// File: contracts/SingleTokenJoin.sol



//SPDX-License-Identifier: Unlicense
pragma experimental ABIEncoderV2;
pragma solidity ^0.7.1;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";

import {
    IPangolinRouter
} from "@pangolindex/exchange-contracts/contracts/pangolin-periphery/interfaces/IPangolinRouter.sol";

import "./interfaces/IBasketFacet.sol";

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

    // Can be any IPangolinRouter or IUniRouter ...
    IPangolinRouter public immutable uniSwapLikeRouter;
    // WETH or WAVAX ...
    IERC20 public immutable INTERMEDIATE_TOKEN;
    struct JoinTokenStruct {
        address inputToken;
        address outputBasket;
        uint256 inputAmount;
        uint256 outputAmount;
        uint256 deadline;
        uint16 referral;
    }
    constructor(address _INTERMEDIATE_TOKEN, address _uniSwapLikeRouter) {
        require(_INTERMEDIATE_TOKEN != address(0), "INTERMEDIATE_ZERO");
        require(_uniSwapLikeRouter != address(0), "UNI_ROUTER_ZERO");

        INTERMEDIATE_TOKEN = IERC20(_INTERMEDIATE_TOKEN);
        uniSwapLikeRouter = IPangolinRouter(_uniSwapLikeRouter);
    }

    function _maxApprove(IERC20 token, address spender) internal {
        if (
            token.allowance(address(this), spender) <
            token.balanceOf(address(this))
        ) {
            token.approve(spender, uint256(-1));
        }
    }



    function joinTokenSingle(JoinTokenStruct calldata _joinTokenStruct)
        external
    {
        // ######## INIT TOKEN #########
        IERC20 inputToken = IERC20(_joinTokenStruct.inputToken);
        IERC20 outputToken = IERC20(_joinTokenStruct.outputBasket);

        inputToken.safeTransferFrom(
            msg.sender,
            address(this),
            _joinTokenStruct.inputAmount
        );

        (address[] memory tokens, uint256[] memory amounts) =
            IBasketFacet(_joinTokenStruct.outputBasket).calcTokensForAmount(
                _joinTokenStruct.outputAmount
            );

        // ######## SWAP TOKEN #########
        address[] memory path = new address[](2);
        if (_joinTokenStruct.inputToken != address(INTERMEDIATE_TOKEN)) {
            _maxApprove(inputToken, address(uniSwapLikeRouter));

            path[0] = _joinTokenStruct.inputToken;
            path[1] = address(INTERMEDIATE_TOKEN);
            uint256[] memory amounts =
                uniSwapLikeRouter.getAmountsOut(
                    _joinTokenStruct.inputAmount,
                    path
                );

            uniSwapLikeRouter.swapExactTokensForTokens(
                _joinTokenStruct.inputAmount,
                amounts[amounts.length - 1],
                path,
                address(this),
                _joinTokenStruct.deadline
            );
        }

        path[0] = address(INTERMEDIATE_TOKEN);

        _maxApprove(INTERMEDIATE_TOKEN, address(uniSwapLikeRouter));
        for (uint256 i; i < tokens.length; i++) {
            path[1] = tokens[i];

            uint256[] memory amountsIn =
                uniSwapLikeRouter.getAmountsIn(amounts[i], path);

            uniSwapLikeRouter.swapTokensForExactTokens(
                amounts[i],
                amountsIn[0],
                path,
                address(this),
                _joinTokenStruct.deadline
            );
            _maxApprove(IERC20(tokens[i]), _joinTokenStruct.outputBasket);
        }

        IBasketFacet(_joinTokenStruct.outputBasket).joinPool(
            _joinTokenStruct.outputAmount,
            _joinTokenStruct.referral
        );

        // ######## SEND TOKEN #########
        uint256 remainingIntermediateBalance =
            INTERMEDIATE_TOKEN.balanceOf(address(this));
        if (remainingIntermediateBalance > 0) {
            INTERMEDIATE_TOKEN.safeTransfer(
                msg.sender,
                remainingIntermediateBalance
            );
        }

        uint256 outputAmount = outputToken.balanceOf(address(this));
        require(outputAmount == _joinTokenStruct.outputAmount, "FAILED_OUTPUT_AMOUNT");

        outputToken.safeTransfer(msg.sender, outputAmount);
    }
}

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



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

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

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

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

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

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

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

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

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

// File: @openzeppelin/contracts/math/SafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

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

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

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

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

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

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

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

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

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

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

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

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

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

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



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

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

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: @pangolindex/exchange-contracts/contracts/pangolin-periphery/interfaces/IPangolinRouter.sol



pragma solidity >=0.6.2;

interface IPangolinRouter {
    function factory() external pure returns (address);
    function WAVAX() 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 addLiquidityAVAX(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountAVAXMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountAVAX, 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 removeLiquidityAVAX(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountAVAXMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountAVAX);
    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 removeLiquidityAVAXWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountAVAXMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountAVAX);
    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 swapExactAVAXForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactAVAX(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForAVAX(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapAVAXForExactTokens(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 removeLiquidityAVAXSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountAVAXMin,
        address to,
        uint deadline
    ) external returns (uint amountAVAX);
    function removeLiquidityAVAXWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountAVAXMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountAVAX);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactAVAXForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForAVAXSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

