Contract Address Details

// SPDX-License-Identifier: MIT
pragma solidity 0.8.20;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/utils/introspection/IERC165.sol";

interface ILegacyMintableERC20 {
    function mint(address _to, uint256 _amount) external;
    function burn(address _from, uint256 _amount) external;

    function l1Token() external view returns (address);
    function l2Bridge() external view returns (address);
}

interface IOptimismMintableERC20 {
    function remoteToken() external view returns (address);
    function bridge() external view returns (address);
    function mint(address _to, uint256 _amount) external;
    function burn(address _from, uint256 _amount) external;
}

contract Semver {
    string public version;

    function toString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0";
        }

        uint256 temp = value;
        uint256 digits;

        while (temp != 0) {
            digits++;
            temp /= 10;
        }

        bytes memory buffer = new bytes(digits);

        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }

        return string(buffer);
    }

    constructor(uint256 major, uint256 minor, uint256 patch) {
        version = string(
            abi.encodePacked(toString(major), ".", toString(minor), ".", toString(patch))
        );
    }
}

contract MyCustomL2Token is IOptimismMintableERC20, ILegacyMintableERC20, ERC20, Semver {
    address public immutable REMOTE_TOKEN;
    address public immutable BRIDGE;

    event Mint(address indexed account, uint256 amount);
    event Burn(address indexed account, uint256 amount);

    modifier onlyBridge() {
        require(msg.sender == BRIDGE, "MyCustomL2Token: only bridge can mint and burn");
        _;
    }

    constructor(
    address _bridge,
    address _remoteToken,
    string memory _name,
    string memory _symbol,
    address _initialHolder,          // 新增：初始持币人
    uint256 _initialSupply           // 新增：初始供应量
        ) ERC20(_name, _symbol) Semver(1, 0, 0) {
            REMOTE_TOKEN = _remoteToken;
            BRIDGE = _bridge;

            if (_initialSupply > 0) {
                _mint(_initialHolder, _initialSupply);  // 直接绕开 onlyBridge，调用 ERC20._mint()
                emit Mint(_initialHolder, _initialSupply);
            }
        }


    function mint(address _to, uint256 _amount)
        external
        override(IOptimismMintableERC20, ILegacyMintableERC20)
        onlyBridge
    {
        _mint(_to, _amount);
        emit Mint(_to, _amount);
    }

    function burn(address _from, uint256 _amount)
        external
        override(IOptimismMintableERC20, ILegacyMintableERC20)
        onlyBridge
    {
        _burn(_from, _amount);
        emit Burn(_from, _amount);
    }

    function supportsInterface(bytes4 _interfaceId) external pure returns (bool) {
        bytes4 iface1 = type(IERC165).interfaceId;
        bytes4 iface2 = type(ILegacyMintableERC20).interfaceId;
        bytes4 iface3 = type(IOptimismMintableERC20).interfaceId;
        return _interfaceId == iface1 || _interfaceId == iface2 || _interfaceId == iface3;
    }

    function l1Token() public view override returns (address) {
        return REMOTE_TOKEN;
    }

    function l2Bridge() public view override returns (address) {
        return BRIDGE;
    }

    function remoteToken() public view override returns (address) {
        return REMOTE_TOKEN;
    }

    function bridge() public view override returns (address) {
        return BRIDGE;
    }
}
        

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

pragma solidity ^0.8.20;

import {Context} from "../utils/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.
 *
 * The initial owner is set to the address provided by the deployer. This can
 * later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

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

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

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

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

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

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (interfaces/draft-IERC6093.sol)
pragma solidity ^0.8.20;

/**
 * @dev Standard ERC-20 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-20 tokens.
 */
interface IERC20Errors {
    /**
     * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param balance Current balance for the interacting account.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC20InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC20InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `spender`’s `allowance`. Used in transfers.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     * @param allowance Amount of tokens a `spender` is allowed to operate with.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC20InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `spender` to be approved. Used in approvals.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC20InvalidSpender(address spender);
}

/**
 * @dev Standard ERC-721 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-721 tokens.
 */
interface IERC721Errors {
    /**
     * @dev Indicates that an address can't be an owner. For example, `address(0)` is a forbidden owner in ERC-20.
     * Used in balance queries.
     * @param owner Address of the current owner of a token.
     */
    error ERC721InvalidOwner(address owner);

    /**
     * @dev Indicates a `tokenId` whose `owner` is the zero address.
     * @param tokenId Identifier number of a token.
     */
    error ERC721NonexistentToken(uint256 tokenId);

