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/**
 *Submitted for verification at Etherscan.io on 2020-08-26
 */

// File: @openzeppelin/contracts/token/ERC20/IERC20M.sol

pragma solidity >=0.6.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20M {
	/**
	 * @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: @openzeppelin/contracts/math/SafeMathM.sol

pragma solidity >=0.6.0;

/**
 * @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.
 * `SafeMathM` 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 SafeMathM {
	/**
	 * @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, "SafeMathM: 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) {
		return sub(a, b, "SafeMathM: subtraction overflow");
	}

	/**
	 * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
	 * overflow (when the result is negative).
	 *
	 * 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);
		uint256 c = a - b;

		return c;
	}

	/**
	 * @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) {
		// 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 0;
		}

		uint256 c = a * b;
		require(c / a == b, "SafeMathM: multiplication overflow");

		return c;
	}

	/**
	 * @dev Returns the integer division of two unsigned integers. Reverts 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) {
		return div(a, b, "SafeMathM: division by zero");
	}

	/**
	 * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
	 * division by zero. The result is rounded towards zero.
	 *
	 * Counterpart to Solidity's `/` operator. Note: this function uses a
	 * `revert` opcode (which leaves remaining gas untouched) while Solidity
	 * uses an invalid opcode to revert (consuming all remaining gas).
	 *
	 * Requirements:
	 *
	 * - The divisor cannot be zero.
	 */
	function div(
		uint256 a,
		uint256 b,
		string memory errorMessage
	) internal pure returns (uint256) {
		require(b > 0, errorMessage);
		uint256 c = a / b;
		// assert(a == b * c + a % b); // There is no case in which this doesn't hold

		return c;
	}

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

	/**
	 * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
	 * Reverts with custom message 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,
		string memory errorMessage
	) internal pure returns (uint256) {
		require(b != 0, errorMessage);
		return a % b;
	}
}

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

pragma solidity >=0.6.2;

/**
 * @dev Collection of functions related to the address type
 */
library AddressM {
	/**
	 * @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) {
		// According to EIP-1052, 0x0 is the value returned for not-yet created accounts
		// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
		// for accounts without code, i.e. `keccak256('')`
		bytes32 codehash;
		bytes32 accountHash =
			0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
		// solhint-disable-next-line no-inline-assembly
		assembly {
			codehash := extcodehash(account)
		}
		return (codehash != accountHash && codehash != 0x0);
	}

	/**
	 * @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,
			"AddressM: insufficient balance"
		);

		// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
		(bool success, ) = recipient.call{ value: amount }("");
		require(
			success,
			"AddressM: 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, "AddressM: low-level call failed");
	}

	/**
	 * @dev Same as {xref-AddressM-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-AddressM-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,
				"AddressM: low-level call with value failed"
			);
	}

	/**
	 * @dev Same as {xref-AddressM-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,
			"AddressM: insufficient balance for call"
		);
		return _functionCallWithValue(target, data, value, errorMessage);
	}

	function _functionCallWithValue(
		address target,
		bytes memory data,
		uint256 weiValue,
		string memory errorMessage
	) private returns (bytes memory) {
		require(isContract(target), "AddressM: call to non-contract");

		// solhint-disable-next-line avoid-low-level-calls
		(bool success, bytes memory returndata) =
			target.call{ value: weiValue }(data);
		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/SafeERC20M.sol

pragma solidity >=0.6.0;

/**
 * @title SafeERC20M
 * @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 SafeERC20M for IERC20M;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20M {
	using SafeMathM for uint256;
	using AddressM for address;

	function safeTransfer(
		IERC20M token,
		address to,
		uint256 value
	) internal {
		_callOptionalReturn(
			token,
			abi.encodeWithSelector(token.transfer.selector, to, value)
		);
	}

	function safeTransferFrom(
		IERC20M 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
	 * {IERC20M-approve}, and its usage is discouraged.
	 *
	 * Whenever possible, use {safeIncreaseAllowance} and
	 * {safeDecreaseAllowance} instead.
	 */
	function safeApprove(
		IERC20M 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),
			"SafeERC20M: approve from non-zero to non-zero allowance"
		);
		_callOptionalReturn(
			token,
			abi.encodeWithSelector(token.approve.selector, spender, value)
		);
	}