// File: contracts/interfaces/IBasketFacet.sol



// SPDX-License-Identifier: MIT
pragma experimental ABIEncoderV2;
pragma solidity ^0.7.1;

interface IBasketFacet {
    event TokenAdded(address indexed _token);
    event TokenRemoved(address indexed _token);
    event EntryFeeSet(uint256 fee);
    event ExitFeeSet(uint256 fee);
    event AnnualizedFeeSet(uint256 fee);
    event FeeBeneficiarySet(address indexed beneficiary);
    event EntryFeeBeneficiaryShareSet(uint256 share);
    event ExitFeeBeneficiaryShareSet(uint256 share);

    event PoolJoined(address indexed who, uint256 amount, uint16 _referral);
    event PoolExited(address indexed who, uint256 amount, uint16 _referral);
    event FeeCharged(uint256 amount);
    event LockSet(uint256 lockBlock);
    event CapSet(uint256 cap);

    /**
        @notice Sets entry fee paid when minting
        @param _fee Amount of fee. 1e18 == 100%, capped at 10%
    */
    function setEntryFee(uint256 _fee) external;

    /**
        @notice Get the entry fee
        @return Current entry fee
    */
    function getEntryFee() external view returns (uint256);

    /**
        @notice Set the exit fee paid when exiting
        @param _fee Amount of fee. 1e18 == 100%, capped at 10%
    */
    function setExitFee(uint256 _fee) external;

    /**
        @notice Get the exit fee
        @return Current exit fee
    */
    function getExitFee() external view returns (uint256);

    /**
        @notice Set the annualized fee. Often referred to as streaming fee
        @param _fee Amount of fee. 1e18 == 100%, capped at 10%
    */
    function setAnnualizedFee(uint256 _fee) external;

    /**
        @notice Get the annualized fee.
        @return Current annualized fee.
    */
    function getAnnualizedFee() external view returns (uint256);

    /**
        @notice Set the address receiving the fees.
    */
    function setFeeBeneficiary(address _beneficiary) external;

    /**
        @notice Get the fee benificiary
        @return The current fee beneficiary
    */
    function getFeeBeneficiary() external view returns (address);

    /**
        @notice Set the fee beneficiaries share of the entry fee
        @notice _share Share of the fee. 1e18 == 100%. Capped at 100%
    */
    function setEntryFeeBeneficiaryShare(uint256 _share) external;

    /**
        @notice Get the entry fee beneficiary share
        @return Feeshare amount
    */
    function getEntryFeeBeneficiaryShare() external view returns (uint256);

    /**
        @notice Set the fee beneficiaries share of the exit fee
        @notice _share Share of the fee. 1e18 == 100%. Capped at 100%
    */
    function setExitFeeBeneficiaryShare(uint256 _share) external;

    /**
        @notice Get the exit fee beneficiary share
        @return Feeshare amount
    */
    function getExitFeeBeneficiaryShare() external view returns (uint256);

    /**
        @notice Calculate the oustanding annualized fee
        @return Amount of pool tokens to be minted to charge the annualized fee
    */
    function calcOutStandingAnnualizedFee() external view returns (uint256);

    /**
        @notice Charges the annualized fee
    */
    function chargeOutstandingAnnualizedFee() external;

    /**
        @notice Pulls underlying from caller and mints the pool token
        @param _amount Amount of pool tokens to mint
        @param _referral Partners may receive rewards with their referral code
    */
    function joinPool(uint256 _amount, uint16 _referral) external;

    /**
        @notice Burns pool tokens from the caller and returns underlying assets
    */
    function exitPool(uint256 _amount, uint16 _referral) external;

    /**
        @notice Get if the pool is locked or not. (not accepting exit and entry)
        @return Boolean indicating if the pool is locked
    */
    function getLock() external view returns (bool);

    /**
        @notice Get the block until which the pool is locked
        @return The lock block
    */
    function getLockBlock() external view returns (uint256);

    /**
        @notice Set the lock block
        @param _lock Block height of the lock
    */
    function setLock(uint256 _lock) external;

    /**
        @notice Get the maximum of pool tokens that can be minted
        @return Cap
    */
    function getCap() external view returns (uint256);

    /**
        @notice Set the maximum of pool tokens that can be minted
        @param _maxCap Max cap
    */
    function setCap(uint256 _maxCap) external;

    /**
        @notice Get the amount of tokens owned by the pool
        @param _token Addres of the token
        @return Amount owned by the contract
    */
    function balance(address _token) external view returns (uint256);

    /**
        @notice Get the tokens in the pool
        @return Array of tokens in the pool
    */
    function getTokens() external view returns (address[] memory);

    /**
        @notice Add a token to the pool. Should have at least a balance of 10**6
        @param _token Address of the token to add
    */
    function addToken(address _token) external;

    /**
        @notice Removes a token from the pool
        @param _token Address of the token to remove
    */
    function removeToken(address _token) external;

    /**
        @notice Checks if a token was added to the pool
        @param _token address of the token
        @return If token is in the pool or not
    */
    function getTokenInPool(address _token) external view returns (bool);

    /**
        @notice Calculate the amounts of underlying needed to mint that pool amount.
        @param _amount Amount of pool tokens to mint
        @return tokens Tokens needed
        @return amounts Amounts of underlying needed
    */
    function calcTokensForAmount(uint256 _amount)
        external
        view
        returns (address[] memory tokens, uint256[] memory amounts);

    /**
        @notice Calculate the amounts of underlying to receive when burning that pool amount
        @param _amount Amount of pool tokens to burn
        @return tokens Tokens returned
        @return amounts Amounts of underlying returned
    */
    function calcTokensForAmountExit(uint256 _amount)
        external
        view
        returns (address[] memory tokens, uint256[] memory amounts);
}

// File: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.2 <0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

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