// File: @openzeppelin/contracts/GSN/Context.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../utils/Context.sol";

// 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/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/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: @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);
            }
        }
    }
}

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



// SPDX-License-Identifier: MIT

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;
    }
}

// File: contracts/Pausable.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

import "@openzeppelin/contracts/GSN/Context.sol";

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 */
contract Pausable is Context {
    event Paused(address account);
    event Shutdown(address account);
    event Unpaused(address account);
    event Open(address account);

    bool public paused;
    bool public stopEverything;

    modifier whenNotPaused() {
        require(!paused, "Pausable: paused");
        _;
    }
    modifier whenPaused() {
        require(paused, "Pausable: not paused");
        _;
    }

    modifier whenNotShutdown() {
        require(!stopEverything, "Pausable: shutdown");
        _;
    }

    modifier whenShutdown() {
        require(stopEverything, "Pausable: not shutdown");
        _;
    }

    /// @dev Pause contract operations, if contract is not paused.
    function _pause() internal virtual whenNotPaused {
        paused = true;
        emit Paused(_msgSender());
    }

    /// @dev Unpause contract operations, allow only if contract is paused and not shutdown.
    function _unpause() internal virtual whenPaused whenNotShutdown {
        paused = false;
        emit Unpaused(_msgSender());
    }

    /// @dev Shutdown contract operations, if not already shutdown.
    function _shutdown() internal virtual whenNotShutdown {
        stopEverything = true;
        paused = true;
        emit Shutdown(_msgSender());
    }

    /// @dev Open contract operations, if contract is in shutdown state
    function _open() internal virtual whenShutdown {
        stopEverything = false;
        emit Open(_msgSender());
    }
}

// File: contracts/interfaces/bloq/ISwapManager.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

import "../uniswap/IUniswapV2Router02.sol";

/* solhint-disable func-name-mixedcase */

interface ISwapManager {
    event OracleCreated(address indexed _sender, address indexed _newOracle, uint256 _period);

    function N_DEX() external view returns (uint256);

    function ROUTERS(uint256 i) external view returns (IUniswapV2Router02);

    function bestOutputFixedInput(
        address _from,
        address _to,
        uint256 _amountIn
    )
        external
        view
        returns (
            address[] memory path,
            uint256 amountOut,
            uint256 rIdx
        );

    function bestPathFixedInput(
        address _from,
        address _to,
        uint256 _amountIn,
        uint256 _i
    ) external view returns (address[] memory path, uint256 amountOut);

    function bestInputFixedOutput(
        address _from,
        address _to,
        uint256 _amountOut
    )
        external
        view
        returns (
            address[] memory path,
            uint256 amountIn,
            uint256 rIdx
        );

    function bestPathFixedOutput(
        address _from,
        address _to,
        uint256 _amountOut,
        uint256 _i
    ) external view returns (address[] memory path, uint256 amountIn);

    function safeGetAmountsOut(
        uint256 _amountIn,
        address[] memory _path,
        uint256 _i
    ) external view returns (uint256[] memory result);

    function unsafeGetAmountsOut(
        uint256 _amountIn,
        address[] memory _path,
        uint256 _i
    ) external view returns (uint256[] memory result);

    function safeGetAmountsIn(
        uint256 _amountOut,
        address[] memory _path,
        uint256 _i
    ) external view returns (uint256[] memory result);

    function unsafeGetAmountsIn(
        uint256 _amountOut,
        address[] memory _path,
        uint256 _i
    ) external view returns (uint256[] memory result);

    function comparePathsFixedInput(
        address[] memory pathA,
        address[] memory pathB,
        uint256 _amountIn,
        uint256 _i
    ) external view returns (address[] memory path, uint256 amountOut);

    function comparePathsFixedOutput(
        address[] memory pathA,
        address[] memory pathB,
        uint256 _amountOut,
        uint256 _i
    ) external view returns (address[] memory path, uint256 amountIn);

    function ours(address a) external view returns (bool);

    function oracleCount() external view returns (uint256);

    function oracleAt(uint256 idx) external view returns (address);

    function getOracle(
        address _tokenA,
        address _tokenB,
        uint256 _period,
        uint256 _i
    ) external view returns (address);

    function createOrUpdateOracle(
        address _tokenA,
        address _tokenB,
        uint256 _period,
        uint256 _i
    ) external returns (address oracleAddr);

    function consultForFree(
        address _from,
        address _to,
        uint256 _amountIn,
        uint256 _period,
        uint256 _i
    ) external view returns (uint256 amountOut, uint256 lastUpdatedAt);

