// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;


/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library MathUtil {
    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }
}

contract ReentrancyGuard {
    uint256 private _guardCounter;

    constructor () internal {
        _guardCounter = 1;
    }

    modifier nonReentrant() {
        _guardCounter += 1;
        uint256 localCounter = _guardCounter;
        _;
        require(localCounter == _guardCounter, "ReentrancyGuard: reentrant call");
    }
}

interface ICurveGauge {
    function deposit(uint256) external;
    function balanceOf(address) external view returns (uint256);
    function withdraw(uint256) external;
    function claim_rewards() external;
    function reward_tokens(uint256) external view returns(address);//v2
    function rewarded_token() external view returns(address);//v1
}

interface ICurveVoteEscrow {
    function create_lock(uint256, uint256) external;
    function increase_amount(uint256) external;
    function increase_unlock_time(uint256) external;
    function withdraw() external;
    function smart_wallet_checker() external view returns (address);
}

interface IWalletChecker {
    function check(address) external view returns (bool);
}

interface IVoting{
    function vote(uint256, bool, bool) external; //voteId, support, executeIfDecided
    function getVote(uint256) external view returns(bool,bool,uint64,uint64,uint64,uint64,uint256,uint256,uint256,bytes memory); 
    function vote_for_gauge_weights(address,uint256) external;
}

interface IMinter{
    function mint(address) external;
}

interface IRegistry{
    function get_registry() external view returns(address);
    function get_address(uint256 _id) external view returns(address);
    function gauge_controller() external view returns(address);
    function get_lp_token(address) external view returns(address);
    function get_gauges(address) external view returns(address[10] memory,uint128[10] memory);
}

interface IStaker{
    function deposit(address, address) external;
    function withdraw(address) external;
    function withdraw(address, address, uint256) external;
    function withdrawAll(address, address) external;
    function createLock(uint256, uint256) external;
    function increaseAmount(uint256) external;
    function increaseTime(uint256) external;
    function release() external;
    function claimCrv(address) external returns (uint256);
    function claimRewards(address) external;
    function claimFees(address,address) external;
    function setStashAccess(address, bool) external;
    function vote(uint256,address,bool) external;
    function voteGaugeWeight(address,uint256) external;
    function balanceOfPool(address) external view returns (uint256);
    function operator() external view returns (address);
    function execute(address _to, uint256 _value, bytes calldata _data) external returns (bool, bytes memory);
}

interface IRewards{
    function stake(address, uint256) external;
    function stakeFor(address, uint256) external;
    function withdraw(address, uint256) external;
    function exit(address) external;
    function getReward(address) external;
    function queueNewRewards(uint256) external;
    function notifyRewardAmount(uint256) external;
    function addExtraReward(address) external;
    function stakingToken() external view returns (address);
    function rewardToken() external view returns(address);
    function earned(address account) external view returns (uint256);
}

interface IStash{
    function stashRewards() external returns (bool);
    function processStash() external returns (bool);
    function claimRewards() external returns (bool);
}

interface IFeeDistro{
    function claim() external;
    function token() external view returns(address);
}

interface ITokenMinter{
    function mint(address,uint256) external;
    function burn(address,uint256) external;
}

interface IDeposit{
    function isShutdown() external view returns(bool);
    function balanceOf(address _account) external view returns(uint256);
    function totalSupply() external view returns(uint256);
    function poolInfo(uint256) external view returns(address,address,address,address,address, bool);
    function rewardClaimed(uint256,address,uint256) external;
    function withdrawTo(uint256,uint256,address) external;
    function claimRewards(uint256,address) external returns(bool);
    function rewardArbitrator() external returns(address);
    function setGaugeRedirect(uint256 _pid) external returns(bool);
}

interface ICrvDeposit{
    function deposit(uint256, bool) external;
    function lockIncentive() external view returns(uint256);
}

interface IRewardFactory{
    function setAccess(address,bool) external;
    function CreateCrvRewards(uint256,address) external returns(address);
    function CreateTokenRewards(address,address,address) external returns(address);
    function activeRewardCount(address) external view returns(uint256);
    function addActiveReward(address,uint256) external returns(bool);
    function removeActiveReward(address,uint256) external returns(bool);
}

interface IStashFactory{
    function CreateStash(uint256,address,address,uint256) external returns(address);
}

interface ITokenFactory{
    function CreateDepositToken(address) external returns(address);
}

interface IPools{
    function addPool(address _lptoken, address _gauge, uint256 _stashVersion) external returns(bool);
    function shutdownPool(uint256 _pid) external returns(bool);
    function poolInfo(uint256) external view returns(address,address,address,address,address,bool);
    function poolLength() external view returns (uint256);
    function gaugeMap(address) external view returns(bool);
    function setPoolManager(address _poolM) external;
}

interface IVestedEscrow{
    function fund(address[] calldata _recipient, uint256[] calldata _amount) external returns(bool);
}

