creation_sourcecode: {{
    "language": "Solidity",
    "sources": {
      "@openzeppelin/contracts/access/Ownable.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../utils/Context.sol\";\n\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\nabstract contract Ownable is Context {\n    address private _owner;\n\n    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n    /**\n     * @dev Initializes the contract setting the deployer as the initial owner.\n     */\n    constructor() {\n        _transferOwnership(_msgSender());\n    }\n\n    /**\n     * @dev Throws if called by any account other than the owner.\n     */\n    modifier onlyOwner() {\n        _checkOwner();\n        _;\n    }\n\n    /**\n     * @dev Returns the address of the current owner.\n     */\n    function owner() public view virtual returns (address) {\n        return _owner;\n    }\n\n    /**\n     * @dev Throws if the sender is not the owner.\n     */\n    function _checkOwner() internal view virtual {\n        require(owner() == _msgSender(), \"Ownable: caller is not the owner\");\n    }\n\n    /**\n     * @dev Leaves the contract without owner. It will not be possible to call\n     * `onlyOwner` functions anymore. Can only be called by the current owner.\n     *\n     * NOTE: Renouncing ownership will leave the contract without an owner,\n     * thereby removing any functionality that is only available to the owner.\n     */\n    function renounceOwnership() public virtual onlyOwner {\n        _transferOwnership(address(0));\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Can only be called by the current owner.\n     */\n    function transferOwnership(address newOwner) public virtual onlyOwner {\n        require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n        _transferOwnership(newOwner);\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Internal function without access restriction.\n     */\n    function _transferOwnership(address newOwner) internal virtual {\n        address oldOwner = _owner;\n        _owner = newOwner;\n        emit OwnershipTransferred(oldOwner, newOwner);\n    }\n}\n"
      },
      "@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in\n * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].\n *\n * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by\n * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't\n * need to send a transaction, and thus is not required to hold Ether at all.\n */\ninterface IERC20Permit {\n    /**\n     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,\n     * given ``owner``'s signed approval.\n     *\n     * IMPORTANT: The same issues {IERC20-approve} has related to transaction\n     * ordering also apply here.\n     *\n     * Emits an {Approval} event.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     * - `deadline` must be a timestamp in the future.\n     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`\n     * over the EIP712-formatted function arguments.\n     * - the signature must use ``owner``'s current nonce (see {nonces}).\n     *\n     * For more information on the signature format, see the\n     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP\n     * section].\n     */\n    function permit(\n        address owner,\n        address spender,\n        uint256 value,\n        uint256 deadline,\n        uint8 v,\n        bytes32 r,\n        bytes32 s\n    ) external;\n\n    /**\n     * @dev Returns the current nonce for `owner`. This value must be\n     * included whenever a signature is generated for {permit}.\n     *\n     * Every successful call to {permit} increases ``owner``'s nonce by one. This\n     * prevents a signature from being used multiple times.\n     */\n    function nonces(address owner) external view returns (uint256);\n\n    /**\n     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.\n     */\n    // solhint-disable-next-line func-name-mixedcase\n    function DOMAIN_SEPARATOR() external view returns (bytes32);\n}\n"
      },
      "@openzeppelin/contracts/token/ERC20/IERC20.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n    /**\n     * @dev Emitted when `value` tokens are moved from one account (`from`) to\n     * another (`to`).\n     *\n     * Note that `value` may be zero.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 value);\n\n    /**\n     * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n     * a call to {approve}. `value` is the new allowance.\n     */\n    event Approval(address indexed owner, address indexed spender, uint256 value);\n\n    /**\n     * @dev Returns the amount of tokens in existence.\n     */\n    function totalSupply() external view returns (uint256);\n\n    /**\n     * @dev Returns the amount of tokens owned by `account`.\n     */\n    function balanceOf(address account) external view returns (uint256);\n\n    /**\n     * @dev Moves `amount` tokens from the caller's account to `to`.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transfer(address to, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Returns the remaining number of tokens that `spender` will be\n     * allowed to spend on behalf of `owner` through {transferFrom}. This is\n     * zero by default.