// SPDX-License-Identifier: MIT


pragma solidity 0.7.5;

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) {
        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;
        return c;
    }
}

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 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 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 {
            if (returndata.length > 0) {
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            if (returndata.length > 0) {
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

interface IOwnable {
    function manager() external view returns (address);

    function renounceManagement() external;

    function pushManagement(address newOwner_) external;

    function pullManagement() external;
}

contract Ownable is IOwnable {

    address internal _owner;
    address internal _newOwner;

    event OwnershipPushed(address indexed previousOwner, address indexed newOwner);
    event OwnershipPulled(address indexed previousOwner, address indexed newOwner);

    constructor () {
        _owner = msg.sender;
        emit OwnershipPushed(address(0), _owner);
    }

    function manager() public view override returns (address) {
        return _owner;
    }

    modifier onlyManager() {
        require(_owner == msg.sender, "Ownable: caller is not the owner");
        _;
    }

    function renounceManagement() public virtual override onlyManager() {
        emit OwnershipPushed(_owner, address(0));
        _owner = address(0);
    }

    function pushManagement(address newOwner_) public virtual override onlyManager() {
        require(newOwner_ != address(0), "Ownable: new owner is the zero address");
        emit OwnershipPushed(_owner, newOwner_);
        _newOwner = newOwner_;
    }

    function pullManagement() public virtual override {
        require(msg.sender == _newOwner, "Ownable: must be new owner to pull");
        emit OwnershipPulled(_owner, _newOwner);
        _owner = _newOwner;
    }
}

interface IERC20 {
    function decimals() external view returns (uint8);

    function balanceOf(address account) external view returns (uint256);

    function transfer(address recipient, uint256 amount) external returns (bool);

    function approve(address spender, uint256 amount) external returns (bool);

    function totalSupply() external view returns (uint256);

    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));
    }

    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        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");
        }
    }
}

interface IERC20Mintable {
    function mint(uint256 amount_) external;

    function mint(address account_, uint256 ammount_) external;
}

interface IGWSERC20 {
    function burnFrom(address account_, uint256 amount_) external;
}

interface IBondCalculator {
    function valuation(address pair_, uint amount_) external view returns (uint _value);
}

contract GenerationalWealthSocietyTreasury is Ownable {

    using SafeMath for uint;
    using SafeERC20 for IERC20;

    event Deposit(address indexed token, uint amount, uint value);
    event Withdrawal(address indexed token, uint amount, uint value);
    event CreateDebt(address indexed debtor, address indexed token, uint amount, uint value);
    event RepayDebt(address indexed debtor, address indexed token, uint amount, uint value);
    event ReservesManaged(address indexed token, uint amount);
    event ReservesUpdated(uint indexed totalReserves);
    event ReservesAudited(uint indexed totalReserves);
    event RewardsMinted(address indexed caller, address indexed recipient, uint amount);
    event ChangeQueued(MANAGING indexed managing, address queued);
    event ChangeActivated(MANAGING indexed managing, address activated, bool result);

    enum MANAGING {RESERVEDEPOSITOR, RESERVESPENDER, RESERVETOKEN, RESERVEMANAGER, LIQUIDITYDEPOSITOR, LIQUIDITYTOKEN, LIQUIDITYMANAGER, DEBTOR, REWARDMANAGER, SGWS}

    address public immutable GWS;
    uint public immutable blocksNeededForQueue;

    address[] public reserveTokens; // Push only, beware false-positives.
    mapping(address => bool) public isReserveToken;
    mapping(address => uint) public reserveTokenQueue; // Delays changes to mapping.

    address[] public reserveDepositors; // Push only, beware false-positives. Only for viewing.
    mapping(address => bool) public isReserveDepositor;
    mapping(address => uint) public reserveDepositorQueue; // Delays changes to mapping.

