;
        _year = 100 * (N - 49) + _year + L;

        year = uint(_year);
        month = uint(_month);
        day = uint(_day);
    }

    function timestampFromDate(uint year, uint month, uint day) internal pure returns (uint timestamp) {
        timestamp = _daysFromDate(year, month, day) * SECONDS_PER_DAY;
    }
    function timestampFromDateTime(uint year, uint month, uint day, uint hour, uint minute, uint second) internal pure returns (uint timestamp) {
        timestamp = _daysFromDate(year, month, day) * SECONDS_PER_DAY + hour * SECONDS_PER_HOUR + minute * SECONDS_PER_MINUTE + second;
    }
    function timestampToDate(uint timestamp) internal pure returns (uint year, uint month, uint day) {
        (year, month, day) = _daysToDate(timestamp / SECONDS_PER_DAY);
    }
    function timestampToDateTime(uint timestamp) internal pure returns (uint year, uint month, uint day, uint hour, uint minute, uint second) {
        (year, month, day) = _daysToDate(timestamp / SECONDS_PER_DAY);
        uint secs = timestamp % SECONDS_PER_DAY;
        hour = secs / SECONDS_PER_HOUR;
        secs = secs % SECONDS_PER_HOUR;
        minute = secs / SECONDS_PER_MINUTE;
        second = secs % SECONDS_PER_MINUTE;
    }

    function isValidDate(uint year, uint month, uint day) internal pure returns (bool valid) {
        if (year >= 1970 && month > 0 && month <= 12) {
            uint daysInMonth = _getDaysInMonth(year, month);
            if (day > 0 && day <= daysInMonth) {
                valid = true;
            }
        }
    }
    function isValidDateTime(uint year, uint month, uint day, uint hour, uint minute, uint second) internal pure returns (bool valid) {
        if (isValidDate(year, month, day)) {
            if (hour < 24 && minute < 60 && second < 60) {
                valid = true;
            }
        }
    }
    function isLeapYear(uint timestamp) internal pure returns (bool leapYear) {
        (uint year,,) = _daysToDate(timestamp / SECONDS_PER_DAY);
        leapYear = _isLeapYear(year);
    }
    function _isLeapYear(uint year) internal pure returns (bool leapYear) {
        leapYear = ((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0);
    }
    function isWeekDay(uint timestamp) internal pure returns (bool weekDay) {
        weekDay = getDayOfWeek(timestamp) <= DOW_FRI;
    }
    function isWeekEnd(uint timestamp) internal pure returns (bool weekEnd) {
        weekEnd = getDayOfWeek(timestamp) >= DOW_SAT;
    }
    function getDaysInMonth(uint timestamp) internal pure returns (uint daysInMonth) {
        (uint year, uint month,) = _daysToDate(timestamp / SECONDS_PER_DAY);
        daysInMonth = _getDaysInMonth(year, month);
    }
    function _getDaysInMonth(uint year, uint month) internal pure returns (uint daysInMonth) {
        if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12) {
            daysInMonth = 31;
        } else if (month != 2) {
            daysInMonth = 30;
        } else {
            daysInMonth = _isLeapYear(year) ? 29 : 28;
        }
    }
    // 1 = Monday, 7 = Sunday
    function getDayOfWeek(uint timestamp) internal pure returns (uint dayOfWeek) {
        uint _days = timestamp / SECONDS_PER_DAY;
        dayOfWeek = (_days + 3) % 7 + 1;
    }

    function getYear(uint timestamp) internal pure returns (uint year) {
        (year,,) = _daysToDate(timestamp / SECONDS_PER_DAY);
    }
    function getMonth(uint timestamp) internal pure returns (uint month) {
        (,month,) = _daysToDate(timestamp / SECONDS_PER_DAY);
    }
    function getDay(uint timestamp) internal pure returns (uint day) {
        (,,day) = _daysToDate(timestamp / SECONDS_PER_DAY);
    }
    function getHour(uint timestamp) internal pure returns (uint hour) {
        uint secs = timestamp % SECONDS_PER_DAY;
        hour = secs / SECONDS_PER_HOUR;
    }
    function getMinute(uint timestamp) internal pure returns (uint minute) {
        uint secs = timestamp % SECONDS_PER_HOUR;
        minute = secs / SECONDS_PER_MINUTE;
    }
    function getSecond(uint timestamp) internal pure returns (uint second) {
        second = timestamp % SECONDS_PER_MINUTE;
    }

