// File: @openzeppelin/contracts/math/SafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
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) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        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) {
        // 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) {
        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) {
        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) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    /**
     * @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) {
        require(b <= a, "SafeMath: subtraction overflow");
        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) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

    /**
     * @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. 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) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        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) {
        require(b > 0, "SafeMath: modulo by zero");
        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) {
        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.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * 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) {
        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) {
        require(b > 0, errorMessage);
        return a % b;
    }
}

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



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    /**
     * @dev Converts a `uint256` to its ASCII `string` representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        uint256 index = digits - 1;
        temp = value;
        while (temp != 0) {
            buffer[index--] = bytes1(uint8(48 + temp % 10));
            temp /= 10;
        }
        return string(buffer);
    }
}

// File: @solv/v2-solidity-utils/contracts/access/AdminControl.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.7.6;

import "../openzeppelin/utils/ContextUpgradeable.sol";
import "../openzeppelin/proxy/Initializable.sol";

abstract contract AdminControl is Initializable, ContextUpgradeable {

    event NewAdmin(address oldAdmin, address newAdmin);
    event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin);

    address public admin;
    address public pendingAdmin;

    modifier onlyAdmin() {
        require(_msgSender() == admin, "only admin");
        _;
    }

    function __AdminControl_init(address admin_) internal initializer {
        admin = admin_;
    }

    function setPendingAdmin(address newPendingAdmin_) external virtual onlyAdmin {
        emit NewPendingAdmin(pendingAdmin, newPendingAdmin_);
        pendingAdmin = newPendingAdmin_;        
    }

    function acceptAdmin() external virtual {
        require(_msgSender() == pendingAdmin, "only pending admin");
        emit NewAdmin(admin, pendingAdmin);
        admin = pendingAdmin;
        pendingAdmin = address(0);
    }

}
// File: @solv/v2-solidity-utils/contracts/helpers/ERC20TransferHelper.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.7.6;
import "../misc/Constants.sol";

interface ERC20Interface {
    function balanceOf(address account) external view returns (uint256);

    function transfer(address recipient, uint256 amount)
        external
        returns (bool);

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);
}

// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library ERC20TransferHelper {
    function doTransferIn(
        address underlying,
        address from,
        uint256 amount
    ) internal returns (uint256) {
        if (underlying == Constants.ETH_ADDRESS) {
            // Sanity checks
            require(tx.origin == from || msg.sender == from, "sender mismatch");
            require(msg.value == amount, "value mismatch");

            return amount;
        } else {
            require(msg.value == 0, "don't support msg.value");
            uint256 balanceBefore = ERC20Interface(underlying).balanceOf(
                address(this)
            );
            (bool success, bytes memory data) = underlying.call(
                abi.encodeWithSelector(
                    ERC20Interface.transferFrom.selector,
                    from,
                    address(this),
                    amount
                )
            );
            require(
                success && (data.length == 0 || abi.decode(data, (bool))),
                "STF"
            );

            // Calculate the amount that was *actually* transferred
            uint256 balanceAfter = ERC20Interface(underlying).balanceOf(
                address(this)
            );
            require(
                balanceAfter >= balanceBefore,
                "TOKEN_TRANSFER_IN_OVERFLOW"
            );
            return balanceAfter - balanceBefore; // underflow already checked above, just subtract
        }
    }

    function doTransferOut(
        address underlying,
        address payable to,
        uint256 amount
    ) internal {
        if (underlying == Constants.ETH_ADDRESS) {
            (bool success, ) = to.call{value: amount}(new bytes(0));
            require(success, "STE");
        } else {
            (bool success, bytes memory data) = underlying.call(
                abi.encodeWithSelector(
                    ERC20Interface.transfer.selector,
                    to,
                    amount
                )
            );
            require(
                success && (data.length == 0 || abi.decode(data, (bool))),
                "ST"
            );
        }
    }

    function getCashPrior(address underlying_) internal view returns (uint256) {
        if (underlying_ == Constants.ETH_ADDRESS) {
            uint256 startingBalance = sub(address(this).balance, msg.value);
            return startingBalance;
        } else {
            ERC20Interface token = ERC20Interface(underlying_);
            return token.balanceOf(address(this));
        }
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }
}

