Accounts
0xc7...bbd1
0xC7...bBD1

0xC7...bBD1

$500
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Contract Metadata
Compiler
0.8.20+commit.a1b79de6
Language
Solidity
Contract Source Code
File 1 of 8: ContextUpgradeable.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;
import {Initializable} from "../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;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}
Contract Source Code
File 2 of 8: EnumerableSet.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/structs/EnumerableSet.sol)
// This file was procedurally generated from scripts/generate/templates/EnumerableSet.js.

pragma solidity ^0.8.20;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```solidity
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 *
 * [WARNING]
 * ====
 * Trying to delete such a structure from storage will likely result in data corruption, rendering the structure
 * unusable.
 * See https://github.com/ethereum/solidity/pull/11843[ethereum/solidity#11843] for more info.
 *
 * In order to clean an EnumerableSet, you can either remove all elements one by one or create a fresh instance using an
 * array of EnumerableSet.
 * ====
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position is the index of the value in the `values` array plus 1.
        // Position 0 is used to mean a value is not in the set.
        mapping(bytes32 value => uint256) _positions;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._positions[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We cache the value's position to prevent multiple reads from the same storage slot
        uint256 position = set._positions[value];

        if (position != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.

            uint256 valueIndex = position - 1;
            uint256 lastIndex = set._values.length - 1;

            if (valueIndex != lastIndex) {
                bytes32 lastValue = set._values[lastIndex];

                // Move the lastValue to the index where the value to delete is
                set._values[valueIndex] = lastValue;
                // Update the tracked position of the lastValue (that was just moved)
                set._positions[lastValue] = position;
            }

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the tracked position for the deleted slot
            delete set._positions[value];

            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._positions[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }

    // Bytes32Set

    struct Bytes32Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        bytes32[] memory store = _values(set._inner);
        bytes32[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }
}
Contract Source Code
File 3 of 8: IERC721Receiver.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.20;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be
     * reverted.
     *
     * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}
Contract Source Code
File 4 of 8: ISpaceKid.sol
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

interface ISpaceKid {
    function getTokensByOwner(address owner) external view returns (uint256[] memory);

    function mint(address to, uint256 tokenId) external;

    function tokenURI(uint256 tokenId) external view returns (string memory);

    function totalSupply() external view virtual returns (uint256);

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

    function ownerOf(uint256 tokenId) external view returns (address);

    function safeTransferFrom(address from, address to, uint256 tokenId) external;
}
Contract Source Code
File 5 of 8: Initializable.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.20;

