// File: @openzeppelin/contracts/math/SafeMath.sol

pragma solidity ^0.5.0;

/**
 * @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.
     *
     * _Available since v2.4.0._
     */
    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.
     *
     * _Available since v2.4.0._
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        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.
     *
     * _Available since v2.4.0._
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol

pragma solidity ^0.5.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
 * the optional functions; to access them see {ERC20Detailed}.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/utils/Address.sol

pragma solidity ^0.5.5;

/**
 * @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) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

    /**
     * @dev Converts an `address` into `address payable`. Note that this is
     * simply a type cast: the actual underlying value is not changed.
     *
     * _Available since v2.4.0._
     */
    function toPayable(address account) internal pure returns (address payable) {
        return address(uint160(account));
    }

    /**
     * @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].
     *
     * _Available since v2.4.0._
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-call-value
        (bool success, ) = recipient.call.value(amount)("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
}

// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol

pragma solidity ^0.5.0;




/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    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.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: @openzeppelin/contracts/utils/ReentrancyGuard.sol

pragma solidity ^0.5.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 *
 * _Since v2.5.0:_ this module is now much more gas efficient, given net gas
 * metering changes introduced in the Istanbul hardfork.
 */
contract ReentrancyGuard {
    bool private _notEntered;

    constructor () internal {
        // Storing an initial non-zero value makes deployment a bit more
        // expensive, but in exchange the refund on every call to nonReentrant
        // will be lower in amount. Since refunds are capped to a percetange of
        // the total transaction's gas, it is best to keep them low in cases
        // like this one, to increase the likelihood of the full refund coming
        // into effect.
        _notEntered = true;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_notEntered, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _notEntered = false;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _notEntered = true;
    }
}

// File: @openzeppelin/contracts/GSN/Context.sol

pragma solidity ^0.5.0;

/*
 * @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.
 */
contract Context {
    // Empty internal constructor, to prevent people from mistakenly deploying
    // an instance of this contract, which should be used via inheritance.
    constructor () internal { }
    // solhint-disable-previous-line no-empty-blocks

    function _msgSender() internal view returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: @openzeppelin/contracts/ownership/Ownable.sol

pragma solidity ^0.5.0;

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
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(isOwner(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Returns true if the caller is the current owner.
     */
    function isOwner() public view returns (bool) {
        return _msgSender() == _owner;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public onlyOwner {
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     */
    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: contracts/711/dependencies/IWETH.sol

pragma solidity >=0.5.0;

interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint value) external returns (bool);
    function withdraw(uint) external;
}

// File: contracts/711/dependencies/uniswapv2/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);
    function migrator() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
    function setMigrator(address) external;
}

// File: contracts/711/dependencies/uniswapv2/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/711/dependencies/uniswapv2/interfaces/IUniswapV2Router02.sol

pragma solidity >=0.5.0;

interface IUniswapV2Router02 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

// File: contracts/711/dependencies/IStakingRewards.sol

pragma solidity ^0.5.0;


interface IStakingRewards {
    // Views
    function lastTimeRewardApplicable() external view returns (uint256);
    function rewardPerToken() external view returns (uint256);
    function earned(address account) external view returns (uint256);
    function getRewardForDuration() external view returns (uint256);
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function rewardsToken() external view returns (IERC20);
    function stakingToken() external view returns (IERC20);
    function rewardRate() external view returns (uint256);

    // Mutative
    function stake(uint256 amount) external;
    function stakeFor(address to, uint256 amount) external;
    function withdraw() external;
    function getReward() external;
    function exit() external;
    
    function notifyRewardAmount(uint256 reward) external;
}

// File: contracts/711/dependencies/IAgentRegistry.sol

pragma solidity >=0.5.0;

interface IAgentRegistry {
    function agents() external returns (uint256);
    function register(string calldata _nameString) external payable;
    function getAgentAddressById(uint256 _agentId) external view returns (address payable);
    function getAgentAddressByName(bytes32 _agentName) external view returns (address payable);
    function isAgent(address _agent) external view returns (bool);
}

