// Sources flattened with hardhat v2.1.2 https://hardhat.org

// File @openzeppelin/contracts/math/SafeMath.sol@v3.4.1

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}


// File @openzeppelin/contracts/utils/Context.sol@v3.4.1

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with 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 Context {
    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/Ownable.sol@v3.4.1

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @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.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: 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), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}


// File @openzeppelin/contracts/utils/EnumerableSet.sol@v3.4.1

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library 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];
    }

    // Bytes32Set

    struct Bytes32Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }


    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
}


// File @openzeppelin/contracts/utils/Address.sol@v3.4.1

// SPDX-License-Identifier: MIT

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/access/AccessControl.sol@v3.4.1

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;



/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControl is Context {
    using EnumerableSet for EnumerableSet.AddressSet;
    using Address for address;

    struct RoleData {
        EnumerableSet.AddressSet members;
        bytes32 adminRole;
    }

    mapping (bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view returns (bool) {
        return _roles[role].members.contains(account);
    }

    /**
     * @dev Returns the number of accounts that have `role`. Can be used
     * together with {getRoleMember} to enumerate all bearers of a role.
     */
    function getRoleMemberCount(bytes32 role) public view returns (uint256) {
        return _roles[role].members.length();
    }

    /**
     * @dev Returns one of the accounts that have `role`. `index` must be a
     * value between 0 and {getRoleMemberCount}, non-inclusive.
     *
     * Role bearers are not sorted in any particular way, and their ordering may
     * change at any point.
     *
     * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
     * you perform all queries on the same block. See the following
     * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
     * for more information.
     */
    function getRoleMember(bytes32 role, uint256 index) public view returns (address) {
        return _roles[role].members.at(index);
    }

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) public virtual {
        require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to grant");

        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) public virtual {
        require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to revoke");

        _revokeRole(role, account);
    }

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) public virtual {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        emit RoleAdminChanged(role, _roles[role].adminRole, adminRole);
        _roles[role].adminRole = adminRole;
    }

    function _grantRole(bytes32 role, address account) private {
        if (_roles[role].members.add(account)) {
            emit RoleGranted(role, account, _msgSender());
        }
    }

    function _revokeRole(bytes32 role, address account) private {
        if (_roles[role].members.remove(account)) {
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}


// File @openzeppelin/contracts/token/ERC20/IERC20.sol@v3.4.1

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}


// File @openzeppelin/contracts/token/ERC20/SafeERC20.sol@v3.4.1

// SPDX-License-Identifier: MIT

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 @uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol@v1.0.1

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}


// File contracts/oracle/IOracle.sol

/*
    Copyright 2020 Cook Finance Devs, based on the works of the Cook Finance Squad

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

pragma solidity ^0.6.2;

abstract contract IOracle {
    function update() external virtual returns (uint256);

    function pairAddress() external view virtual returns (address);
}


// File contracts/oracle/IWETH.sol

pragma solidity ^0.6.2;

abstract contract IWETH {
    function deposit() public payable virtual;
}


// File contracts/oracle/IPriceConsumerV3.sol

pragma solidity ^0.6.2;

abstract contract IPriceConsumerV3 {
    function getLatestPrice() public view virtual returns (int256);
}


// File contracts/core/IPool.sol

/*
    Copyright 2020 Cook Finance Devs, based on the works of the Cook Finance Squad

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

pragma solidity ^0.6.2;
pragma experimental ABIEncoderV2;

abstract contract IPool {
    function stake(uint256 value) external virtual;

    function unstake(uint256 value) external virtual;

    function harvest(uint256 value) public virtual;

    function claim(uint256 value) public virtual;

    function zapStake(uint256 value, address userAddress) external virtual;
}


// File contracts/external/UniswapV2Library.sol

pragma solidity >=0.5.0;


library UniswapV2Library {
    using SafeMath for uint256;

    // returns sorted token addresses, used to handle return values from pairs sorted in this order
    function sortTokens(address tokenA, address tokenB)
        internal
        pure
        returns (address token0, address token1)
    {
        require(tokenA != tokenB, "UniswapV2Library: IDENTICAL_ADDRESSES");
        (token0, token1) = tokenA < tokenB
            ? (tokenA, tokenB)
            : (tokenB, tokenA);
        require(token0 != address(0), "UniswapV2Library: ZERO_ADDRESS");
    }

