// File: Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)

pragma solidity 0.8.14;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// File: Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity 0.8.14;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
// File: ERC1155Holder.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC1155/utils/ERC1155Holder.sol)

pragma solidity 0.8.14;

import "./ERC1155Receiver.sol";

/**
 * Simple implementation of `ERC1155Receiver` that will allow a contract to hold ERC1155 tokens.
 *
 * IMPORTANT: When inheriting this contract, you must include a way to use the received tokens, otherwise they will be
 * stuck.
 *
 * @dev _Available since v3.1._
 */
contract ERC1155Holder is ERC1155Receiver {
    function onERC1155Received(
        address,
        address,
        uint256,
        uint256,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC1155Received.selector;
    }

    function onERC1155BatchReceived(
        address,
        address,
        uint256[] memory,
        uint256[] memory,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC1155BatchReceived.selector;
    }
}
// File: ERC1155Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC1155/utils/ERC1155Receiver.sol)

pragma solidity 0.8.14;

import "./IERC1155Receiver.sol";
import "./ERC165.sol";

/**
 * @dev _Available since v3.1._
 */
abstract contract ERC1155Receiver is ERC165, IERC1155Receiver {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return interfaceId == type(IERC1155Receiver).interfaceId || super.supportsInterface(interfaceId);
    }
}
// File: ERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity 0.8.14;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}
// File: ERC721Holder.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/utils/ERC721Holder.sol)

pragma solidity 0.8.14;

import "./IERC721Receiver.sol";

/**
 * @dev Implementation of the {IERC721Receiver} interface.
 *
 * Accepts all token transfers.
 * Make sure the contract is able to use its token with {IERC721-safeTransferFrom}, {IERC721-approve} or {IERC721-setApprovalForAll}.
 */
contract ERC721Holder is IERC721Receiver {
    /**
     * @dev See {IERC721Receiver-onERC721Received}.
     *
     * Always returns `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address,
        address,
        uint256,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC721Received.selector;
    }
}
// File: IERC1155.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC1155/IERC1155.sol)

pragma solidity 0.8.14;

import "./IERC165.sol";

/**
 * @dev Required interface of an ERC1155 compliant contract, as defined in the
 * https://eips.ethereum.org/EIPS/eip-1155[EIP].
 *
 * _Available since v3.1._
 */
interface IERC1155 is IERC165 {
    /**
     * @dev Emitted when `value` tokens of token type `id` are transferred from `from` to `to` by `operator`.
     */
    event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);

    /**
     * @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
     * transfers.
     */
    event TransferBatch(
        address indexed operator,
        address indexed from,
        address indexed to,
        uint256[] ids,
        uint256[] values
    );

    /**
     * @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
     * `approved`.
     */
    event ApprovalForAll(address indexed account, address indexed operator, bool approved);

    /**
     * @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
     *
     * If an {URI} event was emitted for `id`, the standard
     * https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
     * returned by {IERC1155MetadataURI-uri}.
     */
    event URI(string value, uint256 indexed id);

    /**
     * @dev Returns the amount of tokens of token type `id` owned by `account`.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function balanceOf(address account, uint256 id) external view returns (uint256);

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}.
     *
     * Requirements:
     *
     * - `accounts` and `ids` must have the same length.
     */
    function balanceOfBatch(address[] calldata accounts, uint256[] calldata ids)
        external
        view
        returns (uint256[] memory);

    /**
     * @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
     *
     * Emits an {ApprovalForAll} event.
     *
     * Requirements:
     *
     * - `operator` cannot be the caller.
     */
    function setApprovalForAll(address operator, bool approved) external;

    /**
     * @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
     *
     * See {setApprovalForAll}.
     */
    function isApprovedForAll(address account, address operator) external view returns (bool);

    /**
     * @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
     *
     * Emits a {TransferSingle} event.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - If the caller is not `from`, it must be have been approved to spend ``from``'s tokens via {setApprovalForAll}.
     * - `from` must have a balance of tokens of type `id` of at least `amount`.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
     * acceptance magic value.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 id,
        uint256 amount,
        bytes calldata data
    ) external;

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
     *
     * Emits a {TransferBatch} event.
     *
     * Requirements:
     *
     * - `ids` and `amounts` must have the same length.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
     * acceptance magic value.
     */
    function safeBatchTransferFrom(
        address from,
        address to,
        uint256[] calldata ids,
        uint256[] calldata amounts,
        bytes calldata data
    ) external;
}
// File: IERC1155Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC1155/IERC1155Receiver.sol)

pragma solidity 0.8.14;

import "./IERC165.sol";