// File: @solv/v2-solidity-utils/contracts/helpers/VNFTTransferHelper.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.7.6;

interface ERC721Interface {
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;
}

interface VNFTInterface {
    function transferFrom(
        address from,
        address to,
        uint256 tokenId,
        uint256 units
    ) external returns (uint256 newTokenId);

    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        uint256 units,
        bytes calldata data
    ) external returns (uint256 newTokenId);

    function transferFrom(
        address from,
        address to,
        uint256 tokenId,
        uint256 targetTokenId,
        uint256 units
    ) external;

    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        uint256 targetTokenId,
        uint256 units,
        bytes calldata data
    ) external;
}

library VNFTTransferHelper {
    function doTransferIn(
        address underlying,
        address from,
        uint256 tokenId
    ) internal {
        ERC721Interface token = ERC721Interface(underlying);
        token.transferFrom(from, address(this), tokenId);
    }

    function doTransferOut(
        address underlying,
        address to,
        uint256 tokenId
    ) internal {
        ERC721Interface token = ERC721Interface(underlying);
        token.transferFrom(address(this), to, tokenId);
    }

    function doTransferIn(
        address underlying,
        address from,
        uint256 tokenId,
        uint256 units
    ) internal {
        VNFTInterface token = VNFTInterface(underlying);
        token.safeTransferFrom(from, address(this), tokenId, units, "");
    }

    function doTransferOut(
        address underlying,
        address to,
        uint256 tokenId,
        uint256 units
    ) internal returns (uint256 newTokenId) {
        VNFTInterface token = VNFTInterface(underlying);
        newTokenId = token.safeTransferFrom(
            address(this),
            to,
            tokenId,
            units,
            ""
        );
    }

    function doTransferOut(
        address underlying,
        address to,
        uint256 tokenId,
        uint256 targetTokenId,
        uint256 units
    ) internal {
        VNFTInterface token = VNFTInterface(underlying);
        token.safeTransferFrom(
            address(this),
            to,
            tokenId,
            targetTokenId,
            units,
            ""
        );
    }
}

// File: @solv/v2-solidity-utils/contracts/misc/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
    //   http://aa.usno.navy.mil/faq/docs/JD_Formula.php
    // 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: @solv/v2-solidity-utils/contracts/misc/Constants.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.7.6;

library Constants {
    enum ClaimType {
        LINEAR,
        ONE_TIME,
        STAGED
    }

    enum VoucherType {
        STANDARD_VESTING,
        FLEXIBLE_DATE_VESTING,
        BOUNDING
    }

    uint32 internal constant FULL_PERCENTAGE = 10000;
    address internal constant ETH_ADDRESS =
        0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
}

// File: @solv/v2-solidity-utils/contracts/misc/StringConvertor.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.7.6;

import '@openzeppelin/contracts/utils/Strings.sol';
import '@openzeppelin/contracts/math/SafeMath.sol';
import './BokkyPooBahsDateTimeLibrary.sol';

library StringConvertor {

    using Strings for uint256;
    using SafeMath for uint256;

    /**
     * @dev Converts a `uint256` to its ASCII `string` representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        uint256 index = digits - 1;
        temp = value;
        while (temp != 0) {
            buffer[index--] = bytes1(uint8(48 + temp % 10));
            temp /= 10;
        }
        return string(buffer);
    }

    function uint2decimal(uint256 self, uint8 decimals) 
        internal
        pure
        returns (bytes memory)
    {
        uint256 base = 10 ** decimals;
        string memory round = self.div(base).toString();
        string memory fraction = self.mod(base).toString();
        uint256 fractionLength = bytes(fraction).length;