    address[] public reserveSpenders; // Push only, beware false-positives. Only for viewing.
    mapping(address => bool) public isReserveSpender;
    mapping(address => uint) public reserveSpenderQueue; // Delays changes to mapping.

    address[] public liquidityTokens; // Push only, beware false-positives.
    mapping(address => bool) public isLiquidityToken;
    mapping(address => uint) public LiquidityTokenQueue; // Delays changes to mapping.

    address[] public liquidityDepositors; // Push only, beware false-positives. Only for viewing.
    mapping(address => bool) public isLiquidityDepositor;
    mapping(address => uint) public LiquidityDepositorQueue; // Delays changes to mapping.

    mapping(address => address) public bondCalculator; // bond calculator for liquidity token

    address[] public reserveManagers; // Push only, beware false-positives. Only for viewing.
    mapping(address => bool) public isReserveManager;
    mapping(address => uint) public ReserveManagerQueue; // Delays changes to mapping.

    address[] public liquidityManagers; // Push only, beware false-positives. Only for viewing.
    mapping(address => bool) public isLiquidityManager;
    mapping(address => uint) public LiquidityManagerQueue; // Delays changes to mapping.

    address[] public debtors; // Push only, beware false-positives. Only for viewing.
    mapping(address => bool) public isDebtor;
    mapping(address => uint) public debtorQueue; // Delays changes to mapping.
    mapping(address => uint) public debtorBalance;

    address[] public rewardManagers; // Push only, beware false-positives. Only for viewing.
    mapping(address => bool) public isRewardManager;
    mapping(address => uint) public rewardManagerQueue; // Delays changes to mapping.

    address public sGWS;
    uint public sGWSQueue; // Delays change to sGWS address

    uint public totalReserves; // Risk-free value of all assets
    uint public totalDebt;

    constructor (
        address _GWS,
        address _DAI,
        uint _blocksNeededForQueue
    ) {
        require(_GWS != address(0));
        GWS = _GWS;

        isReserveToken[_DAI] = true;
        reserveTokens.push(_DAI);

//        isLiquidityToken[_GWSDAI] = true;
//        liquidityTokens.push(_GWSDAI);

        blocksNeededForQueue = _blocksNeededForQueue;
    }

    /**
        @notice allow approved address to deposit an asset for GWS
        @param _amount uint
        @param _token address
        @param _profit uint
        @return send_ uint
     */
    function deposit(uint _amount, address _token, uint _profit) external returns (uint send_) {
        require(isReserveToken[_token] || isLiquidityToken[_token], "Not accepted");
        IERC20(_token).safeTransferFrom(msg.sender, address(this), _amount);

        if (isReserveToken[_token]) {
            require(isReserveDepositor[msg.sender], "Not approved");
        } else {
            require(isLiquidityDepositor[msg.sender], "Not approved");
        }

        uint value = valueOf(_token, _amount);
        // mint GWS needed and store amount of rewards for distribution
        send_ = value.sub(_profit);
        IERC20Mintable(GWS).mint(msg.sender, send_);

        totalReserves = totalReserves.add(value);
        emit ReservesUpdated(totalReserves);

        emit Deposit(_token, _amount, value);
    }

    /**
        @notice allow approved address to burn GWS for reserves
        @param _amount uint
        @param _token address
     */
    function withdraw(uint _amount, address _token) external {
        require(isReserveToken[_token], "Not accepted");
        // Only reserves can be used for redemptions
        require(isReserveSpender[msg.sender] == true, "Not approved");

        uint value = valueOf(_token, _amount);
        IGWSERC20(GWS).burnFrom(msg.sender, value);

        totalReserves = totalReserves.sub(value);
        emit ReservesUpdated(totalReserves);