    // calculates the CREATE2 address for a pair without making any external calls
    function pairFor(
        address factory,
        address tokenA,
        address tokenB
    ) internal pure returns (address pair) {
        (address token0, address token1) = sortTokens(tokenA, tokenB);
        pair = address(
            uint256(
                keccak256(
                    abi.encodePacked(
                        hex"ff",
                        factory,
                        keccak256(abi.encodePacked(token0, token1)),
                        hex"96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f" // init code hash
                    )
                )
            )
        );
    }

    // fetches and sorts the reserves for a pair
    function getReserves(
        address factory,
        address tokenA,
        address tokenB
    ) internal view returns (uint256 reserveA, uint256 reserveB) {
        (address token0, ) = sortTokens(tokenA, tokenB);
        (uint256 reserve0, uint256 reserve1, ) =
            IUniswapV2Pair(pairFor(factory, tokenA, tokenB)).getReserves();
        (reserveA, reserveB) = tokenA == token0
            ? (reserve0, reserve1)
            : (reserve1, reserve0);
    }

    // given some amount of an asset and pair reserves, returns an equivalent amount of the other asset
    function quote(
        uint256 amountA,
        uint256 reserveA,
        uint256 reserveB
    ) internal pure returns (uint256 amountB) {
        require(amountA > 0, "UniswapV2Library: INSUFFICIENT_AMOUNT");
        require(
            reserveA > 0 && reserveB > 0,
            "UniswapV2Library: INSUFFICIENT_LIQUIDITY"
        );
        amountB = amountA.mul(reserveB) / reserveA;
    }

    // given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset
    function getAmountOut(
        uint256 amountIn,
        uint256 reserveIn,
        uint256 reserveOut
    ) internal pure returns (uint256 amountOut) {
        require(amountIn > 0, "UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT");
        require(
            reserveIn > 0 && reserveOut > 0,
            "UniswapV2Library: INSUFFICIENT_LIQUIDITY"
        );
        uint256 amountInWithFee = amountIn.mul(997);
        uint256 numerator = amountInWithFee.mul(reserveOut);
        uint256 denominator = reserveIn.mul(1000).add(amountInWithFee);
        amountOut = numerator / denominator;
    }

    // given an output amount of an asset and pair reserves, returns a required input amount of the other asset
    function getAmountIn(
        uint256 amountOut,
        uint256 reserveIn,
        uint256 reserveOut
    ) internal pure returns (uint256 amountIn) {
        require(amountOut > 0, "UniswapV2Library: INSUFFICIENT_OUTPUT_AMOUNT");
        require(
            reserveIn > 0 && reserveOut > 0,
            "UniswapV2Library: INSUFFICIENT_LIQUIDITY"
        );
        uint256 numerator = reserveIn.mul(amountOut).mul(1000);
        uint256 denominator = reserveOut.sub(amountOut).mul(997);
        amountIn = (numerator / denominator).add(1);
    }

    // performs chained getAmountOut calculations on any number of pairs
    function getAmountsOut(
        address factory,
        uint256 amountIn,
        address[] memory path
    ) internal view returns (uint256[] memory amounts) {
        require(path.length >= 2, "UniswapV2Library: INVALID_PATH");
        amounts = new uint256[](path.length);
        amounts[0] = amountIn;
        for (uint256 i; i < path.length - 1; i++) {
            (uint256 reserveIn, uint256 reserveOut) =
                getReserves(factory, path[i], path[i + 1]);
            amounts[i + 1] = getAmountOut(amounts[i], reserveIn, reserveOut);
        }
    }

    // performs chained getAmountIn calculations on any number of pairs
    function getAmountsIn(
        address factory,
        uint256 amountOut,
        address[] memory path
    ) internal view returns (uint256[] memory amounts) {
        require(path.length >= 2, "UniswapV2Library: INVALID_PATH");
        amounts = new uint256[](path.length);
        amounts[amounts.length - 1] = amountOut;
        for (uint256 i = path.length - 1; i > 0; i--) {
            (uint256 reserveIn, uint256 reserveOut) =
                getReserves(factory, path[i - 1], path[i]);
            amounts[i - 1] = getAmountIn(amounts[i], reserveIn, reserveOut);
        }
    }
}


// File contracts/core/CookDistribution.sol

pragma solidity ^0.6.2;










/**
 * @title TokenVesting
 * @dev A token holder contract that can release its token balance gradually like a
 * typical vesting scheme, with a cliff and vesting period.
 */
contract CookDistribution is Ownable, AccessControl {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    event AllocationRegistered(address indexed beneficiary, uint256 amount);
    event TokensWithdrawal(address userAddress, uint256 amount);

    struct Allocation {
        uint256 amount;
        uint256 released;
        bool blackListed;
        bool isRegistered;
    }