        bytes memory fullStr = abi.encodePacked(round, '.');
        if (fractionLength < decimals) {
            for (uint8 i = 0; i < decimals - fractionLength; i++) {
                fullStr = abi.encodePacked(fullStr, '0');
            }
        }

        return abi.encodePacked(fullStr, fraction);
    }

    function trim(bytes memory self, uint256 cutLength) 
        internal 
        pure
        returns (bytes memory newString)
    {
        newString = new bytes(self.length - cutLength);
        uint256 index = newString.length;
        while (index-- > 0) {
            newString[index] = self[index];
        }
    }

    function addThousandsSeparator(bytes memory self)
        internal
        pure
        returns (bytes memory newString)
    {
        if (self.length <= 6) {
            return self;
        }

        newString = new bytes(self.length + (self.length - 4) / 3);
        uint256 oriIndex = self.length - 1;
        uint256 newIndex = newString.length - 1;
        for (uint256 i = 0; i < self.length; i++) {
            if (i >= 6 && i % 3 == 0) {
                newString[newIndex--] = ',';
            }
            newString[newIndex--] = self[oriIndex--];
        }
    }

    function addressToString(address self) 
        internal 
        pure 
        returns (string memory) 
    {
        bytes32 value = bytes32(uint256(self));
        bytes memory alphabet = "0123456789abcdef";

        bytes memory str = new bytes(42);
        str[0] = '0';
        str[1] = 'x';
        for (uint i = 0; i < 20; i++) {
            str[2+i*2] = alphabet[uint8(value[i + 12] >> 4)];
            str[3+i*2] = alphabet[uint8(value[i + 12] & 0x0f)];
        }
        return string(str);
    }

    function datetimeToString(uint256 timestamp) 
        internal
        pure
        returns (string memory)
    {
        (uint256 year, uint256 month, uint256 day, uint256 hour, uint256 minute, uint256 second)
            = BokkyPooBahsDateTimeLibrary.timestampToDateTime(timestamp);
        return 
            string(
                abi.encodePacked(
                    year.toString(), '/', 
                    month < 10 ? '0' : '', month.toString(), '/', 
                    day < 10 ? '0' : '', day.toString(), ' ',
                    hour < 10 ? '0' : '', hour.toString(), ':', 
                    minute < 10 ? '0' : '', minute.toString(), ':',
                    second < 10 ? '0' : '',  second.toString()
                )
            );
    }

    function dateToString(uint256 timestamp)
        internal
        pure
        returns (string memory)
    {
        (uint256 year, uint256 month, uint256 day)
            = BokkyPooBahsDateTimeLibrary.timestampToDate(timestamp);
        return 
            string(
                abi.encodePacked(
                    year.toString(), '/', 
                    month < 10 ? '0' : '', month.toString(), '/', 
                    day < 10 ? '0' : '', day.toString()
                )
            );
    }

    function uintArray2str(uint64[] memory array) 
        internal 
        pure 
        returns (string memory) 
    {
        bytes memory pack = abi.encodePacked('[');
        for (uint256 i = 0; i < array.length; i++) {
            if (i == array.length - 1) {
                pack = abi.encodePacked(pack, uint256(array[i]).toString());
            } else {
                pack = abi.encodePacked(pack, uint256(array[i]).toString(), ',');
            }
        }
        return string(abi.encodePacked(pack, ']'));
    }

    function percentArray2str(uint32[] memory array) 
        internal 
        pure 
        returns (string memory) 
    {
        bytes memory pack = abi.encodePacked('[');
        for (uint256 i = 0; i < array.length; i++) {
            bytes memory percent = abi.encodePacked('"', uint2decimal(array[i], 2), '%"');

            if (i == array.length - 1) {
                pack = abi.encodePacked(pack, percent);
            } else {
                pack = abi.encodePacked(pack, percent, ',');
            }
        }
        return string(abi.encodePacked(pack, ']'));
    }

