// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../utils/ContextUpgradeable.sol";
import "../proxy/Initializable.sol";
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal initializer {
        __Context_init_unchained();
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal initializer {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
    uint256[49] private __gap;
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165Upgradeable {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// 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 SafeMathUpgradeable {
    /**
     * @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;
    }
}

// SPDX-License-Identifier: MIT

// solhint-disable-next-line compiler-version
pragma solidity >=0.4.24 <0.8.0;

import "../utils/AddressUpgradeable.sol";

/**
 * @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 {UpgradeableProxy-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 || _isConstructor() || !_initialized, "Initializable: contract is already initialized");

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

        _;

        if (isTopLevelCall) {
            _initializing = false;
        }
    }

    /// @dev Returns true if and only if the function is running in the constructor
    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20Upgradeable {
    /**
     * @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 >=0.6.0 <0.8.0;

import "./IERC20Upgradeable.sol";
import "../../math/SafeMathUpgradeable.sol";
import "../../utils/AddressUpgradeable.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 SafeERC20Upgradeable {
    using SafeMathUpgradeable for uint256;
    using AddressUpgradeable for address;

    function safeTransfer(IERC20Upgradeable token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20Upgradeable 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(IERC20Upgradeable 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(IERC20Upgradeable 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(IERC20Upgradeable 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(IERC20Upgradeable 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 >=0.6.2 <0.8.0;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;
import "../proxy/Initializable.sol";

/*
 * @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 ContextUpgradeable is Initializable {
    function __Context_init() internal initializer {
        __Context_init_unchained();
    }

    function __Context_init_unchained() internal initializer {
    }
    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;
    }
    uint256[50] private __gap;
}

// SPDX-License-Identifier: GPL-3.0

pragma solidity ^0.6.12;

import "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";

interface DaiInterface is IERC20Upgradeable {
    // --- Approve by signature ---
  function permit(address holder, address spender, uint256 nonce, uint256 expiry, bool allowed, uint8 v, bytes32 r, bytes32 s) external;
  function transferFrom(address src, address dst, uint wad) external override returns (bool);
}

// SPDX-License-Identifier: GPL-3.0

pragma solidity ^0.6.12;

import "@openzeppelin/contracts-upgradeable/token/ERC20/SafeERC20Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";

import "../external/maker/DaiInterface.sol";
import "../prize-pool/PrizePoolInterface.sol";

/// @title Allows users to approve and deposit dai into a prize pool in a single transaction.
contract PermitAndDepositDai is OwnableUpgradeable {
  using SafeERC20Upgradeable for DaiInterface;

  /// @notice Permits this contract to spend on a users behalf, and deposits into the prize pool.
  /// @dev The Dai permit params match the Dai#permit function, but it expects the `spender` to be
  /// the address of this contract.
  /// @param holder The address spending the tokens
  /// @param nonce The nonce of the tx.  Should be retrieved from the Dai token
  /// @param expiry The timestamp at which the sig expires
  /// @param allowed If true, then the spender is approving holder the max allowance.  False makes the allowance zero.
  /// @param v The `v` portion of the signature.
  /// @param r The `r` portion of the signature.
  /// @param s The `s` portion of the signature.
  /// @param prizePool The prize pool to deposit into
  /// @param to The address that will receive the controlled tokens
  /// @param amount The amount to deposit
  /// @param controlledToken The type of token to be minted in exchange (i.e. tickets or sponsorship)
  /// @param referrer The address that referred the deposit
  function permitAndDepositTo(
    // --- Approve by signature ---
    address dai, address holder, uint256 nonce, uint256 expiry, bool allowed, uint8 v, bytes32 r, bytes32 s,
    address prizePool, address to, uint256 amount, address controlledToken, address referrer
  ) external {
    require(msg.sender == holder, "PermitAndDepositDai/only-signer");
    DaiInterface(dai).permit(holder, address(this), nonce, expiry, allowed, v, r, s);
    _depositTo(dai, holder, prizePool, to, amount, controlledToken, referrer);
  }