    function addYears(uint timestamp, uint _years) internal pure returns (uint newTimestamp) {
        (uint year, uint month, uint day) = _daysToDate(timestamp / SECONDS_PER_DAY);
        year += _years;
        uint daysInMonth = _getDaysInMonth(year, month);
        if (day > daysInMonth) {
            day = daysInMonth;
        }
        newTimestamp = _daysFromDate(year, month, day) * SECONDS_PER_DAY + timestamp % SECONDS_PER_DAY;
        require(newTimestamp >= timestamp);
    }
    function addMonths(uint timestamp, uint _months) internal pure returns (uint newTimestamp) {
        (uint year, uint month, uint day) = _daysToDate(timestamp / SECONDS_PER_DAY);
        month += _months;
        year += (month - 1) / 12;
        month = (month - 1) % 12 + 1;
        uint daysInMonth = _getDaysInMonth(year, month);
        if (day > daysInMonth) {
            day = daysInMonth;
        }
        newTimestamp = _daysFromDate(year, month, day) * SECONDS_PER_DAY + timestamp % SECONDS_PER_DAY;
        require(newTimestamp >= timestamp);
    }
    function addDays(uint timestamp, uint _days) internal pure returns (uint newTimestamp) {
        newTimestamp = timestamp + _days * SECONDS_PER_DAY;
        require(newTimestamp >= timestamp);
    }
    function addHours(uint timestamp, uint _hours) internal pure returns (uint newTimestamp) {
        newTimestamp = timestamp + _hours * SECONDS_PER_HOUR;
        require(newTimestamp >= timestamp);
    }
    function addMinutes(uint timestamp, uint _minutes) internal pure returns (uint newTimestamp) {
        newTimestamp = timestamp + _minutes * SECONDS_PER_MINUTE;
        require(newTimestamp >= timestamp);
    }
    function addSeconds(uint timestamp, uint _seconds) internal pure returns (uint newTimestamp) {
        newTimestamp = timestamp + _seconds;
        require(newTimestamp >= timestamp);
    }

    function subYears(uint timestamp, uint _years) internal pure returns (uint newTimestamp) {
        (uint year, uint month, uint day) = _daysToDate(timestamp / SECONDS_PER_DAY);
        year -= _years;
        uint daysInMonth = _getDaysInMonth(year, month);
        if (day > daysInMonth) {
            day = daysInMonth;
        }
        newTimestamp = _daysFromDate(year, month, day) * SECONDS_PER_DAY + timestamp % SECONDS_PER_DAY;
        require(newTimestamp <= timestamp);
    }
    function subMonths(uint timestamp, uint _months) internal pure returns (uint newTimestamp) {
        (uint year, uint month, uint day) = _daysToDate(timestamp / SECONDS_PER_DAY);
        uint yearMonth = year * 12 + (month - 1) - _months;
        year = yearMonth / 12;
        month = yearMonth % 12 + 1;
        uint daysInMonth = _getDaysInMonth(year, month);
        if (day > daysInMonth) {
            day = daysInMonth;
        }
        newTimestamp = _daysFromDate(year, month, day) * SECONDS_PER_DAY + timestamp % SECONDS_PER_DAY;
        require(newTimestamp <= timestamp);
    }
    function subDays(uint timestamp, uint _days) internal pure returns (uint newTimestamp) {
        newTimestamp = timestamp - _days * SECONDS_PER_DAY;
        require(newTimestamp <= timestamp);
    }
    function subHours(uint timestamp, uint _hours) internal pure returns (uint newTimestamp) {
        newTimestamp = timestamp - _hours * SECONDS_PER_HOUR;
        require(newTimestamp <= timestamp);
    }
    function subMinutes(uint timestamp, uint _minutes) internal pure returns (uint newTimestamp) {
        newTimestamp = timestamp - _minutes * SECONDS_PER_MINUTE;
        require(newTimestamp <= timestamp);
    }
    function subSeconds(uint timestamp, uint _seconds) internal pure returns (uint newTimestamp) {
        newTimestamp = timestamp - _seconds;
        require(newTimestamp <= timestamp);
    }