}
// File: @solv/v2-solidity-utils/contracts/openzeppelin/math/SafeMathUpgradeable.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMathUpgradeable {
    /**
     * @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) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        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) {
        // 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) {
        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) {
        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) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    /**
     * @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) {
        require(b <= a, "SafeMath: subtraction overflow");
        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) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

    /**
     * @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. 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) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        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) {
        require(b > 0, "SafeMath: modulo by zero");
        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) {
        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.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * 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) {
        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) {
        require(b > 0, errorMessage);
        return a % b;
    }
}

// File: @solv/v2-solidity-utils/contracts/openzeppelin/proxy/Initializable.sol



// SPDX-License-Identifier: MIT

// solhint-disable-next-line compiler-version
pragma solidity >=0.4.24 <0.8.0;

import "../utils/AddressUpgradeable.sol";

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {UpgradeableProxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {

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

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

    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        require(_initializing || _isConstructor() || !_initialized, "Initializable: contract is already initialized");

        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }

        _;

        if (isTopLevelCall) {
            _initializing = false;
        }
    }

    /// @dev Returns true if and only if the function is running in the constructor
    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}

// File: @solv/v2-solidity-utils/contracts/openzeppelin/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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 `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @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);
}

// File: @solv/v2-solidity-utils/contracts/openzeppelin/utils/AddressUpgradeable.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.2 <0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 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");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

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

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

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

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

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @solv/v2-solidity-utils/contracts/openzeppelin/utils/ContextUpgradeable.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;
import "../proxy/Initializable.sol";

/*
 * @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 GSN 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 ContextUpgradeable is Initializable {
    function __Context_init() internal initializer {
        __Context_init_unchained();
    }

    function __Context_init_unchained() internal initializer {
    }
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
    uint256[50] private __gap;
}

// File: @solv/v2-solidity-utils/contracts/openzeppelin/utils/EnumerableSetUpgradeable.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library EnumerableSetUpgradeable {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;

        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping (bytes32 => uint256) _indexes;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];

        if (valueIndex != 0) { // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.

            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;

            // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.

            bytes32 lastvalue = set._values[lastIndex];

            // Move the last value to the index where the value to delete is
            set._values[toDeleteIndex] = lastvalue;
            // Update the index for the moved value
            set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the index for the deleted slot
            delete set._indexes[value];

            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        require(set._values.length > index, "EnumerableSet: index out of bounds");
        return set._values[index];
    }

    // Bytes32Set

    struct Bytes32Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }


    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
}

// File: @solv/v2-solidity-utils/contracts/openzeppelin/utils/ReentrancyGuardUpgradeable.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;
import "../proxy/Initializable.sol";

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    function __ReentrancyGuard_init() internal initializer {
        __ReentrancyGuard_init_unchained();
    }

    function __ReentrancyGuard_init_unchained() internal initializer {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
    uint256[49] private __gap;
}

// File: @solv/v2-vnft-core/contracts/interface/optional/IUnderlyingContainer.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.7.6;

interface IUnderlyingContainer {
    function totalUnderlyingAmount() external view returns (uint256);
    function underlying() external view returns (address);
}
// File: contracts/FlexibleDateVestingPool.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.7.6;
pragma abicoder v2;

import "@solv/v2-solidity-utils/contracts/access/AdminControl.sol";
import "@solv/v2-solidity-utils/contracts/misc/Constants.sol";
import "@solv/v2-solidity-utils/contracts/misc/StringConvertor.sol";
import "@solv/v2-solidity-utils/contracts/helpers/ERC20TransferHelper.sol";
import "@solv/v2-solidity-utils/contracts/helpers/VNFTTransferHelper.sol";
import "@solv/v2-solidity-utils/contracts/openzeppelin/utils/ReentrancyGuardUpgradeable.sol";
import "@solv/v2-solidity-utils/contracts/openzeppelin/utils/EnumerableSetUpgradeable.sol";
import "@solv/v2-solidity-utils/contracts/openzeppelin/math/SafeMathUpgradeable.sol";
import "@solv/v2-solidity-utils/contracts/openzeppelin/token/ERC20/IERC20.sol";
import "@solv/v2-vnft-core/contracts/interface/optional/IUnderlyingContainer.sol";
import "./interface/IFlexibleDateVestingPool.sol";
import "./interface/external/IICToken.sol";