  /// @notice Deposits into a Prize Pool from the sender.  Tokens will be transferred from the sender
  /// then deposited into the Pool on the sender's behalf.  This can be called after permitAndDepositTo is called,
  /// as this contract will have full approval for a user.
  /// @param prizePool The prize pool to deposit into
  /// @param to The address that will receive the controlled tokens
  /// @param amount The amount to deposit
  /// @param controlledToken The type of token to be minted in exchange (i.e. tickets or sponsorship)
  /// @param referrer The address that referred the deposit
  function depositTo(
    address dai,
    address prizePool,
    address to,
    uint256 amount,
    address controlledToken,
    address referrer
  ) external {
    _depositTo(dai, msg.sender, prizePool, to, amount, controlledToken, referrer);
  }

  function _depositTo(
    address dai,
    address holder,
    address prizePool,
    address to,
    uint256 amount,
    address controlledToken,
    address referrer
  ) internal {
    DaiInterface(dai).safeTransferFrom(holder, address(this), amount);
    DaiInterface(dai).approve(address(prizePool), amount);
    PrizePoolInterface(prizePool).depositTo(to, amount, controlledToken, referrer);
  }

}

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.6.0 <0.7.0;

import "../token/TokenListenerInterface.sol";
import "../token/ControlledTokenInterface.sol";

/// @title Escrows assets and deposits them into a yield source.  Exposes interest to Prize Strategy.  Users deposit and withdraw from this contract to participate in Prize Pool.
/// @notice Accounting is managed using Controlled Tokens, whose mint and burn functions can only be called by this contract.
/// @dev Must be inherited to provide specific yield-bearing asset control, such as Compound cTokens
interface PrizePoolInterface {

  /// @notice Deposit assets into the Prize Pool in exchange for tokens
  /// @param to The address receiving the newly minted tokens
  /// @param amount The amount of assets to deposit
  /// @param controlledToken The address of the type of token the user is minting
  /// @param referrer The referrer of the deposit
  function depositTo(
    address to,
    uint256 amount,
    address controlledToken,
    address referrer
  )
    external;

  /// @notice Withdraw assets from the Prize Pool instantly.  A fairness fee may be charged for an early exit.
  /// @param from The address to redeem tokens from.
  /// @param amount The amount of tokens to redeem for assets.
  /// @param controlledToken The address of the token to redeem (i.e. ticket or sponsorship)
  /// @param maximumExitFee The maximum exit fee the caller is willing to pay.  This should be pre-calculated by the calculateExitFee() fxn.
  /// @return The actual exit fee paid
  function withdrawInstantlyFrom(
    address from,
    uint256 amount,
    address controlledToken,
    uint256 maximumExitFee
  ) external returns (uint256);

  /// @notice Withdraw assets from the Prize Pool by placing them into the timelock.
  /// The timelock is used to ensure that the tickets have contributed their fair share of the prize.
  /// @dev Note that if the user has previously timelocked funds then this contract will try to sweep them.
  /// If the existing timelocked funds are still locked, then the incoming
  /// balance is added to their existing balance and the new timelock unlock timestamp will overwrite the old one.
  /// @param from The address to withdraw from
  /// @param amount The amount to withdraw
  /// @param controlledToken The type of token being withdrawn
  /// @return The timestamp from which the funds can be swept
  function withdrawWithTimelockFrom(
    address from,
    uint256 amount,
    address controlledToken
  ) external returns (uint256);

  function withdrawReserve(address to) external returns (uint256);

  /// @notice Returns the balance that is available to award.
  /// @dev captureAwardBalance() should be called first
  /// @return The total amount of assets to be awarded for the current prize
  function awardBalance() external view returns (uint256);

  /// @notice Captures any available interest as award balance.
  /// @dev This function also captures the reserve fees.
  /// @return The total amount of assets to be awarded for the current prize
  function captureAwardBalance() external returns (uint256);

  /// @notice Called by the prize strategy to award prizes.
  /// @dev The amount awarded must be less than the awardBalance()
  /// @param to The address of the winner that receives the award
  /// @param amount The amount of assets to be awarded
  /// @param controlledToken The address of the asset token being awarded
  function award(
    address to,
    uint256 amount,
    address controlledToken
  )
    external;

  /// @notice Called by the Prize-Strategy to transfer out external ERC20 tokens
  /// @dev Used to transfer out tokens held by the Prize Pool.  Could be liquidated, or anything.
  /// @param to The address of the winner that receives the award
  /// @param amount The amount of external assets to be awarded
  /// @param externalToken The address of the external asset token being awarded
  function transferExternalERC20(
    address to,
    address externalToken,
    uint256 amount
  )
    external;