	function safeIncreaseAllowance(
		IERC20M 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(
		IERC20M token,
		address spender,
		uint256 value
	) internal {
		uint256 newAllowance =
			token.allowance(address(this), spender).sub(
				value,
				"SafeERC20M: 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(IERC20M 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 {AddressM.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,
				"SafeERC20M: low-level call failed"
			);
		if (returndata.length > 0) {
			// Return data is optional
			// solhint-disable-next-line max-line-length
			require(
				abi.decode(returndata, (bool)),
				"SafeERC20M: ERC20 operation did not succeed"
			);
		}
	}
}

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

pragma solidity >=0.6.0;

/**
 * @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 v3.0.0, only sets of type `address` (`AddressSet`) and `uint256`
 * (`UintSet`) are supported.
 */
library EnumerableSet {
	// 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];
	}

	// 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(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(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(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(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: @openzeppelin/contracts/GSN/ContextM.sol

pragma solidity >=0.6.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with 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 ContextM {
	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;
	}
}

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

pragma solidity >=0.6.0;

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

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

	/**
	 * @dev Initializes the contract setting the deployer as the initial owner.
	 */
	constructor() {
		address msgSender = _msgSender();
		_owner = msgSender;
		emit OwnershipTransferred(address(0), msgSender);
	}

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

	/**
	 * @dev Throws if called by any account other than the owner.
	 */
	modifier onlyOwner() {
		require(_owner == _msgSender(), "OwnableM: caller is not the owner");
		_;
	}

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

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

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

pragma solidity >=0.6.0;

/**
 * @dev Implementation of the {IERC20M} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20M-approve}.
 */
contract ERC20M is ContextM, IERC20M {
	using SafeMathM for uint256;
	using AddressM for address;

	mapping(address => uint256) private _balances;

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

	uint256 private _totalSupply;

	string private _name;
	string private _symbol;
	uint8 private _decimals;

	/**
	 * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
	 * a default value of 18.
	 *
	 * To select a different value for {decimals}, use {_setupDecimals}.
	 *
	 * All three of these values are immutable: they can only be set once during
	 * construction.
	 */
	constructor(string memory name, string memory symbol) public {
		_name = name;
		_symbol = symbol;
		_decimals = 18;
	}

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

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

	/**
	 * @dev Returns the number of decimals used to get its user representation.
	 * For example, if `decimals` equals `2`, a balance of `505` tokens should
	 * be displayed to a user as `5,05` (`505 / 10 ** 2`).
	 *
	 * Tokens usually opt for a value of 18, imitating the relationship between
	 * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
	 * called.
	 *
	 * NOTE: This information is only used for _display_ purposes: it in
	 * no way affects any of the arithmetic of the contract, including
	 * {IERC20M-balanceOf} and {IERC20M-transfer}.
	 */
	function decimals() public view returns (uint8) {
		return _decimals;
	}

	/**
	 * @dev See {IERC20M-totalSupply}.
	 */
	function totalSupply() public view override returns (uint256) {
		return _totalSupply;
	}

	/**
	 * @dev See {IERC20M-balanceOf}.
	 */
	function balanceOf(address account) public view override returns (uint256) {
		return _balances[account];
	}

	/**
	 * @dev See {IERC20M-transfer}.
	 *
	 * Requirements:
	 *
	 * - `recipient` cannot be the zero address.
	 * - the caller must have a balance of at least `amount`.
	 */
	function transfer(address recipient, uint256 amount)
		public
		virtual
		override
		returns (bool)
	{
		_transfer(_msgSender(), recipient, amount);
		return true;
	}

	/**
	 * @dev See {IERC20M-allowance}.
	 */
	function allowance(address owner, address spender)
		public
		view
		virtual
		override
		returns (uint256)
	{
		return _allowances[owner][spender];
	}

