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



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../utils/Context.sol";
/**
 * @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/math/SafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

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

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

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

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

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

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

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

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

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }

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

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

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

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using 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: @openzeppelin/contracts/utils/Address.sol



// 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/utils/Context.sol



// 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: contracts/access/Operator.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.8.0;

import {Context, Ownable} from '@openzeppelin/contracts/access/Ownable.sol';

abstract contract Operator is Context, Ownable {
    address private _operator;

    event OperatorTransferred(
        address indexed previousOperator,
        address indexed newOperator
    );

    constructor() {
        _operator = _msgSender();
        emit OperatorTransferred(address(0), _operator);
    }

    function operator() public view returns (address) {
        return _operator;
    }

    modifier onlyOperator() {
        require(
            _operator == _msgSender(),
            'operator: caller is not the operator'
        );
        _;
    }

    function isOperator() public view returns (bool) {
        return _msgSender() == _operator;
    }

    function transferOperator(address newOperator_) public onlyOwner {
        _transferOperator(newOperator_);
    }

    function _transferOperator(address newOperator_) internal {
        require(
            newOperator_ != address(0),
            'operator: zero address given for new operator'
        );
        emit OperatorTransferred(address(0), newOperator_);
        _operator = newOperator_;
    }
}

// File: contracts/boardroom/RedeemPool.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.8.0;

import {IERC20} from '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import {SafeMath} from '@openzeppelin/contracts/math/SafeMath.sol';
import {SafeERC20} from '@openzeppelin/contracts/token/ERC20/SafeERC20.sol';

import {IUniswapV2Router01} from '../interfaces/IUniswapV2Router.sol';
import {Operator} from '../access/Operator.sol';
import {IBurnProxy} from '../treasury/IBurnProxy.sol';

interface IRedeemPool {
    event RedeemStart(address indexed starter, uint256 reward);
    event DepositBond(address indexed owner, uint256 amount);
    event RewardClaimed(address indexed owner, uint256 amount);
    event ReCharge(
        address indexed owner,
        address indexed token,
        uint256 indexed rid,
        uint256 amount
    );
    event ReChargeETH(
        address indexed owner,
        uint256 indexed rid,
        uint256 amount
    );
    event Withdrawal(
        address indexed from,
        address indexed to,
        uint256 indexed at
    );

    function rechargeCash(uint256 _rid, uint256 _amount) external;
}

contract RedeemPool is IRedeemPool, Operator {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    struct Redeemseat {
        uint256 lastSnapshotIndex;
        uint256 deposit;
        uint256 rewardEarned;
    }

    struct RedeemSnapshot {
        uint256 start;
        uint256 end;
        uint256 rewardAll;
        uint256 deposit;
        uint256 maxDeposit;
        uint256 rewardPerBond;
    }

    RedeemSnapshot[] public history;
    mapping(address => Redeemseat) public seats;

    // rid => reward amount
    mapping(uint256 => uint256) public currentReward;
    mapping(uint256 => uint256) public lastReward;
    mapping(uint256 => uint256) public historyReward;

    address public bond;
    address public cash;
    address public swapRouter;
    address public burn;
    uint256 public cashToClaim = 0;
    uint256 public nextEpoch;
    uint256 public limitRatio = 1e19;
    uint256 public period = 86400;
    uint256 public epochDuration = 30 days;

    constructor(
        address _bond,
        address _cash,
        uint256 _nextEpoch,
        address _swapRouter
    ) {
        bond = _bond;
        cash = _cash;
        nextEpoch = _nextEpoch;
        swapRouter = _swapRouter;
        history.push(
            RedeemSnapshot({
                start: 0,
                end: block.timestamp,
                deposit: 0,
                maxDeposit: 0,
                rewardAll: 0,
                rewardPerBond: 0
            })
        );
    }

    function lastSnapshotIndex() public view returns (uint256) {
        return history.length.sub(1);
    }

    function canDeposit() public view returns (bool) {
        if (history[lastSnapshotIndex()].end >= block.timestamp) {
            return true;
        }
        if (block.timestamp < nextEpoch) {
            return false;
        }
        if (IERC20(cash).balanceOf(address(this)).sub(cashToClaim) > 0) {
            return true;
        }
        return false;
    }

    function setPeriod(uint256 _period) public onlyOperator {
        period = _period;
    }

    function setNextEpoch(uint256 _nextEpoch) public onlyOperator {
        nextEpoch = _nextEpoch;
    }

    function setEpochDuration(uint256 _epochDuration) public onlyOperator {
        epochDuration = _epochDuration;
    }

    function setLimitRatio(uint256 _limitRatio) public onlyOperator {
        limitRatio = _limitRatio;
        RedeemSnapshot memory snapShot = history[lastSnapshotIndex()];
        if (snapShot.end >= block.timestamp) {
            snapShot.maxDeposit = snapShot.rewardAll.mul(limitRatio).div(1e18);
        }
        history[lastSnapshotIndex()] = snapShot;
    }