        IERC20(_token).safeTransfer(msg.sender, _amount);

        emit Withdrawal(_token, _amount, value);
    }

    /**
        @notice allow approved address to borrow reserves
        @param _amount uint
        @param _token address
     */
    function incurDebt(uint _amount, address _token) external {
        require(isDebtor[msg.sender], "Not approved");
        require(isReserveToken[_token], "Not accepted");

        uint value = valueOf(_token, _amount);

        uint maximumDebt = IERC20(sGWS).balanceOf(msg.sender);
        // Can only borrow against sGWS held
        uint availableDebt = maximumDebt.sub(debtorBalance[msg.sender]);
        require(value <= availableDebt, "Exceeds debt limit");

        debtorBalance[msg.sender] = debtorBalance[msg.sender].add(value);
        totalDebt = totalDebt.add(value);

        totalReserves = totalReserves.sub(value);
        emit ReservesUpdated(totalReserves);

        IERC20(_token).transfer(msg.sender, _amount);

        emit CreateDebt(msg.sender, _token, _amount, value);
    }

    /**
        @notice allow approved address to repay borrowed reserves with reserves
        @param _amount uint
        @param _token address
     */
    function repayDebtWithReserve(uint _amount, address _token) external {
        require(isDebtor[msg.sender], "Not approved");
        require(isReserveToken[_token], "Not accepted");

        IERC20(_token).safeTransferFrom(msg.sender, address(this), _amount);

        uint value = valueOf(_token, _amount);
        debtorBalance[msg.sender] = debtorBalance[msg.sender].sub(value);
        totalDebt = totalDebt.sub(value);

        totalReserves = totalReserves.add(value);
        emit ReservesUpdated(totalReserves);

        emit RepayDebt(msg.sender, _token, _amount, value);
    }

    /**
        @notice allow approved address to repay borrowed reserves with GWS
        @param _amount uint
     */
    function repayDebtWithGWS(uint _amount) external {
        require(isDebtor[msg.sender], "Not approved");

        IGWSERC20(GWS).burnFrom(msg.sender, _amount);

        debtorBalance[msg.sender] = debtorBalance[msg.sender].sub(_amount);
        totalDebt = totalDebt.sub(_amount);

        emit RepayDebt(msg.sender, GWS, _amount, _amount);
    }

    /**
        @notice allow approved address to withdraw assets
        @param _token address
        @param _amount uint
     */
    function manage(address _token, uint _amount) external {
        if (isLiquidityToken[_token]) {
            require(isLiquidityManager[msg.sender], "Not approved");
        } else {
            require(isReserveManager[msg.sender], "Not approved");
        }

        uint value = valueOf(_token, _amount);
        require(value <= excessReserves(), "Insufficient reserves");

        totalReserves = totalReserves.sub(value);
        emit ReservesUpdated(totalReserves);

        IERC20(_token).safeTransfer(msg.sender, _amount);

        emit ReservesManaged(_token, _amount);
    }

    /**
        @notice send epoch reward to staking contract
     */
    function mintRewards(address _recipient, uint _amount) external {
        require(isRewardManager[msg.sender], "Not approved");
        require(_amount <= excessReserves(), "Insufficient reserves");

        IERC20Mintable(GWS).mint(_recipient, _amount);

        emit RewardsMinted(msg.sender, _recipient, _amount);
    }

    /**
        @notice returns excess reserves not backing tokens
        @return uint
     */
    function excessReserves() public view returns (uint) {
        return totalReserves.sub(IERC20(GWS).totalSupply().sub(totalDebt));
    }

    /**
        @notice takes inventory of all tracked assets
        @notice always consolidate to recognized reserves before audit
     */
    function auditReserves() external onlyManager() {
        uint reserves;
        for (uint i = 0; i < reserveTokens.length; i++) {
            reserves = reserves.add(
                valueOf(reserveTokens[i], IERC20(reserveTokens[i]).balanceOf(address(this)))
            );
        }
        for (uint i = 0; i < liquidityTokens.length; i++) {
            reserves = reserves.add(
                valueOf(liquidityTokens[i], IERC20(liquidityTokens[i]).balanceOf(address(this)))
            );
        }
        totalReserves = reserves;
        emit ReservesUpdated(reserves);
        emit ReservesAudited(reserves);
    }

