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// This contract is part of Zellic’s smart contract dataset, which is a collection of publicly available contract code gathered as of March 2023.

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


// 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 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

     * ====

     *

     * [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 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");

        (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");

        (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");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**

     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the

     * revert reason 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 {
            // 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);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

/**

 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in

 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].

 *

 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by

 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't

 * need to send a transaction, and thus is not required to hold Ether at all.

 */
interface IERC20Permit {
    /**

     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,

     * given ``owner``'s signed approval.

     *

     * IMPORTANT: The same issues {IERC20-approve} has related to transaction

     * ordering also apply here.

     *

     * Emits an {Approval} event.

     *

     * Requirements:

     *

     * - `spender` cannot be the zero address.

     * - `deadline` must be a timestamp in the future.

     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`

     * over the EIP712-formatted function arguments.

     * - the signature must use ``owner``'s current nonce (see {nonces}).

     *

     * For more information on the signature format, see the

     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP

     * section].

     */
    function permit(

        address owner,

        address spender,

        uint256 value,

        uint256 deadline,

        uint8 v,

        bytes32 r,

        bytes32 s

    ) external;

    /**

     * @dev Returns the current nonce for `owner`. This value must be

     * included whenever a signature is generated for {permit}.

     *

     * Every successful call to {permit} increases ``owner``'s nonce by one. This

     * prevents a signature from being used multiple times.

     */
    function nonces(address owner) external view returns (uint256);

    /**

     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.

     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}

// File: @openzeppelin/contracts/security/ReentrancyGuard.sol


// OpenZeppelin Contracts (last updated v4.8.0) (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**

 * @dev Contract module that helps prevent reentrant calls to a function.

 *

 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier

 * available, which can be applied to functions to make sure there are no nested

 * (reentrant) calls to them.

 *

 * Note that because there is a single `nonReentrant` guard, functions marked as

 * `nonReentrant` may not call one another. This can be worked around by making

 * those functions `private`, and then adding `external` `nonReentrant` entry

 * points to them.

 *

 * TIP: If you would like to learn more about reentrancy and alternative ways

 * to protect against it, check out our blog post

 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].

 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**

     * @dev Prevents a contract from calling itself, directly or indirectly.

     * Calling a `nonReentrant` function from another `nonReentrant`

     * function is not supported. It is possible to prevent this from happening

     * by making the `nonReentrant` function external, and making it call a

     * `private` function that does the actual work.

     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol


// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^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 IERC165 {
    /**

     * @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);
}

// File: @openzeppelin/contracts/token/ERC721/IERC721.sol


// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;


/**

 * @dev Required interface of an ERC721 compliant contract.

 */
interface IERC721 is IERC165 {
    /**

     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.

     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**

     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.

     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**

     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.

     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**

     * @dev Returns the number of tokens in ``owner``'s account.

     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**

     * @dev Returns the owner of the `tokenId` token.

     *

     * Requirements:

     *

     * - `tokenId` must exist.

     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**

     * @dev Safely transfers `tokenId` token from `from` to `to`.

     *

     * Requirements:

     *

     * - `from` cannot be the zero address.

     * - `to` cannot be the zero address.

     * - `tokenId` token must exist and be owned by `from`.

     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.

     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.

     *

     * Emits a {Transfer} event.

     */
    function safeTransferFrom(

        address from,

        address to,

        uint256 tokenId,

        bytes calldata data

    ) external;

    /**

     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients

     * are aware of the ERC721 protocol to prevent tokens from being forever locked.

     *

     * Requirements:

     *

     * - `from` cannot be the zero address.

     * - `to` cannot be the zero address.

     * - `tokenId` token must exist and be owned by `from`.

     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.

     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.

     *

     * Emits a {Transfer} event.

     */
    function safeTransferFrom(

        address from,

        address to,

        uint256 tokenId

    ) external;

    /**

     * @dev Transfers `tokenId` token from `from` to `to`.

     *

     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.

     *

     * Requirements:

     *

     * - `from` cannot be the zero address.

     * - `to` cannot be the zero address.

     * - `tokenId` token must be owned by `from`.

     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.

     *

     * Emits a {Transfer} event.

     */
    function transferFrom(

        address from,

        address to,

        uint256 tokenId

    ) external;

    /**

     * @dev Gives permission to `to` to transfer `tokenId` token to another account.

     * The approval is cleared when the token is transferred.

     *

     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.

     *

     * Requirements:

     *

     * - The caller must own the token or be an approved operator.

     * - `tokenId` must exist.

     *

     * Emits an {Approval} event.