// File: contracts/711/ADDRESSBOOK.sol

pragma solidity ^0.5.0;

contract ADDRESSBOOK {
    address constant public FEE_APPROVER = 0x6C70d504932AA318f8070De13F3c4Ab69A87953f;
    address payable constant public VAULT = 0xB1ff949285107B7b967c0d05886F2513488D0042;
    address constant public REWARDS_DISTRIBUTOR = 0xB3c39777142320F7C5329bF87287A707C77266e3;
    address constant public STAKING_CONTRACT = 0x29d44e1726e4368e5A7Abf4fbC481a874AebCf00;
    address constant public ZAP = 0x0797778B9110D03FF64fF25192e2a980Bf4523b8;
    address constant public TOKEN_ADDRESS_711 = 0x9d4709e7C38e7857636c342a37547E191125E028;
    address constant public AGENT_REGISTRY = 0x35C9Dbd51D926838cAc8eB33ebDbEA5e2930b247;
    address constant public UNISWAP_V2_PAIR_711_WETH = 0xF295b0fa1A89c8a06109fB2D2c860a96Fb39dca5;
}

// File: contracts/711/ZapIn_711_V2.sol

// ███████╗░█████╗░██████╗░██████╗░███████╗██████╗░░░░███████╗██╗
// ╚════██║██╔══██╗██╔══██╗██╔══██╗██╔════╝██╔══██╗░░░██╔════╝██║
// ░░███╔═╝███████║██████╔╝██████╔╝█████╗░░██████╔╝░░░█████╗░░██║
// ██╔══╝░░██╔══██║██╔═══╝░██╔═══╝░██╔══╝░░██╔══██╗░░░██╔══╝░░██║
// ███████╗██║░░██║██║░░░░░██║░░░░░███████╗██║░░██║██╗██║░░░░░██║
// ╚══════╝╚═╝░░╚═╝╚═╝░░░░░╚═╝░░░░░╚══════╝╚═╝░░╚═╝╚═╝╚═╝░░░░░╚═╝
// Copyright (C) 2020 zapper, nodar, suhail, seb, sumit, apoorv

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

// SPDX-License-Identifier: GPLv2
pragma solidity ^0.5.16;














// import "@uniswap/lib/contracts/libraries/Babylonian.sol";
library Babylonian {
    function sqrt(uint256 y) internal pure returns (uint256 z) {
        if (y > 3) {
            z = y;
            uint256 x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
        // else z = 0
    }
}

contract ZapIn_711_V2 is ReentrancyGuard, Ownable, ADDRESSBOOK {
    using SafeMath for uint256;
    using Address for address;
    using SafeERC20 for IERC20;

    event AmountToAgent(address indexed from, address indexed agent, uint256 ethAmount);
    event AmountToVault(address indexed from, uint256 ethAmount);
    event AmountToInvest(address indexed from, uint256 ethAmount, uint256 lpBought);

    mapping (address => uint256) public referralRewards;

    bool public stopped = false;
    uint16 public goodwill;
    address payable public vault;
    address public stakingContract;
    IAgentRegistry public agentRegistry;

    IUniswapV2Router02 private constant uniswapRouter = IUniswapV2Router02(
        0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D
    );
    IUniswapV2Factory
        private constant UniSwapV2FactoryAddress = IUniswapV2Factory(
        0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f
    );
    uint256
        private constant deadline = 0xf000000000000000000000000000000000000000000000000000000000000000;
    address
        private constant wethTokenAddress = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
    address
        private constant ethTokenAddress = address(0); // only accepts ETH

    constructor() public {
        goodwill = 1000;
        vault = VAULT;
        stakingContract = STAKING_CONTRACT;
        agentRegistry = IAgentRegistry(AGENT_REGISTRY);
    }

    // circuit breaker modifiers
    modifier stopInEmergency {
        if (stopped) {
            revert("Temporarily Paused");
        } else {
            _;
        }
    }

    // Zap in with referral id
    function ZapInWithId(
        address _staker,
        uint256 _minPoolTokens,
        uint256 _agentId
    ) public payable stopInEmergency returns (uint256) {
        //query agent
        address payable _agent = agentRegistry.getAgentAddressById(_agentId);
        ZapIn(_staker, _minPoolTokens, _agent);
    }

    // Zap in with referral name
    function ZapInWithName(
        address _staker,
        uint256 _minPoolTokens,
        bytes32 _agentName
    ) public payable stopInEmergency returns (uint256) {
        //query agent
        address payable _agent = agentRegistry.getAgentAddressByName(_agentName);
        ZapIn(_staker, _minPoolTokens, _agent);
    }

    /**
    @notice This function is used to single sided add liquidity to Uniswap V2 ETH/7-11 pair and stake
    @param _minPoolTokens Reverts if less tokens received than this
    @return Amount of stake amount
     */
    function ZapIn(
        address _staker,
        uint256 _minPoolTokens,
        address payable _agent
    ) public payable nonReentrant stopInEmergency returns (uint256) {
        require(msg.value > 0, "Error: ETH not sent");
        if(msg.sender == _agent || !(agentRegistry.isAgent(_agent))){
            _agent = address(0);
        }
        