    /**
     * @dev Indicates an error related to the ownership over a particular token. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param tokenId Identifier number of a token.
     * @param owner Address of the current owner of a token.
     */
    error ERC721IncorrectOwner(address sender, uint256 tokenId, address owner);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC721InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC721InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     * @param tokenId Identifier number of a token.
     */
    error ERC721InsufficientApproval(address operator, uint256 tokenId);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC721InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC721InvalidOperator(address operator);
}

/**
 * @dev Standard ERC-1155 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-1155 tokens.
 */
interface IERC1155Errors {
    /**
     * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param balance Current balance for the interacting account.
     * @param needed Minimum amount required to perform a transfer.
     * @param tokenId Identifier number of a token.
     */
    error ERC1155InsufficientBalance(address sender, uint256 balance, uint256 needed, uint256 tokenId);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC1155InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC1155InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     * @param owner Address of the current owner of a token.
     */
    error ERC1155MissingApprovalForAll(address operator, address owner);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC1155InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC1155InvalidOperator(address operator);

    /**
     * @dev Indicates an array length mismatch between ids and values in a safeBatchTransferFrom operation.
     * Used in batch transfers.
     * @param idsLength Length of the array of token identifiers
     * @param valuesLength Length of the array of token amounts
     */
    error ERC1155InvalidArrayLength(uint256 idsLength, uint256 valuesLength);
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.3.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "./IERC20.sol";
import {IERC20Metadata} from "./extensions/IERC20Metadata.sol";
import {Context} from "../../utils/Context.sol";
import {IERC20Errors} from "../../interfaces/draft-IERC6093.sol";

/**
 * @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}.
 *
 * 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].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * 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 ERC-20
 * applications.
 */
abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
    mapping(address account => uint256) private _balances;

    mapping(address account => mapping(address spender => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * Both 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 returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual 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 default value returned by this function, unless
     * it's 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 returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual 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 `value`.
     */
    function transfer(address to, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, value);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `value` 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 value) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, value);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Skips emitting an {Approval} event indicating an allowance update. This is not
     * required by the ERC. See {xref-ERC20-_approve-address-address-uint256-bool-}[_approve].
     *
     * 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 `value`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `value`.
     */
    function transferFrom(address from, address to, uint256 value) public virtual returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, value);
        _transfer(from, to, value);
        return true;
    }

    /**
     * @dev Moves a `value` 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.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _transfer(address from, address to, uint256 value) internal {
        if (from == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        if (to == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(from, to, value);
    }

    /**
     * @dev Transfers a `value` amount of tokens from `from` to `to`, or alternatively mints (or burns) if `from`
     * (or `to`) is the zero address. All customizations to transfers, mints, and burns should be done by overriding
     * this function.
     *
     * Emits a {Transfer} event.
     */
    function _update(address from, address to, uint256 value) internal virtual {
        if (from == address(0)) {
            // Overflow check required: The rest of the code assumes that totalSupply never overflows
            _totalSupply += value;
        } else {
            uint256 fromBalance = _balances[from];
            if (fromBalance < value) {
                revert ERC20InsufficientBalance(from, fromBalance, value);
            }
            unchecked {
                // Overflow not possible: value <= fromBalance <= totalSupply.
                _balances[from] = fromBalance - value;
            }
        }

        if (to == address(0)) {
            unchecked {
                // Overflow not possible: value <= totalSupply or value <= fromBalance <= totalSupply.
                _totalSupply -= value;
            }
        } else {
            unchecked {
                // Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
                _balances[to] += value;
            }
        }

        emit Transfer(from, to, value);
    }

    /**
     * @dev Creates a `value` amount of tokens and assigns them to `account`, by transferring it from address(0).
     * Relies on the `_update` mechanism
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _mint(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(address(0), account, value);
    }

    /**
     * @dev Destroys a `value` amount of tokens from `account`, lowering the total supply.
     * Relies on the `_update` mechanism.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead
     */
    function _burn(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        _update(account, address(0), value);
    }

    /**
     * @dev Sets `value` 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.
     *
     * Overrides to this logic should be done to the variant with an additional `bool emitEvent` argument.
     */
    function _approve(address owner, address spender, uint256 value) internal {
        _approve(owner, spender, value, true);
    }

    /**
     * @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
     *
     * By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made by
     * `_spendAllowance` during the `transferFrom` operation set the flag to false. This saves gas by not emitting any
     * `Approval` event during `transferFrom` operations.
     *
     * Anyone who wishes to continue emitting `Approval` events on the`transferFrom` operation can force the flag to
     * true using the following override:
     *
     * ```solidity
     * function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
     *     super._approve(owner, spender, value, true);
     * }
     * ```
     *
     * Requirements are the same as {_approve}.
     */
    function _approve(address owner, address spender, uint256 value, bool emitEvent) internal virtual {
        if (owner == address(0)) {
            revert ERC20InvalidApprover(address(0));
        }
        if (spender == address(0)) {
            revert ERC20InvalidSpender(address(0));
        }
        _allowances[owner][spender] = value;
        if (emitEvent) {
            emit Approval(owner, spender, value);
        }
    }