\n     *\n     * This value changes when {approve} or {transferFrom} are called.\n     */\n    function allowance(address owner, address spender) external view returns (uint256);\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * IMPORTANT: Beware that changing an allowance with this method brings the risk\n     * that someone may use both the old and the new allowance by unfortunate\n     * transaction ordering. One possible solution to mitigate this race\n     * condition is to first reduce the spender's allowance to 0 and set the\n     * desired value afterwards:\n     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address spender, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Moves `amount` tokens from `from` to `to` using the\n     * allowance mechanism. `amount` is then deducted from the caller's\n     * allowance.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(\n        address from,\n        address to,\n        uint256 amount\n    ) external returns (bool);\n}\n"
      },
      "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../IERC20.sol\";\nimport \"../extensions/draft-IERC20Permit.sol\";\nimport \"../../../utils/Address.sol\";\n\n/**\n * @title SafeERC20\n * @dev Wrappers around ERC20 operations that throw on failure (when the token\n * contract returns false). Tokens that return no value (and instead revert or\n * throw on failure) are also supported, non-reverting calls are assumed to be\n * successful.\n * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,\n * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.\n */\nlibrary SafeERC20 {\n    using Address for address;\n\n    function safeTransfer(\n        IERC20 token,\n        address to,\n        uint256 value\n    ) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));\n    }\n\n    function safeTransferFrom(\n        IERC20 token,\n        address from,\n        address to,\n        uint256 value\n    ) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));\n    }\n\n    /**\n     * @dev Deprecated. This function has issues similar to the ones found in\n     * {IERC20-approve}, and its usage is discouraged.\n     *\n     * Whenever possible, use {safeIncreaseAllowance} and\n     * {safeDecreaseAllowance} instead.\n     */\n    function safeApprove(\n        IERC20 token,\n        address spender,\n        uint256 value\n    ) internal {\n        // safeApprove should only be called when setting an initial allowance,\n        // or when resetting it to zero. To increase and decrease it, use\n        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'\n        require(\n            (value == 0) || (token.allowance(address(this), spender) == 0),\n            \"SafeERC20: approve from non-zero to non-zero allowance\"\n        );\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));\n    }\n\n    function safeIncreaseAllowance(\n        IERC20 token,\n        address spender,\n        uint256 value\n    ) internal {\n        uint256 newAllowance = token.allowance(address(this), spender) + value;\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    function safeDecreaseAllowance(\n        IERC20 token,\n        address spender,\n        uint256 value\n    ) internal {\n        unchecked {\n            uint256 oldAllowance = token.allowance(address(this), spender);\n            require(oldAllowance >= value, \"SafeERC20: decreased allowance below zero\");\n            uint256 newAllowance = oldAllowance - value;\n            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n        }\n    }\n\n    function safePermit(\n        IERC20Permit token,\n        address owner,\n        address spender,\n        uint256 value,\n        uint256 deadline,\n        uint8 v,\n        bytes32 r,\n        bytes32 s\n    ) internal {\n        uint256 nonceBefore = token.nonces(owner);\n        token.permit(owner, spender, value, deadline, v, r, s);\n        uint256 nonceAfter = token.nonces(owner);\n        require(nonceAfter == nonceBefore + 1, \"SafeERC20: permit did not succeed\");\n    }\n\n    /**\n     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement\n     * on the return value: the return value is optional (but if data is returned, it must not be false).\n     * @param token The token targeted by the call.\n     * @param data The call data (encoded using abi.encode or one of its variants).\n     */\n    function _callOptionalReturn(IERC20 token, bytes memory data) private {\n        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since\n        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that\n        // the target address contains contract code and also asserts for success in the low-level call.\n\n        bytes memory returndata = address(token).functionCall(data, \"SafeERC20: low-level call failed\");\n        if (returndata.length > 0) {\n            // Return data is optional\n            require(abi.decode(returndata, (bool)), \"SafeERC20: ERC20 operation did not succeed\");\n        }\n    }\n}\n"
      },
