// File: src/contracts/factory/Factory.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.7;

import "../controller/ControllerInterface.sol";
import "./FactoryInterface.sol";
import "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";

/// @title AMKT Factory
/// @author Alongside Finance
/// @notice Allows Merchants to initiate burn/mint requests and allows issuers to approve or deny them
contract Factory is FactoryInterface, OwnableUpgradeable, PausableUpgradeable {
    ///=============================================================================================
    /// Events
    ///=============================================================================================

    event IssuerDepositAddressSet(address indexed merchant, address indexed sender, string depositAddress);

    event MerchantDepositAddressSet(address indexed merchant, string depositAddress);

    event MintRequestAdd(
        uint256 indexed nonce,
        address indexed requester,
        uint256 amount,
        string depositAddress,
        string txid,
        uint256 timestamp,
        bytes32 requestHash
    );

    event MintRequestCancel(uint256 indexed nonce, address indexed requester, bytes32 requestHash);

    event MintConfirmed(
        uint256 indexed nonce,
        address indexed requester,
        uint256 amount,
        string depositAddress,
        string txid,
        uint256 timestamp,
        bytes32 requestHash
    );

    event MintRejected(
        uint256 indexed nonce,
        address indexed requester,
        uint256 amount,
        string depositAddress,
        string txid,
        uint256 timestamp,
        bytes32 requestHash
    );

    event Burned(
        uint256 indexed nonce,
        address indexed requester,
        uint256 amount,
        string depositAddress,
        uint256 timestamp,
        bytes32 requestHash
    );

    event BurnConfirmed(
        uint256 indexed nonce,
        address indexed requester,
        uint256 amount,
        string depositAddress,
        string txid,
        uint256 timestamp,
        bytes32 inputRequestHash
    );

    ///=============================================================================================
    /// Data Structres
    ///=============================================================================================

    enum RequestStatus {
        NULL,
        PENDING,
        CANCELED,
        APPROVED,
        REJECTED
    }

    struct Request {
        address requester; // sender of the request.
        uint256 amount; // amount of token to mint/burn.
        string depositAddress; // issuer's asset address in mint, merchant's asset address in burn.
        string txid; // asset txid for sending/redeeming asset in the mint/burn process.
        uint256 nonce; // serial number allocated for each request.
        uint256 timestamp; // time of the request creation.
        RequestStatus status; // status of the request.
    }

    ///=============================================================================================
    /// State Variables
    ///=============================================================================================

    ControllerInterface public controller;

    // mapping between merchant to its per-mint limit.
    mapping(address => uint256) public merchantMintLimit;

    // mapping between merchant to its per-burn limit.
    mapping(address => uint256) public merchantBurnLimit;

    // mapping between merchant to the corresponding issuer deposit address, used in the minting process.
    // by using a different deposit address per merchant the issuer can identify which merchant deposited.
    mapping(address => string) public issuerDepositAddress;

    // mapping between merchant to the its deposit address where the asset should be moved to, used in the burning process.
    mapping(address => string) public merchantDepositAddress;

    // mapping between a mint request hash and the corresponding request nonce.
    mapping(bytes32 => uint256) public mintRequestNonce;

    // mapping between a burn request hash and the corresponding request nonce.
    mapping(bytes32 => uint256) public burnRequestNonce;

    Request[] public mintRequests;
    Request[] public burnRequests;

    ///=============================================================================================
    /// Initializer
    ///=============================================================================================

    function initialize(address _controller) external initializer {
        controller = ControllerInterface(_controller);

        __Ownable_init();
        __Pausable_init();

        transferOwnership(_controller);
    }

    ///=============================================================================================
    /// Modifiers
    ///=============================================================================================

    modifier onlyMerchant() {
        require(controller.isMerchant(msg.sender), "sender not a merchant.");
        _;
    }

    modifier onlyIssuer() {
        require(controller.isIssuer(msg.sender), "sender not a issuer.");
        _;
    }

    ///=============================================================================================
    /// Setters
    ///=============================================================================================

    /// @notice sets the address for the merchant to deposit thier assets
    /// @param merchant address
    /// @param depositAddress string
    /// @return bool
    function setIssuerDepositAddress(address merchant, string memory depositAddress)
        external
        override
        onlyIssuer
        returns (bool)
    {
        require(merchant != address(0), "invalid merchant address");
        require(controller.isMerchant(merchant), "merchant address is not a real merchant.");
        require(!isEmptyString(depositAddress), "invalid asset deposit address");

        issuerDepositAddress[merchant] = depositAddress;
        emit IssuerDepositAddressSet(merchant, msg.sender, depositAddress);
        return true;
    }