/**
 * @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]
 * ```solidity
 * 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 Storage of the initializable contract.
     *
     * It's implemented on a custom ERC-7201 namespace to reduce the risk of storage collisions
     * when using with upgradeable contracts.
     *
     * @custom:storage-location erc7201:openzeppelin.storage.Initializable
     */
    struct InitializableStorage {
        /**
         * @dev Indicates that the contract has been initialized.
         */
        uint64 _initialized;
        /**
         * @dev Indicates that the contract is in the process of being initialized.
         */
        bool _initializing;
    }

    // keccak256(abi.encode(uint256(keccak256("openzeppelin.storage.Initializable")) - 1)) & ~bytes32(uint256(0xff))
    bytes32 private constant INITIALIZABLE_STORAGE = 0xf0c57e16840df040f15088dc2f81fe391c3923bec73e23a9662efc9c229c6a00;

    /**
     * @dev The contract is already initialized.
     */
    error InvalidInitialization();

    /**
     * @dev The contract is not initializing.
     */
    error NotInitializing();

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint64 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.
     *
     * Similar to `reinitializer(1)`, except that in the context of a constructor an `initializer` may be invoked any
     * number of times. This behavior in the constructor can be useful during testing and is not expected to be used in
     * production.
     *
     * Emits an {Initialized} event.
     */
    modifier initializer() {
        // solhint-disable-next-line var-name-mixedcase
        InitializableStorage storage $ = _getInitializableStorage();

        // Cache values to avoid duplicated sloads
        bool isTopLevelCall = !$._initializing;
        uint64 initialized = $._initialized;

        // Allowed calls:
        // - initialSetup: the contract is not in the initializing state and no previous version was
        //                 initialized
        // - construction: the contract is initialized at version 1 (no reininitialization) and the
        //                 current contract is just being deployed
        bool initialSetup = initialized == 0 && isTopLevelCall;
        bool construction = initialized == 1 && address(this).code.length == 0;

        if (!initialSetup && !construction) {
            revert InvalidInitialization();
        }
        $._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.
     *
     * 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.
     *
     * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
     * cannot be nested. If one is invoked in the context of another, execution will revert.
     *
     * 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.
     *
     * WARNING: Setting the version to 2**64 - 1 will prevent any future reinitialization.
     *
     * Emits an {Initialized} event.
     */
    modifier reinitializer(uint64 version) {
        // solhint-disable-next-line var-name-mixedcase
        InitializableStorage storage $ = _getInitializableStorage();

        if ($._initializing || $._initialized >= version) {
            revert InvalidInitialization();
        }
        $._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() {
        _checkInitializing();
        _;
    }

    /**
     * @dev Reverts if the contract is not in an initializing state. See {onlyInitializing}.
     */
    function _checkInitializing() internal view virtual {
        if (!_isInitializing()) {
            revert NotInitializing();
        }
    }

    /**
     * @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.
     *
     * Emits an {Initialized} event the first time it is successfully executed.
     */
    function _disableInitializers() internal virtual {
        // solhint-disable-next-line var-name-mixedcase
        InitializableStorage storage $ = _getInitializableStorage();

        if ($._initializing) {
            revert InvalidInitialization();
        }
        if ($._initialized != type(uint64).max) {
            $._initialized = type(uint64).max;
            emit Initialized(type(uint64).max);
        }
    }

    /**
     * @dev Returns the highest version that has been initialized. See {reinitializer}.
     */
    function _getInitializedVersion() internal view returns (uint64) {
        return _getInitializableStorage()._initialized;
    }

    /**
     * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
     */
    function _isInitializing() internal view returns (bool) {
        return _getInitializableStorage()._initializing;
    }

    /**
     * @dev Returns a pointer to the storage namespace.
     */
    // solhint-disable-next-line var-name-mixedcase
    function _getInitializableStorage() private pure returns (InitializableStorage storage $) {
        assembly {
            $.slot := INITIALIZABLE_STORAGE
        }
    }
}
Contract Source Code
File 6 of 8: OwnableUpgradeable.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;

