Contract Source Code:
File 1 of 1 : Token
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.7 <0.9.0;
//import "@openzeppelin/contracts/utils/Strings.sol";
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _HEX_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) {
// Inspired by OraclizeAPI's implementation - MIT licence
// https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
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);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
if (value == 0) {
return "0x00";
}
uint256 temp = value;
uint256 length = 0;
while (temp != 0) {
length++;
temp >>= 8;
}
return toHexString(value, length);
}
/**
* @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] = _HEX_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);
}
}
//import "../utils/Context.sol";
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
//import "../../utils/Address.sol";
/**
* @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 functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value
) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
//import "@openzeppelin/contracts/access/Ownable.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev 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);
}
}
//import "./IERC165.sol";
/**
* @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);
}
//import "./IERC721.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes calldata data
) external;
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
}
//import "./IERC721Receiver.sol";
/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/
interface IERC721Receiver {
/**
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
* by `operator` from `from`, this function is called.
*
* It must return its Solidity selector to confirm the token transfer.
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
*
* The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
*/
function onERC721Received(
address operator,
address from,
uint256 tokenId,
bytes calldata data
) external returns (bytes4);
}
//import "./extensions/IERC721Metadata.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Metadata is IERC721 {
/**
* @dev Returns the token collection name.
*/
function name() external view returns (string memory);
/**
* @dev Returns the token collection symbol.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
*/
function tokenURI(uint256 tokenId) external view returns (string memory);
}
//import "../../utils/introspection/ERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
//import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
/**
* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
* the Metadata extension, but not including the Enumerable extension, which is available separately as
* {ERC721Enumerable}.
*/
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
using Address for address;
using Strings for uint256;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Mapping from token ID to owner address
mapping(uint256 => address) private _owners;
// Mapping owner address to token count
mapping(address => uint256) private _balances;
// Mapping from token ID to approved address
mapping(uint256 => address) private _tokenApprovals;
// Mapping from owner to operator approvals
mapping(address => mapping(address => bool)) private _operatorApprovals;
/**
* @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
return
interfaceId == type(IERC721).interfaceId ||
interfaceId == type(IERC721Metadata).interfaceId ||
super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721-balanceOf}.
*/
function balanceOf(address owner) public view virtual override returns (uint256) {
require(owner != address(0), "ERC721: address zero is not a valid owner");
return _balances[owner];
}
/**
* @dev See {IERC721-ownerOf}.
*/
function ownerOf(uint256 tokenId) public view virtual override returns (address) {
address owner = _owners[tokenId];
require(owner != address(0), "ERC721: invalid token ID");
return owner;
}
/**
* @dev See {IERC721Metadata-name}.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev See {IERC721Metadata-symbol}.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev See {IERC721Metadata-tokenURI}.
*/
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
_requireMinted(tokenId);
string memory baseURI = _baseURI();
return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
}
/**
* @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
* token will be the concatenation of the `baseURI` and the `tokenId`. Empty
* by default, can be overridden in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return "";
}
/**
* @dev See {IERC721-approve}.
*/
function approve(address to, uint256 tokenId) public virtual override {
address owner = ERC721.ownerOf(tokenId);
require(to != owner, "ERC721: approval to current owner");
require(
_msgSender() == owner || isApprovedForAll(owner, _msgSender()),
"ERC721: approve caller is not token owner nor approved for all"
);
_approve(to, tokenId);
}
/**
* @dev See {IERC721-getApproved}.
*/
function getApproved(uint256 tokenId) public view virtual override returns (address) {
_requireMinted(tokenId);
return _tokenApprovals[tokenId];
}
/**
* @dev See {IERC721-setApprovalForAll}.
*/
function setApprovalForAll(address operator, bool approved) public virtual override {
_setApprovalForAll(_msgSender(), operator, approved);
}
/**
* @dev See {IERC721-isApprovedForAll}.
*/
function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @dev See {IERC721-transferFrom}.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) public virtual override {
//solhint-disable-next-line max-line-length
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner nor approved");
_transfer(from, to, tokenId);
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) public virtual override {
safeTransferFrom(from, to, tokenId, "");
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes memory data
) public virtual override {
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner nor approved");
_safeTransfer(from, to, tokenId, data);
}
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* `data` is additional data, it has no specified format and it is sent in call to `to`.