/**
 * @dev _Available since v3.1._
 */
interface IERC1155Receiver is IERC165 {
    /**
     * @dev Handles the receipt of a single ERC1155 token type. This function is
     * called at the end of a `safeTransferFrom` after the balance has been updated.
     *
     * NOTE: To accept the transfer, this must return
     * `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
     * (i.e. 0xf23a6e61, or its own function selector).
     *
     * @param operator The address which initiated the transfer (i.e. msg.sender)
     * @param from The address which previously owned the token
     * @param id The ID of the token being transferred
     * @param value The amount of tokens being transferred
     * @param data Additional data with no specified format
     * @return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` if transfer is allowed
     */
    function onERC1155Received(
        address operator,
        address from,
        uint256 id,
        uint256 value,
        bytes calldata data
    ) external returns (bytes4);

    /**
     * @dev Handles the receipt of a multiple ERC1155 token types. This function
     * is called at the end of a `safeBatchTransferFrom` after the balances have
     * been updated.
     *
     * NOTE: To accept the transfer(s), this must return
     * `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
     * (i.e. 0xbc197c81, or its own function selector).
     *
     * @param operator The address which initiated the batch transfer (i.e. msg.sender)
     * @param from The address which previously owned the token
     * @param ids An array containing ids of each token being transferred (order and length must match values array)
     * @param values An array containing amounts of each token being transferred (order and length must match ids array)
     * @param data Additional data with no specified format
     * @return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if transfer is allowed
     */
    function onERC1155BatchReceived(
        address operator,
        address from,
        uint256[] calldata ids,
        uint256[] calldata values,
        bytes calldata data
    ) external returns (bytes4);
}
// File: IERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity 0.8.14;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// File: IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)

pragma solidity 0.8.14;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}
// File: IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)

pragma solidity 0.8.14;

import "./IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;
}
// File: IERC721Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)

pragma solidity 0.8.14;

/**
 * @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);
}
// File: Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity 0.8.14;

import "./Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
// File: ReentrancyGuard.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)

pragma solidity 0.8.14;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}
// File: SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)

pragma solidity 0.8.14;

import "./IERC20.sol";
import "./Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
// File: Staker.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.14;

/******************************************************************************\
* Staking contract for https://twitter.com/OccultTower
/******************************************************************************/

import "./IERC721.sol";
import "./IERC20.sol";
import "./SafeERC20.sol";
import "./ERC721Holder.sol";
import "./ReentrancyGuard.sol";
import "./Ownable.sol";

contract Staker is ERC721Holder, ReentrancyGuard, Ownable {
    using SafeERC20 for IERC20;

    /* ========== STATE VARIABLES ========== */

    event PaymentReceived(address from, uint256 amount);

    bool public paused = true;
    uint16 public totalStake;
    uint16 public totalBurnt;
    uint16 public stakeCount;
    uint16 public burntCount;
    uint64 stakingDuration = 365 * 3 days;
    uint256 startPeriod;
    uint256 endPeriod;
    uint256 constant internal _precision = 1E18;
    mapping(address => uint256) userStartTime;
    mapping(address => uint256) rewards;
    mapping(address => uint16) burntBalance;
    mapping(address => uint16) stakedBalance;
    mapping(uint16 => address) stakedAssets;
    mapping(uint16 => address) burnt;
    mapping(address => uint16[]) userBurnt;
    mapping(address => uint16[]) userStaked;

    IERC721 public stakingToken721 = IERC721(0x594D888dEB4c0c66f495f48F55c61fAaDF0f63D8);
    IERC20 public stakingToken20 = IERC20(0xC807f4B1bf8e79a9279ACFCea5fA7A78E2C7d179);

    constructor() payable {
    }

    receive() external payable virtual {
        emit PaymentReceived(_msgSender(), msg.value);
    }
    
    // pause staking
    function pause(bool _paused) external onlyOwner {
        if (_paused == false) {
            require(stakingToken20.balanceOf(address(this)) > 0,"Staking: missing reward token");

            if (startPeriod == 0) {
                startPeriod = block.timestamp;
                endPeriod = block.timestamp + stakingDuration;
            }
        }
        paused = _paused;
    }

    //block number when user started staking
    function userStart(address user) public view returns (uint256) {
        return (userStartTime[user]);
    }