import {ContextUpgradeable} from "../utils/ContextUpgradeable.sol";
import {Initializable} from "../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.
 *
 * The initial owner is set to the address provided by the deployer. 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 {
    /// @custom:storage-location erc7201:openzeppelin.storage.Ownable
    struct OwnableStorage {
        address _owner;
    }

    // keccak256(abi.encode(uint256(keccak256("openzeppelin.storage.Ownable")) - 1)) & ~bytes32(uint256(0xff))
    bytes32 private constant OwnableStorageLocation = 0x9016d09d72d40fdae2fd8ceac6b6234c7706214fd39c1cd1e609a0528c199300;

    function _getOwnableStorage() private pure returns (OwnableStorage storage $) {
        assembly {
            $.slot := OwnableStorageLocation
        }
    }

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

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

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    function __Ownable_init(address initialOwner) internal onlyInitializing {
        __Ownable_init_unchained(initialOwner);
    }

    function __Ownable_init_unchained(address initialOwner) internal onlyInitializing {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @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) {
        OwnableStorage storage $ = _getOwnableStorage();
        return $._owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling 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 {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        OwnableStorage storage $ = _getOwnableStorage();
        address oldOwner = $._owner;
        $._owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
Contract Source Code
File 7 of 8: ReentrancyGuardUpgradeable.sol
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/ReentrancyGuard.sol)

pragma solidity ^0.8.20;
import {Initializable} from "../proxy/utils/Initializable.sol";

/**
 * @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 ReentrancyGuardUpgradeable is Initializable {
    // 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;

    /// @custom:storage-location erc7201:openzeppelin.storage.ReentrancyGuard
    struct ReentrancyGuardStorage {
        uint256 _status;
    }

    // keccak256(abi.encode(uint256(keccak256("openzeppelin.storage.ReentrancyGuard")) - 1)) & ~bytes32(uint256(0xff))
    bytes32 private constant ReentrancyGuardStorageLocation = 0x9b779b17422d0df92223018b32b4d1fa46e071723d6817e2486d003becc55f00;

    function _getReentrancyGuardStorage() private pure returns (ReentrancyGuardStorage storage $) {
        assembly {
            $.slot := ReentrancyGuardStorageLocation
        }
    }

    /**
     * @dev Unauthorized reentrant call.
     */
    error ReentrancyGuardReentrantCall();

    function __ReentrancyGuard_init() internal onlyInitializing {
        __ReentrancyGuard_init_unchained();
    }

    function __ReentrancyGuard_init_unchained() internal onlyInitializing {
        ReentrancyGuardStorage storage $ = _getReentrancyGuardStorage();
        $._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 {
        ReentrancyGuardStorage storage $ = _getReentrancyGuardStorage();
        // On the first call to nonReentrant, _status will be NOT_ENTERED
        if ($._status == ENTERED) {
            revert ReentrancyGuardReentrantCall();
        }

        // Any calls to nonReentrant after this point will fail
        $._status = ENTERED;
    }

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

    /**
     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
     * `nonReentrant` function in the call stack.
     */
    function _reentrancyGuardEntered() internal view returns (bool) {
        ReentrancyGuardStorage storage $ = _getReentrancyGuardStorage();
        return $._status == ENTERED;
    }
}
Contract Source Code
File 8 of 8: SpaceKidStake.sol
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/utils/ReentrancyGuardUpgradeable.sol";
import "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
import "./interfaces/ISpaceKid.sol";

contract SpaceKidStake is OwnableUpgradeable, ReentrancyGuardUpgradeable, IERC721Receiver {
    using EnumerableSet for EnumerableSet.UintSet;

    ISpaceKid public spaceKid;
    uint256 public unlockTime;

    struct StakingStatus {
        uint256 lastPoint;
        uint256 lastStakedTokenCount;
        uint256 timestamp;
    }

    struct Multiplier {
        uint256 from;
        uint256 to;
        uint256 multiplier;
    }

    mapping(address => StakingStatus) private _stakingStatus;
    mapping(address => EnumerableSet.UintSet) private _stakedTokens;
    Multiplier[] private _multipliers;

    uint256 public constant BOOST_MANTISSA = 10 ** 2;

    event Stake(address owner, uint256[] tokenIds, uint256 lastPoint, uint256 lastStakedTokenCount, uint256 timestamp);
    event Claim(address owner, uint256[] tokenIds);
    event SetUnlockTime(uint256 unlockTime);
    event SetMultiplier(Multiplier[] multipliers);