	/**
	 * @dev See {IERC20M-approve}.
	 *
	 * Requirements:
	 *
	 * - `spender` cannot be the zero address.
	 */
	function approve(address spender, uint256 amount)
		public
		virtual
		override
		returns (bool)
	{
		_approve(_msgSender(), spender, amount);
		return true;
	}

	/**
	 * @dev See {IERC20M-transferFrom}.
	 *
	 * Emits an {Approval} event indicating the updated allowance. This is not
	 * required by the EIP. See the note at the beginning of {ERC20};
	 *
	 * Requirements:
	 * - `sender` and `recipient` cannot be the zero address.
	 * - `sender` must have a balance of at least `amount`.
	 * - the caller must have allowance for ``sender``'s tokens of at least
	 * `amount`.
	 */
	function transferFrom(
		address sender,
		address recipient,
		uint256 amount
	) public virtual override returns (bool) {
		_transfer(sender, recipient, amount);
		_approve(
			sender,
			_msgSender(),
			_allowances[sender][_msgSender()].sub(
				amount,
				"ERC20: transfer amount exceeds allowance"
			)
		);
		return true;
	}

	/**
	 * @dev Atomically increases the allowance granted to `spender` by the caller.
	 *
	 * This is an alternative to {approve} that can be used as a mitigation for
	 * problems described in {IERC20M-approve}.
	 *
	 * Emits an {Approval} event indicating the updated allowance.
	 *
	 * Requirements:
	 *
	 * - `spender` cannot be the zero address.
	 */
	function increaseAllowance(address spender, uint256 addedValue)
		public
		virtual
		returns (bool)
	{
		_approve(
			_msgSender(),
			spender,
			_allowances[_msgSender()][spender].add(addedValue)
		);
		return true;
	}

	/**
	 * @dev Atomically decreases the allowance granted to `spender` by the caller.
	 *
	 * This is an alternative to {approve} that can be used as a mitigation for
	 * problems described in {IERC20M-approve}.
	 *
	 * Emits an {Approval} event indicating the updated allowance.
	 *
	 * Requirements:
	 *
	 * - `spender` cannot be the zero address.
	 * - `spender` must have allowance for the caller of at least
	 * `subtractedValue`.
	 */
	function decreaseAllowance(address spender, uint256 subtractedValue)
		public
		virtual
		returns (bool)
	{
		_approve(
			_msgSender(),
			spender,
			_allowances[_msgSender()][spender].sub(
				subtractedValue,
				"ERC20M: decreased allowance below zero"
			)
		);
		return true;
	}

	/**
	 * @dev Moves tokens `amount` from `sender` to `recipient`.
	 *
	 * This is internal function is equivalent to {transfer}, and can be used to
	 * e.g. implement automatic token fees, slashing mechanisms, etc.
	 *
	 * Emits a {Transfer} event.
	 *
	 * Requirements:
	 *
	 * - `sender` cannot be the zero address.
	 * - `recipient` cannot be the zero address.
	 * - `sender` must have a balance of at least `amount`.
	 */
	function _transfer(
		address sender,
		address recipient,
		uint256 amount
	) internal virtual {
		require(sender != address(0), "ERC20M: transfer from the zero address");
		require(
			recipient != address(0),
			"ERC20M: transfer to the zero address"
		);

		_beforeTokenTransfer(sender, recipient, amount);

		_balances[sender] = _balances[sender].sub(
			amount,
			"ERC20M: transfer amount exceeds balance"
		);
		_balances[recipient] = _balances[recipient].add(amount);
		emit Transfer(sender, recipient, amount);
	}

	/** @dev Creates `amount` tokens and assigns them to `account`, increasing
	 * the total supply.
	 *
	 * Emits a {Transfer} event with `from` set to the zero address.
	 *
	 * Requirements
	 *
	 * - `to` cannot be the zero address.
	 */
	function _mint(address account, uint256 amount) internal virtual {
		require(account != address(0), "ERC20M: mint to the zero address");

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

		_totalSupply = _totalSupply.add(amount);
		_balances[account] = _balances[account].add(amount);
		emit Transfer(address(0), account, amount);
	}