        // Default
        uint256 toVault = msg.value.mul(goodwill).div(10000); // 10% to vault
        uint256 toInvest = msg.value.sub(toVault); // 90% to swap
        
        // And if it is referred by an agent
        if(_agent != address(0)){
            toVault = msg.value.mul(500).div(10000); // 5% to vault
            toInvest = msg.value.mul(9250).div(10000); // 92.5% to swap
            uint256 toAgent = msg.value.sub(toVault).sub(toInvest); // 2.5% to agent
            // Transfer to agnet
            _agent.transfer(toAgent);
            referralRewards[_agent] = referralRewards[_agent].add(toAgent);
            emit AmountToAgent(msg.sender, _agent, toAgent);
        }

        // Transfer to vault
        vault.transfer(toVault);
        emit AmountToVault(msg.sender, toVault);
        // Single sided add liquidity
        uint256 LPBought = _performZapIn(
            _staker,
            ethTokenAddress,
            TOKEN_ADDRESS_711,
            wethTokenAddress,
            toInvest
        );
        emit AmountToInvest(msg.sender, toInvest, LPBought);
        require(LPBought >= _minPoolTokens, "ERR: High Slippage");

        // Stake LP token
        IERC20(UNISWAP_V2_PAIR_711_WETH).safeApprove(stakingContract, LPBought);
        IStakingRewards(stakingContract).stakeFor(_staker, LPBought);

        return LPBought;
    }

    function _performZapIn(
        address _toWhomToIssue,
        address _FromTokenContractAddress,
        address _ToUnipoolToken0,
        address _ToUnipoolToken1,
        uint256 _amount
    ) internal returns (uint256) {
        address intermediate = _getIntermediate(
            _FromTokenContractAddress,
            _amount,
            _ToUnipoolToken0,
            _ToUnipoolToken1
        );

        // swap to intermediate
        uint256 interAmt = _token2Token(
            _FromTokenContractAddress,
            intermediate,
            _amount
        );

        // divide to swap in amounts
        uint256 token0Bought;
        uint256 token1Bought;

        IUniswapV2Pair pair = IUniswapV2Pair(
            UniSwapV2FactoryAddress.getPair(_ToUnipoolToken0, _ToUnipoolToken1)
        );
        (uint256 res0, uint256 res1, ) = pair.getReserves();

        if (intermediate == _ToUnipoolToken0) {
            uint256 amountToSwap = calculateSwapInAmount(res0, interAmt);
            //if no reserve or a new pair is created
            if (amountToSwap <= 0) amountToSwap = interAmt.div(2);
            token1Bought = _token2Token(
                intermediate,
                _ToUnipoolToken1,
                amountToSwap
            );
            token0Bought = interAmt.sub(amountToSwap);
        } else {
            uint256 amountToSwap = calculateSwapInAmount(res1, interAmt);
            //if no reserve or a new pair is created
            if (amountToSwap <= 0) amountToSwap = interAmt.div(2);
            token0Bought = _token2Token(
                intermediate,
                _ToUnipoolToken0,
                amountToSwap
            );
            token1Bought = interAmt.sub(amountToSwap);
        }

        return
            _uniDeposit(
                _toWhomToIssue,
                _ToUnipoolToken0,
                _ToUnipoolToken1,
                token0Bought,
                token1Bought
            );
    }

    function _uniDeposit(
        address _toWhomToIssue,
        address _ToUnipoolToken0,
        address _ToUnipoolToken1,
        uint256 token0Bought,
        uint256 token1Bought
    ) internal returns (uint256) {
        IERC20(_ToUnipoolToken0).safeIncreaseAllowance(
            address(uniswapRouter),
            token0Bought
        );
        IERC20(_ToUnipoolToken1).safeIncreaseAllowance(
            address(uniswapRouter),
            token1Bought
        );

        (uint256 amountA, uint256 amountB, uint256 LP) = uniswapRouter
            .addLiquidity(
            _ToUnipoolToken0,
            _ToUnipoolToken1,
            token0Bought,
            token1Bought,
            1,
            1,
            address(this),
            deadline
        );

        //Returning Residue in token0, if any.
        if (token0Bought.sub(amountA) > 0) {
            IERC20(_ToUnipoolToken0).safeTransfer(
                _toWhomToIssue,
                token0Bought.sub(amountA)
            );
        }