    function diffYears(uint fromTimestamp, uint toTimestamp) internal pure returns (uint _years) {
        require(fromTimestamp <= toTimestamp);
        (uint fromYear,,) = _daysToDate(fromTimestamp / SECONDS_PER_DAY);
        (uint toYear,,) = _daysToDate(toTimestamp / SECONDS_PER_DAY);
        _years = toYear - fromYear;
    }
    function diffMonths(uint fromTimestamp, uint toTimestamp) internal pure returns (uint _months) {
        require(fromTimestamp <= toTimestamp);
        (uint fromYear, uint fromMonth,) = _daysToDate(fromTimestamp / SECONDS_PER_DAY);
        (uint toYear, uint toMonth,) = _daysToDate(toTimestamp / SECONDS_PER_DAY);
        _months = toYear * 12 + toMonth - fromYear * 12 - fromMonth;
    }
    function diffDays(uint fromTimestamp, uint toTimestamp) internal pure returns (uint _days) {
        require(fromTimestamp <= toTimestamp);
        _days = (toTimestamp - fromTimestamp) / SECONDS_PER_DAY;
    }
    function diffHours(uint fromTimestamp, uint toTimestamp) internal pure returns (uint _hours) {
        require(fromTimestamp <= toTimestamp);
        _hours = (toTimestamp - fromTimestamp) / SECONDS_PER_HOUR;
    }
    function diffMinutes(uint fromTimestamp, uint toTimestamp) internal pure returns (uint _minutes) {
        require(fromTimestamp <= toTimestamp);
        _minutes = (toTimestamp - fromTimestamp) / SECONDS_PER_MINUTE;
    }
    function diffSeconds(uint fromTimestamp, uint toTimestamp) internal pure returns (uint _seconds) {
        require(fromTimestamp <= toTimestamp);
        _seconds = toTimestamp - fromTimestamp;
    }
}

// File: lib/openzeppelin-contracts/contracts/interfaces/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (interfaces/IERC20.sol)

pragma solidity ^0.8.0;

import "../token/ERC20/IERC20.sol";

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-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/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/draft-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;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    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));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    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");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    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");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

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



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

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

// File: lib/openzeppelin-contracts/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: lib/openzeppelin-contracts/contracts/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

// File: src/DCAOrder.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.20;

import {IERC20} from "oz/token/ERC20/IERC20.sol";
import {SafeERC20} from "oz/token/ERC20/utils/SafeERC20.sol";
import {IGPv2Settlement} from "./interfaces/IGPv2Settlement.sol";
import {IConditionalOrder} from "./interfaces/IConditionalOrder.sol";
import {IDCAOrder} from "./interfaces/IDCAOrder.sol";
import {GPv2Order} from "./libraries/GPv2Order.sol";
import {GPv2EIP1271, EIP1271Verifier} from "./interfaces/EIP1271Verifier.sol";
import {BokkyPooBahsDateTimeLibrary} from "date/BokkyPooBahsDateTimeLibrary.sol";
import {SafeMath} from "oz/utils/math/SafeMath.sol";
import {Math} from "oz/utils/math/Math.sol";

error OrderCancelled();
error NotOwner();
error NotReceiver();
error ReceiverIsOrder();
error MissingOwner();
error AlreadyInitialized();
error IntervalMustBeGreaterThanZero();
error InvalidStartTime();
error InvalidEndTime();
error NotWithinStartAndEndTimes();
error ZeroSellAmount();
error OrderExecutionTimeLessThanCurrentTime();

contract DCAOrder is IConditionalOrder, EIP1271Verifier, IDCAOrder {
  using GPv2Order for GPv2Order.Data;
  using SafeERC20 for IERC20;

