OpenZeppelinのERC1155の取扱説明書

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC1155/ERC1155.sol)

pragma solidity ^0.8.20;

import {IERC1155} from "./IERC1155.sol";
import {IERC1155Receiver} from "./IERC1155Receiver.sol";
import {IERC1155MetadataURI} from "./extensions/IERC1155MetadataURI.sol";
import {Context} from "../../utils/Context.sol";
import {IERC165, ERC165} from "../../utils/introspection/ERC165.sol";
import {Arrays} from "../../utils/Arrays.sol";
import {IERC1155Errors} from "../../interfaces/draft-IERC6093.sol";

/**
 * @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
 */
abstract contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI, IERC1155Errors {
    using Arrays for uint256[];
    using Arrays for address[];

    mapping(uint256 id => mapping(address account => uint256)) private _balances;

    mapping(address account => mapping(address operator => 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 /* id */) public view virtual returns (string memory) {
        return _uri;
    }

    /**
     * @dev See {IERC1155-balanceOf}.
     */
    function balanceOf(address account, uint256 id) public view virtual returns (uint256) {
        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 returns (uint256[] memory) {
        if (accounts.length != ids.length) {
            revert ERC1155InvalidArrayLength(ids.length, accounts.length);
        }

        uint256[] memory batchBalances = new uint256[](accounts.length);

        for (uint256 i = 0; i < accounts.length; ++i) {
            batchBalances[i] = balanceOf(accounts.unsafeMemoryAccess(i), ids.unsafeMemoryAccess(i));
        }

        return batchBalances;
    }

    /**
     * @dev See {IERC1155-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual {
        _setApprovalForAll(_msgSender(), operator, approved);
    }

    /**
     * @dev See {IERC1155-isApprovedForAll}.
     */
    function isApprovedForAll(address account, address operator) public view virtual returns (bool) {
        return _operatorApprovals[account][operator];
    }

    /**
     * @dev See {IERC1155-safeTransferFrom}.
     */
    function safeTransferFrom(address from, address to, uint256 id, uint256 value, bytes memory data) public virtual {
        address sender = _msgSender();
        if (from != sender && !isApprovedForAll(from, sender)) {
            revert ERC1155MissingApprovalForAll(sender, from);
        }
        _safeTransferFrom(from, to, id, value, data);
    }

    /**
     * @dev See {IERC1155-safeBatchTransferFrom}.
     */
    function safeBatchTransferFrom(
        address from,
        address to,
        uint256[] memory ids,
        uint256[] memory values,
        bytes memory data
    ) public virtual {
        address sender = _msgSender();
        if (from != sender && !isApprovedForAll(from, sender)) {
            revert ERC1155MissingApprovalForAll(sender, from);
        }
        _safeBatchTransferFrom(from, to, ids, values, data);
    }

    /**
     * @dev Transfers a `value` amount of tokens of type `id` from `from` to `to`. Will mint (or burn) if `from`
     * (or `to`) is the zero address.
     *
     * Emits a {TransferSingle} event if the arrays contain one element, and {TransferBatch} otherwise.
     *
     * Requirements:
     *
     * - If `to` refers to a smart contract, it must implement either {IERC1155Receiver-onERC1155Received}
     *   or {IERC1155Receiver-onERC1155BatchReceived} and return the acceptance magic value.
     * - `ids` and `values` must have the same length.
     *
     * NOTE: The ERC-1155 acceptance check is not performed in this function. See {_updateWithAcceptanceCheck} instead.
     */
    function _update(address from, address to, uint256[] memory ids, uint256[] memory values) internal virtual {
        if (ids.length != values.length) {
            revert ERC1155InvalidArrayLength(ids.length, values.length);
        }

        address operator = _msgSender();

        for (uint256 i = 0; i < ids.length; ++i) {
            uint256 id = ids.unsafeMemoryAccess(i);
            uint256 value = values.unsafeMemoryAccess(i);

            if (from != address(0)) {
                uint256 fromBalance = _balances[id][from];
                if (fromBalance < value) {
                    revert ERC1155InsufficientBalance(from, fromBalance, value, id);
                }
                unchecked {
                    // Overflow not possible: value <= fromBalance
                    _balances[id][from] = fromBalance - value;
                }
            }

            if (to != address(0)) {
                _balances[id][to] += value;
            }
        }

        if (ids.length == 1) {
            uint256 id = ids.unsafeMemoryAccess(0);
            uint256 value = values.unsafeMemoryAccess(0);
            emit TransferSingle(operator, from, to, id, value);
        } else {
            emit TransferBatch(operator, from, to, ids, values);
        }
    }

