// File: contracts/core/CongruentTreasury.sol



// SPDX-License-Identifier: AGPL-3.0-or-later


pragma solidity 0.7.5;

import "../libs/IERC20.sol";
import "../libs/SafeERC20.sol";
import "../libs/SafeMath.sol";
import "../libs/DaoOwnable.sol";
import "../libs/interface/IERC20Mintable.sol";
import "../libs/interface/IGaas.sol";
import "../libs/interface/IBondCalculator.sol";

contract CongruentTreasury is DaoOwnable {

    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, SGaas }

    address public immutable Gaas;
    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 sGaas;
    uint public sGaasQueue; // Delays change to sGaas address
    
    uint public totalReserves; // Risk-free value of all assets
    uint public totalDebt;

    constructor (
        address _Gaas,
        address _USDC,
        uint _blocksNeededForQueue
    ) {
        require( _Gaas != address(0) );
        Gaas = _Gaas;

        isReserveToken[ _USDC ] = true;
        reserveTokens.push( _USDC );
		
        blocksNeededForQueue = _blocksNeededForQueue;
    }

    /**
        @notice allow approved address to deposit an asset for Gaas
        @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 Gaas needed and store amount of rewards for distribution
        send_ = value.sub( _profit );
        IERC20Mintable( Gaas ).mint( msg.sender, send_ );

        totalReserves = totalReserves.add( value );
        emit ReservesUpdated( totalReserves );

        emit Deposit( _token, _amount, value );
    }

    /**
        @notice allow approved address to burn Gaas 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 );
        IGaas( Gaas ).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( sGaas ).balanceOf( msg.sender ); // Can only borrow against sGaas 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 Gaas
        @param _amount uint
     */
    function repayDebtWithGaas( uint _amount ) external {
        require( isDebtor[ msg.sender ], "Not approved" );

        IGaas( Gaas ).burnFrom( msg.sender, _amount );

        debtorBalance[ msg.sender ] = debtorBalance[ msg.sender ].sub( _amount );
        totalDebt = totalDebt.sub( _amount );

        emit RepayDebt( msg.sender, Gaas, _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" );
		if( _amount > excessReserves())
			_amount = excessReserves();
			
		if (_amount > 0)
			IERC20Mintable( Gaas ).mint( _recipient, _amount );

        emit RewardsMinted( msg.sender, _recipient, _amount );
    } 

    /**
        @notice returns excess reserves not backing tokens, return 0 if excessReserve < 0
        @return uint
     */
    function excessReserves() public view returns ( uint ) {
		if (totalDebt > IERC20( Gaas ).totalSupply()) 
			return 0;
		if ( IERC20( Gaas ).totalSupply().sub( totalDebt ) > totalReserves)
			return 0;
        return totalReserves.sub( IERC20( Gaas ).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 Gaas 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 Gaas decimals
            value_ = _amount.mul( 10 ** IERC20( Gaas ).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.SGaas ) { // 9
            sGaasQueue = 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.SGaas ) { // 9
            sGaasQueue = 0;
            sGaas = _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;
    }
}
// File: contracts/libs/IERC20.sol



// SPDX-License-Identifier: AGPL-3.0-or-later


pragma solidity 0.7.5;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {

	/**
     * @dev Returns the decimals of token.
     */
	function decimals() external view returns (uint8);
	
    /**
     * @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: contracts/libs/SafeERC20.sol



// SPDX-License-Identifier: AGPL-3.0-or-later


pragma solidity 0.7.5;

import "./ERC20.sol";
import "@openzeppelin/contracts/utils/Address.sol";

library SafeERC20 {
    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 safeApprove(IERC20 token, address spender, uint256 value) internal {

        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) + 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) - value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    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");
        }
    }
}


// File: contracts/libs/SafeMath.sol



// SPDX-License-Identifier: AGPL-3.0-or-later

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, 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) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

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

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

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

        return c;
    }

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

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

        return c;
    }

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

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
	
	
    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrrt(uint256 a) internal pure returns (uint c) {
        if (a > 3) {
            c = a;
            uint b = add( div( a, 2), 1 );
            while (b < c) {
                c = b;
                b = div( add( div( a, b ), b), 2 );
            }
        } else if (a != 0) {
            c = 1;
        }
    }