    /// @notice Allows a merchant to relay what address they receive assets to
    /// @param depositAddress string
    /// @return bool
    function setMerchantDepositAddress(string memory depositAddress) external override onlyMerchant returns (bool) {
        require(!isEmptyString(depositAddress), "invalid asset deposit address");

        merchantDepositAddress[msg.sender] = depositAddress;
        emit MerchantDepositAddressSet(msg.sender, depositAddress);
        return true;
    }

    /// @notice Sets the maximum mint limit allowed per merchant
    /// @param merchant address
    /// @param amount uint256
    /// @return bool
    function setMerchantMintLimit(address merchant, uint256 amount) external override onlyIssuer returns (bool) {
        merchantMintLimit[merchant] = amount;
        return true;
    }

    /// @notice Sets the maximum burn limit allowed per merchant
    /// @param merchant address
    /// @param amount uint256
    /// @return bool
    function setMerchantBurnLimit(address merchant, uint256 amount) external override onlyIssuer returns (bool) {
        merchantBurnLimit[merchant] = amount;
        return true;
    }

    ///=============================================================================================
    /// Merchant Mint Logic
    ///=============================================================================================

    /// @notice Allows a merchant to initiate a mint request
    /// @param amount uint256
    /// @param txid string
    /// @param depositAddress string
    /// @return bool
    function addMintRequest(
        uint256 amount,
        string memory txid,
        string memory depositAddress
    ) external override onlyMerchant whenNotPaused returns (uint256) {
        require(!isEmptyString(depositAddress), "invalid asset deposit address");
        require(compareStrings(depositAddress, issuerDepositAddress[msg.sender]), "wrong asset deposit address");
        require(amount <= merchantMintLimit[msg.sender], "exceeds mint limit");
        uint256 nonce = mintRequests.length;
        uint256 timestamp = getTimestamp();

        Request memory request = Request({
            requester: msg.sender,
            amount: amount,
            depositAddress: depositAddress,
            txid: txid,
            nonce: nonce,
            timestamp: timestamp,
            status: RequestStatus.PENDING
        });

        bytes32 requestHash = calcRequestHash(request);
        mintRequestNonce[requestHash] = nonce;
        mintRequests.push(request);

        emit MintRequestAdd(nonce, msg.sender, amount, depositAddress, txid, timestamp, requestHash);
        return nonce;
    }

    /// @notice Allows a merchant to cancel a mint request
    /// @param requestHash bytes32
    /// @return bool
    function cancelMintRequest(bytes32 requestHash) external override onlyMerchant whenNotPaused returns (bool) {
        uint256 nonce;
        Request memory request;

        (nonce, request) = getPendingMintRequest(requestHash);

        require(msg.sender == request.requester, "cancel sender is different than pending request initiator");
        mintRequests[nonce].status = RequestStatus.CANCELED;

        emit MintRequestCancel(nonce, msg.sender, requestHash);
        return true;
    }

    ///=============================================================================================
    /// Issuer Mint Logic
    ///=============================================================================================

    /// @notice Allows a issuer to confirm a mint request
    /// @param requestHash bytes32
    /// @return bool
    function confirmMintRequest(bytes32 requestHash) external override onlyIssuer returns (bool) {
        uint256 nonce;
        Request memory request;

        (nonce, request) = getPendingMintRequest(requestHash);

        mintRequests[nonce].status = RequestStatus.APPROVED;
        require(controller.mint(request.requester, request.amount), "mint failed");

        require(merchantMintLimit[request.requester] >= request.amount, "exceeds merchant limits");
        merchantMintLimit[request.requester] -= request.amount;

        emit MintConfirmed(
            request.nonce,
            request.requester,
            request.amount,
            request.depositAddress,
            request.txid,
            request.timestamp,
            requestHash
        );
        return true;
    }

    /// @notice Allows a issuer to reject a mint request
    /// @param requestHash bytes32
    /// @return bool
    function rejectMintRequest(bytes32 requestHash) external override onlyIssuer returns (bool) {
        uint256 nonce;
        Request memory request;

        (nonce, request) = getPendingMintRequest(requestHash);

        mintRequests[nonce].status = RequestStatus.REJECTED;

        emit MintRejected(
            request.nonce,
            request.requester,
            request.amount,
            request.depositAddress,
            request.txid,
            request.timestamp,
            requestHash
        );
        return true;
    }

    ///=============================================================================================
    /// Merchant Burn Logic
    ///=============================================================================================