    /// get the data we want and pay the gas to update
    function consult(
        address _from,
        address _to,
        uint256 _amountIn,
        uint256 _period,
        uint256 _i
    )
        external
        returns (
            uint256 amountOut,
            uint256 lastUpdatedAt,
            bool updated
        );

    function updateOracles() external returns (uint256 updated, uint256 expected);

    function updateOracles(address[] memory _oracleAddrs)
        external
        returns (uint256 updated, uint256 expected);
}

// File: contracts/interfaces/uniswap/IUniswapV2Router01.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

interface IUniswapV2Router01 {
    function factory() external pure returns (address);

    function swapExactTokensForTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapTokensForExactTokens(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactETHForTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function swapTokensForExactETH(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactTokensForETH(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapETHForExactTokens(
        uint256 amountOut,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function quote(
        uint256 amountA,
        uint256 reserveA,
        uint256 reserveB
    ) external pure returns (uint256 amountB);

    function getAmountOut(
        uint256 amountIn,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountOut);

    function getAmountIn(
        uint256 amountOut,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountIn);

    function getAmountsOut(uint256 amountIn, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);

    function getAmountsIn(uint256 amountOut, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);
}

// File: contracts/interfaces/uniswap/IUniswapV2Router02.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

import "./IUniswapV2Router01.sol";

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;

    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable;

    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
}

// File: contracts/interfaces/vesper/IController.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

interface IController {
    function aaveReferralCode() external view returns (uint16);

    function feeCollector(address) external view returns (address);

    function founderFee() external view returns (uint256);

    function founderVault() external view returns (address);

    function interestFee(address) external view returns (uint256);

    function isPool(address) external view returns (bool);

    function pools() external view returns (address);

    function strategy(address) external view returns (address);

    function rebalanceFriction(address) external view returns (uint256);

    function poolRewards(address) external view returns (address);

    function treasuryPool() external view returns (address);

    function uniswapRouter() external view returns (address);

    function withdrawFee(address) external view returns (uint256);
}

// File: contracts/interfaces/vesper/IStrategy.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

interface IStrategy {
    function rebalance() external;

    function deposit(uint256 amount) external;

    function beforeWithdraw() external;

    function withdraw(uint256 amount) external;

    function withdrawAll() external;

    function isUpgradable() external view returns (bool);

    function isReservedToken(address _token) external view returns (bool);

    function token() external view returns (address);

    function pool() external view returns (address);

    function totalLocked() external view returns (uint256);

    //Lifecycle functions
    function pause() external;

    function unpause() external;
}

// File: contracts/interfaces/vesper/IVesperPool.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

interface IVesperPool is IERC20 {
    function approveToken() external;

    function deposit() external payable;

    function deposit(uint256) external;

    function multiTransfer(uint256[] memory) external returns (bool);

    function permit(
        address,
        address,
        uint256,
        uint256,
        uint8,
        bytes32,
        bytes32
    ) external;

    function rebalance() external;

    function resetApproval() external;

    function sweepErc20(address) external;

    function withdraw(uint256) external;

    function withdrawETH(uint256) external;

    function withdrawByStrategy(uint256) external;

    function feeCollector() external view returns (address);

    function getPricePerShare() external view returns (uint256);

    function token() external view returns (address);

    function tokensHere() external view returns (uint256);

    function totalValue() external view returns (uint256);

    function withdrawFee() external view returns (uint256);
}

// File: contracts/strategies/OraclesBase.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "../interfaces/bloq/ISwapManager.sol";
import "../interfaces/vesper/IStrategy.sol";
import "../interfaces/vesper/IController.sol";
import "../interfaces/vesper/IVesperPool.sol";
import "../Pausable.sol";

abstract contract OraclesBase is Pausable {
    using SafeERC20 for IERC20;
    IController public immutable controller;

    uint256 public oraclePeriod = 3600; // 1h
    uint256 public oracleRouterIdx = 0; // Uniswap V2
    uint256 public swapSlippage = 10000; // 100% Don't use oracles by default

    address internal constant ETH = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    address internal constant WETH = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
    address internal constant VSP = 0x1b40183EFB4Dd766f11bDa7A7c3AD8982e998421;
    uint256 internal constant MAX_UINT_VALUE = type(uint256).max;
    ISwapManager public swapManager = ISwapManager(0xe382d9f2394A359B01006faa8A1864b8a60d2710);

    event UpdatedOracleConfig(
        uint256 oldPeriod,
        uint256 newPeriod,
        uint256 oldRouterIdx,
        uint256 newRouterIdx
    );
    event UpdatedSwapManager(address indexed previousSwapManager, address indexed newSwapManager);
    event UpdatedSwapSlippage(uint256 oldSwapSlippage, uint256 newSwapSlippage);

    constructor(address _controller) public {
        controller = IController(_controller);
    }

    modifier onlyController() {
        require(_msgSender() == address(controller), "Caller is not the controller");
        _;
    }

