// SPDX-License-Identifier: MIT

// solhint-disable-next-line compiler-version
pragma solidity ^0.8.0;

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {

    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        require(_initializing || !_initialized, "Initializable: contract is already initialized");

        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }

        _;

        if (isTopLevelCall) {
            _initializing = false;
        }
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^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);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../IERC20.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 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) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _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");
        }
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^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);
            }
        }
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^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 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) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

pragma solidity >=0.6.2;

interface IUniswapV2Router01 {
    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);
}

pragma solidity >=0.6.2;

import './IUniswapV2Router01.sol';

interface IUniswapV2Router02 is IUniswapV2Router01 {
    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;
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.3;

import "@openzeppelin/contracts/proxy/utils/Initializable.sol";
import "@openzeppelin/contracts/utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (governor) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the governor account will be the one that deploys the contract. This
 * can later be changed with {transferGovernorship}.
 *
 */
contract Governed is Context, Initializable {
    address public governor;
    address private proposedGovernor;

    event UpdatedGovernor(address indexed previousGovernor, address indexed proposedGovernor);

    /**
     * @dev Initializes the contract setting the deployer as the initial governor.
     */
    constructor() {
        address msgSender = _msgSender();
        governor = msgSender;
        emit UpdatedGovernor(address(0), msgSender);
    }

    /**
     * @dev If inheriting child is using proxy then child contract can use
     * _initializeGoverned() function to initialization this contract
     */
    function _initializeGoverned() internal initializer {
        address msgSender = _msgSender();
        governor = msgSender;
        emit UpdatedGovernor(address(0), msgSender);
    }

    /**
     * @dev Throws if called by any account other than the governor.
     */
    modifier onlyGovernor {
        require(governor == _msgSender(), "not-the-governor");
        _;
    }

    /**
     * @dev Transfers governorship of the contract to a new account (`proposedGovernor`).
     * Can only be called by the current owner.
     */
    function transferGovernorship(address _proposedGovernor) external onlyGovernor {
        require(_proposedGovernor != address(0), "proposed-governor-is-zero");
        proposedGovernor = _proposedGovernor;
    }

    /**
     * @dev Allows new governor to accept governorship of the contract.
     */
    function acceptGovernorship() external {
        require(proposedGovernor == _msgSender(), "not-the-proposed-governor");
        emit UpdatedGovernor(governor, proposedGovernor);
        governor = proposedGovernor;
        proposedGovernor = address(0);
    }
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.3;

interface IAddressList {
    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);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.3;

interface IAddressListFactory {
    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);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.3;

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

import "@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";

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);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.3;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "../bloq/IAddressList.sol";

interface IVesperPool is IERC20 {
    function deposit() external payable;

    function deposit(uint256 _share) external;

    function multiTransfer(address[] memory _recipients, uint256[] memory _amounts) external returns (bool);

    function excessDebt(address _strategy) external view returns (uint256);

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

    function poolRewards() external returns (address);

    function reportEarning(
        uint256 _profit,
        uint256 _loss,
        uint256 _payback
    ) external;

    function reportLoss(uint256 _loss) external;

    function resetApproval() external;

    function sweepERC20(address _fromToken) external;

    function withdraw(uint256 _amount) external;

    function withdrawETH(uint256 _amount) external;

    function whitelistedWithdraw(uint256 _amount) external;

    function governor() external view returns (address);

    function keepers() external view returns (IAddressList);

    function maintainers() external view returns (IAddressList);

    function feeCollector() external view returns (address);

    function pricePerShare() external view returns (uint256);

    function strategy(address _strategy)
        external
        view
        returns (
            bool _active,
            uint256 _interestFee,
            uint256 _debtRate,
            uint256 _lastRebalance,
            uint256 _totalDebt,
            uint256 _totalLoss,
            uint256 _totalProfit,
            uint256 _debtRatio
        );

    function stopEverything() external view returns (bool);

    function token() external view returns (IERC20);

    function tokensHere() external view returns (uint256);

    function totalDebtOf(address _strategy) external view returns (uint256);

    function totalValue() external view returns (uint256);