// File: @openzeppelin\contracts\token\ERC20\IERC20.sol
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: node_modules\@openzeppelin\contracts\math\SafeMath.sol

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: node_modules\@openzeppelin\contracts\utils\Address.sol

pragma solidity >=0.6.2 <0.8.0;

/**
 * @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
     * ====
     */
    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);
    }

    /**
     * @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) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(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: @openzeppelin\contracts\token\ERC20\SafeERC20.sol
pragma solidity >=0.6.0 <0.8.0;


/**
 * @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 SafeMath for uint256;
    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'
        // solhint-disable-next-line max-line-length
        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).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @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
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: contracts\interfaces\ISushiRewarder.sol

pragma solidity 0.6.12;

interface ISushiRewarder {
    using SafeERC20 for IERC20;
    function onSushiReward(uint256 pid, address user, address recipient, uint256 sushiAmount, uint256 newLpAmount) external;
    function pendingTokens(uint256 pid, address user, uint256 sushiAmount) external view returns (IERC20[] memory, uint256[] memory);
}


// File: contracts\ConvexRewarder.sol

pragma solidity 0.6.12;
/**
 *Submitted for verification at Etherscan.io on 2020-07-17
 */

/*
   ____            __   __        __   _
  / __/__ __ ___  / /_ / /  ___  / /_ (_)__ __
 _\ \ / // // _ \/ __// _ \/ -_)/ __// / \ \ /
/___/ \_, //_//_/\__//_//_/\__/ \__//_/ /_\_\
     /___/

* Docs: https://docs.synthetix.io/
*
*
* MIT License
* ===========
*
* Copyright (c) 2020 Synthetix
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
*/



interface IMasterChefV2 {
    function lpToken(uint i) external view returns (IERC20);
}

interface IConvexChef{
    function userInfo(uint256 _pid, address _account) external view returns(uint256,uint256);
    function claim(uint256 _pid, address _account) external;
    function deposit(uint256 _pid, uint256 _amount) external;
}


contract ConvexRewarder is ISushiRewarder{
    using SafeERC20 for IERC20;
    using SafeMath for uint256;

    IERC20 public immutable rewardToken;
    IERC20 public immutable stakingToken;
    uint256 public constant duration = 5 days;

    address public immutable rewardManager;
    address public immutable sushiMasterChef;
    address public immutable convexMasterChef;
    uint256 public immutable chefPid;

    uint256 public periodFinish = 0;
    uint256 public rewardRate = 0;
    uint256 public lastUpdateTime;
    uint256 public rewardPerTokenStored;
    uint256 public currentRewards = 0;
    uint256 private _totalSupply;
    uint256 public sushiPid;
    uint256 public previousRewardDebt = 0;
    bool public isInit = false;

    mapping(address => uint256) private _balances;
    mapping(address => uint256) private _sushiBalances;
    mapping(address => uint256) public userRewardPerTokenPaid;
    mapping(address => uint256) public rewards;

    address[] public extraRewards;

    event RewardAdded(uint256 reward);
    event Staked(address indexed user, uint256 amount);
    event Withdrawn(address indexed user, uint256 amount);
    event RewardPaid(address indexed user, uint256 reward);

    constructor(
        address stakingToken_,
        address rewardToken_,
        address rewardManager_,
        address sushiMasterChef_,
        address convexMasterChef_,
        uint256 chefPid_
    ) public {
        stakingToken = IERC20(stakingToken_);
        rewardToken = IERC20(rewardToken_);
        rewardManager = rewardManager_;
        sushiMasterChef = sushiMasterChef_;
        convexMasterChef = convexMasterChef_;
        chefPid = chefPid_;
    }

    //stake a dummy token into convex chef to start earning rewards
    //initiate a week's worth of awards
    function init(IERC20 dummyToken) external {
        require(!isInit,"already init");
        isInit = true;
        uint256 balance = dummyToken.balanceOf(msg.sender);
        require(balance != 0, "Balance must exceed 0");
        dummyToken.safeTransferFrom(msg.sender, address(this), balance);
        dummyToken.approve(convexMasterChef, balance);
        IConvexChef(convexMasterChef).deposit(chefPid, balance);
        initRewards();
    }

    //claim from convex master chef and add to rewards
    function harvestFromMasterChef() public {
        IConvexChef(convexMasterChef).claim(chefPid, address(this));
        notifyRewardAmount();
    }