        //Returning Residue in token1, if any
        if (token1Bought.sub(amountB) > 0) {
            IERC20(_ToUnipoolToken1).safeTransfer(
                _toWhomToIssue,
                token1Bought.sub(amountB)
            );
        }

        return LP;
    }

    function _getIntermediate(
        address _FromTokenContractAddress,
        uint256 _amount,
        address _ToUnipoolToken0,
        address _ToUnipoolToken1
    ) internal view returns (address) {
        // set from to weth for eth input
        if (_FromTokenContractAddress == address(0)) {
            _FromTokenContractAddress = wethTokenAddress;
        }

        if (_FromTokenContractAddress == _ToUnipoolToken0) {
            return _ToUnipoolToken0;
        } else if (_FromTokenContractAddress == _ToUnipoolToken1) {
            return _ToUnipoolToken1;
        } else {
            IUniswapV2Pair pair = IUniswapV2Pair(
                UniSwapV2FactoryAddress.getPair(
                    _ToUnipoolToken0,
                    _ToUnipoolToken1
                )
            );
            (uint256 res0, uint256 res1, ) = pair.getReserves();

            uint256 ratio;
            bool isToken0Numerator;
            if (res0 >= res1) {
                ratio = res0 / res1;
                isToken0Numerator = true;
            } else {
                ratio = res1 / res0;
            }

            //find outputs on swap
            uint256 output0 = _calculateSwapOutput(
                _FromTokenContractAddress,
                _amount,
                _ToUnipoolToken0
            );
            uint256 output1 = _calculateSwapOutput(
                _FromTokenContractAddress,
                _amount,
                _ToUnipoolToken1
            );

            if (isToken0Numerator) {
                if (output1 * ratio >= output0) return _ToUnipoolToken1;
                else return _ToUnipoolToken0;
            } else {
                if (output0 * ratio >= output1) return _ToUnipoolToken0;
                else return _ToUnipoolToken1;
            }
        }
    }

    function _calculateSwapOutput(
        address _from,
        uint256 _amt,
        address _to
    ) internal view returns (uint256) {
        // check output via tokenA -> tokenB
        address pairA = UniSwapV2FactoryAddress.getPair(_from, _to);

        uint256 amtA;
        if (pairA != address(0)) {
            address[] memory pathA = new address[](2);
            pathA[0] = _from;
            pathA[1] = _to;

            amtA = uniswapRouter.getAmountsOut(_amt, pathA)[1];
        }

        uint256 amtB;
        // check output via tokenA -> weth -> tokenB
        if ((_from != wethTokenAddress) && _to != wethTokenAddress) {
            address[] memory pathB = new address[](3);
            pathB[0] = _from;
            pathB[1] = wethTokenAddress;
            pathB[2] = _to;

            amtB = uniswapRouter.getAmountsOut(_amt, pathB)[2];
        }

        if (amtA >= amtB) {
            return amtA;
        } else {
            return amtB;
        }
    }

    function calculateSwapInAmount(uint256 reserveIn, uint256 userIn)
        public
        pure
        returns (uint256)
    {
        return
            Babylonian
                .sqrt(
                reserveIn.mul(userIn.mul(3988000) + reserveIn.mul(3988009))
            )
                .sub(reserveIn.mul(1997)) / 1994;
    }

    /**
    @notice This function is used to swap ETH/ERC20 <> ETH/ERC20
    @param _FromTokenContractAddress The token address to swap from. (0x00 for ETH)
    @param _ToTokenContractAddress The token address to swap to. (0x00 for ETH)
    @param tokens2Trade The amount of tokens to swap
    @return tokenBought The quantity of tokens bought
    */
    function _token2Token(
        address _FromTokenContractAddress,
        address _ToTokenContractAddress,
        uint256 tokens2Trade
    ) internal returns (uint256 tokenBought) {
        if (_FromTokenContractAddress == _ToTokenContractAddress) {
            return tokens2Trade;
        }

        if (_FromTokenContractAddress == address(0)) {
            if (_ToTokenContractAddress == wethTokenAddress) {
                IWETH(wethTokenAddress).deposit.value(tokens2Trade)();
                return tokens2Trade;
            }

            address[] memory path = new address[](2);
            path[0] = wethTokenAddress;
            path[1] = _ToTokenContractAddress;
            tokenBought = uniswapRouter.swapExactETHForTokens.value(
                tokens2Trade
            )(1, path, address(this), deadline)[path.length - 1];
        } else if (_ToTokenContractAddress == address(0)) {
            if (_FromTokenContractAddress == wethTokenAddress) {
                IWETH(wethTokenAddress).withdraw(tokens2Trade);
                return tokens2Trade;
            }