    // beneficiary of tokens after they are released
    mapping(address => Allocation) private _beneficiaryAllocations;

    // oracle price data (dayNumber => price)
    mapping(uint256 => uint256) public _oraclePriceFeed;

    // all beneficiary address1
    address[] private _allBeneficiary;

    // vesting start time unix
    uint256 private _start;

    // vesting duration in day
    uint256 public _duration;

    // vesting interval
    uint32 public _interval;

    // released percentage triggered by price, should divided by 100
    uint256 public _advancePercentage;

    // last released percentage triggered date in dayNumber
    uint256 public _lastPriceUnlockDay;

    // next step to unlock
    uint32 public _nextPriceUnlockStep;

    // Max step can be moved
    uint32 public _maxPriceUnlockMoveStep;

    IERC20 private _token;

    IOracle private _oracle;
    IPriceConsumerV3 private _priceConsumer;

    // Date-related constants for sanity-checking dates to reject obvious erroneous inputs
    // SECONDS_PER_DAY = 30 for test only
    uint32 private constant SECONDS_PER_DAY = 86400; /* 86400 seconds in a day */

    uint256[] private _priceKey;
    uint256[] private _percentageValue;
    mapping(uint256 => uint256) private _pricePercentageMapping;

    // Fields for Admin
    // stop everyone from claiming/zapping cook token due to emgergency
    bool public _pauseClaim;

    bytes32 public constant MANAGER_ROLE = keccak256("MANAGER");
    bytes32 public constant ADMIN_ROLE = keccak256("ADMIN");

    constructor(
        IERC20 token_,
        address[] memory beneficiaries_,
        uint256[] memory amounts_,
        uint256 start, // in unix
        uint256 duration, // in day
        uint32 interval, // in day
        address oracle_,
        address priceConsumer_
    ) public {
        // init beneficiaries
        for (uint256 i = 0; i < beneficiaries_.length; i++) {
            require(
                beneficiaries_[i] != address(0),
                "Beneficiary cannot be 0 address."
            );

            require(amounts_[i] > 0, "Cannot allocate zero amount.");

            // store all beneficiaries address
            _allBeneficiary.push(beneficiaries_[i]);

            // Add new allocation to beneficiaryAllocations
            _beneficiaryAllocations[beneficiaries_[i]] = Allocation(
                amounts_[i],
                0,
                false,
                true
            );

            emit AllocationRegistered(beneficiaries_[i], amounts_[i]);
        }

        _token = token_;
        _duration = duration;
        _start = start;
        _interval = interval;
        // init release percentage is 1%
        _advancePercentage = 1;
        _oracle = IOracle(oracle_);
        _priceConsumer = IPriceConsumerV3(priceConsumer_);
        _lastPriceUnlockDay = 0;
        _nextPriceUnlockStep = 0;
        _maxPriceUnlockMoveStep = 1;
        _pauseClaim = false;

        // init price percentage
        _priceKey = [500000, 800000, 1100000, 1400000, 1700000, 2000000, 2300000, 2600000, 2900000, 3200000, 3500000, 3800000, 4100000,
                    4400000, 4700000, 5000000, 5300000, 5600000, 5900000, 6200000, 6500000];
        _percentageValue = [1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100];

        for (uint256 i = 0; i < _priceKey.length; i++) {
            _pricePercentageMapping[_priceKey[i]] = _percentageValue[i];
        }

        // Make the deployer defaul admin role and manager role
        _setupRole(MANAGER_ROLE, msg.sender);
        _setupRole(ADMIN_ROLE, msg.sender);
        _setRoleAdmin(MANAGER_ROLE, ADMIN_ROLE);
    }

    fallback() external payable {
        revert();
    }

    /**
     * @return the start time of the token vesting. in unix
     */
    function start() public view returns (uint256) {
        return _start;
    }

    /**
     * @return the duration of the token vesting. in day
     */
    function duration() public view returns (uint256) {
        return _duration;
    }