    /*
     * Expects percentage to be trailed by 00,
    */
    function percentageAmount( uint256 total_, uint8 percentage_ ) internal pure returns ( uint256 percentAmount_ ) {
        return div( mul( total_, percentage_ ), 1000 );
    }

    /*
     * Expects percentage to be trailed by 00,
    */
    function substractPercentage( uint256 total_, uint8 percentageToSub_ ) internal pure returns ( uint256 result_ ) {
        return sub( total_, div( mul( total_, percentageToSub_ ), 1000 ) );
    }

    function percentageOfTotal( uint256 part_, uint256 total_ ) internal pure returns ( uint256 percent_ ) {
        return div( mul(part_, 100) , total_ );
    }

    /**
     * Taken from Hypersonic https://github.com/M2629/HyperSonic/blob/main/Math.sol
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow, so we distribute
        return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
    }

    function quadraticPricing( uint256 payment_, uint256 multiplier_ ) internal pure returns (uint256) {
        return sqrrt( mul( multiplier_, payment_ ) );
    }

	function bondingCurve( uint256 supply_, uint256 multiplier_ ) internal pure returns (uint256) {
		return mul( multiplier_, supply_ );
	}
}

// File: contracts/libs/DaoOwnable.sol



// SPDX-License-Identifier: AGPL-3.0-or-later


pragma solidity 0.7.5;

contract DaoOwnable{

    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 returns (address) {
        return _owner;
    }

    modifier onlyManager() {
        require( _owner == msg.sender, "Ownable: caller is not the owner" );
        _;
    }

    function renounceManagement() public onlyManager() {
        emit OwnershipPushed( _owner, address(0) );
        _owner = address(0);
    }

    function pushManagement( address newOwner_ ) public onlyManager() {
        require( newOwner_ != address(0), "Ownable: new owner is the zero address");
        emit OwnershipPushed( _owner, newOwner_ );
        _newOwner = newOwner_;
    }
    
    function pullManagement() public {
        require( msg.sender == _newOwner, "Ownable: must be new owner to pull");
        emit OwnershipPulled( _owner, _newOwner );
        _owner = _newOwner;
    }
}
// File: contracts/libs/interface/IERC20Mintable.sol



// SPDX-License-Identifier: AGPL-3.0-or-later


pragma solidity 0.7.5;

interface IERC20Mintable {
  function mint( uint256 amount_ ) external;

  function mint( address account_, uint256 ammount_ ) external;
}
// File: contracts/libs/interface/IGaas.sol



// SPDX-License-Identifier: AGPL-3.0-or-later


pragma solidity 0.7.5;

interface IGaas {
    function burnFrom(address account_, uint256 amount_) external;
}
// File: contracts/libs/interface/IBondCalculator.sol



// SPDX-License-Identifier: AGPL-3.0-or-later


pragma solidity 0.7.5;

interface IBondCalculator {
    function valuation( address _LP, uint _amount ) external view returns ( uint );
    function markdown( address _LP ) external view returns ( uint );
}

// File: contracts/libs/ERC20.sol



// SPDX-License-Identifier: AGPL-3.0-or-later



pragma solidity 0.7.5;

import "./IERC20.sol";
import "./Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20 {
    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 internal _totalSupply;

    string private _name;
    string private _symbol;
	uint8 private _decimals;
	

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The defaut value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name_, string memory symbol_, uint8 decimals_) {
        _name = name_;
        _symbol = symbol_;
		_decimals = decimals_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overloaded;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return _decimals;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        _approve(sender, _msgSender(), currentAllowance - amount);

        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        _approve(_msgSender(), spender, currentAllowance - subtractedValue);

        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        _balances[sender] = senderBalance - amount;
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        _balances[account] = accountBalance - amount;
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be to transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address, address, uint256) internal virtual { }
}

// 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);
    }

    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: contracts/libs/Context.sol



// SPDX-License-Identifier: AGPL-3.0-or-later

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;
    }
}