      "@openzeppelin/contracts/token/ERC721/IERC721.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC721/IERC721.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../../utils/introspection/IERC165.sol\";\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ninterface IERC721 is IERC165 {\n    /**\n     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n\n    /**\n     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.\n     */\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n\n    /**\n     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.\n     */\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of tokens in ``owner``'s account.\n     */\n    function balanceOf(address owner) external view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the `tokenId` token.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     */\n    function ownerOf(uint256 tokenId) external view returns (address owner);\n\n    /**\n     * @dev Safely transfers `tokenId` token from `from` to `to`.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must exist and be owned by `from`.\n     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n     *\n     * Emits a {Transfer} event.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId,\n        bytes calldata data\n    ) external;\n\n    /**\n     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients\n     * are aware of the ERC721 protocol to prevent tokens from being forever locked.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must exist and be owned by `from`.\n     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n     *\n     * Emits a {Transfer} event.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) external;\n\n    /**\n     * @dev Transfers `tokenId` token from `from` to `to`.\n     *\n     * WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721\n     * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must\n     * understand this adds an external call which potentially creates a reentrancy vulnerability.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must be owned by `from`.\n     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) external;\n\n    /**\n     * @dev Gives permission to `to` to transfer `tokenId` token to another account.\n     * The approval is cleared when the token is transferred.\n     *\n     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.\n     *\n     * Requirements:\n     *\n     * - The caller must own the token or be an approved operator.\n     * - `tokenId` must exist.\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address to, uint256 tokenId) external;\n\n    /**\n     * @dev Approve or remove `operator` as an operator for the caller.\n     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.\n     *\n     * Requirements:\n     *\n     * - The `operator` cannot be the caller.\n     *\n     * Emits an {ApprovalForAll} event.\n     */\n    function setApprovalForAll(address operator, bool _approved) external;\n\n    /**\n     * @dev Returns the account approved for `tokenId` token.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     */\n    function getApproved(uint256 tokenId) external view returns (address operator);\n\n    /**\n     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.\n     *\n     * See {setApprovalForAll}\n     */\n    function isApprovedForAll(address owner, address operator) external view returns (bool);\n}\n"
      },
      "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ninterface IERC721Receiver {\n    /**\n     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}\n     * by `operator` from `from`, this function is called.\n     *\n     * It must return its Solidity selector to confirm the token transfer.\n     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.\n     *\n     * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.\n     */\n    function onERC721Received(\n        address operator,\n        address from,\n        uint256 tokenId,\n        bytes calldata data\n    ) external returns (bytes4);\n}\n"
      },
      "@openzeppelin/contracts/token/ERC721/utils/ERC721Holder.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC721/utils/ERC721Holder.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../IERC721Receiver.sol\";\n\n/**\n * @dev Implementation of the {IERC721Receiver} interface.\n *\n * Accepts all token transfers.\n * Make sure the contract is able to use its token with {IERC721-safeTransferFrom}, {IERC721-approve} or {IERC721-setApprovalForAll}.\n */\ncontract ERC721Holder is IERC721Receiver {\n    /**\n     * @dev See {IERC721Receiver-onERC721Received}.\n     *\n     * Always returns `IERC721Receiver.onERC721Received.selector`.\n     */\n    function onERC721Received(\n        address,\n        address,\n        uint256,\n        bytes memory\n    ) public virtual override returns (bytes4) {\n        return this.onERC721Received.selector;\n    }\n}\n"
      },