    /// @notice Allows a merchant to initiate a burn request
    /// @param amount uint256
    /// @return bool
    function burn(uint256 amount, string memory txid) external override onlyMerchant whenNotPaused returns (bool) {
        require(amount <= merchantBurnLimit[msg.sender], "exceeds burn limit");
        string memory depositAddress = merchantDepositAddress[msg.sender];
        require(!isEmptyString(depositAddress), "merchant asset deposit address was not set");

        uint256 nonce = burnRequests.length;
        uint256 timestamp = getTimestamp();

        Request memory request = Request({
            requester: msg.sender,
            amount: amount,
            depositAddress: depositAddress,
            txid: txid,
            nonce: nonce,
            timestamp: timestamp,
            status: RequestStatus.PENDING
        });

        bytes32 requestHash = calcRequestHash(request);
        burnRequestNonce[requestHash] = nonce;
        burnRequests.push(request);

        require(controller.burn(msg.sender, amount), "burn failed");

        emit Burned(nonce, msg.sender, amount, depositAddress, timestamp, requestHash);
        return true;
    }

    ///=============================================================================================
    /// Issuer Burn Logic
    ///=============================================================================================

    /// @notice Allows a issuer to confirm a burn request
    /// @param requestHash bytes32
    /// @return bool
    function confirmBurnRequest(bytes32 requestHash) external override onlyIssuer returns (bool) {
        uint256 nonce;
        Request memory request;

        (nonce, request) = getPendingBurnRequest(requestHash);

        burnRequests[nonce].status = RequestStatus.APPROVED;

        require(merchantBurnLimit[request.requester] >= request.amount, "exceeds merchant limits");
        merchantBurnLimit[request.requester] -= request.amount;

        emit BurnConfirmed(
            request.nonce,
            request.requester,
            request.amount,
            request.depositAddress,
            request.txid,
            request.timestamp,
            requestHash
        );
        return true;
    }

    ///=============================================================================================
    /// Pause Logic
    ///=============================================================================================

    function pause() external override onlyOwner {
        _pause();
    }

    function unpause() external override onlyOwner {
        _unpause();
    }

    ///=============================================================================================
    /// Non Mutable
    ///=============================================================================================

    function getBurnRequestsLength() external view override returns (uint256 length) {
        return burnRequests.length;
    }

    /// @notice Gets a burn request by nonce
    /// @dev Returns the fields present in the request struct and also the request hash
    /// @param nonce uint256
    function getBurnRequest(uint256 nonce)
        external
        view
        override
        returns (
            uint256 requestNonce,
            address requester,
            uint256 amount,
            string memory depositAddress,
            string memory txid,
            uint256 timestamp,
            string memory status,
            bytes32 requestHash
        )
    {
        Request storage request = burnRequests[nonce];
        string memory statusString = getStatusString(request.status);

        requestNonce = request.nonce;
        requester = request.requester;
        amount = request.amount;
        depositAddress = request.depositAddress;
        txid = request.txid;
        timestamp = request.timestamp;
        status = statusString;
        requestHash = calcRequestHash(request);
    }

    /// @notice Gets a mint request by nonce
    /// @dev Returns the fields present in the request struct and also the request hash
    /// @param nonce uint256
    function getMintRequest(uint256 nonce)
        external
        view
        override
        returns (
            uint256 requestNonce,
            address requester,
            uint256 amount,
            string memory depositAddress,
            string memory txid,
            uint256 timestamp,
            string memory status,
            bytes32 requestHash
        )
    {
        Request memory request = mintRequests[nonce];
        string memory statusString = getStatusString(request.status);

        requestNonce = request.nonce;
        requester = request.requester;
        amount = request.amount;
        depositAddress = request.depositAddress;
        txid = request.txid;
        timestamp = request.timestamp;
        status = statusString;
        requestHash = calcRequestHash(request);
    }

    function getTimestamp() internal view returns (uint256) {
        // timestamp is only used for data maintaining purpose, it is not relied on for critical logic.
        return block.timestamp; // solhint-disable-line not-rely-on-time
    }

    function getPendingMintRequest(bytes32 requestHash) internal view returns (uint256 nonce, Request memory request) {
        require(requestHash != 0, "request hash is 0");
        nonce = mintRequestNonce[requestHash];
        request = mintRequests[nonce];
        validatePendingRequest(request, requestHash);
    }

    function getPendingBurnRequest(bytes32 requestHash) internal view returns (uint256 nonce, Request memory request) {
        require(requestHash != 0, "request hash is 0");
        nonce = burnRequestNonce[requestHash];
        request = burnRequests[nonce];
        validatePendingRequest(request, requestHash);
    }