    /**
     * @dev Updates `owner`'s allowance for `spender` based on spent `value`.
     *
     * Does not update the allowance value in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Does not emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 value) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance < type(uint256).max) {
            if (currentAllowance < value) {
                revert ERC20InsufficientAllowance(spender, currentAllowance, value);
            }
            unchecked {
                _approve(owner, spender, currentAllowance - value, false);
            }
        }
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC-20 standard as defined in the ERC.
 */
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 value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the value of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves a `value` amount of 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 value) 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 a `value` amount of tokens 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 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` 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 value) external returns (bool);
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.20;

import {IERC20} from "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC-20 standard.
 */
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);
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;

/**
 * @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;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/introspection/IERC165.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC-165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[ERC].
 *
 * 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[ERC 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);
}
          

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

interface IERC20 {
    function transferFrom(
        address from,
        address to,
        uint256 value
    ) external returns (bool);
}

contract BatchTransfer {
    uint256 public constant MAX_BATCH_SIZE = 180;

    event Transfer(address indexed from, address indexed to, uint256 amount);
    event EthTransferred(address indexed from, address indexed to, uint256 amount);

    event ERC20Transfer(
        address indexed token,
        address indexed from,
        address indexed to,
        uint256 amount
    );

    // 批量转ETH，每人相同金额
    function batchTransferETH(
        address[] calldata recipients,
        uint256 amount
    ) external payable {
        require(recipients.length <= MAX_BATCH_SIZE, "Too many recipients");
        require(amount > 0, "Amount must be greater than zero");

        uint256 totalAmount = recipients.length * amount;
        require(msg.value >= totalAmount, "Insufficient ETH");

        for (uint256 i = 0; i < recipients.length; i++) {
            payable(recipients[i]).transfer(amount);
            emit EthTransferred(msg.sender, recipients[i], amount);
        }

        // Refund extra ETH
        uint256 refund = msg.value - totalAmount;
        if (refund > 0) {
            payable(msg.sender).transfer(refund);
        }
    }

    // 批量转ERC20，每人相同数量
    function batchTransferERC20(
        address token,
        address[] calldata recipients,
        uint256 amount
    ) external {
        require(recipients.length <= MAX_BATCH_SIZE, "Too many recipients");
        require(amount > 0, "Amount must be greater than zero");

        for (uint256 i = 0; i < recipients.length; i++) {
            bool success = IERC20(token).transferFrom(
                msg.sender,
                recipients[i],
                amount
            );
            require(success, "ERC20 transfer failed");
            emit ERC20Transfer(token, msg.sender, recipients[i], amount);
        }
    }
}
          

// SPDX-License-Identifier: MIT
pragma solidity 0.8.20;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/utils/introspection/IERC165.sol";

interface ILegacyMintableERC20 {
    function mint(address _to, uint256 _amount) external;
    function burn(address _from, uint256 _amount) external;

    function l1Token() external view returns (address);
    function l2Bridge() external view returns (address);
}

interface IOptimismMintableERC20 {
    function remoteToken() external view returns (address);
    function bridge() external view returns (address);
    function mint(address _to, uint256 _amount) external;
    function burn(address _from, uint256 _amount) external;
}

contract Semver {
    string public version;

    function toString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0";
        }

        uint256 temp = value;
        uint256 digits;

        while (temp != 0) {
            digits++;
            temp /= 10;
        }

        bytes memory buffer = new bytes(digits);

        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }

        return string(buffer);
    }

    constructor(uint256 major, uint256 minor, uint256 patch) {
        version = string(
            abi.encodePacked(toString(major), ".", toString(minor), ".", toString(patch))
        );
    }
}

contract BridgableToken is IOptimismMintableERC20, ILegacyMintableERC20, ERC20, Semver {
    address public immutable REMOTE_TOKEN;
    address public immutable BRIDGE;

    event Mint(address indexed account, uint256 amount);
    event Burn(address indexed account, uint256 amount);

    modifier onlyBridge() {
        require(msg.sender == BRIDGE, "MyCustomL2Token: only bridge can mint and burn");
        _;
    }

    constructor(
        address _bridge,
        address _remoteToken,
        string memory _name,
        string memory _symbol
    ) ERC20(_name, _symbol) Semver(1, 0, 0) {
        REMOTE_TOKEN = _remoteToken;
        BRIDGE = _bridge;
    }

