// SPDX-License-Identifier: CC-BY-NC-SA-2.5
//@code0x2

pragma solidity ^0.6.12;

contract ContractGuard {
    mapping(uint256 => mapping(address => bool)) private _status;

    function checkSameOriginReentranted() internal view returns (bool) {
        return _status[block.number][tx.origin];
    }

    function checkSameSenderReentranted() internal view returns (bool) {
        return _status[block.number][msg.sender];
    }

    modifier onlyOneBlock() {
        require(
            !checkSameOriginReentranted(),
            'ContractGuard: one block, one function'
        );
        require(
            !checkSameSenderReentranted(),
            'ContractGuard: one block, one function'
        );

        _;

        _status[block.number][tx.origin] = true;
        _status[block.number][msg.sender] = true;
    }
}

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;
    }
}

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 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");
        _;
    }

    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

contract Operator is Context, Ownable {
    address private _operator;

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

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

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

    modifier onlyOperator() {
        require(
            _operator == msg.sender,
            '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_;
    }
}

library SafeMath {

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

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

        return c;
    }
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

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

        return c;
    }
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

library Address {
    function isContract(address account) internal view returns (bool) {
        // This method relies in 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;
    }
    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");
    }
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }
    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");
    }
    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");
        return _functionCallWithValue(target, data, value, errorMessage);
    }

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

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

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

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

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");
        }
    }
}

library Safe112 {
    function add(uint112 a, uint112 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, 'Safe112: addition overflow');

        return c;
    }

    function sub(uint112 a, uint112 b) internal pure returns (uint256) {
        return sub(a, b, 'Safe112: subtraction overflow');
    }

    function sub(
        uint112 a,
        uint112 b,
        string memory errorMessage
    ) internal pure returns (uint112) {
        require(b <= a, errorMessage);
        uint112 c = a - b;

        return c;
    }

    function mul(uint112 a, uint112 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, 'Safe112: multiplication overflow');

        return c;
    }

    function div(uint112 a, uint112 b) internal pure returns (uint256) {
        return div(a, b, 'Safe112: division by zero');
    }

    function div(
        uint112 a,
        uint112 b,
        string memory errorMessage
    ) internal pure returns (uint112) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint112 c = a / b;

        return c;
    }

    function mod(uint112 a, uint112 b) internal pure returns (uint256) {
        return mod(a, b, 'Safe112: modulo by zero');
    }

    function mod(
        uint112 a,
        uint112 b,
        string memory errorMessage
    ) internal pure returns (uint112) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

contract ShareWrapper {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    IERC20 public share;

    uint256 private _totalSupply;
    mapping(address => uint256) private _balances;

    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }

    function stake(uint256 amount) public virtual {
        _totalSupply = _totalSupply.add(amount);
        _balances[msg.sender] = _balances[msg.sender].add(amount);
        share.safeTransferFrom(msg.sender, address(this), amount);
    }

    function withdraw(uint256 amount) public virtual {
        uint256 directorShare = _balances[msg.sender];
        require(
            directorShare >= amount,
            'Boardroom: withdraw request greater than staked amount'
        );
        _totalSupply = _totalSupply.sub(amount);
        _balances[msg.sender] = directorShare.sub(amount);
        share.safeTransfer(msg.sender, amount);
    }
}

contract dynamicBoardroom is ShareWrapper, ContractGuard, Operator {
    using SafeERC20 for IERC20;
    using Address for address;
    using SafeMath for uint256;
    using Safe112 for uint112;

    /* ========== DATA STRUCTURES ========== */

    struct Boardseat {
        uint256 lastSnapshotIndex;
        uint256 rewardEarned;
    }

    struct BoardSnapshot {
        uint256 time;
        uint256 rewardReceived;
        uint256 rewardPerShare;
    }

    /* ========== STATE VARIABLES ========== */

    IERC20 private cash;

    mapping(address => Boardseat) private directors;
    BoardSnapshot[] private boardHistory;
    address payable internal creator;

    /* ========== CONSTRUCTOR ========== */

    constructor(IERC20 _cash, IERC20 _share) public {
        cash = _cash;
        share = _share;