    /**
        @notice returns GWS valuation of asset
        @param _token address
        @param _amount uint
        @return value_ uint
     */
    function valueOf(address _token, uint _amount) public view returns (uint value_) {
        if (isReserveToken[_token]) {
            // convert amount to match GWS decimals
            value_ = _amount.mul(10 ** IERC20(GWS).decimals()).div(10 ** IERC20(_token).decimals());
        } else if (isLiquidityToken[_token]) {
            value_ = IBondCalculator(bondCalculator[_token]).valuation(_token, _amount);
        }
    }

    /**
        @notice queue address to change boolean in mapping
        @param _managing MANAGING
        @param _address address
        @return bool
     */
    function queue(MANAGING _managing, address _address) external onlyManager() returns (bool) {
        require(_address != address(0));
        if (_managing == MANAGING.RESERVEDEPOSITOR) {// 0
            reserveDepositorQueue[_address] = block.number.add(blocksNeededForQueue);
        } else if (_managing == MANAGING.RESERVESPENDER) {// 1
            reserveSpenderQueue[_address] = block.number.add(blocksNeededForQueue);
        } else if (_managing == MANAGING.RESERVETOKEN) {// 2
            reserveTokenQueue[_address] = block.number.add(blocksNeededForQueue);
        } else if (_managing == MANAGING.RESERVEMANAGER) {// 3
            ReserveManagerQueue[_address] = block.number.add(blocksNeededForQueue.mul(2));
        } else if (_managing == MANAGING.LIQUIDITYDEPOSITOR) {// 4
            LiquidityDepositorQueue[_address] = block.number.add(blocksNeededForQueue);
        } else if (_managing == MANAGING.LIQUIDITYTOKEN) {// 5
            LiquidityTokenQueue[_address] = block.number.add(blocksNeededForQueue);
        } else if (_managing == MANAGING.LIQUIDITYMANAGER) {// 6
            LiquidityManagerQueue[_address] = block.number.add(blocksNeededForQueue.mul(2));
        } else if (_managing == MANAGING.DEBTOR) {// 7
            debtorQueue[_address] = block.number.add(blocksNeededForQueue);
        } else if (_managing == MANAGING.REWARDMANAGER) {// 8
            rewardManagerQueue[_address] = block.number.add(blocksNeededForQueue);
        } else if (_managing == MANAGING.SGWS) {// 9
            sGWSQueue = block.number.add(blocksNeededForQueue);
        } else return false;

        emit ChangeQueued(_managing, _address);
        return true;
    }

    /**
        @notice verify queue then set boolean in mapping
        @param _managing MANAGING
        @param _address address
        @param _calculator address
        @return bool
     */
    function toggle(MANAGING _managing, address _address, address _calculator) external onlyManager() returns (bool) {
        require(_address != address(0));
        bool result;
        if (_managing == MANAGING.RESERVEDEPOSITOR) {// 0
            if (requirements(reserveDepositorQueue, isReserveDepositor, _address)) {
                reserveDepositorQueue[_address] = 0;
                if (!listContains(reserveDepositors, _address)) {
                    reserveDepositors.push(_address);
                }
            }
            result = !isReserveDepositor[_address];
            isReserveDepositor[_address] = result;

        } else if (_managing == MANAGING.RESERVESPENDER) {// 1
            if (requirements(reserveSpenderQueue, isReserveSpender, _address)) {
                reserveSpenderQueue[_address] = 0;
                if (!listContains(reserveSpenders, _address)) {
                    reserveSpenders.push(_address);
                }
            }
            result = !isReserveSpender[_address];
            isReserveSpender[_address] = result;