	/**
	 * @dev Destroys `amount` tokens from `account`, reducing the
	 * total supply.
	 *
	 * Emits a {Transfer} event with `to` set to the zero address.
	 *
	 * Requirements
	 *
	 * - `account` cannot be the zero address.
	 * - `account` must have at least `amount` tokens.
	 */
	function _burn(address account, uint256 amount) internal virtual {
		require(account != address(0), "ERC20M: burn from the zero address");

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

		_balances[account] = _balances[account].sub(
			amount,
			"ERC20M: burn amount exceeds balance"
		);
		_totalSupply = _totalSupply.sub(amount);
		emit Transfer(account, address(0), amount);
	}

	/**
	 * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
	 *
	 * This is internal function is equivalent to `approve`, and can be used to
	 * e.g. set automatic allowances for certain subsystems, etc.
	 *
	 * Emits an {Approval} event.
	 *
	 * Requirements:
	 *
	 * - `owner` cannot be the zero address.
	 * - `spender` cannot be the zero address.
	 */
	function _approve(
		address owner,
		address spender,
		uint256 amount
	) internal virtual {
		require(owner != address(0), "ERC20M: approve from the zero address");
		require(spender != address(0), "ERC20M: approve to the zero address");

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

	/**
	 * @dev Sets {decimals} to a value other than the default one of 18.
	 *
	 * WARNING: This function should only be called from the constructor. Most
	 * applications that interact with token contracts will not expect
	 * {decimals} to ever change, and may work incorrectly if it does.
	 */
	function _setupDecimals(uint8 decimals_) internal {
		_decimals = decimals_;
	}

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

// File: contracts/SushiToken.sol

pragma solidity >=0.6.12;

// SushiToken with Governance.
contract SushiToken is ERC20M("SushiToken", "SUSHI"), OwnableM {
	using SafeMathM for uint256;

	/// @notice Creates `_amount` token to `_to`. Must only be called by the owner (MasterChef).
	function mint(address _to, uint256 _amount) public onlyOwner {
		_mint(_to, _amount);
		_moveDelegates(address(0), _delegates[_to], _amount);
	}

	// Copied and modified from YAM code:
	// https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernanceStorage.sol
	// https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernance.sol
	// Which is copied and modified from COMPOUND:
	// https://github.com/compound-finance/compound-protocol/blob/master/contracts/Governance/Comp.sol

	// record of each accounts delegate
	mapping(address => address) internal _delegates;

	/// @notice A checkpoint for marking number of votes from a given block
	struct Checkpoint {
		uint32 fromBlock;
		uint256 votes;
	}

	/// @notice A record of votes checkpoints for each account, by index
	mapping(address => mapping(uint32 => Checkpoint)) public checkpoints;

	/// @notice The number of checkpoints for each account
	mapping(address => uint32) public numCheckpoints;

	/// @notice The EIP-712 typehash for the contract's domain
	bytes32 public constant DOMAIN_TYPEHASH =
		keccak256(
			"EIP712Domain(string name,uint256 chainId,address verifyingContract)"
		);

	/// @notice The EIP-712 typehash for the delegation struct used by the contract
	bytes32 public constant DELEGATION_TYPEHASH =
		keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)");

	/// @notice A record of states for signing / validating signatures
	mapping(address => uint256) public nonces;

	/// @notice An event thats emitted when an account changes its delegate
	event DelegateChanged(
		address indexed delegator,
		address indexed fromDelegate,
		address indexed toDelegate
	);

	/// @notice An event thats emitted when a delegate account's vote balance changes
	event DelegateVotesChanged(
		address indexed delegate,
		uint256 previousBalance,
		uint256 newBalance
	);

	/**
	 * @notice Delegate votes from `msg.sender` to `delegatee`
	 * @param delegator The address to get delegatee for
	 */
	function delegates(address delegator) external view returns (address) {
		return _delegates[delegator];
	}

	/**
	 * @notice Delegate votes from `msg.sender` to `delegatee`
	 * @param delegatee The address to delegate votes to
	 */
	function delegate(address delegatee) external {
		return _delegate(msg.sender, delegatee);
	}