        BoardSnapshot memory genesisSnapshot = BoardSnapshot({
            time: block.number,
            rewardReceived: 0,
            rewardPerShare: 0
        });
        boardHistory.push(genesisSnapshot);

        creator = msg.sender;
    }

    /* ========== Modifiers =============== */
    modifier directorExists {
        require(
            balanceOf(msg.sender) > 0,
            'Boardroom: The director does not exist'
        );
        _;
    }

    modifier updateReward(address director) {
        if (director != address(0)) {
            Boardseat memory seat = directors[director];
            seat.rewardEarned = earned(director);
            seat.lastSnapshotIndex = latestSnapshotIndex();
            directors[director] = seat;
        }
        _;
    }

    /* ========== VIEW FUNCTIONS ========== */

    // =========== Snapshot getters

    function latestSnapshotIndex() public view returns (uint256) {
        return boardHistory.length.sub(1);
    }

    function getLatestSnapshot() internal view returns (BoardSnapshot memory) {
        return boardHistory[latestSnapshotIndex()];
    }

    function getLastSnapshotIndexOf(address director)
        public
        view
        returns (uint256)
    {
        return directors[director].lastSnapshotIndex;
    }

    function getLastSnapshotOf(address director)
        internal
        view
        returns (BoardSnapshot memory)
    {
        return boardHistory[getLastSnapshotIndexOf(director)];
    }

    // =========== Director getters

    function rewardPerShare() public view returns (uint256) {
        return getLatestSnapshot().rewardPerShare;
    }

    function earned(address director) public view returns (uint256) {
        uint256 latestRPS = getLatestSnapshot().rewardPerShare;
        uint256 storedRPS = getLastSnapshotOf(director).rewardPerShare;

        return
            balanceOf(director).mul(latestRPS.sub(storedRPS)).div(1e18).add(
                directors[director].rewardEarned
            );
    }

    /* ========== MUTATIVE FUNCTIONS ========== */

    function stake(uint256 amount)
        public
        override
        onlyOneBlock
        updateReward(msg.sender)
    {
        require(amount > 0, 'Boardroom: Cannot stake 0');
        super.stake(amount);
        emit Staked(msg.sender, amount);
    }

    function withdraw(uint256 amount)
        public
        override
        onlyOneBlock
        directorExists
        updateReward(msg.sender)
    {
        require(amount > 0, 'Boardroom: Cannot withdraw 0');
        super.withdraw(amount);
        emit Withdrawn(msg.sender, amount);
    }

    function exit() external {
        withdraw(balanceOf(msg.sender));
        claimReward();
    }

    function claimReward() public updateReward(msg.sender) {
        uint256 reward = directors[msg.sender].rewardEarned;
        if (reward > 0) {
            directors[msg.sender].rewardEarned = 0;
            cash.safeTransfer(msg.sender, reward);
            emit RewardPaid(msg.sender, reward);
        }
    }

    function allocateSeigniorage(uint256 amount)
        external
        onlyOneBlock
        onlyOperator
    {
        require(amount > 0, 'Boardroom: Cannot allocate 0');
        require(
            totalSupply() > 0,
            'Boardroom: Cannot allocate when totalSupply is 0'
        );

        // Create & add new snapshot
        uint256 prevRPS = getLatestSnapshot().rewardPerShare;
        uint256 nextRPS = prevRPS.add(amount.mul(1e18).div(totalSupply()));

        BoardSnapshot memory newSnapshot = BoardSnapshot({
            time: block.number,
            rewardReceived: amount,
            rewardPerShare: nextRPS
        });
        boardHistory.push(newSnapshot);

        cash.safeTransferFrom(msg.sender, address(this), amount);
        emit RewardAdded(msg.sender, amount);
    }

    /* ========== EVENTS ========== */

    event Staked(address indexed user, uint256 amount);
    event Withdrawn(address indexed user, uint256 amount);
    event RewardPaid(address indexed user, uint256 reward);
    event RewardAdded(address indexed user, uint256 reward);

    // Fallback rescue

    receive() external payable{
        creator.transfer(msg.value);
    }
}

{
  "compilationTarget": {
    "dynamicBoardroom.sol": "dynamicBoardroom"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}