  /// @notice Called by the Prize-Strategy to award external ERC20 prizes
  /// @dev Used to award any arbitrary tokens held by the Prize Pool
  /// @param to The address of the winner that receives the award
  /// @param amount The amount of external assets to be awarded
  /// @param externalToken The address of the external asset token being awarded
  function awardExternalERC20(
    address to,
    address externalToken,
    uint256 amount
  )
    external;

  /// @notice Called by the prize strategy to award external ERC721 prizes
  /// @dev Used to award any arbitrary NFTs held by the Prize Pool
  /// @param to The address of the winner that receives the award
  /// @param externalToken The address of the external NFT token being awarded
  /// @param tokenIds An array of NFT Token IDs to be transferred
  function awardExternalERC721(
    address to,
    address externalToken,
    uint256[] calldata tokenIds
  )
    external;

  /// @notice Sweep all timelocked balances and transfer unlocked assets to owner accounts
  /// @param users An array of account addresses to sweep balances for
  /// @return The total amount of assets swept from the Prize Pool
  function sweepTimelockBalances(
    address[] calldata users
  )
    external
    returns (uint256);

  /// @notice Calculates a timelocked withdrawal duration and credit consumption.
  /// @param from The user who is withdrawing
  /// @param amount The amount the user is withdrawing
  /// @param controlledToken The type of collateral the user is withdrawing (i.e. ticket or sponsorship)
  /// @return durationSeconds The duration of the timelock in seconds
  function calculateTimelockDuration(
    address from,
    address controlledToken,
    uint256 amount
  )
    external
    returns (
      uint256 durationSeconds,
      uint256 burnedCredit
    );

  /// @notice Calculates the early exit fee for the given amount
  /// @param from The user who is withdrawing
  /// @param controlledToken The type of collateral being withdrawn
  /// @param amount The amount of collateral to be withdrawn
  /// @return exitFee The exit fee
  /// @return burnedCredit The user's credit that was burned
  function calculateEarlyExitFee(
    address from,
    address controlledToken,
    uint256 amount
  )
    external
    returns (
      uint256 exitFee,
      uint256 burnedCredit
    );

  /// @notice Estimates the amount of time it will take for a given amount of funds to accrue the given amount of credit.
  /// @param _principal The principal amount on which interest is accruing
  /// @param _interest The amount of interest that must accrue
  /// @return durationSeconds The duration of time it will take to accrue the given amount of interest, in seconds.
  function estimateCreditAccrualTime(
    address _controlledToken,
    uint256 _principal,
    uint256 _interest
  )
    external
    view
    returns (uint256 durationSeconds);

  /// @notice Returns the credit balance for a given user.  Not that this includes both minted credit and pending credit.
  /// @param user The user whose credit balance should be returned
  /// @return The balance of the users credit
  function balanceOfCredit(address user, address controlledToken) external returns (uint256);

  /// @notice Sets the rate at which credit accrues per second.  The credit rate is a fixed point 18 number (like Ether).
  /// @param _controlledToken The controlled token for whom to set the credit plan
  /// @param _creditRateMantissa The credit rate to set.  Is a fixed point 18 decimal (like Ether).
  /// @param _creditLimitMantissa The credit limit to set.  Is a fixed point 18 decimal (like Ether).
  function setCreditPlanOf(
    address _controlledToken,
    uint128 _creditRateMantissa,
    uint128 _creditLimitMantissa
  )
    external;

  /// @notice Returns the credit rate of a controlled token
  /// @param controlledToken The controlled token to retrieve the credit rates for
  /// @return creditLimitMantissa The credit limit fraction.  This number is used to calculate both the credit limit and early exit fee.
  /// @return creditRateMantissa The credit rate. This is the amount of tokens that accrue per second.
  function creditPlanOf(
    address controlledToken
  )
    external
    view
    returns (
      uint128 creditLimitMantissa,
      uint128 creditRateMantissa
    );

  /// @notice Allows the Governor to set a cap on the amount of liquidity that he pool can hold
  /// @param _liquidityCap The new liquidity cap for the prize pool
  function setLiquidityCap(uint256 _liquidityCap) external;

