월 14,850원
5개월 할부 시다른 수강생들이 자주 물어보는 질문이 궁금하신가요?
- 미해결GameFi - 블록체인 Web3 게임 만들기
강좌 코드 다운로드
https://drive.google.com/drive/u/0/folders/1yz72VEbnprMVFEnJrwVfWGUKDEBr9qU1
- 미해결GameFi - 블록체인 Web3 게임 만들기
메타데이터 다운로드 링크가 바뀐거 같습니다.
들어가보니깐 이렇게 나오네요
- 해결됨GameFi - 블록체인 Web3 게임 만들기
SnowmenSales.sol 파일의 buyItem 함수에 대해 질문이 있습니다.
token 을 transfer 할 때, address(this) 와 owner() 의 개념이 혼란스럽습니다.buyer 가 amount 를 지불 할 때 owner() 를 쓴 것은 이해가 됩니다만,snowmenToken.safeTransferFrom(buyer, owner(), amount);아래처럼 snowmenGame 에서 token 을 transfer 할 때는 address(this) 를 사용하는 이유는 무엇인가요?snowmenGame.safeTransferFrom(address(this), buyer, tokenId, quantity, "");owner() 와 address(this) 가 각각 주소값이 다른데, snowmenGame.safeTransferFrom 을 할 때, address(this) 대신에 owner() 를 하면 안되는 걸까요?
- 미해결GameFi - 블록체인 Web3 게임 만들기
postman 실행 시 에러가 발생합니다.
4:50의 Unauthorized까지는 잘 따라왔는데 이후 2번째 지갑 주소를 복사, 붙여넣고 진행하니 이런 에러가 발생합니다. 뭐가 원인인지 알 수 있을까요? "error": "network does not support ENS (operation=\"getResolver\", network=\"maticmum\", code=UNSUPPORTED_OPERATION, version=providers/5.7.2)"
- 미해결GameFi - 블록체인 Web3 게임 만들기
네트워크 변경 시 자동으로 로그아웃이 됩니다.
안녕하세요!네트워크 변경 시 자동으로 로그아웃되어 글 남깁니다.뭄바이 네트워크로 변경하라는 메세지만 뜨고 게임은 일시정지 해야하는데 아예 로그아웃이 되어버립니다.아주 가끔씩 일시정지가 되기도 하는데 될때는 왜 되는지 이유가 뭔지 모르겠습니다 ㅠlogout은 account 변경 확인할때와 useEffect로 isConnected 확인할때만 사용하는데, 네트워크를 변경하게 되면 isConnected가 false로 바뀌기도 하나요?
- 해결됨GameFi - 블록체인 Web3 게임 만들기
Verify 간 오류가 발생합니다.
해당 화면은 game 파일 verify error 화면입니다.안녕하세요 선생님!token파일도, game 파일도 remix에서는 모두 잘 동작하는데 mumbai에서 verify가 되지 않습니다!remix와 mumbai 모두 8.16 버전 사용했고 flatten도 했습니다.뭐가 잘못된건지 감도 잡히지 않아 질문드립니다.바쁘시겠지만 답변 주시면 감사하겠습니다!아래는 코드와 배포주소입니다. SnowmanToken_flattened.solhttps://mumbai.polygonscan.com/address/0x01a444084a2578d7974a1e81a613bdaa4cdedaee// SPDX-License-Identifier: MIT // File: @openzeppelin/contracts/utils/Context.sol // OpenZeppelin Contracts v4.4.1 (utils/Context.sol) pragma solidity ^0.8.0; /** * @dev Provides information about the current execution context, including the * sender of the transaction and its data. While these are generally available * via msg.sender and msg.data, they should not be accessed in such a direct * manner, since when dealing with meta-transactions the account sending and * paying for execution may not be the actual sender (as far as an application * is concerned). * * This contract is only required for intermediate, library-like contracts. */ abstract contract Context { function _msgSender() internal view virtual returns (address) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; } } // File: @openzeppelin/contracts/token/ERC20/IERC20.sol // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol) pragma solidity ^0.8.0; /** * @dev Interface of the ERC20 standard as defined in the EIP. */ interface IERC20 { /** * @dev Emitted when `value` tokens are moved from one account (`from`) to * another (`to`). * * Note that `value` may be zero. */ event Transfer(address indexed from, address indexed to, uint256 value); /** * @dev Emitted when the allowance of a `spender` for an `owner` is set by * a call to {approve}. `value` is the new allowance. */ event Approval(address indexed owner, address indexed spender, uint256 value); /** * @dev Returns the amount of tokens in existence. */ function totalSupply() external view returns (uint256); /** * @dev Returns the amount of tokens owned by `account`. */ function balanceOf(address account) external view returns (uint256); /** * @dev Moves `amount` tokens from the caller's account to `to`. * * Returns a boolean value indicating whether the operation succeeded. * * Emits a {Transfer} event. */ function transfer(address to, uint256 amount) external returns (bool); /** * @dev Returns the remaining number of tokens that `spender` will be * allowed to spend on behalf of `owner` through {transferFrom}. This is * zero by default. * * This value changes when {approve} or {transferFrom} are called. */ function allowance(address owner, address spender) external view returns (uint256); /** * @dev Sets `amount` as the allowance of `spender` over the caller's tokens. * * Returns a boolean value indicating whether the operation succeeded. * * IMPORTANT: Beware that changing an allowance with this method brings the risk * that someone may use both the old and the new allowance by unfortunate * transaction ordering. One possible solution to mitigate this race * condition is to first reduce the spender's allowance to 0 and set the * desired value afterwards: * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729 * * Emits an {Approval} event. */ function approve(address spender, uint256 amount) external returns (bool); /** * @dev Moves `amount` tokens from `from` to `to` using the * allowance mechanism. `amount` is then deducted from the caller's * allowance. * * Returns a boolean value indicating whether the operation succeeded. * * Emits a {Transfer} event. */ function transferFrom( address from, address to, uint256 amount ) external returns (bool); } // File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol) pragma solidity ^0.8.0; /** * @dev Interface for the optional metadata functions from the ERC20 standard. * * _Available since v4.1._ */ interface IERC20Metadata is IERC20 { /** * @dev Returns the name of the token. */ function name() external view returns (string memory); /** * @dev Returns the symbol of the token. */ function symbol() external view returns (string memory); /** * @dev Returns the decimals places of the token. */ function decimals() external view returns (uint8); } // File: @openzeppelin/contracts/token/ERC20/ERC20.sol // OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/ERC20.sol) pragma solidity ^0.8.0; /** * @dev Implementation of the {IERC20} interface. * * This implementation is agnostic to the way tokens are created. This means * that a supply mechanism has to be added in a derived contract using {_mint}. * For a generic mechanism see {ERC20PresetMinterPauser}. * * TIP: For a detailed writeup see our guide * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How * to implement supply mechanisms]. * * We have followed general OpenZeppelin Contracts guidelines: functions revert * instead returning `false` on failure. This behavior is nonetheless * conventional and does not conflict with the expectations of ERC20 * applications. * * Additionally, an {Approval} event is emitted on calls to {transferFrom}. * This allows applications to reconstruct the allowance for all accounts just * by