    function setSwapRouter(address _swapRouter) public onlyOwner {
        swapRouter = _swapRouter;
    }

    function setBurn(address _burn) public onlyOwner {
        burn = _burn;
    }

    function startRedeem() public onlyOperator {
        _startRedeem();
    }

    function _startRedeem() internal {
        uint256 index = lastSnapshotIndex();
        require(
            block.timestamp > history[index].end,
            'last period have not end'
        );
        uint256 cashRemain = history[index].rewardAll.sub(
            history[index].rewardPerBond.mul(history[index].deposit).div(1e18)
        );

        cashToClaim = cashToClaim - cashRemain;

        uint256 rewardAll = IERC20(cash).balanceOf(address(this)).sub(
            cashToClaim
        );
        require(rewardAll > 0, 'require cash balance gt 0');

        cashToClaim = cashToClaim.add(rewardAll);
        history.push(
            RedeemSnapshot({
                start: block.timestamp,
                end: block.timestamp.add(period),
                deposit: 0,
                maxDeposit: rewardAll.mul(limitRatio).div(1e18),
                rewardAll: rewardAll,
                rewardPerBond: 0
            })
        );
        nextEpoch = nextEpoch.add(period).add(epochDuration);

        for (uint256 i = 0; i < 4; i++) {
            lastReward[i] = currentReward[i];
            currentReward[i] = 0;
        }
        _burnBond();
        emit RedeemStart(_msgSender(), rewardAll);
    }

    function _burnBond() internal {
        if (IERC20(bond).balanceOf(address(this)) <= 0) {
            return;
        }
        IERC20(bond).approve(burn, IERC20(bond).balanceOf(address(this)));
        IBurnProxy(burn).burnFrom(
            address(this),
            IERC20(bond).balanceOf(address(this))
        );
    }

    function burnBond() public onlyOperator {
        _burnBond();
    }

    function deposit(uint256 _amount) public updateReward(_msgSender()) {
        address director = _msgSender();
        uint256 index = lastSnapshotIndex();
        RedeemSnapshot memory snapShot = history[index];
        // start redeem by user
        if (block.timestamp > nextEpoch && block.timestamp > snapShot.end) {
            _startRedeem();
            index = lastSnapshotIndex();
            snapShot = history[index];
        }
        require(
            block.timestamp >= snapShot.start &&
                block.timestamp <= snapShot.end,
            'not in redeem period'
        );
        require(
            snapShot.deposit.add(_amount) <= snapShot.maxDeposit,
            'deposit overflow'
        );
        snapShot.deposit = snapShot.deposit.add(_amount);
        snapShot.rewardPerBond = snapShot.rewardAll.mul(1e18).div(
            snapShot.deposit
        );
        if (snapShot.rewardPerBond > 1e18) {
            snapShot.rewardPerBond = 1e18;
        }
        history[index] = snapShot;

        IERC20(bond).safeTransferFrom(director, address(this), _amount);

        Redeemseat memory seat = seats[director];
        seat.lastSnapshotIndex = index;
        seat.deposit = seat.deposit.add(_amount);
        seats[director] = seat;
        emit DepositBond(director, _amount);
    }

    function claimReward() public {
        _claimRewad(_msgSender());
    }

    function claimRewadFor(address _director) public {
        _claimRewad(_director);
    }

    function _claimRewad(address _director) internal updateReward(_director) {
        Redeemseat memory seat = seats[_director];
        uint256 reward = seat.rewardEarned;
        if (reward == 0) {
            return;
        }

        cashToClaim = cashToClaim.sub(reward);
        IERC20(cash).safeTransfer(_director, reward);
        seat.rewardEarned = 0;
        seats[_director] = seat;

        emit RewardClaimed(_director, reward);
    }

    function rechargeCash(uint256 _rid, uint256 _amount) public override {
        recharge(_rid, cash, _amount);
    }

    /**
     * @param _rid 0 donate 1 vault  2 profile 3 seigniorge
     */
    function recharge(
        uint256 _rid,
        address _token,
        uint256 _amount
    ) public {
        IERC20(_token).safeTransferFrom(_msgSender(), address(this), _amount);
        if (_token == cash) {
            currentReward[_rid] = currentReward[_rid].add(_amount);
            historyReward[_rid] = historyReward[_rid].add(_amount);
        }

        emit ReCharge(_msgSender(), _token, _rid, _amount);
    }

    function rechargeETH(uint256 _rid) public payable {
        emit ReChargeETH(_msgSender(), _rid, msg.value);
    }