    /**
     * @return the registerd state.
     */
    function getRegisteredStatus(address userAddress) public view returns (bool) {
        return _beneficiaryAllocations[userAddress].isRegistered;
    }

    function getUserVestingAmount(address userAddress) public view returns (uint256) {
        return _beneficiaryAllocations[userAddress].amount;
    }
    
    function getOraclePriceFeed(uint256 day) public view returns (uint256) {
        return _oraclePriceFeed[day];
    }

    function getUserAvailableAmount(address userAddress, uint256 onDayOrToday) public view returns (uint256) {
        uint256 avalible =
            _getVestedAmount(userAddress, onDayOrToday).sub(
                _beneficiaryAllocations[userAddress].released
            );
        return avalible;
    }

    function getUserVestedAmount(address userAddress, uint256 onDayOrToday)
        public
        view
        returns (uint256 amountVested)
    {
        return _getVestedAmount(userAddress, onDayOrToday);
    }

    /**
     * @dev returns the day number of the current day, in days since the UNIX epoch.
     */
    function today() public view virtual returns (uint256 dayNumber) {
        return uint256(block.timestamp / SECONDS_PER_DAY);
    }

    function startDay() public view returns (uint256) {
        return uint256(_start / SECONDS_PER_DAY);
    }

    function _effectiveDay(uint256 onDayOrToday) internal view returns (uint256) {
        return onDayOrToday == 0 ? today() : onDayOrToday;
    }

    function _getVestedAmount(address userAddress, uint256 onDayOrToday) internal view returns (uint256) {
        uint256 onDay = _effectiveDay(onDayOrToday); // day

        // If after end of vesting, then the vested amount is total amount.
        if (onDay >= (startDay() + _duration)) {
            return _beneficiaryAllocations[userAddress].amount;
        }
        // If it's before the vesting then the vested amount is zero.
        else if (onDay < startDay()) {
            // All are vested (none are not vested)
            return 0;
        }
        // Otherwise a fractional amount is vested.
        else {
            // Compute the exact number of days vested.
            uint256 daysVested = onDay - startDay();
            // Adjust result rounding down to take into consideration the interval.
            uint256 effectiveDaysVested = (daysVested / _interval) * _interval;

            // Compute the fraction vested from schedule using 224.32 fixed point math for date range ratio.
            // Note: This is safe in 256-bit math because max value of X billion tokens = X*10^27 wei, and
            // typical token amounts can fit into 90 bits. Scaling using a 32 bits value results in only 125
            // bits before reducing back to 90 bits by dividing. There is plenty of room left, even for token
            // amounts many orders of magnitude greater than mere billions.

            uint256 vested = 0;

            if (
                _beneficiaryAllocations[userAddress]
                    .amount
                    .mul(effectiveDaysVested)
                    .div(_duration) >
                _beneficiaryAllocations[userAddress]
                    .amount
                    .mul(_advancePercentage)
                    .div(100)
            ) {
                // no price based percentage > date based percentage
                vested = _beneficiaryAllocations[userAddress]
                    .amount
                    .mul(effectiveDaysVested)
                    .div(_duration);
            } else {
                // price based percentage > date based percentage
                vested = _beneficiaryAllocations[userAddress]
                    .amount
                    .mul(_advancePercentage)
                    .div(100);
            }

            return vested;
        }
    }

    /**
    withdraw function
   */
    function withdraw(uint256 withdrawAmount) public {
        address userAddress = msg.sender;

        require(
            _beneficiaryAllocations[userAddress].isRegistered == true,
            "You have to be a registered address."
        );

        require(
            _beneficiaryAllocations[userAddress].blackListed == false,
            "Your address is blacklisted."
        );

        require(
            _pauseClaim == false,
            "Cook token is not claimable due to emgergency"
        );

        require(
            getUserAvailableAmount(userAddress, today()) >= withdrawAmount,
            "insufficient avalible cook balance"
        );

        _beneficiaryAllocations[userAddress].released = _beneficiaryAllocations[
            userAddress
        ]
            .released
            .add(withdrawAmount);

        _token.safeTransfer(userAddress, withdrawAmount);

        emit TokensWithdrawal(userAddress, withdrawAmount);
    }

    function _getPricePercentage(uint256 priceKey) internal view returns (uint256) {
        return _pricePercentageMapping[priceKey];
    }

    function _calWethAmountToPairCook(uint256 cookAmount) internal returns (uint256, address) {
        // get pair address
        IUniswapV2Pair lpPair = IUniswapV2Pair(_oracle.pairAddress());
        uint256 reserve0;
        uint256 reserve1;
        address weth;

        if (lpPair.token0() == address(_token)) {
            (reserve0, reserve1, ) = lpPair.getReserves();
            weth = lpPair.token1();
        } else {
            (reserve1, reserve0, ) = lpPair.getReserves();
            weth = lpPair.token0();
        }

        uint256 wethAmount =
            (reserve0 == 0 && reserve1 == 0)
                ? cookAmount
                : UniswapV2Library.quote(cookAmount, reserve0, reserve1);

        return (wethAmount, weth);
    }

    function zapLP(uint256 cookAmount, address poolAddress) external {
        _zapLP(cookAmount, poolAddress, false);
    }

    function _zapLP(uint256 cookAmount, address poolAddress, bool isWithEth) internal {
        address userAddress = msg.sender;
        _checkValidZap(userAddress, cookAmount);

        uint256 newUniv2 = 0;