    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view returns (uint256) {
        return _balances[account].add(_sushiBalances[account]);
    }

    function localBalanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }

    function sushiBalanceOf(address account) public view returns (uint256) {
        return _sushiBalances[account];
    }

    function extraRewardsLength() external view returns (uint256) {
        return extraRewards.length;
    }

    function addExtraReward(address _reward) external {
        require(msg.sender == rewardManager, "!authorized");
        require(_reward != address(0),"!reward setting");

        extraRewards.push(_reward);
    }
    function clearExtraRewards() external{
        require(msg.sender == rewardManager, "!authorized");
        delete extraRewards;
    }

    modifier updateReward(address account) {
        rewardPerTokenStored = rewardPerToken();
        lastUpdateTime = lastTimeRewardApplicable();
        if (account != address(0)) {
            rewards[account] = earned(account);
            userRewardPerTokenPaid[account] = rewardPerTokenStored;
        }
        _;
    }

    function lastTimeRewardApplicable() public view returns (uint256) {
        return MathUtil.min(block.timestamp, periodFinish);
    }

    function rewardPerToken() public view returns (uint256) {
        uint256 supply = totalSupply();
        if (supply == 0) {
            return rewardPerTokenStored;
        }
        return
            rewardPerTokenStored.add(
                lastTimeRewardApplicable()
                    .sub(lastUpdateTime)
                    .mul(rewardRate)
                    .mul(1e18)
                    .div(supply)
            );
    }

    function earned(address account) public view returns (uint256) {
        return
            _balances[account].add(_sushiBalances[account])
                .mul(rewardPerToken().sub(userRewardPerTokenPaid[account]))
                .div(1e18)
                .add(rewards[account]);
    }

    function stake(uint256 _amount)
        public
        updateReward(msg.sender)
    {
        require(_amount > 0, 'RewardPool : Cannot stake 0');

        //check if new rewards should be pulled from convex chef
        checkHarvest();

        //also stake to linked rewards
        uint256 length = extraRewards.length;
        for(uint i=0; i < length; i++){
            IRewards(extraRewards[i]).stake(msg.sender, _amount);
        }

        //add supply
        _totalSupply = _totalSupply.add(_amount);
        //add to sender balance sheet
        _balances[msg.sender] = _balances[msg.sender].add(_amount);
        //take tokens from sender
        stakingToken.safeTransferFrom(msg.sender, address(this), _amount);

        emit Staked(msg.sender, _amount);
    }

    function stakeAll() external{
        uint256 balance = stakingToken.balanceOf(msg.sender);
        stake(balance);
    }

    function stakeFor(address _for, uint256 _amount)
        public
        updateReward(_for)
    {
        require(_amount > 0, 'RewardPool : Cannot stake 0');

        //check if new rewards should be pulled from convex chef
        checkHarvest();

        //also stake to linked rewards
        uint256 length = extraRewards.length;
        for(uint i=0; i < length; i++){
            IRewards(extraRewards[i]).stake(_for, _amount);
        }

         //add supply
        _totalSupply = _totalSupply.add(_amount);
        //add to _for's balance sheet
        _balances[_for] = _balances[_for].add(_amount);
        //take tokens from sender
        stakingToken.safeTransferFrom(msg.sender, address(this), _amount);

        emit Staked(msg.sender, _amount);
    }

    function withdraw(uint256 _amount, bool claim)
        public
        updateReward(msg.sender)
    {
        require(_amount > 0, 'RewardPool : Cannot withdraw 0');

        //also withdraw from linked rewards
        uint256 length = extraRewards.length;
        for(uint i=0; i < length; i++){
            IRewards(extraRewards[i]).withdraw(msg.sender, _amount);
        }

        _totalSupply = _totalSupply.sub(_amount);
        _balances[msg.sender] = _balances[msg.sender].sub(_amount);
        stakingToken.safeTransfer(msg.sender, _amount);
        emit Withdrawn(msg.sender, _amount);

        if(claim){
            getReward(msg.sender,true);
        }
    }

    function withdrawAll(bool claim) external{
        withdraw(_balances[msg.sender],claim);
    }

    function getReward(address _account, bool _claimExtras) public updateReward(_account){

        uint256 reward = earned(_account);
        if (reward > 0) {
            rewards[_account] = 0;
            rewardToken.safeTransfer(_account, reward);
            emit RewardPaid(_account, reward);
        }

        //also get rewards from linked rewards
        if(_claimExtras){
            uint256 length = extraRewards.length;
            for(uint i=0; i < length; i++){
                IRewards(extraRewards[i]).getReward(_account);
            }
        }

        //check if new rewards should be pulled from convex chef
        checkHarvest();
    }

    function getReward() external{
        getReward(msg.sender,true);
    }

    function checkHarvest() internal{
        //if getting close to the end of the period
        //claim and extend
        if (periodFinish > 0 && block.timestamp >= periodFinish.sub(1 days)  ) {
            harvestFromMasterChef();
        }
    }