    function currentRewardDetail()
        public
        view
        returns (
            uint256,
            uint256,
            uint256,
            uint256,
            uint256
        )
    {
        if (block.timestamp > history[lastSnapshotIndex()].end) {
            return (
                IERC20(cash).balanceOf(address(this)).sub(cashToClaim),
                currentReward[0],
                currentReward[1],
                currentReward[2],
                currentReward[3]
            );
        }
        return (
            history[lastSnapshotIndex()].rewardAll,
            lastReward[0],
            lastReward[1],
            lastReward[2],
            lastReward[3]
        );
    }

    modifier updateReward(address _director) {
        uint256 rewardNew = rewardEarned(_director);
        Redeemseat memory seat = seats[_director];
        if (seat.rewardEarned == rewardNew) {
            _;
            return;
        }
        seat.rewardEarned = rewardNew;
        seat.deposit = 0;
        seats[_director] = seat;
        _;
    }

    function rewardEarned(address _director) public view returns (uint256) {
        Redeemseat memory seat = seats[_director];
        if (seat.deposit == 0) {
            return seat.rewardEarned;
        }
        uint256 lastIndex = lastSnapshotIndex();
        if (
            seat.lastSnapshotIndex == lastIndex &&
            history[lastIndex].end >= block.timestamp
        ) {
            return seat.rewardEarned;
        }
        return
            seat.rewardEarned.add(
                seat
                    .deposit
                    .mul(history[seat.lastSnapshotIndex].rewardPerBond)
                    .div(1e18)
            );
    }

    function historySnapShot() public view returns (uint256, uint256) {
        uint256 totalDeposit = 0;
        uint256 totalReward = 0;
        for (uint256 i = 0; i < history.length; i++) {
            totalDeposit = totalDeposit.add(history[i].deposit);
            totalReward = totalReward.add(history[i].rewardAll);
        }
        return (totalDeposit, totalReward);
    }

    function migrate(uint256 amount, address to) public onlyOwner {
        IERC20(cash).safeTransfer(to, amount);
        emit Withdrawal(_msgSender(), to, block.timestamp);
    }

    function swap(
        address token,
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path
    ) public onlyOperator {
        if (amountIn > IERC20(token).balanceOf(address(this))) {
            amountIn = IERC20(token).balanceOf(address(this));
        }
        require(amountIn > 0, 'token insufficient');
        uint256 cashBefore = IERC20(cash).balanceOf(address(this));
        IERC20(token).approve(swapRouter, amountIn);
        IUniswapV2Router01(swapRouter).swapExactTokensForTokens(
            amountIn,
            amountOutMin,
            path,
            address(this),
            block.timestamp + 10 days
        );
        uint256 amount = IERC20(cash).balanceOf(address(this)).sub(cashBefore);

        uint256 rid = 0;
        currentReward[rid] = currentReward[rid].add(amount);
        historyReward[rid] = historyReward[rid].add(amount);
    }

    function swapETH(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path
    ) public onlyOperator {
        if (amountIn > address(this).balance) {
            amountIn = address(this).balance;
        }
        require(amountIn > 0, 'eth insufficient');
        uint256 cashBefore = IERC20(cash).balanceOf(address(this));
        IUniswapV2Router01(swapRouter).swapExactETHForTokens{value: amountIn}(
            amountOutMin,
            path,
            address(this),
            block.timestamp + 10 days
        );
        uint256 amount = IERC20(cash).balanceOf(address(this)).sub(cashBefore);

        uint256 rid = 0;
        currentReward[rid] = currentReward[rid].add(amount);
        historyReward[rid] = historyReward[rid].add(amount);
    }
}

// File: contracts/interfaces/IUniswapV2Router.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.8.0;

interface IUniswapV2Router01 {
    function factory() external pure returns (address);

    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint256 amountADesired,
        uint256 amountBDesired,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline
    )
        external
        returns (
            uint256 amountA,
            uint256 amountB,
            uint256 liquidity
        );

    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    )
        external
        payable
        returns (
            uint256 amountToken,
            uint256 amountETH,
            uint256 liquidity
        );

    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint256 liquidity,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountA, uint256 amountB);

    function removeLiquidityETH(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountToken, uint256 amountETH);

    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint256 liquidity,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountA, uint256 amountB);

    function removeLiquidityETHWithPermit(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountToken, uint256 amountETH);

    function swapExactTokensForTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapTokensForExactTokens(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactETHForTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function swapTokensForExactETH(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactTokensForETH(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapETHForExactTokens(
        uint256 amountOut,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function quote(
        uint256 amountA,
        uint256 reserveA,
        uint256 reserveB
    ) external pure returns (uint256 amountB);

    function getAmountOut(
        uint256 amountIn,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountOut);

    function getAmountIn(
        uint256 amountOut,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountIn);

    function getAmountsOut(uint256 amountIn, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);

    function getAmountsIn(uint256 amountOut, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountETH);

    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;

    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable;

    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
}

// File: contracts/treasury/IBurnProxy.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.8.0;

interface IBurnProxy {
    function burnFrom(address from, uint256 amount) external;
}