    /**
     * @dev Version of {_update} that performs the token acceptance check by calling
     * {IERC1155Receiver-onERC1155Received} or {IERC1155Receiver-onERC1155BatchReceived} on the receiver address if it
     * contains code (eg. is a smart contract at the moment of execution).
     *
     * IMPORTANT: Overriding this function is discouraged because it poses a reentrancy risk from the receiver. So any
     * update to the contract state after this function would break the check-effect-interaction pattern. Consider
     * overriding {_update} instead.
     */
    function _updateWithAcceptanceCheck(
        address from,
        address to,
        uint256[] memory ids,
        uint256[] memory values,
        bytes memory data
    ) internal virtual {
        _update(from, to, ids, values);
        if (to != address(0)) {
            address operator = _msgSender();
            if (ids.length == 1) {
                uint256 id = ids.unsafeMemoryAccess(0);
                uint256 value = values.unsafeMemoryAccess(0);
                _doSafeTransferAcceptanceCheck(operator, from, to, id, value, data);
            } else {
                _doSafeBatchTransferAcceptanceCheck(operator, from, to, ids, values, data);
            }
        }
    }

    /**
     * @dev Transfers a `value` 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 `value` 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 value, bytes memory data) internal {
        if (to == address(0)) {
            revert ERC1155InvalidReceiver(address(0));
        }
        if (from == address(0)) {
            revert ERC1155InvalidSender(address(0));
        }
        (uint256[] memory ids, uint256[] memory values) = _asSingletonArrays(id, value);
        _updateWithAcceptanceCheck(from, to, ids, values, 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.
     * - `ids` and `values` must have the same length.
     */
    function _safeBatchTransferFrom(
        address from,
        address to,
        uint256[] memory ids,
        uint256[] memory values,
        bytes memory data
    ) internal {
        if (to == address(0)) {
            revert ERC1155InvalidReceiver(address(0));
        }
        if (from == address(0)) {
            revert ERC1155InvalidSender(address(0));
        }
        _updateWithAcceptanceCheck(from, to, ids, values, 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 values 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 a `value` amount of tokens of 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 value, bytes memory data) internal {
        if (to == address(0)) {
            revert ERC1155InvalidReceiver(address(0));
        }
        (uint256[] memory ids, uint256[] memory values) = _asSingletonArrays(id, value);
        _updateWithAcceptanceCheck(address(0), to, ids, values, data);
    }

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {_mint}.
     *
     * Emits a {TransferBatch} event.
     *
     * Requirements:
     *
     * - `ids` and `values` must have the same length.
     * - `to` cannot be the zero address.
     * - 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 values, bytes memory data) internal {
        if (to == address(0)) {
            revert ERC1155InvalidReceiver(address(0));
        }
        _updateWithAcceptanceCheck(address(0), to, ids, values, data);
    }

    /**
     * @dev Destroys a `value` amount of tokens of type `id` from `from`
     *
     * Emits a {TransferSingle} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `from` must have at least `value` amount of tokens of type `id`.
     */
    function _burn(address from, uint256 id, uint256 value) internal {
        if (from == address(0)) {
            revert ERC1155InvalidSender(address(0));
        }
        (uint256[] memory ids, uint256[] memory values) = _asSingletonArrays(id, value);
        _updateWithAcceptanceCheck(from, address(0), ids, values, "");
    }

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {_burn}.
     *
     * Emits a {TransferBatch} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `from` must have at least `value` amount of tokens of type `id`.
     * - `ids` and `values` must have the same length.
     */
    function _burnBatch(address from, uint256[] memory ids, uint256[] memory values) internal {
        if (from == address(0)) {
            revert ERC1155InvalidSender(address(0));
        }
        _updateWithAcceptanceCheck(from, address(0), ids, values, "");
    }

    /**
     * @dev Approve `operator` to operate on all of `owner` tokens
     *
     * Emits an {ApprovalForAll} event.
     *
     * Requirements:
     *
     * - `operator` cannot be the zero address.
     */
    function _setApprovalForAll(address owner, address operator, bool approved) internal virtual {
        if (operator == address(0)) {
            revert ERC1155InvalidOperator(address(0));
        }
        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