  /// @dev The owner of the order. The owner can cancel the order.
  address public owner;
  /// @dev All buyToken orders are sent to this address.
  address public receiver;
  /// @dev The token that is being traded in the order.
  IERC20 public sellToken;
  /// @dev The token that is DCA'd in the order.
  IERC20 public buyToken;
  /// @dev The start time of the DCA order.
  uint256 public startTime;
  /// @dev The end time of the DCA order.
  uint256 public endTime;
  /// @dev The frequency of the DCA order in hours
  uint256 public interval;
  bytes32 public domainSeparator;
  /// @dev Indicates that the order has been cancelled.
  bool public cancelled;
  /// @dev The initial amount of the DCA order.
  uint256 public amount;

  event Initialized(address indexed order);
  event Cancelled(address indexed order);

  /// @dev Initializes the DCAOrder with the specified parameters.
  /// @param _owner The owner of the order.
  /// @param _receiver The receiver of the buyToken orders.
  /// @param _sellToken The token that is being traded in the order.
  /// @param _amount The amount of the DCA order.
  /// @param _buyToken The token that is DCA'd in the order.
  /// @param _startTime The start time of the DCA order.
  /// @param _endTime The end time of the DCA order.
  /// @param _interval The frequency interval of the DCA order in hours.
  /// @param _settlementContract The settlement contract address.
  function initialize(
    address _owner,
    address _receiver,
    address _sellToken,
    address _buyToken,
    uint256 _amount,
    uint256 _startTime,
    uint256 _endTime,
    uint256 _interval,
    address _settlementContract
  ) external override returns (bool) {
    // Ensure that the order is not already initialized.
    if (owner != address(0)) {
      revert AlreadyInitialized();
    }
    // Ensure an owner is set
    if (_owner == address(0)) {
      revert MissingOwner();
    }
    // Ensure that the receiver is not the current contract.
    if (_receiver == address(this)) {
      revert ReceiverIsOrder();
    }
    if (_interval == 0) {
      revert IntervalMustBeGreaterThanZero();
    }
    // Start date must be in the future by at least 3 minutes
    // solhint-disable-next-line not-rely-on-time
    if (_startTime <= block.timestamp + 3 minutes) {
      revert InvalidStartTime();
    }
    // End time must be greater than start time
    if (_endTime <= _startTime) {
      revert InvalidEndTime();
    }
    // Set all the properties
    owner = _owner;
    receiver = _receiver;
    sellToken = IERC20(_sellToken);
    buyToken = IERC20(_buyToken);
    startTime = _startTime;
    endTime = _endTime;
    interval = _interval;
    amount = _amount;
    domainSeparator = IGPv2Settlement(_settlementContract).domainSeparator();
    // Approve the vaut relayer to spend the sell token
    IERC20(_sellToken).safeApprove(address(IGPv2Settlement(_settlementContract).vaultRelayer()), type(uint256).max);
    emit ConditionalOrderCreated(address(this)); // Required by COW to watch this contract
    // Emit Initialized event for indexing
    emit Initialized(address(this));
    return true;
  }

  /// @dev Cancels the order and transfers the funds back to the owner.
  function cancel() external {
    if (msg.sender != owner) {
      revert NotOwner();
    }
    cancelled = true;
    emit Cancelled(address(this));
    // Transfer funds back to owner
    sellToken.safeTransfer(owner, sellToken.balanceOf(address(this)));
  }