     */
    function approve(address to, uint256 tokenId) external;

    /**

     * @dev Approve or remove `operator` as an operator for the caller.

     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.

     *

     * Requirements:

     *

     * - The `operator` cannot be the caller.

     *

     * Emits an {ApprovalForAll} event.

     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**

     * @dev Returns the account approved for `tokenId` token.

     *

     * Requirements:

     *

     * - `tokenId` must exist.

     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**

     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.

     *

     * See {setApprovalForAll}

     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

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


// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**

 * @dev Interface of the ERC20 standard as defined in the EIP.

 */
interface IERC20 {
    /**

     * @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);

    /**

     * @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 `to`.

     *

     * Returns a boolean value indicating whether the operation succeeded.

     *

     * Emits a {Transfer} event.

     */
    function transfer(address to, 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 `from` to `to` 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 from,

        address to,

        uint256 amount

    ) external returns (bool);
}

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


// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;




/**

 * @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'
        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));
        }
    }

    function safePermit(

        IERC20Permit token,

        address owner,

        address spender,

        uint256 value,

        uint256 deadline,

        uint8 v,

        bytes32 r,

        bytes32 s

    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**

     * @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
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

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


// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

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) {
        return msg.data;
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol


// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;


/**

 * @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 Ownable is Context {
    address private _owner;

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

    /**

     * @dev Initializes the contract setting the deployer as the initial owner.

     */
    constructor() {
        _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);
    }
}

// File: contracts/WCAMundialStaking.sol

//SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;






contract WCAMundialStaking is ReentrancyGuard, Ownable {
	using SafeERC20 for IERC20;

	// Interfaces for ERC721 and ERC20
	IERC721 public immutable nftCollection;
	IERC20 public immutable rewardsToken;

	// Constructor function to set the rewards token and the NFT collection addresses
	constructor(IERC721 _nftCollection, IERC20 _rewardsToken) {
		nftCollection = _nftCollection;
		rewardsToken = _rewardsToken;
	}

	address public manager;
	uint256 public startClaimTimestamp = 1685570400; // Jun 01 2023
	uint256 public startUnstakeTimestamp = 1671577200; // Dec 21 2022
	uint256 public endRewardsTimestamp = 1676761200; // Feb 19 2023
	// Almost 20 Token rewards per day => 0.00023149 * 10**18
	uint256 public rewardsPerSeconds = 231490000000000;
	uint256 public rewardExponent = 10**10;
	// Rewards have vesting of 0.13% per day => 0.00000154% per second => 1.54 * 10^-8 => 154 * 10^-10
	uint256 public rewardsLockSeconds = 154;
	bool public _stakingLive = false;

	mapping(uint256 => uint256) public tokenIdTimeStaked;
	mapping(uint256 => address) public tokenIdToStaker;
	mapping(address => uint256[]) public stakerToTokenIds;
	mapping(address => uint256) public stakerRewards;
	mapping(address => uint256) public stakerRewardsClaimed;

	// Modifiers
	modifier onlyOwnerOrManager() {
		require(owner() == msg.sender || manager == msg.sender, "Unauthorized");
		_;
	}

	modifier canClaim() {
		require(block.timestamp >= startClaimTimestamp, "You can't already claim your rewards");
		_;
	}

	modifier canUnstake() {
		require(block.timestamp >= startUnstakeTimestamp, "You can't already unstake your NFTs");
		_;
	}

	modifier stakingIsLive() {
		require(_stakingLive, "Staking isn't live");
		_;
	}

	function setManager(address _manager) external onlyOwner {
		manager = _manager;
	}

	function setRewardsPerSecond(uint256 _rewardsPerSeconds) external onlyOwnerOrManager {
		rewardsPerSeconds = _rewardsPerSeconds;
	}

	function setRewardExponent(uint256 _rewardExponent) external onlyOwnerOrManager {
		rewardExponent = _rewardExponent;
	}

	function setStartClaimTimestamp(uint256 _timestamp) external onlyOwnerOrManager {
		require(_timestamp >= endRewardsTimestamp, "Start claim timestamp must be after end rewards timestamp");
		startClaimTimestamp = _timestamp;
	}

	function setEndRewardsTimestamp(uint256 _timestamp) external onlyOwnerOrManager {
		endRewardsTimestamp = _timestamp;
	}

	function setStartUnstakeTimestamp(uint256 _timestamp) external onlyOwnerOrManager {
		startUnstakeTimestamp = _timestamp;
	}

	function toggleStakingLive() external onlyOwnerOrManager {
		_stakingLive = !_stakingLive;
	}