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

// SPDX-License-Identifier: MIT
pragma solidity 0.8.3;

/// @title Errors library
library Errors {
    string public constant INVALID_COLLATERAL_AMOUNT = "1"; // Collateral must be greater than 0
    string public constant INVALID_SHARE_AMOUNT = "2"; // Share must be greater than 0
    string public constant INVALID_INPUT_LENGTH = "3"; // Input array length must be greater than 0
    string public constant INPUT_LENGTH_MISMATCH = "4"; // Input array length mismatch with another array length
    string public constant NOT_WHITELISTED_ADDRESS = "5"; // Caller is not whitelisted to withdraw without fee
    string public constant MULTI_TRANSFER_FAILED = "6"; // Multi transfer of tokens has failed
    string public constant FEE_COLLECTOR_NOT_SET = "7"; // Fee Collector is not set
    string public constant NOT_ALLOWED_TO_SWEEP = "8"; // Token is not allowed to sweep
    string public constant INSUFFICIENT_BALANCE = "9"; // Insufficient balance to performs operations to follow
    string public constant INPUT_ADDRESS_IS_ZERO = "10"; // Input address is zero
    string public constant FEE_LIMIT_REACHED = "11"; // Fee must be less than MAX_BPS
    string public constant ALREADY_INITIALIZED = "12"; // Data structure, contract, or logic already initialized and can not be called again
    string public constant ADD_IN_LIST_FAILED = "13"; // Cannot add address in address list
    string public constant REMOVE_FROM_LIST_FAILED = "14"; // Cannot remove address from address list
    string public constant STRATEGY_IS_ACTIVE = "15"; // Strategy is already active, an inactive strategy is required
    string public constant STRATEGY_IS_NOT_ACTIVE = "16"; // Strategy is not active, an active strategy is required
    string public constant INVALID_STRATEGY = "17"; // Given strategy is not a strategy of this pool
    string public constant DEBT_RATIO_LIMIT_REACHED = "18"; // Debt ratio limit reached. It must be less than MAX_BPS
    string public constant TOTAL_DEBT_IS_NOT_ZERO = "19"; // Strategy total debt must be 0
    string public constant LOSS_TOO_HIGH = "20"; // Strategy reported loss must be less than current debt
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.3;

/// @dev Based on https://github.com/boringcrypto/BoringSolidity/blob/master/contracts/BoringBatchable.sol
/// @dev WARNING!!! Combining Batchable with `msg.value` can cause double spending issues
contract Batchable {
    /// @dev Helper function to extract a useful revert message from a failed call.
    /// If the returned data is malformed or not correctly abi encoded then this call can fail itself.
    function _getRevertMsg(bytes memory _returnData) internal pure returns (string memory) {
        // If the _res length is less than 68, then the transaction failed silently (without a revert message)
        if (_returnData.length < 68) return "Transaction reverted silently";

        assembly {
            // Slice the sighash.
            _returnData := add(_returnData, 0x04)
        }
        return abi.decode(_returnData, (string)); // All that remains is the revert string
    }

    /// @notice Allows batched call to self (this contract).
    /// @param calls An array of inputs for each call.
    /// @param revertOnFail If True then reverts after a failed call and stops doing further calls.
    // F1: External is ok here because this is the batch function, adding it to a batch makes no sense
    // F2: Calls in the batch may be payable, delegatecall operates in the same context, so each call in the batch has access to msg.value
    // C3: The length of the loop is fully under user control, so can't be exploited
    // C7: Delegatecall is only used on the same contract, so it's safe
    function batch(bytes[] calldata calls, bool revertOnFail) external payable {
        for (uint256 i = 0; i < calls.length; i++) {
            (bool success, bytes memory result) = address(this).delegatecall(calls[i]);
            if (!success && revertOnFail) {
                revert(_getRevertMsg(result));
            }
        }
    }
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.3;

import "../pool/Errors.sol";
import "../interfaces/bloq/IAddressListFactory.sol";
import "../interfaces/vesper/IVesperPool.sol";
import "./UsingSwapManager.sol";
import "./Batchable.sol";

contract BuyBack is UsingSwapManager, Batchable {
    using SafeERC20 for IERC20;