*
* This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
* implement alternative mechanisms to perform token transfer, such as signature-based.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function _safeTransfer(
address from,
address to,
uint256 tokenId,
bytes memory data
) internal virtual {
_transfer(from, to, tokenId);
require(_checkOnERC721Received(from, to, tokenId, data), "ERC721: transfer to non ERC721Receiver implementer");
}
/**
* @dev Returns whether `tokenId` exists.
*
* Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
*
* Tokens start existing when they are minted (`_mint`),
* and stop existing when they are burned (`_burn`).
*/
function _exists(uint256 tokenId) internal view virtual returns (bool) {
return _owners[tokenId] != address(0);
}
/**
* @dev Returns whether `spender` is allowed to manage `tokenId`.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
address owner = ERC721.ownerOf(tokenId);
return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
}
/**
* @dev Safely mints `tokenId` and transfers it to `to`.
*
* Requirements:
*
* - `tokenId` must not exist.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function _safeMint(address to, uint256 tokenId) internal virtual {
_safeMint(to, tokenId, "");
}
/**
* @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
* forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
*/
function _safeMint(
address to,
uint256 tokenId,
bytes memory data
) internal virtual {
_mint(to, tokenId);
require(
_checkOnERC721Received(address(0), to, tokenId, data),
"ERC721: transfer to non ERC721Receiver implementer"
);
}
/**
* @dev Mints `tokenId` and transfers it to `to`.
*
* WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
*
* Requirements:
*
* - `tokenId` must not exist.
* - `to` cannot be the zero address.
*
* Emits a {Transfer} event.
*/
function _mint(address to, uint256 tokenId) internal virtual {
require(to != address(0), "ERC721: mint to the zero address");
require(!_exists(tokenId), "ERC721: token already minted");
_beforeTokenTransfer(address(0), to, tokenId);
_balances[to] += 1;
_owners[tokenId] = to;
emit Transfer(address(0), to, tokenId);
_afterTokenTransfer(address(0), to, tokenId);
}
/**
* @dev Destroys `tokenId`.
* The approval is cleared when the token is burned.
*
* Requirements:
*
* - `tokenId` must exist.
*
* Emits a {Transfer} event.
*/
function _burn(uint256 tokenId) internal virtual {
address owner = ERC721.ownerOf(tokenId);
_beforeTokenTransfer(owner, address(0), tokenId);
// Clear approvals
_approve(address(0), tokenId);
_balances[owner] -= 1;
delete _owners[tokenId];
emit Transfer(owner, address(0), tokenId);
_afterTokenTransfer(owner, address(0), tokenId);
}
/**
* @dev Transfers `tokenId` from `from` to `to`.
* As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
*
* Emits a {Transfer} event.
*/
function _transfer(
address from,
address to,
uint256 tokenId
) internal virtual {
require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
require(to != address(0), "ERC721: transfer to the zero address");
_beforeTokenTransfer(from, to, tokenId);
// Clear approvals from the previous owner
_approve(address(0), tokenId);
_balances[from] -= 1;
_balances[to] += 1;
_owners[tokenId] = to;
emit Transfer(from, to, tokenId);
_afterTokenTransfer(from, to, tokenId);
}
/**
* @dev Approve `to` to operate on `tokenId`
*
* Emits an {Approval} event.
*/
function _approve(address to, uint256 tokenId) internal virtual {
_tokenApprovals[tokenId] = to;
emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
}
/**
* @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, "ERC721: approve to caller");
_operatorApprovals[owner][operator] = approved;
emit ApprovalForAll(owner, operator, approved);
}
/**
* @dev Reverts if the `tokenId` has not been minted yet.
*/
function _requireMinted(uint256 tokenId) internal view virtual {
require(_exists(tokenId), "ERC721: invalid token ID");
}
/**
* @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
* The call is not executed if the target address is not a contract.
*
* @param from address representing the previous owner of the given token ID
* @param to target address that will receive the tokens
* @param tokenId uint256 ID of the token to be transferred
* @param data bytes optional data to send along with the call
* @return bool whether the call correctly returned the expected magic value
*/
function _checkOnERC721Received(
address from,
address to,
uint256 tokenId,
bytes memory data
) private returns (bool) {
if (to.isContract()) {
try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, data) returns (bytes4 retval) {
return retval == IERC721Receiver.onERC721Received.selector;
} catch (bytes memory reason) {
if (reason.length == 0) {
revert("ERC721: transfer to non ERC721Receiver implementer");
} else {
/// @solidity memory-safe-assembly
assembly {
revert(add(32, reason), mload(reason))
}
}
}
} else {
return true;
}
}
/**
* @dev Hook that is called before any token transfer. This includes minting
* and burning.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, ``from``'s `tokenId` 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 tokenId
) 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.