listening to said events. Other implementations of the EIP may not emit * these events, as it isn't required by the specification. * * Finally, the non-standard {decreaseAllowance} and {increaseAllowance} * functions have been added to mitigate the well-known issues around setting * allowances. See {IERC20-approve}. */ contract ERC20 is Context, IERC20, IERC20Metadata { mapping(address => uint256) private _balances; mapping(address => mapping(address => uint256)) private _allowances; uint256 private _totalSupply; string private _name; string private _symbol; /** * @dev Sets the values for {name} and {symbol}. * * The default value of {decimals} is 18. To select a different value for * {decimals} you should overload it. * * All two of these values are immutable: they can only be set once during * construction. */ constructor(string memory name_, string memory symbol_) { _name = name_; _symbol = symbol_; } /** * @dev Returns the name of the token. */ function name() public view virtual override returns (string memory) { return _name; } /** * @dev Returns the symbol of the token, usually a shorter version of the * name. */ function symbol() public view virtual override returns (string memory) { return _symbol; } /** * @dev Returns the number of decimals used to get its user representation. * For example, if `decimals` equals `2`, a balance of `505` tokens should * be displayed to a user as `5.05` (`505 / 10 ** 2`). * * Tokens usually opt for a value of 18, imitating the relationship between * Ether and Wei. This is the value {ERC20} uses, unless this function is * overridden; * * NOTE: This information is only used for _display_ purposes: it in * no way affects any of the arithmetic of the contract, including * {IERC20-balanceOf} and {IERC20-transfer}. */ function decimals() public view virtual override returns (uint8) { return 18; } /** * @dev See {IERC20-totalSupply}. */ function totalSupply() public view virtual override returns (uint256) { return _totalSupply; } /** * @dev See {IERC20-balanceOf}. */ function balanceOf(address account) public view virtual override returns (uint256) { return _balances[account]; } /** * @dev See {IERC20-transfer}. * * Requirements: * * - `to` cannot be the zero address. * - the caller must have a balance of at least `amount`. */ function transfer(address to, uint256 amount) public virtual override returns (bool) { address owner = _msgSender(); _transfer(owner, to, amount); return true; } /** * @dev See {IERC20-allowance}. */ function allowance(address owner, address spender) public view virtual override returns (uint256) { return _allowances[owner][spender]; } /** * @dev See {IERC20-approve}. * * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on * `transferFrom`. This is semantically equivalent to an infinite approval. * * Requirements: * * - `spender` cannot be the zero address. */ function approve(address spender, uint256 amount) public virtual override returns (bool) { address owner = _msgSender(); _approve(owner, spender, amount); return true; } /** * @dev See {IERC20-transferFrom}. * * Emits an {Approval} event indicating the updated allowance. This is not * required by the EIP. See the note at the beginning of {ERC20}. * * NOTE: Does not update the allowance if the current allowance * is the maximum `uint256`. * * Requirements: * * - `from` and `to` cannot be the zero address. * - `from` must have a balance of at least `amount`. * - the caller must have allowance for ``from``'s tokens of at least * `amount`. */ function transferFrom( address from, address to, uint256 amount ) public virtual override returns (bool) { address spender = _msgSender(); _spendAllowance(from, spender, amount); _transfer(from, to, amount); return true; } /** * @dev Atomically increases the allowance granted to `spender` by the caller. * * This is an alternative to {approve} that can be used as a mitigation for * problems described in {IERC20-approve}. * * Emits an {Approval} event indicating the updated allowance. * * Requirements: * * - `spender` cannot be the zero address. */ function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) { address owner = _msgSender(); _approve(owner, spender, allowance(owner, spender) + addedValue); return true; } /** * @dev Atomically decreases the allowance granted to `spender` by the caller. * * This is an alternative to {approve} that can be used as a mitigation for * problems described in {IERC20-approve}. * * Emits an {Approval} event indicating the updated allowance. * * Requirements: * * - `spender` cannot be the zero address. * - `spender` must have allowance for the caller of at least * `subtractedValue`. */ function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) { address owner = _msgSender(); uint256 currentAllowance = allowance(owner, spender); require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero"); unchecked { _approve(owner, spender, currentAllowance - subtractedValue); } return true; } /** * @dev Moves `amount` of tokens from `from` to `to`. * * This internal function is equivalent to {transfer}, and can be used to * e.g. implement automatic token fees, slashing mechanisms, etc. * * Emits a {Transfer} event. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `from` must have a balance of at least `amount`. */ function _transfer( address from, address to, uint256 amount ) internal virtual { require(from != address(0), "ERC20: transfer from the zero address"); require(to != address(0), "ERC20: transfer to the zero address"); _beforeTokenTransfer(from, to, amount); uint256 fromBalance = _balances[from]; require(fromBalance >= amount, "ERC20: transfer amount exceeds balance"); unchecked { _balances[from] = fromBalance - amount; // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by // decrementing then incrementing. _balances[to] += amount; } emit Transfer(from, to, amount); _afterTokenTransfer(from, to, amount); } /** @dev Creates `amount` tokens and assigns them to `account`, increasing * the total supply. * * Emits a {Transfer} event with `from` set to the zero address. * * Requirements: * * - `account` cannot be the zero address. */ function _mint(address account, uint256 amount) internal virtual { require(account != address(0), "ERC20: mint to the zero address"); _beforeTokenTransfer(address(0), account, amount); _totalSupply += amount; unchecked { // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above. _balances[account] += amount; } emit