    /**
     * @notice Update swap manager address
     * @param _swapManager swap manager address
     */
    function updateSwapManager(address _swapManager) external onlyController {
        require(_swapManager != address(0), "sm-address-is-zero");
        require(_swapManager != address(swapManager), "sm-is-same");
        emit UpdatedSwapManager(address(swapManager), _swapManager);
        swapManager = ISwapManager(_swapManager);
    }

    function updateSwapSlippage(uint256 _newSwapSlippage) external onlyController {
        require(_newSwapSlippage <= 10000, "invalid-slippage-value");
        emit UpdatedSwapSlippage(swapSlippage, _newSwapSlippage);
        swapSlippage = _newSwapSlippage;
    }

    function updateOracleConfig(uint256 _newPeriod, uint256 _newRouterIdx) external onlyController {
        require(_newRouterIdx < swapManager.N_DEX(), "invalid-router-index");
        if (_newPeriod == 0) _newPeriod = oraclePeriod;
        require(_newPeriod > 59, "invalid-oracle-period");
        emit UpdatedOracleConfig(oraclePeriod, _newPeriod, oracleRouterIdx, _newRouterIdx);
        oraclePeriod = _newPeriod;
        oracleRouterIdx = _newRouterIdx;
    }

    function _calcAmtOutAfterSlippage(uint256 _amount, uint256 _slippage)
        internal
        pure
        returns (uint256)
    {
        return (_amount * (10000 - _slippage)) / (10000);
    }

    function _simpleOraclePath(address _from, address _to)
        internal
        pure
        returns (address[] memory path)
    {
        if (_from == WETH || _to == WETH) {
            path = new address[](2);
            path[0] = _from;
            path[1] = _to;
        } else {
            path = new address[](3);
            path[0] = _from;
            path[1] = WETH;
            path[2] = _to;
        }
    }

    function _consultOracle(
        address _from,
        address _to,
        uint256 _amt
    ) internal returns (uint256, bool) {
        (uint256 rate, uint256 lastUpdate, ) =
            swapManager.consult(_from, _to, _amt, oraclePeriod, oracleRouterIdx);
        // We're looking at a TWAP ORACLE with a 1 hr Period that has been updated within the last hour
        if ((lastUpdate > (block.timestamp - oraclePeriod)) && (rate != 0)) return (rate, true);
        return (0, false);
    }

    function _getOracleRate(address[] memory path, uint256 _amountIn)
        internal
        returns (uint256 amountOut)
    {
        require(path.length > 1, "invalid-oracle-path");
        amountOut = _amountIn;
        bool isValid;
        for (uint256 i = 0; i < path.length - 1; i++) {
            (amountOut, isValid) = _consultOracle(path[i], path[i + 1], amountOut);
            require(isValid, "invalid-oracle-rate");
        }
    }
}

// File: contracts/strategies/VSPStrategy.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "./OraclesBase.sol";
import "../interfaces/vesper/IVesperPool.sol";
import "../interfaces/bloq/ISwapManager.sol";
import "../../sol-address-list/contracts/interfaces/IAddressListExt.sol";
import "../../sol-address-list/contracts/interfaces/IAddressListFactory.sol";

contract VSPStrategy is OraclesBase {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    uint256 public lastRebalanceBlock;    
    IVesperPool public immutable vvsp;
    IAddressListExt public immutable keepers;
    uint256 public nextPoolIdx;
    address[] public pools;
    uint256[] public liquidationLimit;
    string public constant NAME = "Strategy-VSP";
    string public constant VERSION = "2.0.3";

    constructor(address _controller, address _vvsp) public OraclesBase(_controller) { 
        vvsp = IVesperPool(_vvsp);
        IAddressListFactory factory =
            IAddressListFactory(0xD57b41649f822C51a73C44Ba0B3da4A880aF0029);
        IAddressListExt _keepers = IAddressListExt(factory.createList());
        _keepers.grantRole(keccak256("LIST_ADMIN"), _controller);
        keepers = _keepers;
    }

    modifier onlyKeeper() {
        require(keepers.contains(_msgSender()), "caller-is-not-keeper");
        _;
    }

    function pause() external onlyController {
        _pause();
    }

    function unpause() external onlyController {
        _unpause();
    }

    function updateLiquidationQueue(address[] calldata _pools, uint256[] calldata _limit)
        external
        onlyController
    {
        for (uint256 i = 0; i < _pools.length; i++) {
            require(controller.isPool(_pools[i]), "Not a valid pool");
            require(_limit[i] != 0, "Limit cannot be zero");
        }
        pools = _pools;
        liquidationLimit = _limit;
        nextPoolIdx = 0;
    }

    function isUpgradable() external view returns (bool) {
        return IERC20(vvsp.token()).balanceOf(address(this)) == 0;
    }

    function pool() external view returns (address) {
        return address(vvsp);
    }