* - `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 tokenId
) internal virtual {}
}
//import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor() {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
// On the first call to nonReentrant, _notEntered will be true
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
//import "./Common/IPurchasedChecker.sol";
//--------------------------------------------
// PurchasedChecker interface
//--------------------------------------------
interface IPurchasedChecker {
//--------------------
// function
//--------------------
function checkPurchased( address target ) external view returns (uint256);
function checkPurchasedOnPrivate( address target ) external view returns (uint256);
function checkPurchasedOnPublic( address target ) external view returns (uint256);
}
//import "./Common/IWhitelist.sol";
//--------------------------------------------
// WHITELIST intterface
//--------------------------------------------
interface IWhitelist {
//--------------------
// function
//--------------------
function check( address target ) external view returns (bool);
}
//------------------------------------------------------------
// Token(ERC721)
//------------------------------------------------------------
contract Token is Ownable, ERC721, ReentrancyGuard, IPurchasedChecker {
//--------------------------------------------------------
// 定数
//--------------------------------------------------------
string constant private TOKEN_NAME = "MetaIdol";
string constant private TOKEN_SYMBOL = "MI";
// mainnet
address constant private OWNER_ADDRESS = 0xE2E577A889f2EB52C84c34E4539D33798987B6d2;
// constant
uint256 constant private TOKEN_ID_OFS = 1;
uint256 constant private BLOCK_SEC_MARGIN = 30;
// enum
uint256 constant private INFO_SALE_SUSPENDED = 0;
uint256 constant private INFO_SALE_START = 1;
uint256 constant private INFO_SALE_END = 2;
uint256 constant private INFO_SALE_PRICE = 3;
uint256 constant private INFO_SALE_WHITELISTED = 4;
uint256 constant private INFO_SALE_USER_MINTED = 5;
uint256 constant private INFO_SALE_USER_MINTABLE = 6;
uint256 constant private INFO_MAX = 7;
uint256 constant private USER_INFO_SALE_TYPE = INFO_MAX;
uint256 constant private USER_INFO_TOTAL_SUPPLY = INFO_MAX + 1;
uint256 constant private USER_INFO_TOKEN_MAX = INFO_MAX + 2;
uint256 constant private USER_INFO_MINT_LIMIT = INFO_MAX + 3;
uint256 constant private USER_INFO_MAX = INFO_MAX + 4;
//--------------------------------------------------------
// 管理
//--------------------------------------------------------
address private _manager;
//--------------------------------------------------------
// ストレージ
//--------------------------------------------------------
string private _base_uri_for_hidden;
string private _base_uri_for_revealed;
uint256 private _token_max;
uint256 private _token_reserved;
uint256 private _token_mint_limit;
uint256 private _total_supply;
// PRIVATE(whitelist)
bool private _PRIVATE_SALE_is_suspended;
uint256 private _PRIVATE_SALE_start;
uint256 private _PRIVATE_SALE_end;
uint256 private _PRIVATE_SALE_price;
uint256 private _PRIVATE_SALE_mintable;
IWhitelist[] private _PRIVATE_SALE_arr_whitelist;
mapping( address => uint256 ) private _PRIVATE_SALE_map_user_minted;
// PUBLIC
bool private _PUBLIC_SALE_is_suspended;
uint256 private _PUBLIC_SALE_start;
uint256 private _PUBLIC_SALE_end;
uint256 private _PUBLIC_SALE_price;
uint256 private _PUBLIC_SALE_mintable;
mapping( address => uint256 ) private _PUBLIC_SALE_map_user_minted;
//--------------------------------------------------------
// [modifier] onlyOwnerOrManager
//--------------------------------------------------------
modifier onlyOwnerOrManager() {
require( msg.sender == owner() || msg.sender == manager(), "caller is not the owner neither manager" );
_;
}
//--------------------------------------------------------
// コンストラクタ
//--------------------------------------------------------
constructor() Ownable() ERC721( TOKEN_NAME, TOKEN_SYMBOL ) {
transferOwnership( OWNER_ADDRESS );
_manager = msg.sender;