Transfer(address(0), account, amount); _afterTokenTransfer(address(0), account, amount); } /** * @dev Destroys `amount` tokens from `account`, reducing the * total supply. * * Emits a {Transfer} event with `to` set to the zero address. * * Requirements: * * - `account` cannot be the zero address. * - `account` must have at least `amount` tokens. */ function _burn(address account, uint256 amount) internal virtual { require(account != address(0), "ERC20: burn from the zero address"); _beforeTokenTransfer(account, address(0), amount); uint256 accountBalance = _balances[account]; require(accountBalance >= amount, "ERC20: burn amount exceeds balance"); unchecked { _balances[account] = accountBalance - amount; // Overflow not possible: amount <= accountBalance <= totalSupply. _totalSupply -= amount; } emit Transfer(account, address(0), amount); _afterTokenTransfer(account, address(0), amount); } /** * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens. * * This internal function is equivalent to `approve`, and can be used to * e.g. set automatic allowances for certain subsystems, etc. * * Emits an {Approval} event. * * Requirements: * * - `owner` cannot be the zero address. * - `spender` cannot be the zero address. */ function _approve( address owner, address spender, uint256 amount ) internal virtual { require(owner != address(0), "ERC20: approve from the zero address"); require(spender != address(0), "ERC20: approve to the zero address"); _allowances[owner][spender] = amount; emit Approval(owner, spender, amount); } /** * @dev Updates `owner` s allowance for `spender` based on spent `amount`. * * Does not update the allowance amount in case of infinite allowance. * Revert if not enough allowance is available. * * Might emit an {Approval} event. */ function _spendAllowance( address owner, address spender, uint256 amount ) internal virtual { uint256 currentAllowance = allowance(owner, spender); if (currentAllowance != type(uint256).max) { require(currentAllowance >= amount, "ERC20: insufficient allowance"); unchecked { _approve(owner, spender, currentAllowance - amount); } } } /** * @dev Hook that is called before any transfer of tokens. This includes * minting and burning. * * Calling conditions: * * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens * will be transferred to `to`. * - when `from` is zero, `amount` tokens will be minted for `to`. * - when `to` is zero, `amount` of ``from``'s tokens will be burned. * - `from` and `to` are never both zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _beforeTokenTransfer( address from, address to, uint256 amount ) internal virtual {} /** * @dev Hook that is called after any transfer of tokens. This includes * minting and burning. * * Calling conditions: * * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens * has been transferred to `to`. * - when `from` is zero, `amount` tokens have been minted for `to`. * - when `to` is zero, `amount` of ``from``'s tokens have been burned. * - `from` and `to` are never both zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _afterTokenTransfer( address from, address to, uint256 amount ) internal virtual {} } // File: lecture/SnowmanToken.sol pragma solidity ^0.8.16; contract SnowmanToken is ERC20 { uint256 private constant MAX_SUPPLY = 1_000_000_000 * 10**18; constructor() ERC20("Snowman", "SNOW") { _mint(msg.sender, MAX_SUPPLY); } }SnowmanGame_flattened.solhttps://mumbai.polygonscan.com/address/0x33d31ab92de6d967d4c0c23826b4d949720342be// SPDX-License-Identifier: MIT // File: @openzeppelin/contracts/utils/Address.sol // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol) pragma solidity ^0.8.1; /** * @dev Collection of functions related to the address type */ library Address { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== * * [IMPORTANT] * ==== * You shouldn't rely on `isContract` to protect against flash loan attacks! * * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract * constructor. * ==== */ function isContract(address account) internal view returns (bool) { // This method relies on extcodesize/address.code.length, which returns 0 // for contracts in construction, since the code is only stored at the end // of the constructor execution. return account.code.length > 0; } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); (bool success, ) = recipient.call{value: amount}(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain `call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value ) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value, string memory errorMessage ) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); (bool success, bytes memory returndata) = target.call{value: value}(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { return functionStaticCall(target, data, "Address: low-level static call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall( address target, bytes memory data, string memory errorMessage ) internal view returns (bytes memory) { (bool success, bytes memory returndata) = target.staticcall(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev 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) { (bool success, bytes memory returndata) = target.delegatecall(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract. * * _Available since v4.8._ */ function verifyCallResultFromTarget( address target, bool success, bytes memory returndata, string memory errorMessage ) internal view returns (bytes memory) { if (success) { if (returndata.length == 0) { // only check isContract if the call was successful and the return data is empty // otherwise we already know that it was a contract require(isContract(target), "Address: call to non-contract"); } return returndata; } else { _revert(returndata, errorMessage); } } /** * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the * revert reason or using the provided one. * * _Available since v4.3._ */ function verifyCallResult( bool success, bytes memory returndata, string memory errorMessage ) internal pure returns (bytes memory) { if (success) { return returndata; } else { _revert(returndata, errorMessage); } } function _revert(bytes memory returndata, string memory errorMessage) private pure { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly /// @solidity memory-safe-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } } // File: @openzeppelin/contracts/utils/introspection/IERC165.sol // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol) pragma solidity ^0.8.0; /** * @dev Interface of the ERC165 standard, as defined in the * https://eips.ethereum.org/EIPS/eip-165[EIP]. * * Implementers can declare support of contract interfaces, which can then be * queried by others ({ERC165Checker}). * * For an implementation, see {ERC165}. */ interface IERC165 { /** * @dev Returns true if this contract implements the interface defined by * `interfaceId`. See the corresponding * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section] * to learn more about how these ids are created. * * This function call must use less than 30 000 gas. */ function supportsInterface(bytes4 interfaceId) external view returns (bool); } // File: @openzeppelin/contracts/utils/introspection/ERC165.sol // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol) pragma solidity ^0.8.0; /** * @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: @openzeppelin/contracts/token/ERC1155/IERC1155Receiver.sol // OpenZeppelin Contracts (last updated v4.5.0) (token/ERC1155/IERC1155Receiver.sol) pragma solidity ^0.8.0; /** * @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: @openzeppelin/contracts/token/ERC1155/IERC1155.sol // OpenZeppelin Contracts (last updated v4.7.0) (token/ERC1155/IERC1155.sol) pragma solidity ^0.8.0; /** * @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 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: @openzeppelin/contracts/token/ERC1155/extensions/IERC1155MetadataURI.sol // OpenZeppelin Contracts v4.4.1 (token/ERC1155/extensions/IERC1155MetadataURI.sol) pragma solidity ^0.8.0; /** * @dev Interface of the optional ERC1155MetadataExtension interface, as defined * in the https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[EIP]. * * _Available since v3.1._ */ interface IERC1155MetadataURI is IERC1155 { /** * @dev Returns the URI for token type `id`. * * If the `\{id\}` substring is present in the URI, it must be replaced by * clients with the actual token type ID. */ function uri(uint256 id) external view returns (string memory); } // File: @openzeppelin/contracts/utils/Counters.sol // OpenZeppelin Contracts v4.4.1 (utils/Counters.sol) pragma solidity ^0.8.0; /** * @title Counters * @author Matt Condon (@shrugs) * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number * of elements in a mapping, issuing ERC721 ids, or counting request ids. * * Include with `using Counters for Counters.Counter;` */ library Counters { struct Counter { // This variable should never be directly accessed by users of the library: interactions must be restricted to // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add // this feature: see https://github.com/ethereum/solidity/issues/4637 uint256 _value; // default: 0 } function current(Counter storage counter) internal view returns (uint256) { return counter._value; } function increment(Counter storage counter) internal { unchecked { counter._value += 1; } } function decrement(Counter storage counter) internal { uint256 value = counter._value; require(value > 0, "Counter: decrement overflow"); unchecked { counter._value = value - 1; } } function reset(Counter storage counter) internal { counter._value = 0; } } // File: @openzeppelin/contracts/utils/math/Math.sol // OpenZeppelin Contracts (last updated v4.8.0) (utils/math/Math.sol) pragma solidity ^0.8.0; /** * @dev Standard math utilities missing in the Solidity language. */ library Math { enum Rounding { Down, // Toward negative infinity Up, // Toward infinity Zero // Toward zero } /** * @dev Returns the largest of two numbers. */ function max(uint256 a, uint256 b) internal pure returns (uint256) { return a > b ? a : b; } /** * @dev Returns the smallest of two numbers. */ function min(uint256 a, uint256 b) internal pure returns (uint256) { return a < b ? a : b; } /** * @dev Returns the average of two numbers. The result is rounded towards * zero. */ function average(uint256 a, uint256 b) internal pure returns (uint256) { // (a + b) / 2 can overflow. return (a & b) + (a ^ b) / 2; } /** * @dev Returns the ceiling of the division of two numbers. * * This differs from standard division with `/` in that it rounds up instead * of rounding down. */ function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) { // (a + b - 1) / b can overflow on addition, so we distribute. return a == 0 ? 0 : (a - 1) / b + 1; } /** * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0 * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv) * with further edits by Uniswap Labs also under MIT license. */ function mulDiv( uint256 x, uint256 y, uint256 denominator ) internal pure returns (uint256 result) { unchecked { // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256 // variables such that product = prod1 * 2^256 + prod0. uint256 prod0; // Least significant 256 bits of the product uint256 prod1; // Most significant 256 bits of the product assembly { let mm := mulmod(x, y, not(0)) prod0 := mul(x, y) prod1 := sub(sub(mm, prod0), lt(mm, prod0)) } // Handle non-overflow cases, 256 by 256 division. if (prod1 == 0) { return prod0 / denominator; } // Make sure the result is less than 2^256. Also prevents denominator == 0. require(denominator > prod1); /////////////////////////////////////////////// // 512 by 256 division. /////////////////////////////////////////////// // Make division exact by subtracting the remainder from [prod1 prod0]. uint256 remainder; assembly { // Compute remainder using mulmod. remainder := mulmod(x, y, denominator) // Subtract 256 bit number from 512 bit number. prod1 := sub(prod1, gt(remainder, prod0)) prod0 := sub(prod0, remainder) } // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1. // See https://cs.stackexchange.com/q/138556/92363. // Does not overflow because the denominator cannot be zero at this stage in the function. uint256 twos = denominator & (~denominator + 1); assembly { // Divide denominator by twos. denominator := div(denominator, twos) // Divide [prod1 prod0] by twos. prod0 := div(prod0, twos) // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one. twos := add(div(sub(0, twos), twos), 1) } // Shift in bits from prod1 into prod0. prod0 |= prod1 * twos; // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for // four bits. That is, denominator * inv = 1 mod 2^4. uint256 inverse = (3 * denominator) ^ 2; // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works // in modular arithmetic, doubling the correct bits in each step. inverse *= 2 - denominator * inverse; // inverse mod 2^8 inverse *= 2 - denominator * inverse; // inverse mod 2^16 inverse *= 2 - denominator * inverse; // inverse mod 2^32 inverse *= 2 - denominator * inverse; // inverse mod 2^64 inverse *= 2 - denominator * inverse; // inverse mod 2^128 inverse *= 2 - denominator * inverse; // inverse mod 2^256 // Because the division is now exact we can divide by multiplying with the modular inverse of denominator. // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1 // is no longer required. result = prod0 * inverse; return result; } } /** * @notice Calculates x * y / denominator with full precision, following the selected rounding direction. */ function mulDiv( uint256 x, uint256 y, uint256 denominator, Rounding rounding ) internal pure returns (uint256) { uint256 result = mulDiv(x, y, denominator); if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) { result += 1; } return result; } /** * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down. * * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11). */ function sqrt(uint256 a) internal pure returns (uint256) { if (a == 0) { return 0; } // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target. // // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`. // // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)` // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))` // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)` // // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit. uint256 result = 1 << (log2(a) >> 1); // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128, // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision // into the expected uint128 result. unchecked { result = (result + a / result) >> 1; result = (result + a / result) >> 1; result = (result + a / result) >> 1; result = (result + a / result) >> 1; result = (result + a / result) >> 1; result = (result + a / result) >> 1; result = (result + a / result) >> 1; return min(result, a / result); } } /** * @notice Calculates sqrt(a), following the selected rounding direction. */ function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) { unchecked { uint256 result = sqrt(a); return result + (rounding == Rounding.Up && result * result < a ? 1 : 0); } } /** * @dev Return the log in base 2, rounded down, of a positive value. * Returns 0 if given 0. */ function log2(uint256 value) internal pure returns (uint256) { uint256 result = 0; unchecked { if (value >> 128 > 0) { value >>= 128; result += 128; } if (value >> 64 > 0) { value >>= 64; result += 64; } if (value >> 32 > 0) { value >>= 32; result += 32; } if (value >> 16 > 0) { value >>= 16; result += 16; } if (value >> 8 > 0) { value >>= 8; result += 8; } if (value >> 4 > 0) { value >>= 4; result += 4; } if (value >> 2 > 0) { value >>= 2; result += 2; } if (value >> 1 > 0) { result += 1; } } return result; } /** * @dev Return the log in base 2, following the selected rounding direction, of a positive value. * Returns 0 if given 0. */ function log2(uint256 value, Rounding rounding) internal pure returns (uint256) { unchecked { uint256 result = log2(value); return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0); } } /** * @dev Return the log in base 10, rounded down, of a positive value. * Returns 0 if given 0. */ function log10(uint256 value) internal pure returns (uint256) { uint256 result = 0; unchecked { if (value >= 10**64) { value /= 10**64; result += 64; } if (value >= 10**32) { value /= 10**32; result += 32; } if (value >= 10**16) { value /= 10**16; result += 16; } if (value >= 10**8) { value /= 10**8; result += 8; } if (value >= 10**4) { value /= 10**4; result += 4; } if (value >= 10**2) { value /= 10**2; result += 2; } if (value >= 10**1) { result += 1; } } return result; } /** * @dev Return the log in base 10, following the selected rounding direction, of a positive value. * Returns 0 if given 0. */ function log10(uint256 value, Rounding rounding) internal pure returns (uint256) { unchecked { uint256 result = log10(value); return result + (rounding == Rounding.Up && 10**result < value ? 1 : 0); } } /** * @dev Return the log in base 256, rounded down, of a positive value. * Returns 0 if given 0. * * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string. */ function log256(uint256 value) internal pure returns (uint256) { uint256 result = 0; unchecked { if (value >> 128 > 0) { value >>= 128; result += 16; } if (value >> 64 > 0) { value >>= 64; result += 8; } if (value >> 32 > 0) { value >>= 32; result += 4; } if (value >> 16 > 0) { value >>= 16; result += 2; } if (value >> 8 > 0) { result += 1; } } return result; } /** * @dev Return the log in base 10, following the selected rounding direction, of a positive value. * Returns 0 if given 0. */ function log256(uint256 value, Rounding rounding) internal pure returns (uint256) { unchecked { uint256 result = log256(value); return result + (rounding == Rounding.Up && 1 << (result * 8) < value ? 1 : 0); } } } // File: @openzeppelin/contracts/utils/Strings.sol // OpenZeppelin Contracts (last updated v4.8.0) (utils/Strings.sol) pragma solidity ^0.8.0; /** * @dev String operations. */ library Strings { bytes16 private constant _SYMBOLS = "0123456789abcdef"; uint8 private constant _ADDRESS_LENGTH = 20; /** * @dev Converts a `uint256` to its ASCII `string` decimal representation. */ function toString(uint256 value) internal pure returns (string memory) { unchecked { uint256 length = Math.log10(value) + 1; string memory buffer = new string(length); uint256 ptr; /// @solidity memory-safe-assembly assembly { ptr := add(buffer, add(32, length)) } while (true) { ptr--; /// @solidity memory-safe-assembly assembly { mstore8(ptr, byte(mod(value, 10), _SYMBOLS)) } value /= 10; if (value == 0) break; } return buffer; } } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation. */ function toHexString(uint256 value) internal pure returns (string memory) { unchecked { return toHexString(value, Math.log256(value) + 1); } } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length. */ function toHexString(uint256 value, uint256 length) internal pure returns (string memory) { bytes memory buffer = new bytes(2 * length + 2); buffer[0] = "0"; buffer[1] = "x"; for (uint256 i = 2 * length + 1; i > 1; --i) { buffer[i] = _SYMBOLS[value & 0xf]; value >>= 4; } require(value == 