    /**
        withdraw Vtoken from vvsp => Deposit vpool => withdraw collateral => swap in uni for VSP => transfer vsp to vvsp pool
        VETH => ETH => VSP
     */
    function rebalance() external whenNotPaused onlyKeeper {
        require(
            block.number - lastRebalanceBlock >= controller.rebalanceFriction(address(vvsp)),
            "Can not rebalance"
        );
        lastRebalanceBlock = block.number;

        if (nextPoolIdx == pools.length) {
            nextPoolIdx = 0;
        }

        IVesperPool _poolToken = IVesperPool(pools[nextPoolIdx]);
        uint256 _balance = _poolToken.balanceOf(address(vvsp));
        if (_balance != 0 && address(_poolToken) != address(vvsp)) {
            if (_balance > liquidationLimit[nextPoolIdx]) {
                _balance = liquidationLimit[nextPoolIdx];
            }
            _rebalanceEarned(_poolToken, _balance);
        }
        nextPoolIdx++;
    }

    /// @dev sweep given token to vsp pool
    function sweepErc20(address _fromToken) external {
        uint256 amount = IERC20(_fromToken).balanceOf(address(this));
        IERC20(_fromToken).safeTransfer(address(vvsp), amount);
    }

    function _rebalanceEarned(IVesperPool _poolToken, uint256 _amt) internal {
        IERC20(address(_poolToken)).safeTransferFrom(address(vvsp), address(this), _amt);
        _poolToken.withdraw(_amt);
        IERC20 from = IERC20(_poolToken.token());
        IERC20 vsp = IERC20(vvsp.token());
        (address[] memory path, uint256 amountOut, uint256 rIdx) =
            swapManager.bestOutputFixedInput(
                address(from),
                address(vsp),
                from.balanceOf(address(this))
            );
        if (amountOut != 0) {
            from.safeApprove(address(swapManager.ROUTERS(rIdx)), 0);
            from.safeApprove(address(swapManager.ROUTERS(rIdx)), from.balanceOf(address(this)));
            uint256 minAmtOut =
                (swapSlippage != 10000)
                    ? _calcAmtOutAfterSlippage(
                        _getOracleRate(_simpleOraclePath(VSP, _poolToken.token()), amountOut),
                        swapSlippage
                    )
                    : 1;
            swapManager.ROUTERS(rIdx).swapExactTokensForTokens(
                from.balanceOf(address(this)),
                minAmtOut,
                path,
                address(this),
                now + 30
            );
            vsp.safeTransfer(address(vvsp), vsp.balanceOf(address(this)));
        }
    }
}

// File: sol-address-list/contracts/interfaces/IAddressList.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.6;

interface IAddressList {
    event AddressUpdated(address indexed a, address indexed sender);
    event AddressRemoved(address indexed a, address indexed sender);

    function add(address a) external returns (bool);

    function addValue(address a, uint256 v) external returns (bool);

    function addMulti(address[] calldata addrs) external returns (uint256);

    function addValueMulti(address[] calldata addrs, uint256[] calldata values) external returns (uint256);

    function remove(address a) external returns (bool);

    function removeMulti(address[] calldata addrs) external returns (uint256);

    function get(address a) external view returns (uint256);

    function contains(address a) external view returns (bool);

    function at(uint256 index) external view returns (address, uint256);

    function length() external view returns (uint256);
}

// File: sol-address-list/contracts/interfaces/IAddressListExt.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.6;

import "./IAddressList.sol";

interface IAddressListExt is IAddressList {
    function hasRole(bytes32 role, address account) external view returns (bool);

    function getRoleMemberCount(bytes32 role) external view returns (uint256);

    function getRoleMember(bytes32 role, uint256 index) external view returns (address);

    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    function grantRole(bytes32 role, address account) external;

    function revokeRole(bytes32 role, address account) external;

    function renounceRole(bytes32 role, address account) external;
}

// File: sol-address-list/contracts/interfaces/IAddressListFactory.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.6;

interface IAddressListFactory {
    event ListCreated(address indexed _sender, address indexed _newList);

    function ours(address a) external view returns (bool);

    function listCount() external view returns (uint256);

    function listAt(uint256 idx) external view returns (address);

    function createList() external returns (address listaddr);
}