//-----------------------
// mainnet
//-----------------------
_base_uri_for_hidden = "ipfs://QmX3S9CtNxNBGvy31rNcSCD6LCmwcH3JxTwhUXWzLXBnNJ/";
//_base_uri_for_revealed = "";
_token_max = 1111;
_token_reserved = 50;
_token_mint_limit = 20;
//***********************
// PRIVATE(whitelist)
//***********************
_PRIVATE_SALE_start = 1659013200; // 2022-07-28 22:00:00(JST)
_PRIVATE_SALE_end = 1659099600; // 2022-07-29 22:00:00(JST)
_PRIVATE_SALE_price = 22000000000000000; // 0.022 ETH
_PRIVATE_SALE_mintable = 5; // 5 nft
_PRIVATE_SALE_arr_whitelist.push( IWhitelist(0xc30Be91bDB2B8211eB7225ecfF7C49E61F6F26f6) );
//~~~~~~~~~~~~~~~~~~~~~~~
// PUBLIC
//~~~~~~~~~~~~~~~~~~~~~~~
_PUBLIC_SALE_start = 1659099600; // 2022-07-29 22:00:00(JST)
_PUBLIC_SALE_end = 1659186000; // 2022-07-30 22:00:00(JST)
_PUBLIC_SALE_price = 23000000000000000; // 0.023 ETH
_PUBLIC_SALE_mintable = 0; // no limitation
}
//--------------------------------------------------------
// [public] manager
//--------------------------------------------------------
function manager() public view returns (address) {
return( _manager );
}
//--------------------------------------------------------
// [external/onlyOwner] setManager
//--------------------------------------------------------
function setManager( address target ) external onlyOwner {
_manager = target;
}
//--------------------------------------------------------
// [external] get
//--------------------------------------------------------
function baseUriForHidden() external view returns (string memory) { return( _base_uri_for_hidden ); }
function baseUriForRevealed() external view returns (string memory) { return( _base_uri_for_revealed ); }
function tokenMax() external view returns (uint256) { return( _token_max ); }
function tokenReserved() external view returns (uint256) { return( _token_reserved ); }
function tokenMintLimit() external view returns (uint256) { return( _token_mint_limit ); }
function totalSupply() external view returns (uint256) { return( _total_supply ); }
//--------------------------------------------------------
// [external/onlyOwnerOrManager] set
//--------------------------------------------------------
function setBaseUriForHidden( string calldata uri ) external onlyOwnerOrManager { _base_uri_for_hidden = uri; }
function setBaseUriForRevealed( string calldata uri ) external onlyOwnerOrManager { _base_uri_for_revealed = uri; }
function setTokenMax( uint256 max ) external onlyOwnerOrManager { _token_max = max; }
function setTokenReserved( uint256 reserved ) external onlyOwnerOrManager { _token_reserved = reserved; }
function setTokenMintLimit( uint256 limit ) external onlyOwnerOrManager { _token_mint_limit = limit; }
//--------------------------------------------------------
// [public/override] tokenURI
//--------------------------------------------------------
function tokenURI( uint256 tokenId ) public view override returns (string memory) {
require( _exists( tokenId ), "nonexistent token" );
if( bytes(_base_uri_for_revealed).length > 0 ){
return( string( abi.encodePacked( _base_uri_for_revealed, Strings.toString( tokenId ) ) ) );
}
return( string( abi.encodePacked( _base_uri_for_hidden, Strings.toString( tokenId ) ) ) );
}
//********************************************************
// [public] getInfo - PRIVATE(whitelist)
//********************************************************
function PRIVATE_SALE_getInfo( address target ) public view returns (uint256[INFO_MAX] memory) {
uint256[INFO_MAX] memory arrRet;
if( _PRIVATE_SALE_is_suspended ){ arrRet[INFO_SALE_SUSPENDED] = 1; }
arrRet[INFO_SALE_START] = _PRIVATE_SALE_start;
arrRet[INFO_SALE_END] = _PRIVATE_SALE_end;
arrRet[INFO_SALE_PRICE] = _PRIVATE_SALE_price;
if( _checkWhitelist( _PRIVATE_SALE_arr_whitelist, target ) ){ arrRet[INFO_SALE_WHITELISTED] = 1; }
arrRet[INFO_SALE_USER_MINTED] = _PRIVATE_SALE_map_user_minted[target];
arrRet[INFO_SALE_USER_MINTABLE] = _PRIVATE_SALE_mintable;
return( arrRet );
}
//********************************************************
// [external/onlyOwnerOrManager] write - PRIVATE(whitelist)