  // @dev If the `target`'s balance of `sellToken` is above the specified threshold, sell its entire balance
  // for `buyToken` at the current market price (no limit!).
  function getTradeableOrder() external view override returns (GPv2Order.Data memory) {
    // If the order is cancelled, return an empty order
    if (cancelled) {
      revert OrderCancelled();
    }
    // Order must be between start and end time
    // solhint-disable-next-line not-rely-on-time
    if (block.timestamp < startTime || block.timestamp > endTime) {
      revert NotWithinStartAndEndTimes();
    }
    uint256 orderExecutionTime = currentSlot();
    uint256 orderSellAmount = slotSellAmount();
    // Cannot create order with zero sell amount
    if (orderSellAmount == 0) {
      revert ZeroSellAmount();
    }
    // Create the order
    // ensures that orders queried shortly after one another result in the same hash (to avoid spamming the orderbook)
    // solhint-disable-next-line not-rely-on-time
    uint32 currentTimeBucket = ((uint32(orderExecutionTime) / 900) + 1) * 900;
    return GPv2Order.Data(
      sellToken,
      buyToken,
      receiver, // The receiver
      orderSellAmount,
      1, // 0 buy amount is not allowed
      currentTimeBucket + 900, // between 15 and 30 miunte validity
      keccak256("DollarCostAveraging"),
      0,
      GPv2Order.KIND_SELL,
      false,
      GPv2Order.BALANCE_ERC20,
      GPv2Order.BALANCE_ERC20
    );
    // uint32 currentTimeBucket = ((uint32(block.timestamp) / 900) + 1) * 900;
  }

  /// @param orderDigest The EIP-712 signing digest derived from the order
  /// @param encodedOrder Bytes-encoded order information, originally created by an off-chain bot. Created by concatening the order data (in the form of GPv2Order.Data), the price checker address, and price checker data.
  function isValidSignature(bytes32 orderDigest, bytes calldata encodedOrder) external view override returns (bytes4) {
    GPv2Order.Data memory order = abi.decode(encodedOrder, (GPv2Order.Data));
    require(order.hash(domainSeparator) == orderDigest, "encoded order digest mismatch");

    // If getTradeableOrder() may change between blocks (e.g. because of a variable exchange rate or exprity date, perform a proper attribute comparison with `order` here instead of matching full hashes)
    require(
      IConditionalOrder(this).getTradeableOrder().hash(domainSeparator) == orderDigest,
      "encoded order != tradable order"
    );

    return GPv2EIP1271.MAGICVALUE;
  }

  /// @dev the total number of orders that will be executed between the start and end time
  function orderSlots() public view returns (uint256[] memory slots) {
    uint256 total = Math.ceilDiv(BokkyPooBahsDateTimeLibrary.diffHours(startTime, endTime), interval);
    slots = new uint256[](total);
    // Create execution orders
    for (uint256 i = 0; i < total; i++) {
      uint256 orderExecutionTime = startTime + (i * interval * 1 hours);
      slots[i] = orderExecutionTime;
    }
    return slots;
  }

  /// @dev returns the current slot based on the slots array
  /// @dev a slot is consider current if the current time is greater than the slot time and less than the next slot time (if it exists)
  function currentSlot() public view returns (uint256 slot) {
    uint256[] memory slots = orderSlots();

    // If the current time is between the last slot and the end time, return the last slot
    // solhint-disable-next-line not-rely-on-time
    if (block.timestamp >= slots[slots.length - 1] && block.timestamp <= endTime) {
      return slots[slots.length - 1];
    }

    // No need to reach the last slot, the last slot returns in the previous condition
    for (uint256 i = 0; i < slots.length - 1; i++) {
      // If the current time is between the slot start time and the next slot start time, return the current slot
      // solhint-disable-next-line not-rely-on-time
      if (block.timestamp >= slots[i] && block.timestamp < slots[i + 1]) {
        slot = slots[i];
        break;
      }
    }
  }

  /// @dev returns the sell amount for the each slot
  function slotSellAmount() public view returns (uint256 orderSellAmount) {
    // Execute at the specified frequency
    // Each order sellAmount is the balance of the order divided by the frequency
    // If the current slot is the last slot, the returned amount is the total sellToken balance
    uint256[] memory slots = orderSlots();

    // solhint-disable-next-line not-rely-on-time
    if (block.timestamp >= slots[slots.length - 1] && block.timestamp < endTime) {
      orderSellAmount = sellToken.balanceOf(address(this));
    } else if (block.timestamp >= endTime) {
      return 0;
    } else {
      (, orderSellAmount) = SafeMath.tryDiv(amount, slots.length);
    }
  }
}