            IERC20(_FromTokenContractAddress).safeIncreaseAllowance(
                address(uniswapRouter),
                tokens2Trade
            );

            address[] memory path = new address[](2);
            path[0] = _FromTokenContractAddress;
            path[1] = wethTokenAddress;
            tokenBought = uniswapRouter.swapExactTokensForETH(
                tokens2Trade,
                1,
                path,
                address(this),
                deadline
            )[path.length - 1];
        } else {
            IERC20(_FromTokenContractAddress).safeIncreaseAllowance(
                address(uniswapRouter),
                tokens2Trade
            );

            if (_FromTokenContractAddress != wethTokenAddress) {
                if (_ToTokenContractAddress != wethTokenAddress) {
                    // check output via tokenA -> tokenB
                    address pairA = UniSwapV2FactoryAddress.getPair(
                        _FromTokenContractAddress,
                        _ToTokenContractAddress
                    );
                    address[] memory pathA = new address[](2);
                    pathA[0] = _FromTokenContractAddress;
                    pathA[1] = _ToTokenContractAddress;
                    uint256 amtA;
                    if (pairA != address(0)) {
                        amtA = uniswapRouter.getAmountsOut(
                            tokens2Trade,
                            pathA
                        )[1];
                    }

                    // check output via tokenA -> weth -> tokenB
                    address[] memory pathB = new address[](3);
                    pathB[0] = _FromTokenContractAddress;
                    pathB[1] = wethTokenAddress;
                    pathB[2] = _ToTokenContractAddress;

                    uint256 amtB = uniswapRouter.getAmountsOut(
                        tokens2Trade,
                        pathB
                    )[2];

                    if (amtA >= amtB) {
                        tokenBought = uniswapRouter.swapExactTokensForTokens(
                            tokens2Trade,
                            1,
                            pathA,
                            address(this),
                            deadline
                        )[pathA.length - 1];
                    } else {
                        tokenBought = uniswapRouter.swapExactTokensForTokens(
                            tokens2Trade,
                            1,
                            pathB,
                            address(this),
                            deadline
                        )[pathB.length - 1];
                    }
                } else {
                    address[] memory path = new address[](2);
                    path[0] = _FromTokenContractAddress;
                    path[1] = wethTokenAddress;

                    tokenBought = uniswapRouter.swapExactTokensForTokens(
                        tokens2Trade,
                        1,
                        path,
                        address(this),
                        deadline
                    )[path.length - 1];
                }
            } else {
                address[] memory path = new address[](2);
                path[0] = wethTokenAddress;
                path[1] = _ToTokenContractAddress;
                tokenBought = uniswapRouter.swapExactTokensForTokens(
                    tokens2Trade,
                    1,
                    path,
                    address(this),
                    deadline
                )[path.length - 1];
            }
        }
        require(tokenBought > 0, "Error Swapping Tokens");
    }

    /**
    @notice This function is used to calculate and transfer goodwill
    @param _tokenContractAddress Token in which goodwill is deducted
    @param tokens2Trade The total amount of tokens to be zapped in
    @return The quantity of goodwill deducted
     */
    function _transferGoodwill(
        address _tokenContractAddress,
        uint256 tokens2Trade
    ) internal returns (uint256 goodwillPortion) {
        goodwillPortion = SafeMath.div(
            SafeMath.mul(tokens2Trade, goodwill),
            10000
        );

        if (goodwillPortion == 0) {
            return 0;
        }

        IERC20(_tokenContractAddress).safeTransfer(
            vault,
            goodwillPortion
        );
    }

    function set_new_goodwill(uint16 _new_goodwill) public onlyOwner {
        require(
            _new_goodwill >= 0 && _new_goodwill < 10000,
            "GoodWill Value not allowed"
        );
        goodwill = _new_goodwill;
    }

    function inCaseTokengetsStuck(IERC20 _TokenAddress) public onlyOwner {
        uint256 qty = _TokenAddress.balanceOf(address(this));
        _TokenAddress.safeTransfer(owner(), qty);
    }

    // - to Pause the contract
    function toggleContractActive() public onlyOwner {
        stopped = !stopped;
    }

    // - to withdraw any ETH balance sitting in the contract
    function withdraw() public onlyOwner {
        uint256 contractBalance = address(this).balance;
        address payable _to = owner().toPayable();
        _to.transfer(contractBalance);
    }

    function() external payable {
        require(msg.sender != tx.origin, "Do not send ETH directly");
    }
}