//********************************************************
// is_suspended
function PRIVATE_SALE_suspend( bool flag ) external onlyOwnerOrManager {
_PRIVATE_SALE_is_suspended = flag;
}
// start-end
function PRIVATE_SALE_setStartEnd( uint256 start, uint256 end ) external onlyOwnerOrManager {
_PRIVATE_SALE_start = start;
_PRIVATE_SALE_end = end;
}
// price
function PRIVATE_SALE_setPrice( uint256 price ) external onlyOwnerOrManager {
_PRIVATE_SALE_price = price;
}
// mintable
function PRIVATE_SALE_setMintable( uint256 mintable ) external onlyOwnerOrManager {
_PRIVATE_SALE_mintable = mintable;
}
// whitelist
function PRIVATE_SALE_setWhiteList( address[] calldata lists ) external onlyOwnerOrManager {
delete _PRIVATE_SALE_arr_whitelist;
for( uint256 i=0; i<lists.length; i++ ){
require( lists[i] != address(0), "PRIVATE: invalid list" );
_PRIVATE_SALE_arr_whitelist.push( IWhitelist(lists[i]) );
}
}
//********************************************************
// [external/payable/nonReentrant] mint - PRIVATE(whitelist)
//********************************************************
function PRIVATE_SALE_mint( uint256 num ) external payable nonReentrant {
uint256[INFO_MAX] memory arrInfo = PRIVATE_SALE_getInfo( msg.sender );
require( arrInfo[INFO_SALE_SUSPENDED] == 0, "PRIVATE SALE: suspended" );
require( arrInfo[INFO_SALE_START] == 0 || arrInfo[INFO_SALE_START] <= (block.timestamp+BLOCK_SEC_MARGIN), "PRIVATE SALE: not opend" );
require( arrInfo[INFO_SALE_END] == 0 || (arrInfo[INFO_SALE_END]+BLOCK_SEC_MARGIN) > block.timestamp, "PRIVATE SALE: finished" );
require( arrInfo[INFO_SALE_WHITELISTED] == 1, "PRIVATE SALE: not whitelisted" );
require( arrInfo[INFO_SALE_USER_MINTABLE] == 0 || arrInfo[INFO_SALE_USER_MINTABLE] >= (arrInfo[INFO_SALE_USER_MINTED]+num), "PRIVATE SALE: reached the limit" );
_checkPayment( msg.sender, arrInfo[INFO_SALE_PRICE]*num, msg.value );
_mintTokens( msg.sender, num );
_PRIVATE_SALE_map_user_minted[msg.sender] += num;
}
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// [public] getInfo - PUBLIC
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
function PUBLIC_SALE_getInfo( address target ) public view returns (uint256[INFO_MAX] memory) {
uint256[INFO_MAX] memory arrRet;
if( _PUBLIC_SALE_is_suspended ){ arrRet[INFO_SALE_SUSPENDED] = 1; }
arrRet[INFO_SALE_START] = _PUBLIC_SALE_start;
arrRet[INFO_SALE_END] = _PUBLIC_SALE_end;
arrRet[INFO_SALE_PRICE] = _PUBLIC_SALE_price;
arrRet[INFO_SALE_WHITELISTED] = 1;
arrRet[INFO_SALE_USER_MINTED] = _PUBLIC_SALE_map_user_minted[target];
arrRet[INFO_SALE_USER_MINTABLE] = _PUBLIC_SALE_mintable;
return( arrRet );
}
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// [external/onlyOwnerOrManager] write - PUBLIC
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// is_suspended
function PUBLIC_SALE_suspend( bool flag ) external onlyOwnerOrManager {
_PUBLIC_SALE_is_suspended = flag;
}
// start-end
function PUBLIC_SALE_setStartEnd( uint256 start, uint256 end ) external onlyOwnerOrManager {
_PUBLIC_SALE_start = start;
_PUBLIC_SALE_end = end;
}
// price
function PUBLIC_SALE_setPrice( uint256 price ) external onlyOwnerOrManager {
_PUBLIC_SALE_price = price;
}
// mintable
function PUBLIC_SALE_setMintable( uint256 mintable ) external onlyOwnerOrManager {
_PUBLIC_SALE_mintable = mintable;
}
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// [external/payable/nonReentrant] mint - PUBLIC
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
function PUBLIC_SALE_mint( uint256 num ) external payable nonReentrant {
uint256[INFO_MAX] memory arrInfo = PUBLIC_SALE_getInfo( msg.sender );
require( arrInfo[INFO_SALE_SUSPENDED] == 0, "PUBLIC SALE: suspended" );
require( arrInfo[INFO_SALE_START] == 0 || arrInfo[INFO_SALE_START] <= (block.timestamp+BLOCK_SEC_MARGIN), "PUBLIC SALE: not opend" );
require( arrInfo[INFO_SALE_END] == 0 || (arrInfo[INFO_SALE_END]+BLOCK_SEC_MARGIN) > block.timestamp, "PUBLIC SALE: finished" );
require( arrInfo[INFO_SALE_USER_MINTABLE] == 0 || arrInfo[INFO_SALE_USER_MINTABLE] >= (arrInfo[INFO_SALE_USER_MINTED]+num), "PUBLIC SALE: reached the limit" );