    function mint(address _to, uint256 _amount)
        external
        override(IOptimismMintableERC20, ILegacyMintableERC20)
        onlyBridge
    {
        _mint(_to, _amount);
        emit Mint(_to, _amount);
    }

    function burn(address _from, uint256 _amount)
        external
        override(IOptimismMintableERC20, ILegacyMintableERC20)
        onlyBridge
    {
        _burn(_from, _amount);
        emit Burn(_from, _amount);
    }

    function supportsInterface(bytes4 _interfaceId) external pure returns (bool) {
        bytes4 iface1 = type(IERC165).interfaceId;
        bytes4 iface2 = type(ILegacyMintableERC20).interfaceId;
        bytes4 iface3 = type(IOptimismMintableERC20).interfaceId;
        return _interfaceId == iface1 || _interfaceId == iface2 || _interfaceId == iface3;
    }

    function l1Token() public view override returns (address) {
        return REMOTE_TOKEN;
    }

    function l2Bridge() public view override returns (address) {
        return BRIDGE;
    }

    function remoteToken() public view override returns (address) {
        return REMOTE_TOKEN;
    }

    function bridge() public view override returns (address) {
        return BRIDGE;
    }
}

          

// SPDX-License-Identifier: MIT
pragma solidity 0.8.20;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/utils/introspection/IERC165.sol";

interface ILegacyMintableERC20 {
    function mint(address _to, uint256 _amount) external;
    function burn(address _from, uint256 _amount) external;

    function l1Token() external view returns (address);
    function l2Bridge() external view returns (address);
}

interface IOptimismMintableERC20 {
    function remoteToken() external view returns (address);
    function bridge() external view returns (address);
    function mint(address _to, uint256 _amount) external;
    function burn(address _from, uint256 _amount) external;
}

contract Semver {
    string public version;

    function toString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0";
        }

        uint256 temp = value;
        uint256 digits;

        while (temp != 0) {
            digits++;
            temp /= 10;
        }

        bytes memory buffer = new bytes(digits);

        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }

        return string(buffer);
    }

    constructor(uint256 major, uint256 minor, uint256 patch) {
        version = string(
            abi.encodePacked(
                toString(major),
                ".",
                toString(minor),
                ".",
                toString(patch)
            )
        );
    }
}

contract BridgableToken6 is
    IOptimismMintableERC20,
    ILegacyMintableERC20,
    ERC20,
    Semver
{
    address public immutable REMOTE_TOKEN;
    address public immutable BRIDGE;

    event Mint(address indexed account, uint256 amount);
    event Burn(address indexed account, uint256 amount);

    modifier onlyBridge() {
        require(
            msg.sender == BRIDGE,
            "MyCustomL2Token: only bridge can mint and burn"
        );
        _;
    }

    constructor(
        address _bridge,
        address _remoteToken,
        string memory _name,
        string memory _symbol
    ) ERC20(_name, _symbol) Semver(1, 0, 0) {
        REMOTE_TOKEN = _remoteToken;
        BRIDGE = _bridge;
    }

    function mint(
        address _to,
        uint256 _amount
    )
        external
        override(IOptimismMintableERC20, ILegacyMintableERC20)
        onlyBridge
    {
        _mint(_to, _amount);
        emit Mint(_to, _amount);
    }

    function burn(
        address _from,
        uint256 _amount
    )
        external
        override(IOptimismMintableERC20, ILegacyMintableERC20)
        onlyBridge
    {
        _burn(_from, _amount);
        emit Burn(_from, _amount);
    }

    function supportsInterface(
        bytes4 _interfaceId
    ) external pure returns (bool) {
        bytes4 iface1 = type(IERC165).interfaceId;
        bytes4 iface2 = type(ILegacyMintableERC20).interfaceId;
        bytes4 iface3 = type(IOptimismMintableERC20).interfaceId;
        return
            _interfaceId == iface1 ||
            _interfaceId == iface2 ||
            _interfaceId == iface3;
    }

    function l1Token() public view override returns (address) {
        return REMOTE_TOKEN;
    }

    function l2Bridge() public view override returns (address) {
        return BRIDGE;
    }

    function remoteToken() public view override returns (address) {
        return REMOTE_TOKEN;
    }

    function bridge() public view override returns (address) {
        return BRIDGE;
    }

    function decimals() public pure override returns (uint8) {
        return 6;
    }
}
          