	/**
	 * @notice Delegates votes from signatory to `delegatee`
	 * @param delegatee The address to delegate votes to
	 * @param nonce The contract state required to match the signature
	 * @param expiry The time at which to expire the signature
	 * @param v The recovery byte of the signature
	 * @param r Half of the ECDSA signature pair
	 * @param s Half of the ECDSA signature pair
	 */
	function delegateBySig(
		address delegatee,
		uint256 nonce,
		uint256 expiry,
		uint8 v,
		bytes32 r,
		bytes32 s
	) external {
		bytes32 domainSeparator =
			keccak256(
				abi.encode(
					DOMAIN_TYPEHASH,
					keccak256(bytes(name())),
					getChainId(),
					address(this)
				)
			);

		bytes32 structHash =
			keccak256(
				abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry)
			);

		bytes32 digest =
			keccak256(
				abi.encodePacked("\x19\x01", domainSeparator, structHash)
			);

		address signatory = ecrecover(digest, v, r, s);
		require(
			signatory != address(0),
			"SUSHI::delegateBySig: invalid signature"
		);
		require(
			nonce == nonces[signatory]++,
			"SUSHI::delegateBySig: invalid nonce"
		);
		require(
			block.timestamp <= expiry,
			"SUSHI::delegateBySig: signature expired"
		);
		return _delegate(signatory, delegatee);
	}

	/**
	 * @notice Gets the current votes balance for `account`
	 * @param account The address to get votes balance
	 * @return The number of current votes for `account`
	 */
	function getCurrentVotes(address account) external view returns (uint256) {
		uint32 nCheckpoints = numCheckpoints[account];
		return
			nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;
	}

	/**
	 * @notice Determine the prior number of votes for an account as of a block number
	 * @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
	 * @param account The address of the account to check
	 * @param blockNumber The block number to get the vote balance at
	 * @return The number of votes the account had as of the given block
	 */
	function getPriorVotes(address account, uint256 blockNumber)
		external
		view
		returns (uint256)
	{
		require(
			blockNumber < block.number,
			"SUSHI::getPriorVotes: not yet determined"
		);

		uint32 nCheckpoints = numCheckpoints[account];
		if (nCheckpoints == 0) {
			return 0;
		}

		// First check most recent balance
		if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {
			return checkpoints[account][nCheckpoints - 1].votes;
		}

		// Next check implicit zero balance
		if (checkpoints[account][0].fromBlock > blockNumber) {
			return 0;
		}

		uint32 lower = 0;
		uint32 upper = nCheckpoints - 1;
		while (upper > lower) {
			uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow
			Checkpoint memory cp = checkpoints[account][center];
			if (cp.fromBlock == blockNumber) {
				return cp.votes;
			} else if (cp.fromBlock < blockNumber) {
				lower = center;
			} else {
				upper = center - 1;
			}
		}
		return checkpoints[account][lower].votes;
	}

	function _delegate(address delegator, address delegatee) internal {
		address currentDelegate = _delegates[delegator];
		uint256 delegatorBalance = balanceOf(delegator); // balance of underlying SUSHIs (not scaled);
		_delegates[delegator] = delegatee;

		emit DelegateChanged(delegator, currentDelegate, delegatee);

		_moveDelegates(currentDelegate, delegatee, delegatorBalance);
	}

	function _moveDelegates(
		address srcRep,
		address dstRep,
		uint256 amount
	) internal {
		if (srcRep != dstRep && amount > 0) {
			if (srcRep != address(0)) {
				// decrease old representative
				uint32 srcRepNum = numCheckpoints[srcRep];
				uint256 srcRepOld =
					srcRepNum > 0
						? checkpoints[srcRep][srcRepNum - 1].votes
						: 0;
				uint256 srcRepNew = srcRepOld.sub(amount);
				_writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);
			}

			if (dstRep != address(0)) {
				// increase new representative
				uint32 dstRepNum = numCheckpoints[dstRep];
				uint256 dstRepOld =
					dstRepNum > 0
						? checkpoints[dstRep][dstRepNum - 1].votes
						: 0;
				uint256 dstRepNew = dstRepOld.add(amount);
				_writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);
			}
		}
	}