    //initialize the period of rewards
    //since the reward rate should be same as speed as rewards coming in from the chef
    // it will never catch up unless there is a seed
    // (or if it mines for a week with 0 distribution)
    function initRewards() internal updateReward(address(0)){
        uint256 reward = rewardToken.balanceOf(address(this));
        
        if (block.timestamp >= periodFinish) {
            rewardRate = reward.div(duration);
        } else {
            uint256 remaining = periodFinish.sub(block.timestamp);
            uint256 leftover = remaining.mul(rewardRate);
            reward = reward.add(leftover);
            rewardRate = reward.div(duration);
        }
        currentRewards = reward;
        lastUpdateTime = block.timestamp;
        periodFinish = block.timestamp.add(duration);
        emit RewardAdded(reward);
    }

    function notifyRewardAmount()
        internal
        updateReward(address(0))
    {
        if(!isInit){
            //return smoothly if not init yet.
            //allow stakers to join but dont start distribution
            return;
        }
        //convex chef allows anyone to claim, so we have to look at reward debt difference
        //so that we know how much we have claimed since previous notifyRewardAmount()
        (,uint256 rewardDebt) = IConvexChef(convexMasterChef).userInfo(chefPid, address(this));
        uint256 reward = rewardDebt.sub(previousRewardDebt);
        previousRewardDebt = rewardDebt;
        if(reward == 0) return;
        
        if (block.timestamp >= periodFinish) {
            rewardRate = reward.div(duration);
        } else {
            uint256 remaining = periodFinish.sub(block.timestamp);
            uint256 leftover = remaining.mul(rewardRate);
            reward = reward.add(leftover);
            rewardRate = reward.div(duration);
        }
        currentRewards = reward;
        lastUpdateTime = block.timestamp;
        periodFinish = block.timestamp.add(duration);
        emit RewardAdded(reward);
    }

    function onSushiReward(
        uint256 pid,
        address user,
        address recipient,
        uint256 sushiAmount,
        uint256 newLpAmount
    )
        override
        external
        updateReward(user)
    {
        require(msg.sender == sushiMasterChef);
      
        // On the first call, validate that the pid correctly maps to our stakingToken
        // Sushi MasterChef does not allow modifying a pid after it has been set, so we can trust
        // this to be safe in the future. If we did not validate the pid going forward, there
        // could be an attack vector by setting this contract as rewardContract on a 2nd pid
        uint256 _sushiPid = sushiPid;
        if (_sushiPid == 0) {
            require(IMasterChefV2(msg.sender).lpToken(pid) == stakingToken);
            sushiPid = pid;
        } else {
            require(pid == _sushiPid);
        }

        if (sushiAmount > 0) {
            // if sushiAmount > 0 the call is claiming sushi and should also claim other rewards

            //sushi allows claiming for user and transferring to recipient, but we do not.
            //just claim to original account
            getReward(user,true);
        }

        uint256 userBalance = _sushiBalances[user];
        if (newLpAmount > userBalance) {
            // reported balance in sushi > internal accounting, user has deposited
            uint256 amount = newLpAmount.sub(userBalance);
            uint256 length = extraRewards.length;
            for(uint i=0; i < length; i++){
                IRewards(extraRewards[i]).stake(user, amount);
            }
            _totalSupply = _totalSupply.add(amount);
            _sushiBalances[user] = newLpAmount;

        } else if (newLpAmount < userBalance) {
            // reported balance in sushi < internal accounting, user has withdrawn
            uint256 amount = userBalance.sub(newLpAmount);
            uint256 length = extraRewards.length;
            for(uint i=0; i < length; i++){
                IRewards(extraRewards[i]).withdraw(msg.sender, amount);
            }
            _totalSupply = _totalSupply.sub(amount);
            _sushiBalances[user] = newLpAmount;
        }
    }

    function pendingTokens(
        uint256 pid,
        address user,
        uint256 sushiAmount
    )
        override
        external
        view
        returns (IERC20[] memory, uint256[] memory)
    {
        //extra rewards length
        uint256 length = extraRewards.length;

        //combine base and extras
        IERC20[] memory rewardTokens = new IERC20[](1+length);
        rewardTokens[0] = rewardToken;
        for(uint i=0; i < length; i++){
           rewardTokens[1+i] = IERC20(IRewards(extraRewards[i]).rewardToken());
        }
        uint256[] memory earnedAmounts = new uint256[](1+length);
        earnedAmounts[0] = earned(user);
        for(uint i=0; i < length; i++){
            earnedAmounts[1+i] = IRewards(extraRewards[i]).earned(user);
        }
        return (rewardTokens,earnedAmounts);
    }
}