    /**
     * @dev Performs an acceptance check by calling {IERC1155-onERC1155Received} on the `to` address
     * if it contains code at the moment of execution.
     */
    function _doSafeTransferAcceptanceCheck(
        address operator,
        address from,
        address to,
        uint256 id,
        uint256 value,
        bytes memory data
    ) private {
        if (to.code.length > 0) {
            try IERC1155Receiver(to).onERC1155Received(operator, from, id, value, data) returns (bytes4 response) {
                if (response != IERC1155Receiver.onERC1155Received.selector) {
                    // Tokens rejected
                    revert ERC1155InvalidReceiver(to);
                }
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    // non-ERC1155Receiver implementer
                    revert ERC1155InvalidReceiver(to);
                } else {
                    /// @solidity memory-safe-assembly
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        }
    }

    /**
     * @dev Performs a batch acceptance check by calling {IERC1155-onERC1155BatchReceived} on the `to` address
     * if it contains code at the moment of execution.
     */
    function _doSafeBatchTransferAcceptanceCheck(
        address operator,
        address from,
        address to,
        uint256[] memory ids,
        uint256[] memory values,
        bytes memory data
    ) private {
        if (to.code.length > 0) {
            try IERC1155Receiver(to).onERC1155BatchReceived(operator, from, ids, values, data) returns (
                bytes4 response
            ) {
                if (response != IERC1155Receiver.onERC1155BatchReceived.selector) {
                    // Tokens rejected
                    revert ERC1155InvalidReceiver(to);
                }
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    // non-ERC1155Receiver implementer
                    revert ERC1155InvalidReceiver(to);
                } else {
                    /// @solidity memory-safe-assembly
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        }
    }

    /**
     * @dev Creates an array in memory with only one value for each of the elements provided.
     */
    function _asSingletonArrays(
        uint256 element1,
        uint256 element2
    ) private pure returns (uint256[] memory array1, uint256[] memory array2) {
        /// @solidity memory-safe-assembly
        assembly {
            // Load the free memory pointer
            array1 := mload(0x40)
            // Set array length to 1
            mstore(array1, 1)
            // Store the single element at the next word after the length (where content starts)
            mstore(add(array1, 0x20), element1)

            // Repeat for next array locating it right after the first array
            array2 := add(array1, 0x40)
            mstore(array2, 1)
            mstore(add(array2, 0x20), element2)

            // Update the free memory pointer by pointing after the second array
            mstore(0x40, add(array2, 0x40))
        }
    }
}

function _update(address from, address to, uint256[] memory ids, uint256[] memory values) internal virtual {
    // idsとvaluesの長さが違う場合はリバート
    if (ids.length != values.length) {
        revert ERC1155InvalidArrayLength(ids.length, values.length);
    }

    // 実行者のアドレスを取得
    address operator = _msgSender();

    // idの数だけループ
    for (uint256 i = 0; i < ids.length; ++i) {
        // idを取得
        uint256 id = ids.unsafeMemoryAccess(i);
        // valueを取得
        uint256 value = values.unsafeMemoryAccess(i);

        // formがゼロアドレスでない場合
        if (from != address(0)) {
            // fromのidの残高を取得
            uint256 fromBalance = _balances[id][from];
            // fromの残高がvalueより小さい場合はリバート
            if (fromBalance < value) {
                revert ERC1155InsufficientBalance(from, fromBalance, value, id);
            }
            unchecked {
                // Overflow not possible: value <= fromBalance
                // fromのidの残高からvalueを引く
                _balances[id][from] = fromBalance - value;
            }
        }

        // toがゼロアドレスでない場合
        if (to != address(0)) {
            // toのidの残高を取得
            _balances[id][to] += value;
        }
    }
    // idsの数が1の場合
    if (ids.length == 1) {
        // 各値を取得してシングルイベントを発火
        uint256 id = ids.unsafeMemoryAccess(0);
        uint256 value = values.unsafeMemoryAccess(0);
        emit TransferSingle(operator, from, to, id, value);
    } else {
        // バッチイベントを発火
        emit TransferBatch(operator, from, to, ids, values);
    }
}

function _updateWithAcceptanceCheck(
    address from,
    address to,
    uint256[] memory ids,
    uint256[] memory values,
    bytes memory data
) internal virtual {
    // _updateを実行
    _update(from, to, ids, values);
    // toがゼロアドレスでない場合はmintかtransfer
    if (to != address(0)) {
        // 実行者のアドレスを取得
        address operator = _msgSender();
        // idsの数が1の場合
        if (ids.length == 1) {
            // idとvalueを取得
            uint256 id = ids.unsafeMemoryAccess(0);
            uint256 value = values.unsafeMemoryAccess(0);
            // ちゃんと受け取れたか確認(単体)
            _doSafeTransferAcceptanceCheck(operator, from, to, id, value, data);
        } else {
            // ちゃんと受け取れたか確認(複数)
            _doSafeBatchTransferAcceptanceCheck(operator, from, to, ids, values, data);
        }
    }
}