	function _writeCheckpoint(
		address delegatee,
		uint32 nCheckpoints,
		uint256 oldVotes,
		uint256 newVotes
	) internal {
		uint32 blockNumber =
			safe32(
				block.number,
				"SUSHI::_writeCheckpoint: block number exceeds 32 bits"
			);

		if (
			nCheckpoints > 0 &&
			checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber
		) {
			checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;
		} else {
			checkpoints[delegatee][nCheckpoints] = Checkpoint(
				blockNumber,
				newVotes
			);
			numCheckpoints[delegatee] = nCheckpoints + 1;
		}

		emit DelegateVotesChanged(delegatee, oldVotes, newVotes);
	}

	function safe32(uint256 n, string memory errorMessage)
		internal
		pure
		returns (uint32)
	{
		require(n < 2**32, errorMessage);
		return uint32(n);
	}

	function getChainId() internal pure returns (uint256) {
		uint256 chainId;
		assembly {
			chainId := chainid()
		}
		return chainId;
	}
}

// File: contracts/MasterChef.sol

pragma solidity >=0.6.12;

interface IMigratorChef {
	// Perform LP token migration from legacy UniswapV2 to SushiSwap.
	// Take the current LP token address and return the new LP token address.
	// Migrator should have full access to the caller's LP token.
	// Return the new LP token address.
	//
	// XXX Migrator must have allowance access to UniswapV2 LP tokens.
	// SushiSwap must mint EXACTLY the same amount of SushiSwap LP tokens or
	// else something bad will happen. Traditional UniswapV2 does not
	// do that so be careful!
	function migrate(IERC20M token) external returns (IERC20M);
}

// MasterChef is the master of Sushi. He can make Sushi and he is a fair guy.
//
// Note that it's ownable and the owner wields tremendous power. The ownership
// will be transferred to a governance smart contract once SUSHI is sufficiently
// distributed and the community can show to govern itself.
//
// Have fun reading it. Hopefully it's bug-free. God bless.
contract MasterChef is OwnableM {
	using SafeMathM for uint256;
	using SafeERC20M for IERC20M;

	// Info of each user.
	struct UserInfo {
		uint256 amount; // How many LP tokens the user has provided.
		uint256 rewardDebt; // Reward debt. See explanation below.
		//
		// We do some fancy math here. Basically, any point in time, the amount of SUSHIs
		// entitled to a user but is pending to be distributed is:
		//
		//   pending reward = (user.amount * pool.accSushiPerShare) - user.rewardDebt
		//
		// Whenever a user deposits or withdraws LP tokens to a pool. Here's what happens:
		//   1. The pool's `accSushiPerShare` (and `lastRewardBlock`) gets updated.
		//   2. User receives the pending reward sent to his/her address.
		//   3. User's `amount` gets updated.
		//   4. User's `rewardDebt` gets updated.
	}

	// Info of each pool.
	struct PoolInfo {
		IERC20M lpToken; // Address of LP token contract.
		uint256 allocPoint; // How many allocation points assigned to this pool. SUSHIs to distribute per block.
		uint256 lastRewardBlock; // Last block number that SUSHIs distribution occurs.
		uint256 accSushiPerShare; // Accumulated SUSHIs per share, times 1e12. See below.
	}

	// The SUSHI TOKEN!
	SushiToken public sushi;
	// Dev address.
	address public devaddr;
	// Block number when bonus SUSHI period ends.
	uint256 public bonusEndBlock;
	// SUSHI tokens created per block.
	uint256 public sushiPerBlock;
	// Bonus muliplier for early sushi makers.
	uint256 public constant BONUS_MULTIPLIER = 10;
	// The migrator contract. It has a lot of power. Can only be set through governance (owner).
	IMigratorChef public migrator;