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract ComonL1Token is ERC20 {
    constructor(
        string memory name_,
        string memory symbol_,
        uint256 initialSupply,
        address to
    ) ERC20(name_, symbol_) {
        _mint(to, initialSupply);
    }

    function mint(address to, uint256 amount) external {
        _mint(to, amount);
    }

    // 任何人都可以 burn 任意地址的余额（前提是已授权或自己）
    function burn(address from, uint256 amount) external {
        _burn(from, amount);
    }
}
          

// SPDX-License-Identifier: MIT
pragma solidity 0.8.20;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

/// @title Semver - 简单版本信息管理合约
contract Semver {
    string public version;

    constructor(uint256 major, uint256 minor, uint256 patch) {
        version = string(
            abi.encodePacked(
                toString(major), ".", toString(minor), ".", toString(patch)
            )
        );
    }

    function toString(uint256 value) internal pure returns (string memory) {
        if (value == 0) return "0";
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }
}

/// @title MyCustomL2Token - 可桥接的 L2 自定义代币
contract MyCustomL2Token is ERC20, Ownable, Semver {
    address public immutable bridge;
    address public immutable remoteToken;

    event Mint(address indexed to, uint256 amount);
    event Burn(address indexed from, uint256 amount);

    constructor(
        address _bridge,
        address _remoteToken,
        string memory _name,
        string memory _symbol,
        address _initialHolder,
        uint256 _initialSupply
    )
        ERC20(_name, _symbol)
        Ownable(_initialHolder)
        Semver(1, 0, 0)
    {
        require(_bridge != address(0), "Bridge address is zero");
        require(_remoteToken != address(0), "Remote token address is zero");
        require(_initialHolder != address(0), "Invalid initial holder");

        bridge = _bridge;
        remoteToken = _remoteToken;

        if (_initialSupply > 0) {
            _mint(_initialHolder, _initialSupply);
            emit Mint(_initialHolder, _initialSupply);
        }
    }

    /// @notice 只有合约拥有者能铸币
    function mint(address to, uint256 amount) external onlyOwner {
        _mint(to, amount);
        emit Mint(to, amount);
    }

    /// @notice 只有合约拥有者能销毁指定账户代币
    function burn(address from, uint256 amount) external onlyOwner {
        _burn(from, amount);
        emit Burn(from, amount);
    }
} 
          

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract MyToken {
    string public name;
    string public symbol;
    uint8 public decimals = 18;
    uint256 public totalSupply;

    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;

    error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);
    error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);
    error ERC20InvalidSender(address sender);
    error ERC20InvalidReceiver(address receiver);
    error ERC20InvalidApprover(address approver);
    error ERC20InvalidSpender(address spender);

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    constructor(
        string memory _name,
        string memory _symbol,
        address initialHolder,
        uint256 initialSupply
    ) {
        require(initialHolder != address(0), "initialHolder is zero address");
        name = _name;
        symbol = _symbol;
        _mint(initialHolder, initialSupply);
    }

    function faucet() external {
        uint256 amount = 1000 * 10 ** uint256(decimals);
        _mint(msg.sender, amount);
    }

    function balanceOf(address account) external view returns (uint256) {
        return _balances[account];
    }

    function transfer(address to, uint256 value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function approve(address spender, uint256 value) external returns (bool) {
        if (msg.sender == address(0)) revert ERC20InvalidApprover(msg.sender);
        if (spender == address(0)) revert ERC20InvalidSpender(spender);

        _allowances[msg.sender][spender] = value;
        emit Approval(msg.sender, spender, value);
        return true;
    }

    function transferFrom(address from, address to, uint256 value) external returns (bool) {
        uint256 currentAllowance = _allowances[from][msg.sender];
        if (currentAllowance < value)
            revert ERC20InsufficientAllowance(msg.sender, currentAllowance, value);

        _transfer(from, to, value);
        _approve(from, msg.sender, currentAllowance - value);
        return true;
    }

    function allowance(address owner, address spender) external view returns (uint256) {
        return _allowances[owner][spender];
    }

    function _transfer(address from, address to, uint256 value) internal {
        if (from == address(0)) revert ERC20InvalidSender(from);
        if (to == address(0)) revert ERC20InvalidReceiver(to);

        uint256 fromBalance = _balances[from];
        if (fromBalance < value)
            revert ERC20InsufficientBalance(from, fromBalance, value);

        _balances[from] = fromBalance - value;
        _balances[to] += value;
        emit Transfer(from, to, value);
    }

    function _approve(address owner, address spender, uint256 value) internal {
        _allowances[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _mint(address account, uint256 value) internal {
        if (account == address(0)) revert ERC20InvalidReceiver(account);
        totalSupply += value;
        _balances[account] += value;
        emit Transfer(address(0), account, value);
    }
}