contract FlexibleDateVestingPool is
    IFlexibleDateVestingPool,
    AdminControl,
    ReentrancyGuardUpgradeable
{
    using EnumerableSetUpgradeable for EnumerableSetUpgradeable.UintSet;
    using StringConvertor for address;
    using StringConvertor for uint64;
    using StringConvertor for uint64[];
    using StringConvertor for uint32[];
    using SafeMathUpgradeable for uint256;

    /// @dev slot => SlotDetail
    mapping(uint256 => SlotDetail) internal _slotDetails;

    mapping(address => EnumerableSetUpgradeable.UintSet) internal _issuerSlots;

    address public underlyingVestingVoucher;
    address public underlyingToken;

    address public manager;

    uint256 public totalAmount;
    mapping(uint256 => uint256) public amountOfSlot;

    modifier onlyManager() {
        require(_msgSender() == manager, "only manager");
        _;
    }

    function initialize(address underlyingVestingVoucher_)
        external
        initializer
    {
        AdminControl.__AdminControl_init(_msgSender());
        underlyingVestingVoucher = underlyingVestingVoucher_;
        underlyingToken = IUnderlyingContainer(underlyingVestingVoucher)
            .underlying();
    }

    function createSlot(
        address issuer_,
        uint8 claimType_,
        uint64 latestStartTime_,
        uint64[] calldata terms_,
        uint32[] calldata percentages_
    ) external onlyManager returns (uint256 slot) {
        require(issuer_ != address(0), "issuer cannot be 0 address");
        slot = getSlot(
            issuer_,
            claimType_,
            latestStartTime_,
            terms_,
            percentages_
        );
        require(!_slotDetails[slot].isValid, "slot already existed");
        require(
            terms_.length == percentages_.length,
            "invalid terms and percentages"
        );
        // latestStartTime should not be later than 2100/01/01 00:00:00
        require(latestStartTime_ < 4102416000, "latest start time too late");
        // number of stages should not be more than 50
        require(percentages_.length <= 50, "too many stages");

        uint256 sumOfPercentages = 0;
        for (uint256 i = 0; i < percentages_.length; i++) {
            // value of each term should not be larger than 10 years
            require(terms_[i] <= 315360000, "term value too large");
            // value of each percentage should not be larger than 10000
            require(percentages_[i] <= Constants.FULL_PERCENTAGE, "percentage value too large");
            sumOfPercentages += percentages_[i];
        }
        require(
            sumOfPercentages == Constants.FULL_PERCENTAGE,
            "not full percentage"
        );

        require(
            (claimType_ == uint8(Constants.ClaimType.LINEAR) &&
                percentages_.length == 1) ||
                (claimType_ == uint8(Constants.ClaimType.ONE_TIME) &&
                    percentages_.length == 1) ||
                (claimType_ == uint8(Constants.ClaimType.STAGED) &&
                    percentages_.length > 1),
            "invalid params"
        );

        _slotDetails[slot] = SlotDetail({
            issuer: issuer_,
            claimType: claimType_,
            startTime: 0,
            latestStartTime: latestStartTime_,
            terms: terms_,
            percentages: percentages_,
            isValid: true
        });