	// Info of each pool.
	PoolInfo[] public poolInfo;
	// Info of each user that stakes LP tokens.
	mapping(uint256 => mapping(address => UserInfo)) public userInfo;
	// Total allocation poitns. Must be the sum of all allocation points in all pools.
	uint256 public totalAllocPoint = 0;
	// The block number when SUSHI mining starts.
	uint256 public startBlock;

	event Deposit(address indexed user, uint256 indexed pid, uint256 amount);
	event Withdraw(address indexed user, uint256 indexed pid, uint256 amount);
	event EmergencyWithdraw(
		address indexed user,
		uint256 indexed pid,
		uint256 amount
	);

	constructor(
		SushiToken _sushi,
		address _devaddr,
		uint256 _sushiPerBlock,
		uint256 _startBlock,
		uint256 _bonusEndBlock
	) public {
		sushi = _sushi;
		devaddr = _devaddr;
		sushiPerBlock = _sushiPerBlock;
		bonusEndBlock = _bonusEndBlock;
		startBlock = _startBlock;
	}

	function poolLength() external view returns (uint256) {
		return poolInfo.length;
	}

	// Add a new lp to the pool. Can only be called by the owner.
	// XXX DO NOT add the same LP token more than once. Rewards will be messed up if you do.
	function add(
		uint256 _allocPoint,
		IERC20M _lpToken,
		bool _withUpdate
	) public onlyOwner {
		if (_withUpdate) {
			massUpdatePools();
		}
		uint256 lastRewardBlock =
			block.number > startBlock ? block.number : startBlock;
		totalAllocPoint = totalAllocPoint.add(_allocPoint);
		poolInfo.push(
			PoolInfo({
				lpToken: _lpToken,
				allocPoint: _allocPoint,
				lastRewardBlock: lastRewardBlock,
				accSushiPerShare: 0
			})
		);
	}

	// Update the given pool's SUSHI allocation point. Can only be called by the owner.
	function set(
		uint256 _pid,
		uint256 _allocPoint,
		bool _withUpdate
	) public onlyOwner {
		if (_withUpdate) {
			massUpdatePools();
		}
		totalAllocPoint = totalAllocPoint.sub(poolInfo[_pid].allocPoint).add(
			_allocPoint
		);
		poolInfo[_pid].allocPoint = _allocPoint;
	}

	// Set the migrator contract. Can only be called by the owner.
	function setMigrator(IMigratorChef _migrator) public onlyOwner {
		migrator = _migrator;
	}

	// Migrate lp token to another lp contract. Can be called by anyone. We trust that migrator contract is good.
	function migrate(uint256 _pid) public {
		require(address(migrator) != address(0), "migrate: no migrator");
		PoolInfo storage pool = poolInfo[_pid];
		IERC20M lpToken = pool.lpToken;
		uint256 bal = lpToken.balanceOf(address(this));
		lpToken.safeApprove(address(migrator), bal);
		IERC20M newLpToken = migrator.migrate(lpToken);
		require(bal == newLpToken.balanceOf(address(this)), "migrate: bad");
		pool.lpToken = newLpToken;
	}

	// Return reward multiplier over the given _from to _to block.
	function getMultiplier(uint256 _from, uint256 _to)
		public
		view
		returns (uint256)
	{
		if (_to <= bonusEndBlock) {
			return _to.sub(_from).mul(BONUS_MULTIPLIER);
		} else if (_from >= bonusEndBlock) {
			return _to.sub(_from);
		} else {
			return
				bonusEndBlock.sub(_from).mul(BONUS_MULTIPLIER).add(
					_to.sub(bonusEndBlock)
				);
		}
	}

	// View function to see pending SUSHIs on frontend.
	function pendingSushi(uint256 _pid, address _user)
		external
		view
		returns (uint256)
	{
		PoolInfo storage pool = poolInfo[_pid];
		UserInfo storage user = userInfo[_pid][_user];
		uint256 accSushiPerShare = pool.accSushiPerShare;
		uint256 lpSupply = pool.lpToken.balanceOf(address(this));
		if (block.number > pool.lastRewardBlock && lpSupply != 0) {
			uint256 multiplier =
				getMultiplier(pool.lastRewardBlock, block.number);
			uint256 sushiReward =
				multiplier.mul(sushiPerBlock).mul(pool.allocPoint).div(
					totalAllocPoint
				);
			accSushiPerShare = accSushiPerShare.add(
				sushiReward.mul(1e12).div(lpSupply)
			);
		}
		return user.amount.mul(accSushiPerShare).div(1e12).sub(user.rewardDebt);
	}