    IERC20 public vsp;
    IVesperPool public vVSP; // vVSP pool will received buyed back VSPs
    address public keepers; // sol-address-list address which contains addresses of keepers

    event MigratedAsset(IERC20 asset, uint256 amount);

    constructor(
        address _governor,
        address _weth,
        IVesperPool _vVSP,
        IAddressListFactory _listFactory,
        ISwapManager _swapManager
    ) UsingSwapManager(_weth, _swapManager) {
        require(address(_vVSP) != address(0), "vvsp-is-null");
        require(address(_listFactory) != address(0), "address-list-factory-is-null");

        governor = _governor;
        vVSP = _vVSP;
        vsp = vVSP.token();
        keepers = _listFactory.createList();
        require(IAddressList(keepers).add(_msgSender()), Errors.ADD_IN_LIST_FAILED);
    }

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

    ////////////////////////////// Only Governor //////////////////////////////

    /**
     * @notice Migrate assets to a new contract
     * @dev The caller has to set the addresses list since we don't maintain a list of them
     * @param _assets List of assets' address to transfer from
     * @param _to Assets recipient
     */
    function migrateAssets(address[] memory _assets, address _to) external onlyGovernor {
        require(_assets.length > 0, "assets-list-is-empty");
        require(_to != address(this), "new-contract-is-invalid");

        for (uint256 i = 0; i < _assets.length; ++i) {
            IERC20 _asset = IERC20(_assets[i]);
            uint256 _balance = _asset.balanceOf(address(this));
            _asset.safeTransfer(_to, _balance);
            emit MigratedAsset(_asset, _balance);
        }
    }

    ///////////////////////////// Only Keeper ///////////////////////////////

    /// @notice Perform a slippage-protected swap for VSP
    /// @dev The vVVSP is the beneficiary of the swap
    /// @dev Have to check allowance to routers before calling this
    function swapForVspAndTransferToVVSP(address _tokenIn, uint256 _amountIn) external onlyKeeper {
        if (_amountIn > 0) {
            uint256 _minAmtOut =
                (swapSlippage != 10000)
                    ? _calcAmtOutAfterSlippage(
                        _getOracleRate(_simpleOraclePath(_tokenIn, address(vsp)), _amountIn),
                        swapSlippage
                    )
                    : 1;
            _safeSwap(_tokenIn, address(vsp), _amountIn, _minAmtOut, address(vVSP));
        }
    }

    /// @notice Deposit vPool tokens and unwrap them
    function depositAndUnwrap(IVesperPool _vPool, uint256 _amount) external onlyKeeper {
        _vPool.transferFrom(_msgSender(), address(this), _amount);
        _vPool.withdraw(_amount);
    }

    /// @notice Withdraw (a.k.a. unwrap) underlying token from vPool
    function unwrap(IVesperPool _vPool, uint256 _amount) public onlyKeeper {
        _vPool.withdraw(_amount);
    }

    /// @notice Withdraw (a.k.a. unwrap) underlying token from vPool
    /// @dev Uses all held vPool tokens
    function unwrapAll(IVesperPool _vPool) external onlyKeeper {
        unwrap(_vPool, _vPool.balanceOf(address(this)));
    }

    /// @notice Transfer VSP tokens to vVSP
    function transferVspToVVSP(uint256 _amount) public onlyKeeper {
        vsp.safeTransfer(address(vVSP), _amount);
    }

    /// @notice Transfer VSP tokens to vVSP
    /// @dev Uses all held VSP tokens
    function transferAllVspToVVSP() external onlyKeeper {
        transferVspToVVSP(vsp.balanceOf(address(this)));
    }