    //number of NFT staked by a user
    function userStakeBalance(address user) public view returns (uint256) {
        return (stakedBalance[user]);
    }

    //number of NFT burnt by a user
    function userBurntBalance(address user) public view returns (uint256) {
        return (burntBalance[user]);
    }

    //pending rewards that can be claimed by a user
    function userPending(address user) public view returns (uint256) {
        return (_calculateRewards(user));
    }

    //show balance of token in contract
    function coinBalance() public view returns (uint256) {
        return stakingToken20.balanceOf(address(this));
    }

    //shows a list of burnt NFT of a user 
    function burntList(address user) public view returns (uint16[] memory ids) {
        return (userBurnt[user]);
    }

    //shows a list of NFT staked by a user
    function stakeList(address user) public view returns (uint16[] memory) {
        return (userStaked[user]);
    }

    //show a list of NFT owned by 1 address
    function nftList(address user) public view returns (uint256 count, uint16[200] memory ownedList) {
        uint16 i;
        uint16 j;
        address nftOwner;
        uint256 ownerBalance;
        uint16[200] memory list;

        unchecked {
            ownerBalance = stakingToken721.balanceOf(user);

            for (i = 0; i <= 7777; i += 1) {
                nftOwner = stakingToken721.ownerOf(i);
                if (nftOwner == user) {
                    list[j] = i;
                    j += 1;
                    if (j == ownerBalance || j == 200) {
                        break;
                    }
                }
            }
        }

        return (ownerBalance, list);
    }

    //allows user to burn a list of NFTs
    function burnNFT(uint16[] memory tokenIds) external nonReentrant {
        uint16 amount;
        bool newBurner;

        require(Address.isContract(msg.sender) == false, "Staking: no contracts");
        require(paused == false, "Staking: is paused");
        require(tokenIds.length != 0, "Staking: No tokenIds provided");

        require(stakingToken721.isApprovedForAll(msg.sender, address(this)) == true,
            "Staking: First must setApprovalForAll in the NFT to this contract");

        unchecked {
            if (userBurnt[msg.sender].length == 0) {
                newBurner = true;
            }

            for (uint16 i = 0; i < tokenIds.length; i += 1) {
                require(stakingToken721.ownerOf(tokenIds[i]) == msg.sender, "Staking: not owner of NFT");

                // Increment the amount which will be staked
                amount += 1;
                // Save who is the staker/depositor of the token
                burnt[tokenIds[i]] = msg.sender;
                userBurnt[msg.sender].push(tokenIds[i]);

                // Transfer user's NFTs to the dead address
                stakingToken721.transferFrom(msg.sender, 0x000000000000000000000000000000000000dEaD, tokenIds[i]);
            }
            burntBalance[msg.sender] += amount;
            totalBurnt += amount;

            if (amount > 0 && newBurner == true) {
                burntCount += 1;
            }
        }
    }

    //allows admin to record a list of burnt NFT where the NFT was burnt without using this contract
	function addBurnt(address[] memory users, uint16[] memory ids) external onlyOwner {
        uint16 i;
        uint16 j;
        address old;
        bool newBurner;
        uint16 amount;

        require(users.length == ids.length, "Staking: The number of addresses is not matching the number of ids");

        unchecked {

            for (i = 0; i < users.length; i++) {

                amount = 0;
                if (userBurnt[users[i]].length == 0) {
                    newBurner = true;
                }

                require(stakingToken721.ownerOf(ids[i]) == 0x000000000000000000000000000000000000dEaD
                    || stakingToken721.ownerOf(ids[i]) == address(stakingToken721)
                    ,"Staking: NFT must be burnt");

                if (burnt[ids[i]] == users[i]) {
                    //skip as already recorded
                } else if (burnt[ids[i]] == address(0)) {
                    //record burnt nft
                    burnt[ids[i]] = users[i];
                    userBurnt[users[i]].push(ids[i]);
                    burntBalance[users[i]] += 1;
                    totalBurnt += 1;

                    if (newBurner == true) {
                        burntCount += 1;
                        newBurner = false;
                    }

                } else if (burnt[ids[i]] != users[i]) {
                    //change address that burnt nft
                    old = burnt[ids[i]];

                    for (j = 0; j < userBurnt[old].length; j++) {
                        if (userBurnt[old][j] == ids[i]) {
                            userBurnt[old][j] = userBurnt[old][userBurnt[old].length-1];
                            userBurnt[old].pop();
                            burntBalance[old] -= 1;
                            break;
                        }
                    }

                    burnt[ids[i]] = users[i];
                    userBurnt[users[i]].push(ids[i]);

                    if (newBurner == true) {
                        burntCount += 1;
                        newBurner = false;
                    }

                    if (userBurnt[old].length == 0) {
                        burntCount -= 1;
                    }
                }
            }
        }
    }