        (, newUniv2) = addLiquidity(cookAmount);

        IERC20(_oracle.pairAddress()).approve(poolAddress, newUniv2);

        IPool(poolAddress).zapStake(newUniv2, userAddress);
    }

    function _checkValidZap(address userAddress, uint256 cookAmount) internal {
        require(_beneficiaryAllocations[userAddress].isRegistered == true, "You have to be a registered address.");

        require(
            _beneficiaryAllocations[userAddress].blackListed == false,
            "Your address is blacklisted"
        );

        require(_pauseClaim == false, "Cook token can not be zap.");

        require(cookAmount > 0, "zero zap amount");

        require(
            getUserAvailableAmount(userAddress, today()) >= cookAmount, "insufficient avalible cook balance"
        );

        _beneficiaryAllocations[userAddress].released = _beneficiaryAllocations[userAddress].released.add(cookAmount);
    }

    function addLiquidity(uint256 cookAmount) internal returns (uint256, uint256) {
        // get pair address
        (uint256 wethAmount, ) = _calWethAmountToPairCook(cookAmount);
        _token.safeTransfer(_oracle.pairAddress(), cookAmount);

        IUniswapV2Pair lpPair = IUniswapV2Pair(_oracle.pairAddress());
        if (lpPair.token0() == address(_token)) {
            // token0 == cook, token1 == weth
            require(IERC20(lpPair.token1()).balanceOf(msg.sender) >= wethAmount, "insufficient weth balance");
            require(IERC20(lpPair.token1()).allowance(msg.sender, address(this)) >= wethAmount, "insufficient weth allowance");
            IERC20(lpPair.token1()).safeTransferFrom(
                msg.sender,
                _oracle.pairAddress(),
                wethAmount
            );
        } else if (lpPair.token1() == address(_token)) {
            // token0 == weth, token1 == cook
            require(IERC20(lpPair.token0()).balanceOf(msg.sender) >= wethAmount, "insufficient weth balance");
            require(IERC20(lpPair.token0()).allowance(msg.sender, address(this)) >= wethAmount, "insufficient weth allowance");
            IERC20(lpPair.token0()).safeTransferFrom(msg.sender, _oracle.pairAddress(), wethAmount);
        }

        return (wethAmount, lpPair.mint(address(this)));
    }

    // Zap into Cook staking pool functions
    function zapCook(uint256 cookAmount, address cookPoolAddress) external {
        address userAddress = msg.sender;
        _checkValidZap(userAddress, cookAmount);
        IERC20(address(_token)).approve(cookPoolAddress, cookAmount);
        IPool(cookPoolAddress).zapStake(cookAmount, userAddress);
    }

    // Admin Functions
    function setPriceBasedMaxStep(uint32 newMaxPriceBasedStep) public {
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");
        _maxPriceUnlockMoveStep = newMaxPriceBasedStep;
    }

    function getPriceBasedMaxSetp() public view returns (uint32) {
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");
        return _maxPriceUnlockMoveStep;
    }

    function getNextPriceUnlockStep() public view returns (uint32) {
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");
        return _nextPriceUnlockStep;
    }

    /**
     * add adddress with allocation
     */
    function addAddressWithAllocation(address beneficiaryAddress, uint256 amount ) public  {
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");

        require(
            _beneficiaryAllocations[beneficiaryAddress].isRegistered == false,
            "The address to be added already exisits."
        );