    /// @notice Approve SwapManager routers if needed
    function doInfinityApproval(IERC20 _unwrapped) external onlyKeeper {
        _doInfinityApprovalIfNeeded(_unwrapped, type(uint256).max);
    }

    /**
     * @notice Add given address in provided address list.
     * @dev Use it to add keeper in keepers list and to add address in feeWhitelist
     * @param _addressToAdd address which we want to add in AddressList.
     */
    function addInKeepersList(address _addressToAdd) external onlyKeeper {
        require(IAddressList(keepers).add(_addressToAdd), Errors.ADD_IN_LIST_FAILED);
    }

    /**
     * @notice Remove given address from provided address list.
     * @dev Use it to remove keeper from keepers list and to remove address from feeWhitelist
     * @param _addressToRemove address which we want to remove from AddressList.
     */
    function removeFromKeepersList(address _addressToRemove) external onlyKeeper {
        require(IAddressList(keepers).remove(_addressToRemove), Errors.REMOVE_FROM_LIST_FAILED);
    }

    ///////////////////////////////////////////////////////////////////////////
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.3;

import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "../Governed.sol";
import "../interfaces/bloq/ISwapManager.sol";

abstract contract UsingSwapManager is Governed {
    using SafeERC20 for IERC20;

    address weth; // Native token
    ISwapManager public swapManager;
    uint256 public oraclePeriod = 3600; // 1h;
    uint256 public oracleRouterIdx = 0; // Uniswap V2;
    uint256 public swapSlippage = 1000; // 10%

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

    constructor(address _weth, ISwapManager _swapManager) {
        require(address(_weth) != address(0), "weth-is-null");
        require(address(_swapManager) != address(0), "swap-manager-is-null");

        weth = _weth;
        swapManager = _swapManager;
    }

    ////////////////////////////// Only Governor //////////////////////////////

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

    /**
     * @notice Update swap slippage value
     * @param _newSwapSlippage new swap slippage
     */
    function updateSwapSlippage(uint256 _newSwapSlippage) external onlyGovernor {
        require(_newSwapSlippage <= 10000, "invalid-slippage-value");
        emit UpdatedSwapSlippage(swapSlippage, _newSwapSlippage);
        swapSlippage = _newSwapSlippage;
    }

    function updateOracleConfig(uint256 _newPeriod, uint256 _newRouterIdx) external onlyGovernor {
        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;
    }

    ///////////////////////////////////////////////////////////////////////////

    /**
     * @notice Safe swap via Uniswap / Sushiswap (better rate of the two)
     * @dev There are many scenarios when token swap via Uniswap can fail, so this
     * method will wrap Uniswap call in a 'try catch' to make it fail safe.
     * however, this method will throw minAmountOut is not met
     * @param _tokenIn address of from token
     * @param _tokenOut address of to token
     * @param _amountIn Amount to be swapped
     * @param _minAmountOut minimum amount out
     */
    function _safeSwap(
        address _tokenIn,
        address _tokenOut,
        uint256 _amountIn,
        uint256 _minAmountOut,
        address _to
    ) internal {
        (address[] memory path, uint256 amountOut, uint256 rIdx) =
            swapManager.bestOutputFixedInput(_tokenIn, _tokenOut, _amountIn);
        if (_minAmountOut == 0) _minAmountOut = 1;
        if (amountOut != 0) {
            swapManager.ROUTERS(rIdx).swapExactTokensForTokens(_amountIn, _minAmountOut, path, _to, block.timestamp);
        }
    }

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

    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");
        }
    }

    function _simpleOraclePath(address _from, address _to) internal view 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) {
        // from, to, amountIn, period, router
        (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 _doInfinityApprovalIfNeeded(IERC20 _asset, uint256 _amountToSwap) internal {
        for (uint256 i = 0; i < swapManager.N_DEX(); i++) {
            if (IERC20(_asset).allowance(address(this), address(swapManager.ROUTERS(i))) < _amountToSwap) {
                IERC20(_asset).safeApprove(address(swapManager.ROUTERS(i)), type(uint256).max);
            }
        }
    }
}