      "@openzeppelin/contracts/utils/Address.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)\n\npragma solidity ^0.8.1;\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * [IMPORTANT]\n     * ====\n     * It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     *\n     * Among others, `isContract` will return false for the following\n     * types of addresses:\n     *\n     *  - an externally-owned account\n     *  - a contract in construction\n     *  - an address where a contract will be created\n     *  - an address where a contract lived, but was destroyed\n     * ====\n     *\n     * [IMPORTANT]\n     * ====\n     * You shouldn't rely on `isContract` to protect against flash loan attacks!\n     *\n     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets\n     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract\n     * constructor.\n     * ====\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies on extcodesize/address.code.length, which returns 0\n        // for contracts in construction, since the code is only stored at the end\n        // of the constructor execution.\n\n        return account.code.length > 0;\n    }\n\n    /**\n     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to\n     * `recipient`, forwarding all available gas and reverting on errors.\n     *\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\n     * imposed by `transfer`, making them unable to receive funds via\n     * `transfer`. {sendValue} removes this limitation.\n     *\n     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\n     *\n     * IMPORTANT: because control is transferred to `recipient`, care must be\n     * taken to not create reentrancy vulnerabilities. Consider using\n     * {ReentrancyGuard} or the\n     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\n     */\n    function sendValue(address payable recipient, uint256 amount) internal {\n        require(address(this).balance >= amount, \"Address: insufficient balance\");\n\n        (bool success, ) = recipient.call{value: amount}(\"\");\n        require(success, \"Address: unable to send value, recipient may have reverted\");\n    }\n\n    /**\n     * @dev Performs a Solidity function call using a low level `call`. A\n     * plain `call` is an unsafe replacement for a function call: use this\n     * function instead.\n     *\n     * If `target` reverts with a revert reason, it is bubbled up by this\n     * function (like regular Solidity function calls).\n     *\n     * Returns the raw returned data. To convert to the expected return value,\n     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\n     *\n     * Requirements:\n     *\n     * - `target` must be a contract.\n     * - calling `target` with `data` must not revert.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, 0, \"Address: low-level call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\n     * `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(\n        address target,\n        bytes memory data,\n        string memory errorMessage\n    ) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, 0, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but also transferring `value` wei to `target`.\n     *\n     * Requirements:\n     *\n     * - the calling contract must have an ETH balance of at least `value`.\n     * - the called Solidity function must be `payable`.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(\n        address target,\n        bytes memory data,\n        uint256 value\n    ) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\n     * with `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(\n        address target,\n        bytes memory data,\n        uint256 value,\n        string memory errorMessage\n    ) internal returns (bytes memory) {\n        require(address(this).balance >= value, \"Address: insufficient balance for call\");\n        (bool success, bytes memory returndata) = target.call{value: value}(data);\n        return verifyCallResultFromTarget(target, success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {\n        return functionStaticCall(target, data, \"Address: low-level static call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(\n        address target,\n        bytes memory data,\n        string memory errorMessage\n    ) internal view returns (bytes memory) {\n        (bool success, bytes memory returndata) = target.staticcall(data);\n        return verifyCallResultFromTarget(target, success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but performing a delegate call.\n     *\n     * _Available since v3.4._\n     */\n    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {\n        return functionDelegateCall(target, data, \"Address: low-level delegate call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n     * but performing a delegate call.\n     *\n     * _Available since v3.4._\n     */\n    function functionDelegateCall(\n        address target,\n        bytes memory data,\n        string memory errorMessage\n    ) internal returns (bytes memory) {\n        (bool success, bytes memory returndata) = target.delegatecall(data);\n        return verifyCallResultFromTarget(target, success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling\n     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.\n     *\n     * _Available since v4.8._\n     */\n    function verifyCallResultFromTarget(\n        address target,\n        bool success,\n        bytes memory returndata,\n        string memory errorMessage\n    ) internal view returns (bytes memory) {\n        if (success) {\n            if (returndata.length == 0) {\n                // only check isContract if the call was successful and the return data is empty\n                // otherwise we already know that it was a contract\n                require(isContract(target), \"Address: call to non-contract\");\n            }\n            return returndata;\n        } else {\n            _revert(returndata, errorMessage);\n        }\n    }\n\n    /**\n     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the\n     * revert reason or using the provided one.