    /// @notice Stakes user's NFTs
    /// @param tokenIds The tokenIds of the NFTs which will be staked
    function stake(uint16[] memory tokenIds) external nonReentrant {
        uint16 amount;
        bool newStaker;

        require(Address.isContract(msg.sender) == false, "Staking: no contracts");
        require(paused == false, "Staking: is paused");
        require(tokenIds.length != 0, "Staking: No tokenIds provided");

        require(stakingToken721.isApprovedForAll(msg.sender, address(this)) == true,
            "Staking: First must setApprovalForAll in the NFT to this contract");

        unchecked {

            if (userStaked[msg.sender].length == 0) {
                newStaker = true;
            }

            for (uint16 i = 0; i < tokenIds.length; i += 1) {
                require(tokenIds[i] > 0, "Staking: does not support id 0");
                require(stakingToken721.ownerOf(tokenIds[i]) == msg.sender, "Staking: not owner of NFT");

                // Increment the amount which will be staked
                amount += 1;
                // Save who is the staker/depositor of the token
                stakedAssets[tokenIds[i]] = msg.sender;
                userStaked[msg.sender].push(tokenIds[i]);

                // Transfer user's NFTs to the staking contract
                stakingToken721.transferFrom(msg.sender, address(this), tokenIds[i]);
            }

            if (amount > 0 && newStaker == true) {
                stakeCount += 1;
            }

            stakedBalance[msg.sender] += amount;
            totalStake += amount;

            if (userStartTime[msg.sender] == 0) {
                userStartTime[msg.sender] = block.timestamp;
            }
        }
    }

    /// @notice Withdraws a list of staked user's NFTs. If no list is provided it will unstake all.
    function withdraw(uint16[] memory tokenIds) external nonReentrant {
        uint16 i;
        uint16 j;
        uint16 clean;
        bool hasStake;
        bool cleaned;

        require(Address.isContract(msg.sender) == false, "Staking: no contracts");

        //claim reward
        _getReward();

        unchecked {

            if (userStaked[msg.sender].length > 0) {
                hasStake = true;
            }

            if (tokenIds.length == 0) {
                //unstake all
                for (i = 0; i < userStaked[msg.sender].length; i += 1) {
                    j = userStaked[msg.sender][i];
                    if (j > 0) {
                        if (stakedAssets[j] == msg.sender) {
                            stakedAssets[j] = address(0);
                            totalStake -= 1;
                            userStaked[msg.sender][i] = 0;

                            if (stakingToken721.ownerOf(j) == address(this)) {
                                // Transfer user's NFTs back to user
                                stakingToken721.safeTransferFrom(address(this), msg.sender, j);
                            }
                        }
                    }
                }
                stakedBalance[msg.sender] = 0;

            } else {
                //unstake chosen id
                for (i = 0; i < tokenIds.length; i += 1) {
                    for (j = 0; j < userStaked[msg.sender].length; j += 1) {
                        if (userStaked[msg.sender][j] == tokenIds[i]) {
                            if (stakedAssets[tokenIds[i]] == msg.sender) {
                                stakedAssets[tokenIds[i]] = address(0);
                                totalStake -= 1;
                                stakedBalance[msg.sender] -= 1;
                                userStaked[msg.sender][j] = 0;

                                if (stakingToken721.ownerOf(tokenIds[i]) == address(this)) {
                                    // Transfer user's NFTs back to user
                                    stakingToken721.safeTransferFrom(address(this), msg.sender, tokenIds[i]);
                                }
                            }
                        }
                    }
                }
            }

            //remove 0 ids
            cleaned = false;
            while (cleaned == false) {
                for (i = 0; i < userStaked[msg.sender].length; i += 1) {
                    clean = 0;
                    if (userStaked[msg.sender].length > 1) {
                        if (userStaked[msg.sender][i] == 0) {
                            userStaked[msg.sender][i] = userStaked[msg.sender][userStaked[msg.sender].length-1];
                            userStaked[msg.sender].pop();
                            clean += 1;
                            break;
                        }
                    } else {
                        userStaked[msg.sender].pop();
                    }
                }
                if (clean == 0) {
                    cleaned = true;
                }
            }

            if (hasStake == true && userStaked[msg.sender].length == 0) {
                stakeCount -= 1;
            }
        }
    }