	function bonus(address _address, uint256 _bonus) external onlyOwnerOrManager {
		stakerRewards[_address] += _bonus;
	}

	function reduce(address _address, uint256 _reduce) external onlyOwnerOrManager {
		stakerRewards[_address] -= _reduce;
	}

	function getTotalRewards(address staker) public view returns (uint256) {
		return getAvailableRewards(staker) + stakerRewardsClaimed[staker];
	}

	function getStakedCount(address staker) external view returns (uint256) {
		return stakerToTokenIds[staker].length;
	}

	function getStakedTokens(address staker) external view returns (uint256[] memory) {
		return stakerToTokenIds[staker];
	}

	function stakeByIds(uint256[] calldata tokenIds) external stakingIsLive {
		for (uint256 i = 0; i < tokenIds.length; i++) {
			uint256 tokenId = tokenIds[i];
			require(nftCollection.ownerOf(tokenId) == msg.sender && tokenIdToStaker[tokenId] == address(0), "You don't own this token!");
			nftCollection.transferFrom(msg.sender, address(this), tokenId);
			stakerToTokenIds[msg.sender].push(tokenId);
			tokenIdTimeStaked[tokenId] = block.timestamp;
			tokenIdToStaker[tokenId] = msg.sender;
		}
	}

	function removeTokenIdFromArray(uint256[] storage array, uint256 tokenId) internal {
		uint256 length = array.length;
		for (uint256 i = 0; i < length; i++) {
			if (array[i] == tokenId) {
				length--;
				if (i < length) {
					array[i] = array[length];
				}
				array.pop();
				break;
			}
		}
	}

	function unstakeByIds(uint256[] calldata tokenIds) public canUnstake nonReentrant {
		for (uint256 i = 0; i < tokenIds.length; i++) {
			uint256 tokenId = tokenIds[i];
			require(tokenIdToStaker[tokenId] == msg.sender, "You don't own this token!");
			stakerRewards[msg.sender] += getRewardsByTokenId(tokenId);
			removeTokenIdFromArray(stakerToTokenIds[msg.sender], tokenId);
			tokenIdToStaker[tokenId] = address(0);
			nftCollection.transferFrom(address(this), msg.sender, tokenId);
		}
	}

	function getRewardsByTokenId(uint256 _tokenId) public view returns (uint256) {
		uint256 timestamp = block.timestamp;
		if (tokenIdToStaker[_tokenId] == address(0) || tokenIdTimeStaked[_tokenId] > endRewardsTimestamp) {
			return 0;
		}
		if (timestamp > endRewardsTimestamp) {
			timestamp = endRewardsTimestamp;
		}
		return ((timestamp - tokenIdTimeStaked[_tokenId]) * rewardsPerSeconds);
	}

	function getAvailableRewards(address _staker) public view returns (uint256) {
		uint256 tokenRewards = 0;
		for (uint256 i = stakerToTokenIds[_staker].length; i > 0; i--) {
			uint256 tokenId = stakerToTokenIds[msg.sender][i - 1];
			tokenRewards += getRewardsByTokenId(tokenId);
		}
		if (tokenRewards == 0 && stakerRewards[_staker] == 0) {
			return 0;
		}
		uint256 availableRewards = stakerRewards[_staker] + tokenRewards - stakerRewardsClaimed[_staker];
		return availableRewards;
	}

	function getClaimableRewards(address _staker) public view returns (uint256) {
		// Calculate the percentage of rewards to unlock based on the time passed since the start of the claim
		if (block.timestamp < startClaimTimestamp) {
			return 0;
		}
		uint256 totalRewards = getTotalRewards(_staker);
		uint256 secondsFromClaimStart = block.timestamp - startClaimTimestamp;
		uint256 rewardsToUnlock = ((totalRewards / rewardExponent) * secondsFromClaimStart * rewardsLockSeconds) - stakerRewardsClaimed[_staker];
		// If the rewards to unlock are more than the total rewards, return the total rewards
		if (rewardsToUnlock > totalRewards) {
			return totalRewards;
		}
		require(rewardsToUnlock <= totalRewards, "You can't claim more than you have");
		// Else return the rewards to unlock
		return rewardsToUnlock;
	}

	function claimRewards() external canClaim nonReentrant {
		uint256 rewardsToUnlock = getClaimableRewards(msg.sender);
		// Require that the sender has claimed in the past
		require(rewardsToUnlock > 0, "You have no rewards to claim");
		stakerRewardsClaimed[msg.sender] += rewardsToUnlock;
		// Send token from owner to staker
		rewardsToken.transferFrom(owner(), msg.sender, rewardsToUnlock);
	}
}