\n     *\n     * _Available since v4.3._\n     */\n    function verifyCallResult(\n        bool success,\n        bytes memory returndata,\n        string memory errorMessage\n    ) internal pure returns (bytes memory) {\n        if (success) {\n            return returndata;\n        } else {\n            _revert(returndata, errorMessage);\n        }\n    }\n\n    function _revert(bytes memory returndata, string memory errorMessage) private pure {\n        // Look for revert reason and bubble it up if present\n        if (returndata.length > 0) {\n            // The easiest way to bubble the revert reason is using memory via assembly\n            /// @solidity memory-safe-assembly\n            assembly {\n                let returndata_size := mload(returndata)\n                revert(add(32, returndata), returndata_size)\n            }\n        } else {\n            revert(errorMessage);\n        }\n    }\n}\n"
      },
      "@openzeppelin/contracts/utils/Context.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n    function _msgSender() internal view virtual returns (address) {\n        return msg.sender;\n    }\n\n    function _msgData() internal view virtual returns (bytes calldata) {\n        return msg.data;\n    }\n}\n"
      },
      "@openzeppelin/contracts/utils/introspection/IERC165.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * https://eips.ethereum.org/EIPS/eip-165[EIP].\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others ({ERC165Checker}).\n *\n * For an implementation, see {ERC165}.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n"
      },
      "@openzeppelin/contracts/utils/math/SafeMath.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)\n\npragma solidity ^0.8.0;\n\n// CAUTION\n// This version of SafeMath should only be used with Solidity 0.8 or later,\n// because it relies on the compiler's built in overflow checks.\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations.\n *\n * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler\n * now has built in overflow checking.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        unchecked {\n            uint256 c = a + b;\n            if (c < a) return (false, 0);\n            return (true, c);\n        }\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        unchecked {\n            if (b > a) return (false, 0);\n            return (true, a - b);\n        }\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        unchecked {\n            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n            // benefit is lost if 'b' is also tested.\n            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n            if (a == 0) return (true, 0);\n            uint256 c = a * b;\n            if (c / a != b) return (false, 0);\n            return (true, c);\n        }\n    }\n\n    /**\n     * @dev Returns the division of two unsigned integers, with a division by zero flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        unchecked {\n            if (b == 0) return (false, 0);\n            return (true, a / b);\n        }\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.\n     *\n     * _Available since v3.4._\n     */\n    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n        unchecked {\n            if (b == 0) return (false, 0);\n            return (true, a % b);\n        }\n    }\n\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `+` operator.\n     *\n     * Requirements:\n     *\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        return a + b;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        return a - b;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity's `*` operator.\n     *\n     * Requirements:\n     *\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        return a * b;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers, reverting on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator.\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        return a / b;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * reverting when dividing by zero.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        return a % b;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n     * overflow (when the result is negative).\n     *\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\n     * message unnecessarily. For custom revert reasons use {trySub}.\n     *\n     * Counterpart to Solidity's `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(\n        uint256 a,\n        uint256 b,\n        string memory errorMessage\n    ) internal pure returns (uint256) {\n        unchecked {\n            require(b <= a, errorMessage);\n            return a - b;\n        }\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers, reverting with custom message on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(\n        uint256 a,\n        uint256 b,\n        string memory errorMessage\n    ) internal pure returns (uint256) {\n        unchecked {\n            require(b > 0, errorMessage);\n            return a / b;\n        }\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * reverting with custom message when dividing by zero.\n     *\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\n     * message unnecessarily. For custom revert reasons use {tryMod}.\n     *\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(\n        uint256 a,\n        uint256 b,\n        string memory errorMessage\n    ) internal pure returns (uint256) {\n        unchecked {\n            require(b > 0, errorMessage);\n            return a % b;\n        }\n    }\n}\n"