// File: src/interfaces/EIP1271Verifier.sol



// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.8.20;

library GPv2EIP1271 {
  /// @dev Value returned by a call to `isValidSignature` if the signature
  /// was verified successfully. The value is defined in EIP-1271 as:
  /// bytes4(keccak256("isValidSignature(bytes32,bytes)"))
  bytes4 internal constant MAGICVALUE = 0x1626ba7e;
}

/// @title EIP1271 Interface
/// @dev Standardized interface for an implementation of smart contract
/// signatures as described in EIP-1271. The code that follows is identical to
/// the code in the standard with the exception of formatting and syntax
/// changes to adapt the code to our Solidity version.
interface EIP1271Verifier {
  /// @dev Should return whether the signature provided is valid for the
  /// provided data
  /// @param _hash      Hash of the data to be signed
  /// @param _signature Signature byte array associated with _data
  ///
  /// MUST return the bytes4 magic value 0x1626ba7e when function passes.
  /// MUST NOT modify state (using STATICCALL for solc < 0.5, view modifier for
  /// solc > 0.5)
  /// MUST allow external calls
  ///
  function isValidSignature(bytes32 _hash, bytes memory _signature) external view returns (bytes4 magicValue);
}

// File: src/interfaces/IConditionalOrder.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
pragma abicoder v2;

import {GPv2Order} from "../libraries/GPv2Order.sol";

interface IConditionalOrder {
  /// Event that should be emitted in constructor so that the service "watching" for conditional orders can start indexing it
  event ConditionalOrderCreated(address indexed);

  /// Returns an order that if posted to the CoW Protocol API would pass signature validation
  /// Reverts in case current order condition is not met
  function getTradeableOrder() external view returns (GPv2Order.Data memory);
}

// File: src/interfaces/IDCAOrder.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
pragma abicoder v2;

interface IDCAOrder {
  function initialize(
    address _owner,
    address _receiver,
    address _sellToken,
    address _buyToken,
    uint256 _amount,
    uint256 _startTime,
    uint256 _endTime,
    uint256 _interval,
    address _settlementContract
  ) external returns (bool);
}

// File: src/interfaces/IGPv2Settlement.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

interface IGPv2Settlement {
  /// @dev Sets a presignature for the specified order UID.
  ///
  /// @param orderUid The unique identifier of the order to pre-sign.
  function setPreSignature(bytes calldata orderUid, bool signed) external;
  function vaultRelayer() external view returns (address);
  function domainSeparator() external view returns (bytes32);
}

// File: src/libraries/GPv2Order.sol



// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity 0.8.20;

import {IERC20} from "oz/interfaces/IERC20.sol";

/// @title Gnosis Protocol v2 Order Library
/// @author Gnosis Developers
library GPv2Order {
  /// @dev The complete data for a Gnosis Protocol order. This struct contains
  /// all order parameters that are signed for submitting to GP.
  struct Data {
    IERC20 sellToken;
    IERC20 buyToken;
    address receiver;
    uint256 sellAmount;
    uint256 buyAmount;
    uint32 validTo;
    bytes32 appData;
    uint256 feeAmount;
    bytes32 kind;
    bool partiallyFillable;
    bytes32 sellTokenBalance;
    bytes32 buyTokenBalance;
  }

  /// @dev The order EIP-712 type hash for the [`GPv2Order.Data`] struct.
  ///
  /// This value is pre-computed from the following expression:
  /// ```
  /// keccak256(
  ///     "Order(" +
  ///         "address sellToken," +
  ///         "address buyToken," +
  ///         "address receiver," +
  ///         "uint256 sellAmount," +
  ///         "uint256 buyAmount," +
  ///         "uint32 validTo," +
  ///         "bytes32 appData," +
  ///         "uint256 feeAmount," +
  ///         "string kind," +
  ///         "bool partiallyFillable" +
  ///         "string sellTokenBalance" +
  ///         "string buyTokenBalance" +
  ///     ")"
  /// )
  /// ```
  bytes32 internal constant TYPE_HASH = hex"d5a25ba2e97094ad7d83dc28a6572da797d6b3e7fc6663bd93efb789fc17e489";