0, "Strings: hex length insufficient"); return string(buffer); } /** * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation. */ function toHexString(address addr) internal pure returns (string memory) { return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH); } } // File: @openzeppelin/contracts/utils/Context.sol // OpenZeppelin Contracts v4.4.1 (utils/Context.sol) pragma solidity ^0.8.0; /** * @dev Provides information about the current execution context, including the * sender of the transaction and its data. While these are generally available * via msg.sender and msg.data, they should not be accessed in such a direct * manner, since when dealing with meta-transactions the account sending and * paying for execution may not be the actual sender (as far as an application * is concerned). * * This contract is only required for intermediate, library-like contracts. */ abstract contract Context { function _msgSender() internal view virtual returns (address) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; } } // File: @openzeppelin/contracts/token/ERC1155/ERC1155.sol // OpenZeppelin Contracts (last updated v4.8.0) (token/ERC1155/ERC1155.sol) pragma solidity ^0.8.0; /** * @dev Implementation of the basic standard multi-token. * See https://eips.ethereum.org/EIPS/eip-1155 * Originally based on code by Enjin: https://github.com/enjin/erc-1155 * * _Available since v3.1._ */ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI { using Address for address; // Mapping from token ID to account balances mapping(uint256 => mapping(address => uint256)) private _balances; // Mapping from account to operator approvals mapping(address => mapping(address => bool)) private _operatorApprovals; // Used as the URI for all token types by relying on ID substitution, e.g. https://token-cdn-domain/{id}.json string private _uri; /** * @dev See {_setURI}. */ constructor(string memory uri_) { _setURI(uri_); } /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) { return interfaceId == type(IERC1155).interfaceId || interfaceId == type(IERC1155MetadataURI).interfaceId || super.supportsInterface(interfaceId); } /** * @dev See {IERC1155MetadataURI-uri}. * * This implementation returns the same URI for *all* token types. It relies * on the token type ID substitution mechanism * https://eips.ethereum.org/EIPS/eip-1155#metadata[defined in the EIP]. * * Clients calling this function must replace the `\{id\}` substring with the * actual token type ID. */ function uri(uint256) public view virtual override returns (string memory) { return _uri; } /** * @dev See {IERC1155-balanceOf}. * * Requirements: * * - `account` cannot be the zero address. */ function balanceOf(address account, uint256 id) public view virtual override returns (uint256) { require(account != address(0), "ERC1155: address zero is not a valid owner"); return _balances[id][account]; } /** * @dev See {IERC1155-balanceOfBatch}. * * Requirements: * * - `accounts` and `ids` must have the same length. */ function balanceOfBatch(address[] memory accounts, uint256[] memory ids) public view virtual override returns (uint256[] memory) { require(accounts.length == ids.length, "ERC1155: accounts and ids length mismatch"); uint256[] memory batchBalances = new uint256[](accounts.length); for (uint256 i = 0; i < accounts.length; ++i) { batchBalances[i] = balanceOf(accounts[i], ids[i]); } return batchBalances; } /** * @dev See {IERC1155-setApprovalForAll}. */ function setApprovalForAll(address operator, bool approved) public virtual override { _setApprovalForAll(_msgSender(), operator, approved); } /** * @dev See {IERC1155-isApprovedForAll}. */ function isApprovedForAll(address account, address operator) public view virtual override returns (bool) { return _operatorApprovals[account][operator]; } /** * @dev See {IERC1155-safeTransferFrom}. */ function safeTransferFrom( address from, address to, uint256 id, uint256 amount, bytes memory data ) public virtual override { require( from == _msgSender() || isApprovedForAll(from, _msgSender()), "ERC1155: caller is not token owner or approved" ); _safeTransferFrom(from, to, id, amount, data); } /** * @dev See {IERC1155-safeBatchTransferFrom}. */ function safeBatchTransferFrom( address from, address to, uint256[] memory ids, uint256[] memory amounts, bytes memory data ) public virtual override { require( from == _msgSender() || isApprovedForAll(from, _msgSender()), "ERC1155: caller is not token owner or approved" ); _safeBatchTransferFrom(from, to, ids, amounts, data); } /** * @dev Transfers `amount` tokens of token type `id` from `from` to `to`. * * Emits a {TransferSingle} event. * * Requirements: * * - `to` cannot be the zero address. * - `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 memory data ) internal virtual { require(to != address(0), "ERC1155: transfer to the zero address"); address operator = _msgSender(); uint256[] memory ids = _asSingletonArray(id); uint256[] memory amounts = _asSingletonArray(amount); _beforeTokenTransfer(operator, from, to, ids, amounts, data); uint256 fromBalance = _balances[id][from]; require(fromBalance >= amount, "ERC1155: insufficient balance for transfer"); unchecked { _balances[id][from] = fromBalance - amount; } _balances[id][to] += amount; emit TransferSingle(operator, from, to, id, amount); _afterTokenTransfer(operator, from, to, ids, amounts, data); _doSafeTransferAcceptanceCheck(operator, from, to, id, amount, data); } /** * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {_safeTransferFrom}. * * Emits a {TransferBatch} event. * * Requirements: * * - 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[] memory ids, uint256[] memory amounts, bytes memory data ) internal virtual { require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch"); require(to != address(0), "ERC1155: transfer to the zero address"); address operator = _msgSender(); _beforeTokenTransfer(operator, from, to, ids, amounts, data); for (uint256 i = 0; i < ids.length; ++i) { uint256 id = ids[i]; uint256 amount = amounts[i]; uint256 fromBalance = _balances[id][from]; require(fromBalance >= amount, "ERC1155: insufficient balance for transfer"); unchecked { _balances[id][from] = fromBalance - amount; } _balances[id][to] += amount; } emit TransferBatch(operator, from, to, ids, amounts); _afterTokenTransfer(operator, from, to, ids, amounts, data); _doSafeBatchTransferAcceptanceCheck(operator, from, to, ids, amounts, data); } /** * @dev