        _beneficiaryAllocations[beneficiaryAddress].isRegistered = true;
        _beneficiaryAllocations[beneficiaryAddress] = Allocation( amount, 0, false, true
        );

        emit AllocationRegistered(beneficiaryAddress, amount);
    }

    /**
     * Add multiple address with multiple allocations
     */
    function addMultipleAddressWithAllocations(address[] memory beneficiaryAddresses, uint256[] memory amounts) public {
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");

        require(beneficiaryAddresses.length > 0 && amounts.length > 0 && beneficiaryAddresses.length == amounts.length,
            "Inconsistent length input"
        );

        for (uint256 i = 0; i < beneficiaryAddresses.length; i++) {
            require(_beneficiaryAllocations[beneficiaryAddresses[i]].isRegistered == false,
                "The address to be added already exisits."
            );
            _beneficiaryAllocations[beneficiaryAddresses[i]].isRegistered = true;
            _beneficiaryAllocations[beneficiaryAddresses[i]] = Allocation(amounts[i], 0, false, true);

            emit AllocationRegistered(beneficiaryAddresses[i], amounts[i]);
        }
    }

    function updatePricePercentage(uint256[] memory priceKey_, uint256[] memory percentageValue_) public {
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");

        require(
            priceKey_.length == percentageValue_.length && priceKey_.length > 0,
            "length inconsistency."
        );

        _priceKey = priceKey_;
        _percentageValue = percentageValue_;

        for (uint256 i = 0; i < _priceKey.length; i++) {
            _pricePercentageMapping[_priceKey[i]] = _percentageValue[i];
        }
    }

    /**
     * return total vested cook amount
     */
    function getTotalAvailable() public view returns (uint256) {uint256 totalAvailable = 0;
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");

        for (uint256 i = 0; i < _allBeneficiary.length; ++i) {
            totalAvailable += getUserAvailableAmount(
                _allBeneficiary[i],
                today()
            );
        }

        return totalAvailable;
    }

    function getLatestSevenSMA() public view returns (uint256) {
        // 7 day sma
        uint256 priceSum = uint256(0);
        uint256 priceCount = uint256(0);
        for (uint32 i = 0; i < 7; ++i) {
            if (_oraclePriceFeed[today() - i] != 0) {
                priceSum = priceSum + _oraclePriceFeed[today() - i];
                priceCount += 1;
            }
        }

        uint256 sevenSMA = 0;
        if (priceCount == 7) {
            sevenSMA = priceSum.div(priceCount);
        }
        return sevenSMA;
    }

    /**
     * update price feed and update price-based unlock percentage
     */
    function updatePriceFeed() public {
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");

        // oracle capture -> 900000000000000000 -> 1 cook = 0.9 ETH
        uint256 cookPrice = _oracle.update();

        // ETH/USD capture -> 127164849196 -> 1ETH = 1271.64USD
        uint256 ethPrice = uint256(_priceConsumer.getLatestPrice());

        uint256 price = cookPrice.mul(ethPrice).div(10**18);

        // update price to _oraclePriceFeed
        _oraclePriceFeed[today()] = price;

        if (today() >= _lastPriceUnlockDay.add(7)) {
            // 7 day sma
            uint256 sevenSMA = getLatestSevenSMA();
            uint256 priceRef = 0;

            for (uint32 i = 0; i < _priceKey.length; ++i) {
                if (sevenSMA >= _priceKey[i]) {
                    priceRef = _pricePercentageMapping[_priceKey[i]];
                }
            }

            // no lower action if the price drop after price-based unlock
            if (priceRef > _advancePercentage) {
                // guard _nextPriceUnlockStep exceed
                if (_nextPriceUnlockStep >= _percentageValue.length) {
                    _nextPriceUnlockStep = uint32(_percentageValue.length - 1);
                }

                // update _advancePercentage to nextStep percentage
                _advancePercentage = _pricePercentageMapping[
                    _priceKey[_nextPriceUnlockStep]
                ];

                // update nextStep value
                _nextPriceUnlockStep =
                    _nextPriceUnlockStep +
                    _maxPriceUnlockMoveStep;

                // update lastUnlcokDay
                _lastPriceUnlockDay = today();
            }
        }
    }

    // Put an evil address into blacklist
    function blacklistAddress(address userAddress) public {
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");
        _beneficiaryAllocations[userAddress].blackListed = true;
    }

    //Remove an address from blacklist
    function removeAddressFromBlacklist(address userAddress) public {
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");
        _beneficiaryAllocations[userAddress].blackListed = false;
    }

    // Pause all claim due to emergency
    function pauseClaim() public {
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");
        _pauseClaim = true;
    }

    // resume cliamable
    function resumeCliam() public {
        require(hasRole(MANAGER_ROLE, msg.sender), "Caller is not a manager");
        _pauseClaim = false;
    }

    // admin emergency to transfer token to owner
    function emergencyWithdraw(uint256 amount) public onlyOwner {
        _token.safeTransfer(msg.sender, amount);
    }

    function getManagerRole() public returns (bytes32) {
        return MANAGER_ROLE;
    }
}