      },
      "contracts/FTStaking.sol": {
        "content": "// SPDX-License-Identifier: MIT\npragma solidity ^0.8.0;\n\nimport \"@openzeppelin/contracts/token/ERC721/IERC721.sol\";\nimport \"@openzeppelin/contracts/token/ERC20/IERC20.sol\";\nimport \"@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol\";\nimport \"@openzeppelin/contracts/token/ERC721/utils/ERC721Holder.sol\";\nimport \"@openzeppelin/contracts/access/Ownable.sol\";\nimport \"@openzeppelin/contracts/utils/math/SafeMath.sol\";\n\n/// @author Serhii\n/// @title ERC721 NFT Staking Contract\n/// @notice Staking Contract that uses the Synthetix Staking model to distribute ERC20 token rewards in a dynamic way,\n/// proportionally based on the amount of ERC721 tokens staked by each staker at any given time.\n\n\n\ncontract FTStaking is ERC721Holder, Ownable {\n    using SafeERC20 for IERC20;\n    using SafeMath for uint256;\n\n    IERC20 public immutable rewardToken;\n    IERC721 public immutable nftCollection;\n    IERC20 public immutable ftStaked;\n\n    uint256 public maxSupply;\n    uint256 public initialReward;\n    uint256 public claimedTime;\n\n\n    mapping(address => uint256) private rewards;\n    mapping(uint256 => address) public stakedAssets;\n    mapping(address => uint256[]) private tokensStaked;\n    mapping(uint256 => uint256) public tokenIdToIndex;\n    mapping(uint256 => uint256) public tokenIdTimeStamp;\n    mapping(address => uint256) public totalEarned;\n\n    /// @param _nftCollection the address of the ERC721 Contract\n    /// @param _rewardToken the address of the ERC20 token used for rewards\n    constructor(IERC721 _nftCollection, IERC20 _rewardToken, IERC20 _ftStaked) {\n        nftCollection = _nftCollection;\n        rewardToken = _rewardToken;\n        ftStaked = _ftStaked;\n        claimedTime = 60 * 60 * 24 * 30;\n    }\n\n    /// @notice functon called by the users to Stake NFTs\n    /// @param tokenIds array of Token IDs of the NFTs to be staked\n    /// @dev the Token IDs have to be prevoiusly approved for transfer in the\n    /// ERC721 contract with the address of this contract\n    function stake(uint256[] calldata tokenIds) external updateReward(msg.sender) {\n        require(tokenIds.length != 0, \"Staking: No tokenIds provided\");\n        require(maxSupply > 0, \"Staking: Max supply exceed\");\n        \n        uint256 amount = tokenIds.length;\n\n        for (uint256 i; i < amount;) {\n            nftCollection.safeTransferFrom(msg.sender, address(this), tokenIds[i]);\n\n            stakedAssets[tokenIds[i]] = msg.sender;\n            tokensStaked[msg.sender].push(tokenIds[i]);\n            tokenIdToIndex[tokenIds[i]] = tokensStaked[msg.sender].length - 1;\n            tokenIdTimeStamp[tokenIds[i]] = block.timestamp;\n            unchecked {\n                i++;\n            }\n        }\n        ftStaked.transfer(msg.sender, amount * 1e1);\n        emit Staked(msg.sender, tokenIds);\n    }\n\n    /// @notice function called by the user to unstake NFTs from staking\n    /// @param tokenIds array of Token IDs of the NFTs to be unstake\n    function unstake(uint256[] memory tokenIds) public updateReward(msg.sender) {\n        require(tokenIds.length != 0, \"Staking: No tokenIds provided\");\n        if(rewards[msg.sender] > 0 ) claimRewards();\n        for (uint256 i; i < tokenIds.length;) {\n            require(stakedAssets[tokenIds[i]] == msg.sender, \"Staking: Not the staker of the token\");\n\n            delete stakedAssets[tokenIds[i]];\n\n            uint256[] storage userTokens = tokensStaked[msg.sender];\n            uint256 userTokensAmount = userTokens.length - 1;\n            if (tokenIdToIndex[tokenIds[i]] != userTokensAmount) {\n                userTokens[tokenIdToIndex[tokenIds[i]]] = userTokens[userTokensAmount];\n                tokenIdToIndex[userTokens[userTokensAmount]] = tokenIdToIndex[tokenIds[i]];\n            }\n            userTokens.pop();\n            nftCollection.safeTransferFrom(address(this), msg.sender, tokenIds[i]);\n\n            unchecked {\n                i++;\n            }\n        }\n        ftStaked.transferFrom(msg.sender, address(this), tokenIds.length * 1e1);\n        emit Unstaked(msg.sender, tokenIds);\n    }\n\n    /// @notice function called by the user to claim his accumulated rewards\n    function claimRewards() public updateReward(msg.sender) {\n\n        require(rewards[msg.sender] > 0, \"Empty rewards\");\n        \n        totalEarned[msg.sender] += rewards[msg.sender];\n\n        