Sets a new URI for all token types, by relying on the token type ID * substitution mechanism * https://eips.ethereum.org/EIPS/eip-1155#metadata[defined in the EIP]. * * By this mechanism, any occurrence of the `\{id\}` substring in either the * URI or any of the amounts in the JSON file at said URI will be replaced by * clients with the token type ID. * * For example, the `https://token-cdn-domain/\{id\}.json` URI would be * interpreted by clients as * `https://token-cdn-domain/000000000000000000000000000000000000000000000000000000000004cce0.json` * for token type ID 0x4cce0. * * See {uri}. * * Because these URIs cannot be meaningfully represented by the {URI} event, * this function emits no events. */ function _setURI(string memory newuri) internal virtual { _uri = newuri; } /** * @dev Creates `amount` tokens of token type `id`, and assigns them to `to`. * * Emits a {TransferSingle} event. * * Requirements: * * - `to` cannot be the zero address. * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the * acceptance magic value. */ function _mint( address to, uint256 id, uint256 amount, bytes memory data ) internal virtual { require(to != address(0), "ERC1155: mint to the zero address"); address operator = _msgSender(); uint256[] memory ids = _asSingletonArray(id); uint256[] memory amounts = _asSingletonArray(amount); _beforeTokenTransfer(operator, address(0), to, ids, amounts, data); _balances[id][to] += amount; emit TransferSingle(operator, address(0), to, id, amount); _afterTokenTransfer(operator, address(0), to, ids, amounts, data); _doSafeTransferAcceptanceCheck(operator, address(0), to, id, amount, data); } /** * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {_mint}. * * 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 _mintBatch( address to, uint256[] memory ids, uint256[] memory amounts, bytes memory data ) internal virtual { require(to != address(0), "ERC1155: mint to the zero address"); require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch"); address operator = _msgSender(); _beforeTokenTransfer(operator, address(0), to, ids, amounts, data); for (uint256 i = 0; i < ids.length; i++) { _balances[ids[i]][to] += amounts[i]; } emit TransferBatch(operator, address(0), to, ids, amounts); _afterTokenTransfer(operator, address(0), to, ids, amounts, data); _doSafeBatchTransferAcceptanceCheck(operator, address(0), to, ids, amounts, data); } /** * @dev Destroys `amount` tokens of token type `id` from `from` * * Emits a {TransferSingle} event. * * Requirements: * * - `from` cannot be the zero address. * - `from` must have at least `amount` tokens of token type `id`. */ function _burn( address from, uint256 id, uint256 amount ) internal virtual { require(from != address(0), "ERC1155: burn from the zero address"); address operator = _msgSender(); uint256[] memory ids = _asSingletonArray(id); uint256[] memory amounts = _asSingletonArray(amount); _beforeTokenTransfer(operator, from, address(0), ids, amounts, ""); uint256 fromBalance = _balances[id][from]; require(fromBalance >= amount, "ERC1155: burn amount exceeds balance"); unchecked { _balances[id][from] = fromBalance - amount; } emit TransferSingle(operator, from, address(0), id, amount); _afterTokenTransfer(operator, from, address(0), ids, amounts, ""); } /** * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {_burn}. * * Emits a {TransferBatch} event. * * Requirements: * * - `ids` and `amounts` must have the same length. */ function _burnBatch( address from, uint256[] memory ids, uint256[] memory amounts ) internal virtual { require(from != address(0), "ERC1155: burn from the zero address"); require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch"); address operator = _msgSender(); _beforeTokenTransfer(operator, from, address(0), ids, amounts, ""); for (uint256 i = 0; i < ids.length; i++) { uint256 id = ids[i]; uint256 amount = amounts[i]; uint256 fromBalance = _balances[id][from]; require(fromBalance >= amount, "ERC1155: burn amount exceeds balance"); unchecked { _balances[id][from] = fromBalance - amount; } } emit TransferBatch(operator, from, address(0), ids, amounts); _afterTokenTransfer(operator, from, address(0), ids, amounts, ""); } /** * @dev Approve `operator` to operate on all of `owner` tokens * * Emits an {ApprovalForAll} event. */ function _setApprovalForAll( address owner, address operator, bool approved ) internal virtual { require(owner != operator, "ERC1155: setting approval status for self"); _operatorApprovals[owner][operator] = approved; emit ApprovalForAll(owner, operator, approved); } /** * @dev Hook that is called before any token transfer. This includes minting * and burning, as well as batched variants. * * The same hook is called on both single and batched variants. For single * transfers, the length of the `ids` and `amounts` arrays will be 1. * * Calling conditions (for each `id` and `amount` pair): * * - When `from` and `to` are both non-zero, `amount` of ``from``'s tokens * of token type `id` will be transferred to `to`. * - When `from` is zero, `amount` tokens of token type `id` will be minted * for `to`. * - when `to` is zero, `amount` of ``from``'s tokens of token type `id` * will be burned. * - `from` and `to` are never both zero. * - `ids` and `amounts` have the same, non-zero length. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _beforeTokenTransfer( address operator, address from, address to, uint256[] memory ids, uint256[] memory amounts, bytes memory data ) internal virtual {} /** * @dev Hook that is called after any token transfer. This includes minting * and burning, as well as batched variants. * * The same hook is called on both single and batched variants. For single * transfers, the length of the `id` and `amount` arrays will be 1. * * Calling conditions (for each `id` and `amount` pair): * * - When `from` and `to` are both non-zero, `amount` of ``from``'s tokens * of token type `id` will be transferred to `to`. * - When `from` is zero, `amount` tokens of token type `id` will be minted * for `to`. * - when `to` is zero, `amount` of ``from``'s tokens of token type `id` * will be burned. * - `from` and `to` are never both zero. * - `ids` and `amounts` have the same, non-zero length. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _afterTokenTransfer( address operator, address from, address to, uint256[] memory ids, uint256[] memory amounts, bytes memory data ) internal virtual {} function _doSafeTransferAcceptanceCheck( address operator, address from, address to, uint256 id, uint256 amount, bytes memory data ) private { if (to.isContract()) { try IERC1155Receiver(to).onERC1155Received(operator, from, id, amount, data) returns (bytes4 response) { if (response != IERC1155Receiver.onERC1155Received.selector) { revert("ERC1155: ERC1155Receiver rejected tokens"); } } catch Error(string memory reason) { revert(reason); } catch { revert("ERC1155: transfer to non-ERC1155Receiver implementer"); } } } function _doSafeBatchTransferAcceptanceCheck( address operator, address from, address to, uint256[] memory ids, uint256[] memory amounts, bytes memory data ) private { if (to.isContract()) { try IERC1155Receiver(to).onERC1155BatchReceived(operator, from, ids, amounts, data) returns ( bytes4 response ) { if (response != IERC1155Receiver.onERC1155BatchReceived.selector) { revert("ERC1155: ERC1155Receiver rejected tokens"); } } catch Error(string memory reason) { revert(reason); } catch { revert("ERC1155: transfer to non-ERC1155Receiver implementer"); } } } function _asSingletonArray(uint256 element) private pure returns (uint256[] memory) { uint256[] memory array = new uint256[](1); array[0] = element; return array; } } // File: @openzeppelin/contracts/token/ERC1155/extensions/ERC1155Supply.sol // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC1155/extensions/ERC1155Supply.sol) pragma solidity ^0.8.0; /** * @dev Extension of ERC1155 that adds tracking of total supply per id. * * Useful for scenarios where Fungible and Non-fungible tokens have to be * clearly identified. Note: While a totalSupply of 1 might mean the * corresponding is an NFT, there is no guarantees that no other token with the * same id are not going to be minted. */ abstract contract ERC1155Supply is ERC1155 { mapping(uint256 => uint256) private _totalSupply; /** * @dev Total amount of tokens in with a given id. */ function totalSupply(uint256 id) public view virtual returns (uint256) { return _totalSupply[id]; } /** * @dev Indicates whether any token exist with a given id, or not. */ function exists(uint256 id) public view virtual returns (bool) { return ERC1155Supply.totalSupply(id) > 0; } /** * @dev See {ERC1155-_beforeTokenTransfer}. */ function _beforeTokenTransfer( address operator, address from, address to, uint256[] memory ids, uint256[] memory amounts, bytes memory data ) internal virtual override { super._beforeTokenTransfer(operator, from, to, ids, amounts, data); if (from == address(0)) { for (uint256 i = 0; i < ids.length; ++i) { _totalSupply[ids[i]] += amounts[i]; } } if (to == address(0)) { for (uint256 i = 0; i < ids.length; ++i) { uint256 id = ids[i]; uint256 amount = amounts[i]; uint256 supply = _totalSupply[id]; require(supply >= amount, "ERC1155: burn amount exceeds totalSupply"); unchecked { _totalSupply[id] = supply - amount; } } } } } // File: @openzeppelin/contracts/access/Ownable.sol // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol) pragma solidity ^0.8.0; /** * @dev Contract module which provides a basic access control mechanism, where * there is an account (an owner) that can be granted exclusive access to * specific functions. * * By default, the owner account will be the one that deploys the contract. This * can later be changed with {transferOwnership}. * * This module is used through inheritance. It will make available the modifier * `onlyOwner`, which can be applied to your functions to restrict their use to * the owner. */ abstract contract Ownable is Context { address private _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ constructor() { _transferOwnership(_msgSender()); } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { _checkOwner(); _; } /** * @dev Returns the address of the current owner. */ function owner() public view virtual returns (address) { return _owner; } /** * @dev Throws if the sender is not the owner. */ function _checkOwner() internal view virtual { require(owner() == _msgSender(), "Ownable: caller is not the owner"); } /** * @dev Leaves the contract without owner. It will not be possible to call * `onlyOwner` functions anymore. Can only be called by the current owner. * * NOTE: Renouncing ownership will leave the contract without an owner, * thereby removing any functionality that is only available to the owner. */ function renounceOwnership() public virtual onlyOwner { _transferOwnership(address(0)); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Can only be called by the current owner. */ function transferOwnership(address newOwner) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); _transferOwnership(newOwner); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Internal function without access restriction. */ function _transferOwnership(address newOwner) internal virtual { address oldOwner = _owner; _owner = newOwner; emit OwnershipTransferred(oldOwner, newOwner); } } // File: lecture/SnowmanGame.sol pragma solidity ^0.8.16; contract SnowmanGame is ERC1155Supply, Ownable { using Strings for uint256; using Counters for Counters.Counter; Counters.Counter public folderId; mapping(uint256 => string) public metadataHash; mapping(address => bool) private _authorized; modifier onlyAuthorized() { require(_authorized[msg.sender] || owner() == msg.sender, "not authorized"); _; } constructor() ERC1155("") { folderId.increment(); } function mint(address receiver, uint256 tokenId, uint256 quantity) external onlyAuthorized { _mint(receiver, tokenId, quantity, ""); } function confirmUpload(string calldata cidHash) external onlyOwner { metadataHash[folderId.current()] = cidHash; folderId.increment(); } function getIds(uint256 numOfMeta) external view returns (uint256[] memory) { uint256[] memory ids = new uint256[](numOfMeta); for(uint256 i = 0 ; i < ids.length; i++) { uint256 tokenId = (folderId.current() << 128) | i; ids[i] = tokenId; } return ids; } function tokenToFolderId(uint256 tokenId) public pure returns(uint256) { return tokenId >> 128; } function uri(uint256 tokenId) public view override returns (string memory) { return ( string( abi.encodePacked( "ipfs://", metadataHash[tokenToFolderId(tokenId)], "/", Strings.toString(tokenId), ".json" ) ) ); } function addAuthorized(address authorized) external onlyOwner { _authorized[authorized] = true; } function removeAuthorized(address authorized) external onlyOwner { _authorized[authorized] = false; } }