function _safeTransferFrom(address from, address to, uint256 id, uint256 value, bytes memory data) internal {
    // toがゼロアドレスの場合はリバート
    if (to == address(0)) {
        revert ERC1155InvalidReceiver(address(0));
    }
    // fromがゼロアドレスの場合はリバート
    if (from == address(0)) {
        revert ERC1155InvalidSender(address(0));
    }
    // 1つのidとvalueを配列にする
    (uint256[] memory ids, uint256[] memory values) = _asSingletonArrays(id, value);
    // _updateWithAcceptanceCheckを実行
    _updateWithAcceptanceCheck(from, to, ids, values, data);
}

function _safeBatchTransferFrom(
    address from,
    address to,
    uint256[] memory ids,
    uint256[] memory values,
    bytes memory data
) internal {
    // toがゼロアドレスの場合はリバート
    if (to == address(0)) {
        revert ERC1155InvalidReceiver(address(0));
    }
    // fromがゼロアドレスの場合はリバート
    if (from == address(0)) {
        revert ERC1155InvalidSender(address(0));
    }
    // idsとvaluesの長さが違う場合はリバート
    _updateWithAcceptanceCheck(from, to, ids, values, data);
}

function _mint(address to, uint256 id, uint256 value, bytes memory data) internal {
    // toがゼロアドレスの場合はリバート
    if (to == address(0)) {
        revert ERC1155InvalidReceiver(address(0));
    }
    // idとvalueを配列にする
    (uint256[] memory ids, uint256[] memory values) = _asSingletonArrays(id, value);
    // _updateWithAcceptanceCheckを実行してmint
    _updateWithAcceptanceCheck(address(0), to, ids, values, data);
}

function _mintBatch(address to, uint256[] memory ids, uint256[] memory values, bytes memory data) internal {
    // toがゼロアドレスの場合はリバート
    if (to == address(0)) {
        revert ERC1155InvalidReceiver(address(0));
    }
    // _updateWithAcceptanceCheckを実行して複数mint
    _updateWithAcceptanceCheck(address(0), to, ids, values, data);
}

function _burn(address from, uint256 id, uint256 value) internal {
    // fromがゼロアドレスの場合はリバート
    if (from == address(0)) {
        revert ERC1155InvalidSender(address(0));
    }
    // idとvalueを配列にする
    (uint256[] memory ids, uint256[] memory values) = _asSingletonArrays(id, value);
    // _updateWithAcceptanceCheckを実行してburn
    _updateWithAcceptanceCheck(from, address(0), ids, values, "");
}

function _burnBatch(address from, uint256[] memory ids, uint256[] memory values) internal {
    // fromがゼロアドレスの場合はリバート
    if (from == address(0)) {
        revert ERC1155InvalidSender(address(0));
    }
    // _updateWithAcceptanceCheckを実行して複数burn
    _updateWithAcceptanceCheck(from, address(0), ids, values, "");
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

import "@openzeppelin/contracts/token/ERC1155/ERC1155.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC1155/extensions/ERC1155Burnable.sol";

contract GameItems is ERC1155, Ownable, ERC1155Burnable {
    uint256 public constant GOLD = 0;
    uint256 public constant SILVER = 1;
    uint256 public constant THORS_HAMMER = 2;
    uint256 public constant SWORD = 3;
    uint256 public constant SHIELD = 4;

    constructor(
        address initialOwner
    ) ERC1155("https://example.com/{id}.json") Ownable(initialOwner) {
        _mint(initialOwner, GOLD, 10 ** 18, "");
        _mint(initialOwner, SILVER, 10 ** 27, "");
        _mint(initialOwner, THORS_HAMMER, 1, "");
        _mint(initialOwner, SWORD, 10, "");
        _mint(initialOwner, SHIELD, 10, "");
    }

    function setURI(string memory newuri) public onlyOwner {
        _setURI(newuri);
    }

    function mint(
        address account,
        uint256 id,
        uint256 amount,
        bytes memory data
    ) public onlyOwner {
        _mint(account, id, amount, data);
    }

    function mintBatch(
        address to,
        uint256[] memory ids,
        uint256[] memory amounts,
        bytes memory data
    ) public onlyOwner {
        _mintBatch(to, ids, amounts, data);
    }
}