    function initialize(address owner, address _spaceKid, uint256 _unlockTime) external initializer {
        __Ownable_init(owner);
        __ReentrancyGuard_init();
        spaceKid = ISpaceKid(_spaceKid);
        _setUnlockTime(_unlockTime);
    }

    function setUnlockTime(uint256 _unlockTime) external onlyOwner {
        _setUnlockTime(_unlockTime);
    }

    function setMultiplier(Multiplier[] memory multipliers) external onlyOwner {
        require(multipliers.length > 0, "INVALID MULTIPLIER SIZE");
        delete _multipliers;

        for (uint256 index = 0; index < multipliers.length; index++) {
            Multiplier memory currentMultiplier = multipliers[index];

            require(currentMultiplier.from < currentMultiplier.to, "INVALID MULTIPLIER RANGE");
            require(currentMultiplier.multiplier > 0, "INVALID MULTIPLIER");
            if (index > 0) {
                Multiplier memory previousMultiplier = multipliers[index - 1];
                require(previousMultiplier.to == currentMultiplier.from, "MISMATCHED MULTIPLIER RANGE");
            }

            _multipliers.push(currentMultiplier);
        }
        emit SetMultiplier(multipliers);
    }

    function stake(uint256[] memory tokenIds) external nonReentrant {
        if (unlockTime != 0) {
            require(unlockTime > block.timestamp, "CANNOT STAKE");
        }
        require(tokenIds.length > 0, "INVALID SIZE");
        address owner = msg.sender;
        require(spaceKid.isApprovedForAll(owner, address(this)), 'NEED APPROVAL');
        EnumerableSet.UintSet storage stakedTokens = _stakedTokens[owner];

        for (uint256 index = 0; index < tokenIds.length; index++) {
            uint256 tokenId = tokenIds[index];
            require(spaceKid.ownerOf(tokenId) == owner, 'ONLY OWNER CAN STAKE');
            assert(stakedTokens.add(tokenId));
            spaceKid.safeTransferFrom(owner, address(this), tokenId);
        }

        StakingStatus storage stakingStatus = _stakingStatus[owner];
        stakingStatus.lastPoint = getStakingPoint(owner, block.timestamp);
        stakingStatus.timestamp = block.timestamp;
        stakingStatus.lastStakedTokenCount = stakedTokens.length();

        emit Stake(owner, tokenIds, stakingStatus.lastPoint, stakingStatus.lastStakedTokenCount, stakingStatus.timestamp);
    }

    function claim(uint256[] memory tokenIds) external nonReentrant {
        require(unlockTime != 0 && unlockTime <= block.timestamp, "CANNOT CLAIM");
        require(tokenIds.length > 0, "INVALID SIZE");
        address owner = msg.sender;

        for (uint256 index = 0; index < tokenIds.length; index++) {
            uint256 tokenId = tokenIds[index];
            require(_stakedTokens[owner].contains(tokenId), 'INVALID TOKEN');
            assert(_stakedTokens[owner].remove(tokenId));
            spaceKid.safeTransferFrom(address(this), owner, tokenId);
        }

        emit Claim(owner, tokenIds);
    }

    function getMultipliers() external view returns (Multiplier[] memory) {
        return _multipliers;
    }

    function getStakingStatus(address user) external view returns (StakingStatus memory) {
        return _stakingStatus[user];
    }

    function getStakedTokens(address user) external view returns (uint256[] memory) {
        return _stakedTokens[user].values();
    }

    function getStakingPoint(address user, uint256 _calculateTo) public view returns (uint256) {
        StakingStatus memory stakingStatus = _stakingStatus[user];
        uint256 snapshotTime = stakingStatus.timestamp;
        if (snapshotTime == 0) {
            return 0;
        }
        require(_calculateTo >= snapshotTime, "INVALID CALCULATE TO");

        uint256 boost = _getBoost(stakingStatus.lastStakedTokenCount);
        uint256 calculateTo = _calculateTo;
        if (unlockTime != 0 && unlockTime < calculateTo) {
            calculateTo = unlockTime;
        }
        uint256 cumulativePoint = 0;
        for(uint256 index = 0; index < _multipliers.length; index++) {
            Multiplier memory multiplier = _multipliers[index];
            if (multiplier.to <= snapshotTime) {
                continue;
            }

            if (multiplier.from >= calculateTo) {
                break;
            }

            uint256 start = snapshotTime > multiplier.from ? snapshotTime : multiplier.from;
            uint256 end = calculateTo < multiplier.to ? calculateTo : multiplier.to;

            if (start >= end) {
                continue;
            }

            uint256 elapsed = end - start;
            cumulativePoint += _calculateStakingPoint(elapsed, multiplier.multiplier, boost);
        }
        return stakingStatus.lastPoint + cumulativePoint;
    }

    function _calculateStakingPoint(uint256 elapsed, uint256 multiplier, uint256 boost) internal pure returns (uint256) {
        return (elapsed * multiplier * boost) / BOOST_MANTISSA;
    }

    function _setUnlockTime(uint256 _unlockTime) internal {
        require(_unlockTime > block.timestamp, "INVALID UNLOCK TIME");
        unlockTime = _unlockTime;