        _issuerSlots[issuer_].add(slot);

        emit CreateSlot(
            slot,
            issuer_,
            claimType_,
            latestStartTime_,
            terms_,
            percentages_
        );
    }

    function mint(
        address minter_,
        uint256 slot_,
        uint256 vestingAmount_
    ) external nonReentrant onlyManager {
        amountOfSlot[slot_] = amountOfSlot[slot_].add(vestingAmount_);
        totalAmount = totalAmount.add(vestingAmount_);
        ERC20TransferHelper.doTransferIn(
            underlyingToken,
            minter_,
            vestingAmount_
        );
        emit Mint(minter_, slot_, vestingAmount_);
    }

    function claim(
        uint256 slot_,
        address to_,
        uint256 claimAmount
    ) external nonReentrant onlyManager {
        if (claimAmount > amountOfSlot[slot_]) {
            claimAmount = amountOfSlot[slot_];
        }
        amountOfSlot[slot_] = amountOfSlot[slot_].sub(claimAmount);
        totalAmount = totalAmount.sub(claimAmount);

        SlotDetail storage slotDetail = _slotDetails[slot_];
        uint64 finalTerm = slotDetail.claimType ==
            uint8(Constants.ClaimType.LINEAR)
            ? slotDetail.terms[0]
            : slotDetail.claimType == uint8(Constants.ClaimType.ONE_TIME)
            ? 0
            : stagedTermsToVestingTerm(slotDetail.terms);
        uint64 startTime = slotDetail.startTime > 0
            ? slotDetail.startTime
            : slotDetail.latestStartTime;

        // Since the `startTime` and `terms` are read from storage, and their values have been 
        // checked before stored when minting a new voucher, so there is no need here to check 
        // the overflow of the values of `maturities`.
        uint64[] memory maturities = new uint64[](slotDetail.terms.length);
        maturities[0] = startTime + slotDetail.terms[0];
        for (uint256 i = 1; i < maturities.length; i++) {
            maturities[i] = maturities[i - 1] + slotDetail.terms[i];
        }

        IERC20(underlyingToken).approve(
            address(IICToken(underlyingVestingVoucher).vestingPool()),
            claimAmount
        );
        (, uint256 vestingVoucherId) = IICToken(underlyingVestingVoucher).mint(
            finalTerm,
            claimAmount,
            maturities,
            slotDetail.percentages,
            ""
        );
        VNFTTransferHelper.doTransferOut(
            address(underlyingVestingVoucher),
            to_,
            vestingVoucherId
        );
        emit Claim(slot_, to_, claimAmount);
    }

    function setStartTime(
        address setter_,
        uint256 slot_,
        uint64 startTime_
    ) external onlyManager {
        SlotDetail storage slotDetail = _slotDetails[slot_];
        require(slotDetail.isValid, "invalid slot");
        require(setter_ == slotDetail.issuer, "only issuer");
        require(
            startTime_ <= slotDetail.latestStartTime,
            "exceeds latestStartTime"
        );
        if (slotDetail.startTime > 0) {
            require(block.timestamp < slotDetail.startTime, "unchangeable");
        }

        emit SetStartTime(slot_, slotDetail.startTime, startTime_);
        slotDetail.startTime = startTime_;
    }

    function isClaimable(uint256 slot_) external view returns (bool) {
        SlotDetail storage slotDetail = _slotDetails[slot_];
        return
            (slotDetail.isValid &&
                (slotDetail.startTime == 0 &&
                    block.timestamp >= slotDetail.latestStartTime)) ||
            (slotDetail.startTime > 0 &&
                block.timestamp >= slotDetail.startTime);
    }

    function getSlot(
        address issuer_,
        uint8 claimType_,
        uint64 latestStartTime_,
        uint64[] calldata terms_,
        uint32[] calldata percentages_
    ) public view returns (uint256) {
        return
            uint256(
                keccak256(
                    abi.encode(
                        underlyingToken,
                        underlyingVestingVoucher,
                        issuer_,
                        claimType_,
                        latestStartTime_,
                        terms_,
                        percentages_
                    )
                )
            );
    }

    function getSlotDetail(uint256 slot_)
        external
        view
        returns (SlotDetail memory)
    {
        return _slotDetails[slot_];
    }