  /// @dev The marker value for a sell order for computing the order struct
  /// hash. This allows the EIP-712 compatible wallets to display a
  /// descriptive string for the order kind (instead of 0 or 1).
  ///
  /// This value is pre-computed from the following expression:
  /// ```
  /// keccak256("sell")
  /// ```
  bytes32 internal constant KIND_SELL = hex"f3b277728b3fee749481eb3e0b3b48980dbbab78658fc419025cb16eee346775";

  /// @dev The OrderKind marker value for a buy order for computing the order
  /// struct hash.
  ///
  /// This value is pre-computed from the following expression:
  /// ```
  /// keccak256("buy")
  /// ```
  bytes32 internal constant KIND_BUY = hex"6ed88e868af0a1983e3886d5f3e95a2fafbd6c3450bc229e27342283dc429ccc";

  /// @dev The TokenBalance marker value for using direct ERC20 balances for
  /// computing the order struct hash.
  ///
  /// This value is pre-computed from the following expression:
  /// ```
  /// keccak256("erc20")
  /// ```
  bytes32 internal constant BALANCE_ERC20 = hex"5a28e9363bb942b639270062aa6bb295f434bcdfc42c97267bf003f272060dc9";

  /// @dev The TokenBalance marker value for using Balancer Vault external
  /// balances (in order to re-use Vault ERC20 approvals) for computing the
  /// order struct hash.
  ///
  /// This value is pre-computed from the following expression:
  /// ```
  /// keccak256("external")
  /// ```
  bytes32 internal constant BALANCE_EXTERNAL = hex"abee3b73373acd583a130924aad6dc38cfdc44ba0555ba94ce2ff63980ea0632";

  /// @dev The TokenBalance marker value for using Balancer Vault internal
  /// balances for computing the order struct hash.
  ///
  /// This value is pre-computed from the following expression:
  /// ```
  /// keccak256("internal")
  /// ```
  bytes32 internal constant BALANCE_INTERNAL = hex"4ac99ace14ee0a5ef932dc609df0943ab7ac16b7583634612f8dc35a4289a6ce";

  /// @dev Marker address used to indicate that the receiver of the trade
  /// proceeds should the owner of the order.
  ///
  /// This is chosen to be `address(0)` for gas efficiency as it is expected
  /// to be the most common case.
  address internal constant RECEIVER_SAME_AS_OWNER = address(0);

  /// @dev The byte length of an order unique identifier.
  uint256 internal constant UID_LENGTH = 56;

  /// @dev Returns the actual receiver for an order. This function checks
  /// whether or not the [`receiver`] field uses the marker value to indicate
  /// it is the same as the order owner.
  ///
  /// @return receiver The actual receiver of trade proceeds.
  function actualReceiver(Data memory order, address owner) internal pure returns (address receiver) {
    if (order.receiver == RECEIVER_SAME_AS_OWNER) {
      receiver = owner;
    } else {
      receiver = order.receiver;
    }
  }

  /// @dev Return the EIP-712 signing hash for the specified order.
  ///
  /// @param order The order to compute the EIP-712 signing hash for.
  /// @param domainSeparator The EIP-712 domain separator to use.
  /// @return orderDigest The 32 byte EIP-712 struct hash.
  function hash(Data memory order, bytes32 domainSeparator) internal pure returns (bytes32 orderDigest) {
    bytes32 structHash;

    // NOTE: Compute the EIP-712 order struct hash in place. As suggested
    // in the EIP proposal, noting that the order struct has 10 fields, and
    // including the type hash `(12 + 1) * 32 = 416` bytes to hash.
    // <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-712.md#rationale-for-encodedata>
    // solhint-disable-next-line no-inline-assembly
    assembly {
      let dataStart := sub(order, 32)
      let temp := mload(dataStart)
      mstore(dataStart, TYPE_HASH)
      structHash := keccak256(dataStart, 416)
      mstore(dataStart, temp)
    }