    //user can claim reward
    function getReward() external nonReentrant {
        require(Address.isContract(msg.sender) == false, "Staking: No contracts");
        _getReward();
    }

    //code to claim reward
    function _getReward() internal {
        uint256 reward;

        // update the current reward balance
        _updateRewards();

        unchecked {

            reward = rewards[msg.sender];

            //if token is running out then pay out the balance remaining
            if (reward > stakingToken20.balanceOf(address(this))) {
                reward = stakingToken20.balanceOf(address(this));
            }

            if (reward > 0) {
                SafeERC20.safeTransfer(stakingToken20, msg.sender, reward);
            }

            rewards[msg.sender] -= reward;
        }
    }

    /**
     * @notice function that update pending rewards
     * and shift them to rewardsToClaim
     * @dev update rewards claimable
     * and check the time spent since deposit for the `msg.sender`
     */
    function _updateRewards() internal {

        unchecked {

            rewards[msg.sender] = _calculateRewards(msg.sender);
            
            if (block.timestamp >= endPeriod) {
                userStartTime[msg.sender] = endPeriod;
            } else {
                userStartTime[msg.sender] = block.timestamp;
            }
        }
    }

    /**
     * @notice calculate rewards based on the number of staked and burnt NFTs
     * @dev the higher is the precision and the more the time remaining will be precise
     * @param stakeHolder, address of the user to be checked
     * @return uint256 amount of claimable tokens of the specified address
     */
     
    function _calculateRewards(address stakeHolder) internal view returns (uint256) {
        uint256 cal;
        uint256 totalStakeBonus;
        uint256 totalBurntCount;
        uint256 bonusPoolTokens;
        uint256 bonusPoolDailyDist;
        uint256 burntTokenCount;
        uint256 dailyTokenDist;
        uint256 stakingBonusCount;
        uint256 burntTokenMult;
        uint256 dailyBonusPoolDist;
        uint256 yearlyTokenDist;

        unchecked {

            if (stakedBalance[stakeHolder] == 0 || burntBalance[stakeHolder] == 0 || startPeriod == 0) {
                cal = 0;
            } else {

                totalStakeBonus = _precision * (totalStake - stakeCount);
                totalBurntCount = _precision * (totalBurnt - burntCount);
                bonusPoolTokens = totalStakeBonus + totalBurntCount * 5 / 4;
                if (bonusPoolTokens == 0) {
                    bonusPoolTokens = 1;
                }
                bonusPoolDailyDist = _precision * _precision * 2223 / bonusPoolTokens;
                burntTokenCount = burntBalance[stakeHolder] - 1;
                dailyTokenDist = _precision * (stakedBalance[stakeHolder] + burntTokenCount);
                stakingBonusCount = stakedBalance[stakeHolder] - 1;
                burntTokenMult = burntTokenCount * 5 / 4;
                dailyBonusPoolDist = (stakingBonusCount + burntTokenMult) * bonusPoolDailyDist;
                yearlyTokenDist = (dailyTokenDist + dailyBonusPoolDist) * 365;

                cal = yearlyTokenDist * _percentageTimeRemaining(stakeHolder) * (stakingDuration / 365 days) / _precision;
            }
        }

        return (cal + rewards[stakeHolder]);
    }

    /**
     * @notice function that returns the remaining time in seconds of the staking period
     * @dev the higher is the precision and the more the time remaining will be precise
     * @param stakeHolder, address of the user to be checked
     * @return uint256 percentage of time remaining * precision
     */
    function _percentageTimeRemaining(address stakeHolder) internal view returns (uint256) {
        uint256 startTime;
        uint256 timeRemaining;

        unchecked {

            if (endPeriod > block.timestamp) {
                if (startPeriod > userStartTime[stakeHolder]) {
                    startTime = startPeriod;
                } else {
                    startTime = userStartTime[stakeHolder];
                }

                timeRemaining = stakingDuration - (block.timestamp - startTime);
                return (_precision * (stakingDuration - timeRemaining)) / stakingDuration;
            } else {

                if (startPeriod > userStartTime[stakeHolder]) {
                    startTime = 0;
                } else {
                    startTime = stakingDuration - (endPeriod - userStartTime[stakeHolder]);
                }
                return ((_precision * (stakingDuration - startTime)) / stakingDuration);
            }
        }
    }
}