        } else if (_managing == MANAGING.RESERVETOKEN) {// 2
            if (requirements(reserveTokenQueue, isReserveToken, _address)) {
                reserveTokenQueue[_address] = 0;
                if (!listContains(reserveTokens, _address)) {
                    reserveTokens.push(_address);
                }
            }
            result = !isReserveToken[_address];
            isReserveToken[_address] = result;

        } else if (_managing == MANAGING.RESERVEMANAGER) {// 3
            if (requirements(ReserveManagerQueue, isReserveManager, _address)) {
                reserveManagers.push(_address);
                ReserveManagerQueue[_address] = 0;
                if (!listContains(reserveManagers, _address)) {
                    reserveManagers.push(_address);
                }
            }
            result = !isReserveManager[_address];
            isReserveManager[_address] = result;

        } else if (_managing == MANAGING.LIQUIDITYDEPOSITOR) {// 4
            if (requirements(LiquidityDepositorQueue, isLiquidityDepositor, _address)) {
                liquidityDepositors.push(_address);
                LiquidityDepositorQueue[_address] = 0;
                if (!listContains(liquidityDepositors, _address)) {
                    liquidityDepositors.push(_address);
                }
            }
            result = !isLiquidityDepositor[_address];
            isLiquidityDepositor[_address] = result;

        } else if (_managing == MANAGING.LIQUIDITYTOKEN) {// 5
            if (requirements(LiquidityTokenQueue, isLiquidityToken, _address)) {
                LiquidityTokenQueue[_address] = 0;
                if (!listContains(liquidityTokens, _address)) {
                    liquidityTokens.push(_address);
                }
            }
            result = !isLiquidityToken[_address];
            isLiquidityToken[_address] = result;
            bondCalculator[_address] = _calculator;

        } else if (_managing == MANAGING.LIQUIDITYMANAGER) {// 6
            if (requirements(LiquidityManagerQueue, isLiquidityManager, _address)) {
                LiquidityManagerQueue[_address] = 0;
                if (!listContains(liquidityManagers, _address)) {
                    liquidityManagers.push(_address);
                }
            }
            result = !isLiquidityManager[_address];
            isLiquidityManager[_address] = result;

        } else if (_managing == MANAGING.DEBTOR) {// 7
            if (requirements(debtorQueue, isDebtor, _address)) {
                debtorQueue[_address] = 0;
                if (!listContains(debtors, _address)) {
                    debtors.push(_address);
                }
            }
            result = !isDebtor[_address];
            isDebtor[_address] = result;

        } else if (_managing == MANAGING.REWARDMANAGER) {// 8
            if (requirements(rewardManagerQueue, isRewardManager, _address)) {
                rewardManagerQueue[_address] = 0;
                if (!listContains(rewardManagers, _address)) {
                    rewardManagers.push(_address);
                }
            }
            result = !isRewardManager[_address];
            isRewardManager[_address] = result;

        } else if (_managing == MANAGING.SGWS) {// 9
            sGWSQueue = 0;
            sGWS = _address;
            result = true;

        } else return false;

        emit ChangeActivated(_managing, _address, result);
        return true;
    }

    /**
        @notice checks requirements and returns altered structs
        @param queue_ mapping( address => uint )
        @param status_ mapping( address => bool )
        @param _address address
        @return bool
     */
    function requirements(
        mapping(address => uint) storage queue_,
        mapping(address => bool) storage status_,
        address _address
    ) internal view returns (bool) {
        if (!status_[_address]) {
            require(queue_[_address] != 0, "Must queue");
            require(queue_[_address] <= block.number, "Queue not expired");
            return true;
        }
        return false;
    }

    /**
        @notice checks array to ensure against duplicate
        @param _list address[]
        @param _token address
        @return bool
     */
    function listContains(address[] storage _list, address _token) internal view returns (bool) {
        for (uint i = 0; i < _list.length; i++) {
            if (_list[i] == _token) {
                return true;
            }
        }
        return false;
    }
}