rewardToken.safeTransfer(msg.sender, rewards[msg.sender]);\n\n        emit RewardPaid(msg.sender, rewards[msg.sender]);\n\n        delete rewards[msg.sender];\n        \n    }\n\n    /// @notice function called by the user to unstake all NFTs and claim the rewards in one transaction\n    function unstakeAll() external updateReward(msg.sender) {\n        totalEarned[msg.sender] = 0;\n        unstake(tokensStaked[msg.sender]);\n    }\n\n    /// @notice function useful for Front End to see the stake and rewards for users\n    /// @param _user the address of the user to get informations for\n    /// @return _tokensStaked an array of NFT Token IDs that are staked by the user\n    /// @return _availableRewards the rewards accumulated by the user\n    /// @return _totalEarned the sum of rewards\n    function userStakeInfo(address _user) public view returns (uint256[] memory _tokensStaked, uint256 _availableRewards, uint256 _totalEarned)\n    {\n         uint availableRewards;\n         if(calculateRewards(_user) > totalEarned[_user] ) {\n            availableRewards = calculateRewards(_user) - totalEarned[_user];\n         }\n        _tokensStaked = tokensStaked[_user];\n        _availableRewards= availableRewards;\n        _totalEarned = totalEarned[_user];\n    }\n\n    /// @notice getter function to get the reward per month for staking one NFT\n    /// @param _stakedMonth the period of token staked\n    /// @return _rewardPerToken the amount of token per month rewarded for staking one NFT\n    function getRewardPerToken(uint256 _stakedMonth) public view returns (uint256 _rewardPerToken) {\n        if(_stakedMonth == 1) {\n            return initialReward;\n        }\n        else if( _stakedMonth > 1 && _stakedMonth <= 3 ) {\n            return ( initialReward + initialReward / 2 ) * _stakedMonth - ( initialReward / 2 );\n        } else if(_stakedMonth > 3 && _stakedMonth <= 6) { \n            return initialReward * (_stakedMonth * 2 - 2) ;\n        } else if(_stakedMonth > 6) {\n            return initialReward * (_stakedMonth * 3 - 8);\n        } else {\n            return 0;\n        }\n    }\n\n    /// @notice function for the Owner of the Contract to start a Staking period and set the\n    /// amount of ERC20 Tokens to be distributed as rewards in said period\n    /// @param _maxSupply the maximum rewards amount for the staking\n    /// @param _initialReward the initial rewards amount for the montly staking\n    /// @dev  the Staking Contract have to already own enough Rewards Tokens to distribute all the rewards,\n    /// so make sure to send all the tokens to the contract before calling this function\n    function startStakingPeriod(uint256 _maxSupply, uint256 _initialReward) external onlyOwner {\n        require(_maxSupply > 0, \"Staking: MaxSupply must be greater than 0\");\n        require(_initialReward > 0, \"Staking: InitialReward must be greater than 0\");\n        require(_maxSupply > _initialReward, \"Staking: MaxSupply must be greater than initialReward\");\n\n        initialReward = _initialReward;\n                \n        maxSupply = _maxSupply;\n\n        emit StakingStarted(_maxSupply, _initialReward);\n\n    }\n\n    /// @notice used to calculate the earned rewards for a user\n    /// @param _user the address of the user to calculate available rewards for\n    /// @return _rewards the amount of tokens available as rewards for the passed address\n    function calculateRewards(address _user) public view returns (uint256 _rewards) {\n\n        uint256 totalRewards;\n        \n        for(uint256 i; i < tokensStaked[_user].length;) {\n            uint256 stakedPeriod = SafeMath.div((block.timestamp - tokenIdTimeStamp[tokensStaked[_user][i]]), claimedTime);\n            \n            if(stakedPeriod > 0 ) {\n                totalRewards += getRewardPerToken(stakedPeriod);\n            }\n            unchecked {\n                i++;\n            }\n        }\n\n        if(totalRewards >= maxSupply) totalRewards = maxSupply;\n        return totalRewards;\n    }\n\n\n    function setClaimTime(uint256 _claimTime) public onlyOwner() {\n        claimedTime = _claimTime;\n    }\n\n    function setInitialReward(uint256 _initialReward) public onlyOwner() {\n        initialReward = _initialReward;\n    }\n\n    /// @notice modifier used to keep track of the dynamic rewards for user each time a deposit or unstake is made\n    modifier updateReward(address account) {\n        if (account != address(0)) {\n            rewards[account] = calculateRewards(account) - totalEarned[account];\n            maxSupply -= rewards[account];\n        }\n        _;\n    }\n\n    event StakingStarted(uint256 mxsupply, uint256 initReward);\n    event Staked(address indexed user, uint256[] tokenIds);\n    event Unstaked(address indexed user, uint256[] tokenIds);\n    event RewardPaid(address indexed user, uint256 reward);\n}\n"
      }
    },
    "settings": {
      "optimizer": {
        "enabled": true,
        "runs": 200
      },
      "outputSelection": {
        "*": {
          "*": [
            "evm.bytecode",
            "evm.deployedBytecode",
            "devdoc",
            "userdoc",
            "metadata",
            "abi"
          ]
        }
      },
      "libraries": {}
    }
  }}