    // NOTE: Now that we have the struct hash, compute the EIP-712 signing
    // hash using scratch memory past the free memory pointer. The signing
    // hash is computed from `"\x19\x01" || domainSeparator || structHash`.
    // <https://docs.soliditylang.org/en/v0.7.6/internals/layout_in_memory.html#layout-in-memory>
    // <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-712.md#specification>
    // solhint-disable-next-line no-inline-assembly
    assembly {
      let freeMemoryPointer := mload(0x40)
      mstore(freeMemoryPointer, "\x19\x01")
      mstore(add(freeMemoryPointer, 2), domainSeparator)
      mstore(add(freeMemoryPointer, 34), structHash)
      orderDigest := keccak256(freeMemoryPointer, 66)
    }
  }

  /// @dev Packs order UID parameters into the specified memory location. The
  /// result is equivalent to `abi.encodePacked(...)` with the difference that
  /// it allows re-using the memory for packing the order UID.
  ///
  /// This function reverts if the order UID buffer is not the correct size.
  ///
  /// @param orderUid The buffer pack the order UID parameters into.
  /// @param orderDigest The EIP-712 struct digest derived from the order
  /// parameters.
  /// @param owner The address of the user who owns this order.
  /// @param validTo The epoch time at which the order will stop being valid.
  function packOrderUidParams(bytes memory orderUid, bytes32 orderDigest, address owner, uint32 validTo) internal pure {
    require(orderUid.length == UID_LENGTH, "GPv2: uid buffer overflow");

    // NOTE: Write the order UID to the allocated memory buffer. The order
    // parameters are written to memory in **reverse order** as memory
    // operations write 32-bytes at a time and we want to use a packed
    // encoding. This means, for example, that after writing the value of
    // `owner` to bytes `20:52`, writing the `orderDigest` to bytes `0:32`
    // will **overwrite** bytes `20:32`. This is desirable as addresses are
    // only 20 bytes and `20:32` should be `0`s:
    //
    //        |           1111111111222222222233333333334444444444555555
    //   byte | 01234567890123456789012345678901234567890123456789012345
    // -------+---------------------------------------------------------
    //  field | [.........orderDigest..........][......owner.......][vT]
    // -------+---------------------------------------------------------
    // mstore |                         [000000000000000000000000000.vT]
    //        |                     [00000000000.......owner.......]
    //        | [.........orderDigest..........]
    //
    // Additionally, since Solidity `bytes memory` are length prefixed,
    // 32 needs to be added to all the offsets.
    //
    // solhint-disable-next-line no-inline-assembly
    assembly {
      mstore(add(orderUid, 56), validTo)
      mstore(add(orderUid, 52), owner)
      mstore(add(orderUid, 32), orderDigest)
    }
  }

  /// @dev Extracts specific order information from the standardized unique
  /// order id of the protocol.
  ///
  /// @param orderUid The unique identifier used to represent an order in
  /// the protocol. This uid is the packed concatenation of the order digest,
  /// the validTo order parameter and the address of the user who created the
  /// order. It is used by the user to interface with the contract directly,
  /// and not by calls that are triggered by the solvers.
  /// @return orderDigest The EIP-712 signing digest derived from the order
  /// parameters.
  /// @return owner The address of the user who owns this order.
  /// @return validTo The epoch time at which the order will stop being valid.
  function extractOrderUidParams(bytes calldata orderUid)
    internal
    pure
    returns (bytes32 orderDigest, address owner, uint32 validTo)
  {
    require(orderUid.length == UID_LENGTH, "GPv2: invalid uid");

    // Use assembly to efficiently decode packed calldata.
    // solhint-disable-next-line no-inline-assembly
    assembly {
      orderDigest := calldataload(orderUid.offset)
      owner := shr(96, calldataload(add(orderUid.offset, 32)))
      validTo := shr(224, calldataload(add(orderUid.offset, 52)))
    }
  }
}