    function getIssuerSlots(address issuer_)
        external
        view
        returns (uint256[] memory slots)
    {
        slots = new uint256[](_issuerSlots[issuer_].length());
        for (uint256 i = 0; i < slots.length; i++) {
            slots[i] = _issuerSlots[issuer_].at(i);
        }
    }

    function getIssuerSlotDetails(address issuer_)
        external
        view
        returns (SlotDetail[] memory slotDetails)
    {
        slotDetails = new SlotDetail[](_issuerSlots[issuer_].length());
        for (uint256 i = 0; i < slotDetails.length; i++) {
            slotDetails[i] = _slotDetails[_issuerSlots[issuer_].at(i)];
        }
    }

    function slotProperties(uint256 slot_)
        external
        view
        returns (string memory)
    {
        SlotDetail storage slotDetail = _slotDetails[slot_];
        return
            string(
                abi.encodePacked(
                    abi.encodePacked(
                        '{"underlyingToken":"',
                        underlyingToken.addressToString(),
                        '","underlyingVesting":"',
                        underlyingVestingVoucher.addressToString(),
                        '","claimType:"',
                        _parseClaimType(slotDetail.claimType),
                        '","terms:"',
                        slotDetail.terms.uintArray2str(),
                        '","percentages:"',
                        slotDetail.percentages.percentArray2str()
                    ),
                    abi.encodePacked(
                        '","issuer":"',
                        slotDetail.issuer.addressToString(),
                        '","startTime:"',
                        slotDetail.startTime.toString(),
                        '","latestStartTime:"',
                        slotDetail.latestStartTime.toString(),
                        '"}'
                    )
                )
            );
    }

    function setManager(address newManager_) external onlyAdmin {
        require(newManager_ != address(0), "new manager cannot be 0 address");
        emit NewManager(manager, newManager_);
        manager = newManager_;
    }

    function stagedTermsToVestingTerm(uint64[] memory terms_)
        private
        pure
        returns (uint64 vestingTerm)
    {
        for (uint256 i = 1; i < terms_.length; i++) {
            // The value of `terms_` are read from storage, and their values have been checked before 
            // stored, so there is no need here to check the overflow of `vestingTerm`.
            vestingTerm += terms_[i];
        }
    }

    function _parseClaimType(uint8 claimTypeInNum_)
        private
        pure
        returns (string memory)
    {
        return
            claimTypeInNum_ == 0 ? "LINEAR" : claimTypeInNum_ == 1
                ? "ONE_TIME"
                : claimTypeInNum_ == 2
                ? "STAGED"
                : "UNKNOWN";
    }
}

// File: contracts/interface/IFlexibleDateVestingPool.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.7.6;

interface IFlexibleDateVestingPool {

    struct SlotDetail {
        address issuer;
        uint8 claimType;
        uint64 startTime;
        uint64 latestStartTime;
        uint64[] terms;
        uint32[] percentages;
        bool isValid;
    }

    /** ===== Begin of events emited by FlexibleDateVestingPool ===== */
    event NewManager(address oldManager, address newManager);

    event CreateSlot (
        uint256 indexed slot,
        address indexed issuer,
        uint8 claimType,
        uint64 latestStartTime,
        uint64[] terms,
        uint32[] percentages
    );

    event Mint (
        address indexed minter,
        uint256 indexed slot,
        uint256 vestingAmount
    );

    event Claim (
        uint256 indexed slot,
        address indexed claimer,
        uint256 claimAmount
    );

    event SetStartTime (
        uint256 indexed slot,
        uint64 oldStartTime,
        uint64 newStartTime
    );
    /** ===== End of events emited by FlexibleDateVestingPool ===== */

}
// File: contracts/interface/external/IICToken.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.7.6;

interface IICToken {

    function mint(
        uint64 term, 
        uint256 amount,
        uint64[] calldata maturities, 
        uint32[] calldata percentages,
        string memory originalInvestor
    ) 
        external 
        returns (uint256 slot, uint256 tokenId);
    
    function vestingPool() external view returns (address vestingPoolAddress);

}