        emit SetUnlockTime(_unlockTime);
    }

    function _getBoost(uint256 count) internal view returns (uint256) {
        if (count > 0 && count < 5) {
            return 500 * count;
        } else if (count >=5 && count < 10) {
            return 600 * count;
        } else {
            return 750 * count;
        }
    }

    function onERC721Received(address, address, uint256, bytes memory) public virtual override returns (bytes4) {
        return this.onERC721Received.selector;
    }
}
Settings
{
  "compilationTarget": {
    "contracts/SpaceKidStake.sol": "SpaceKidStake"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}
ABI
[{"inputs":[],"name":"InvalidInitialization","type":"error"},{"inputs":[],"name":"NotInitializing","type":"error"},{"inputs":[{"internalType":"address","name":"owner","type":"address"}],"name":"OwnableInvalidOwner","type":"error"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"OwnableUnauthorizedAccount","type":"error"},{"inputs":[],"name":"ReentrancyGuardReentrantCall","type":"error"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"address","name":"owner","type":"address"},{"indexed":false,"internalType":"uint256[]","name":"tokenIds","type":"uint256[]"}],"name":"Claim","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"uint64","name":"version","type":"uint64"}],"name":"Initialized","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"previousOwner","type":"address"},{"indexed":true,"internalType":"address","name":"newOwner","type":"address"}],"name":"OwnershipTransferred","type":"event"},{"anonymous":false,"inputs":[{"components":[{"internalType":"uint256","name":"from","type":"uint256"},{"internalType":"uint256","name":"to","type":"uint256"},{"internalType":"uint256","name":"multiplier","type":"uint256"}],"indexed":false,"internalType":"struct SpaceKidStake.Multiplier[]","name":"multipliers","type":"tuple[]"}],"name":"SetMultiplier","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"uint256","name":"unlockTime","type":"uint256"}],"name":"SetUnlockTime","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"address","name":"owner","type":"address"},{"indexed":false,"internalType":"uint256[]","name":"tokenIds","type":"uint256[]"},{"indexed":false,"internalType":"uint256","name":"lastPoint","type":"uint256"},{"indexed":false,"internalType":"uint256","name":"lastStakedTokenCount","type":"uint256"},{"indexed":false,"internalType":"uint256","name":"timestamp","type":"uint256"}],"name":"Stake","type":"event"},{"inputs":[],"name":"BOOST_MANTISSA","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256[]","name":"tokenIds","type":"uint256[]"}],"name":"claim","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"getMultipliers","outputs":[{"components":[{"internalType":"uint256","name":"from","type":"uint256"},{"internalType":"uint256","name":"to","type":"uint256"},{"internalType":"uint256","name":"multiplier","type":"uint256"}],"internalType":"struct SpaceKidStake.Multiplier[]","name":"","type":"tuple[]"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"user","type":"address"}],"name":"getStakedTokens","outputs":[{"internalType":"uint256[]","name":"","type":"uint256[]"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"user","type":"address"},{"internalType":"uint256","name":"_calculateTo","type":"uint256"}],"name":"getStakingPoint","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"user","type":"address"}],"name":"getStakingStatus","outputs":[{"components":[{"internalType":"uint256","name":"lastPoint","type":"uint256"},{"internalType":"uint256","name":"lastStakedTokenCount","type":"uint256"},{"internalType":"uint256","name":"timestamp","type":"uint256"}],"internalType":"struct SpaceKidStake.StakingStatus","name":"","type":"tuple"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"_spaceKid","type":"address"},{"internalType":"uint256","name":"_unlockTime","type":"uint256"}],"name":"initialize","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"},{"internalType":"uint256","name":"","type":"uint256"},{"internalType":"bytes","name":"","type":"bytes"}],"name":"onERC721Received","outputs":[{"internalType":"bytes4","name":"","type":"bytes4"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"renounceOwnership","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"components":[{"internalType":"uint256","name":"from","type":"uint256"},{"internalType":"uint256","name":"to","type":"uint256"},{"internalType":"uint256","name":"multiplier","type":"uint256"}],"internalType":"struct SpaceKidStake.Multiplier[]","name":"multipliers","type":"tuple[]"}],"name":"setMultiplier","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"_unlockTime","type":"uint256"}],"name":"setUnlockTime","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"spaceKid","outputs":[{"internalType":"contract ISpaceKid","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256[]","name":"tokenIds","type":"uint256[]"}],"name":"stake","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"unlockTime","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"}]