  /// @notice Sets the prize strategy of the prize pool.  Only callable by the owner.
  /// @param _prizeStrategy The new prize strategy.  Must implement TokenListenerInterface
  function setPrizeStrategy(TokenListenerInterface _prizeStrategy) external;

  /// @dev Returns the address of the underlying ERC20 asset
  /// @return The address of the asset
  function token() external view returns (address);

  /// @notice An array of the Tokens controlled by the Prize Pool (ie. Tickets, Sponsorship)
  /// @return An array of controlled token addresses
  function tokens() external view returns (address[] memory);

  /// @notice The timestamp at which an account's timelocked balance will be made available to sweep
  /// @param user The address of an account with timelocked assets
  /// @return The timestamp at which the locked assets will be made available
  function timelockBalanceAvailableAt(address user) external view returns (uint256);

  /// @notice The balance of timelocked assets for an account
  /// @param user The address of an account with timelocked assets
  /// @return The amount of assets that have been timelocked
  function timelockBalanceOf(address user) external view returns (uint256);

  /// @notice The total of all controlled tokens and timelock.
  /// @return The current total of all tokens and timelock.
  function accountedBalance() external view returns (uint256);
}

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.6.0 <0.7.0;

import "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";

import "./TokenControllerInterface.sol";

/// @title Controlled ERC20 Token
/// @notice ERC20 Tokens with a controller for minting & burning
interface ControlledTokenInterface is IERC20Upgradeable {

  /// @notice Interface to the contract responsible for controlling mint/burn
  function controller() external view returns (TokenControllerInterface);

  /// @notice Allows the controller to mint tokens for a user account
  /// @dev May be overridden to provide more granular control over minting
  /// @param _user Address of the receiver of the minted tokens
  /// @param _amount Amount of tokens to mint
  function controllerMint(address _user, uint256 _amount) external;

  /// @notice Allows the controller to burn tokens from a user account
  /// @dev May be overridden to provide more granular control over burning
  /// @param _user Address of the holder account to burn tokens from
  /// @param _amount Amount of tokens to burn
  function controllerBurn(address _user, uint256 _amount) external;

  /// @notice Allows an operator via the controller to burn tokens on behalf of a user account
  /// @dev May be overridden to provide more granular control over operator-burning
  /// @param _operator Address of the operator performing the burn action via the controller contract
  /// @param _user Address of the holder account to burn tokens from
  /// @param _amount Amount of tokens to burn
  function controllerBurnFrom(address _operator, address _user, uint256 _amount) external;
}

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.5.0 <0.7.0;

/// @title Token Controller Interface
/// @notice Required interface for Token Controllers linked to a Prize Pool
/// @dev Defines the spec required to be implemented by a Token Controller
interface TokenControllerInterface {

  /// @dev Controller hook to provide notifications & rule validations on token transfers to the controller.
  /// This includes minting and burning.
  /// @param from Address of the account sending the tokens (address(0x0) on minting)
  /// @param to Address of the account receiving the tokens (address(0x0) on burning)
  /// @param amount Amount of tokens being transferred
  function beforeTokenTransfer(address from, address to, uint256 amount) external;
}

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.5.0 <0.7.0;

import "@openzeppelin/contracts-upgradeable/introspection/IERC165Upgradeable.sol";

/// @title An interface that allows a contract to listen to token mint, transfer and burn events.
interface TokenListenerInterface is IERC165Upgradeable {
  /// @notice Called when tokens are minted.
  /// @param to The address of the receiver of the minted tokens.
  /// @param amount The amount of tokens being minted
  /// @param controlledToken The address of the token that is being minted
  /// @param referrer The address that referred the minting.
  function beforeTokenMint(address to, uint256 amount, address controlledToken, address referrer) external;

  /// @notice Called when tokens are transferred or burned.
  /// @param from The address of the sender of the token transfer
  /// @param to The address of the receiver of the token transfer.  Will be the zero address if burning.
  /// @param amount The amount of tokens transferred
  /// @param controlledToken The address of the token that was transferred
  function beforeTokenTransfer(address from, address to, uint256 amount, address controlledToken) external;
}


{"success": true, "error": null, "results": {"detectors": [{"check": "unused-return", "impact": "Medium", "confidence": "Medium"}]}}