    function getMintRequestsLength() external view override returns (uint256 length) {
        return mintRequests.length;
    }

    function validatePendingRequest(Request memory request, bytes32 requestHash) internal pure {
        require(request.status == RequestStatus.PENDING, "request is not pending");
        require(requestHash == calcRequestHash(request), "given request hash does not match a pending request");
    }

    function calcRequestHash(Request memory request) internal pure returns (bytes32) {
        return
            keccak256(
                abi.encode(
                    request.requester,
                    request.amount,
                    request.depositAddress,
                    request.txid,
                    request.nonce,
                    request.timestamp
                )
            );
    }

    function compareStrings(string memory a, string memory b) internal pure returns (bool) {
        return (keccak256(abi.encodePacked(a)) == keccak256(abi.encodePacked(b)));
    }

    function isEmptyString(string memory a) internal pure returns (bool) {
        return (compareStrings(a, ""));
    }

    function getStatusString(RequestStatus status) internal pure returns (string memory) {
        if (status == RequestStatus.PENDING) {
            return "pending";
        } else if (status == RequestStatus.CANCELED) {
            return "canceled";
        } else if (status == RequestStatus.APPROVED) {
            return "approved";
        } else if (status == RequestStatus.REJECTED) {
            return "rejected";
        } else {
            // this fallback can never be reached.
            return "unknown";
        }
    }
}

// File: src/contracts/controller/ControllerInterface.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.7;

interface ControllerInterface {
    function mint(address to, uint256 amount) external returns (bool);

    function burn(address from, uint256 value) external returns (bool);

    function factoryPause(bool pause) external returns (bool);

    function isIssuer(address addr) external view returns (bool);

    function isMerchant(address addr) external view returns (bool);

    function getToken() external view returns (address);
}

// File: src/contracts/factory/FactoryInterface.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.7;

interface FactoryInterface {
    function pause() external;

    function unpause() external;

    function setIssuerDepositAddress(address merchant, string memory depositAddress) external returns (bool);

    function setMerchantDepositAddress(string memory depositAddress) external returns (bool);

    function setMerchantMintLimit(address merchant, uint256 amount) external returns (bool);

    function setMerchantBurnLimit(address merchant, uint256 amount) external returns (bool);

    function addMintRequest(
        uint256 amount,
        string memory txid,
        string memory depositAddress
    ) external returns (uint256);

    function cancelMintRequest(bytes32 requestHash) external returns (bool);

    function confirmMintRequest(bytes32 requestHash) external returns (bool);

    function rejectMintRequest(bytes32 requestHash) external returns (bool);

    function burn(uint256 amount, string memory txid) external returns (bool);

    function confirmBurnRequest(bytes32 requestHash) external returns (bool);

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

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

    function getBurnRequest(uint256 nonce)
        external
        view
        returns (
            uint256 requestNonce,
            address requester,
            uint256 amount,
            string memory depositAddress,
            string memory txid,
            uint256 timestamp,
            string memory status,
            bytes32 requestHash
        );

    function getMintRequest(uint256 nonce)
        external
        view
        returns (
            uint256 requestNonce,
            address requester,
            uint256 amount,
            string memory depositAddress,
            string memory txid,
            uint256 timestamp,
            string memory status,
            bytes32 requestHash
        );
}

// File: lib/openzeppelin-contracts-upgradeable/contracts/security/PausableUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)

pragma solidity ^0.8.0;

import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    function __Pausable_init() internal onlyInitializing {
        __Pausable_init_unchained();
    }

    function __Pausable_init_unchained() internal onlyInitializing {
        _paused = false;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        _requireNotPaused();
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        _requirePaused();
        _;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        require(!paused(), "Pausable: paused");
    }

    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        require(paused(), "Pausable: not paused");
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// File: lib/openzeppelin-contracts-upgradeable/contracts/access/OwnableUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/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 onlyInitializing {
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal onlyInitializing {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

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

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        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 {
        _transferOwnership(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");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// File: lib/openzeppelin-contracts-upgradeable/contracts/utils/ContextUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;
import "../proxy/utils/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 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 onlyInitializing {
    }

    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// File: lib/openzeppelin-contracts-upgradeable/contracts/proxy/utils/Initializable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

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 proxied contracts do not make use of 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.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * 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.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

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

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
     * initialization step. This is essential to configure modules that are added through upgrades and that require
     * initialization.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized < type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }
}

// File: lib/openzeppelin-contracts-upgradeable/contracts/utils/AddressUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @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
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 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");

        (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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // 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
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}