_checkPayment( msg.sender, arrInfo[INFO_SALE_PRICE]*num, msg.value );
_mintTokens( msg.sender, num );
_PUBLIC_SALE_map_user_minted[msg.sender] += num;
}
//--------------------------------------------------------
// [internal] _checkWhitelist
//--------------------------------------------------------
function _checkWhitelist( IWhitelist[] storage lists, address target ) internal view returns (bool) {
for( uint256 i=0; i<lists.length; i++ ){
if( lists[i].check(target) ){
return( true );
}
}
return( false );
}
//--------------------------------------------------------
// [internal] _checkPayment
//--------------------------------------------------------
function _checkPayment( address msgSender, uint256 price, uint256 payment ) internal {
require( price <= payment, "insufficient value" );
// refund if overpaymented
if( price < payment ){
uint256 change = payment - price;
address payable target = payable( msgSender );
target.transfer( change );
}
}
//--------------------------------------------------------
// [internal] _mintTokens
//--------------------------------------------------------
function _mintTokens( address to, uint256 num ) internal {
require( _total_supply >= _token_reserved, "reservation not finished" );
require( (_total_supply+num) <= _token_max, "exceeded the supply range" );
require( _token_mint_limit == 0 || _token_mint_limit >= num, "reached mint limitation" );
for( uint256 i=0; i<num; i++ ){
_mint( to, _total_supply+(TOKEN_ID_OFS+i) );
}
_total_supply += num;
}
//--------------------------------------------------------
// [external/onlyOwnerOrManager] reserveTokens
//--------------------------------------------------------
function reserveTokens( uint256 num ) external onlyOwnerOrManager {
require( (_total_supply+num) <= _token_reserved, "exceeded the reservation range" );
for( uint256 i=0; i<num; i++ ){
_mint( owner(), _total_supply+(TOKEN_ID_OFS+i) );
}
_total_supply += num;
}
//--------------------------------------------------------
// [external] getUserInfo
//--------------------------------------------------------
function getUserInfo( address target ) external view returns (uint256[USER_INFO_MAX] memory) {
uint256[USER_INFO_MAX] memory userInfo;
uint256[INFO_MAX] memory info;
// PRIVATE(whitelist)
if( _checkWhitelist( _PRIVATE_SALE_arr_whitelist, target ) && (_PRIVATE_SALE_end == 0 || _PRIVATE_SALE_end > (block.timestamp+BLOCK_SEC_MARGIN/2)) ){
userInfo[USER_INFO_SALE_TYPE] = 1;
info = PRIVATE_SALE_getInfo( target );
}
// PUBLIC
else{
userInfo[USER_INFO_SALE_TYPE] = 2;
info = PUBLIC_SALE_getInfo( target );
}
for( uint256 i=0; i<INFO_MAX; i++ ){
userInfo[i] = info[i];
}
userInfo[USER_INFO_TOTAL_SUPPLY] = _total_supply;
userInfo[USER_INFO_TOKEN_MAX] = _token_max;
userInfo[USER_INFO_MINT_LIMIT] = _token_mint_limit;
return( userInfo );
}
//--------------------------------------------------------
// [external] for PurchasedChecker
//--------------------------------------------------------
function checkPurchased( address target ) external view override returns (uint256) { return( _PRIVATE_SALE_map_user_minted[target] + _PUBLIC_SALE_map_user_minted[target] ); }
function checkPurchasedOnPrivate( address target ) external override view returns (uint256){ return( _PRIVATE_SALE_map_user_minted[target] ); }
function checkPurchasedOnPublic( address target ) external override view returns (uint256){ return( _PUBLIC_SALE_map_user_minted[target] ); }
//--------------------------------------------------------
// [external] checkBalance
//--------------------------------------------------------
function checkBalance() external view returns (uint256) {
return( address(this).balance );
}
//--------------------------------------------------------
// [external/onlyOwnerOrManager] withdraw
//--------------------------------------------------------
function withdraw( uint256 amount ) external onlyOwnerOrManager {
require( amount <= address(this).balance, "insufficient balance" );
address payable target = payable( owner() );
target.transfer( amount );
}
}