	// Update reward vairables for all pools. Be careful of gas spending!
	function massUpdatePools() public {
		uint256 length = poolInfo.length;
		for (uint256 pid = 0; pid < length; ++pid) {
			updatePool(pid);
		}
	}

	// Update reward variables of the given pool to be up-to-date.
	function updatePool(uint256 _pid) public {
		PoolInfo storage pool = poolInfo[_pid];
		if (block.number <= pool.lastRewardBlock) {
			return;
		}
		uint256 lpSupply = pool.lpToken.balanceOf(address(this));
		if (lpSupply == 0) {
			pool.lastRewardBlock = block.number;
			return;
		}
		uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number);
		uint256 sushiReward =
			multiplier.mul(sushiPerBlock).mul(pool.allocPoint).div(
				totalAllocPoint
			);
		sushi.mint(devaddr, sushiReward.div(10));
		sushi.mint(address(this), sushiReward);
		pool.accSushiPerShare = pool.accSushiPerShare.add(
			sushiReward.mul(1e12).div(lpSupply)
		);
		pool.lastRewardBlock = block.number;
	}

	// Deposit LP tokens to MasterChef for SUSHI allocation.
	function deposit(uint256 _pid, uint256 _amount) public {
		PoolInfo storage pool = poolInfo[_pid];
		UserInfo storage user = userInfo[_pid][msg.sender];
		updatePool(_pid);
		if (user.amount > 0) {
			uint256 pending =
				user.amount.mul(pool.accSushiPerShare).div(1e12).sub(
					user.rewardDebt
				);
			safeSushiTransfer(msg.sender, pending);
		}
		pool.lpToken.safeTransferFrom(
			address(msg.sender),
			address(this),
			_amount
		);
		user.amount = user.amount.add(_amount);
		user.rewardDebt = user.amount.mul(pool.accSushiPerShare).div(1e12);
		emit Deposit(msg.sender, _pid, _amount);
	}

	// Withdraw LP tokens from MasterChef.
	function withdraw(uint256 _pid, uint256 _amount) public {
		PoolInfo storage pool = poolInfo[_pid];
		UserInfo storage user = userInfo[_pid][msg.sender];
		require(user.amount >= _amount, "withdraw: not good");
		updatePool(_pid);
		uint256 pending =
			user.amount.mul(pool.accSushiPerShare).div(1e12).sub(
				user.rewardDebt
			);
		safeSushiTransfer(msg.sender, pending);
		user.amount = user.amount.sub(_amount);
		user.rewardDebt = user.amount.mul(pool.accSushiPerShare).div(1e12);
		pool.lpToken.safeTransfer(address(msg.sender), _amount);
		emit Withdraw(msg.sender, _pid, _amount);
	}

	// Withdraw without caring about rewards. EMERGENCY ONLY.
	function emergencyWithdraw(uint256 _pid) public {
		PoolInfo storage pool = poolInfo[_pid];
		UserInfo storage user = userInfo[_pid][msg.sender];
		pool.lpToken.safeTransfer(address(msg.sender), user.amount);
		emit EmergencyWithdraw(msg.sender, _pid, user.amount);
		user.amount = 0;
		user.rewardDebt = 0;
	}

	// Safe sushi transfer function, just in case if rounding error causes pool to not have enough SUSHIs.
	function safeSushiTransfer(address _to, uint256 _amount) internal {
		uint256 sushiBal = sushi.balanceOf(address(this));
		if (_amount > sushiBal) {
			sushi.transfer(_to, sushiBal);
		} else {
			sushi.transfer(_to, _amount);
		}
	}

	// Update dev address by the previous dev.
	function dev(address _devaddr) public {
		require(msg.sender == devaddr, "dev: wut?");
		devaddr = _devaddr;
	}
}