Contract Name:
MutantBitsYachtClub
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.6;
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/security/Pausable.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "./BBYC.sol";
import "./BoredBitsChemistryClub.sol";
//Based on Yuga Labs' Smart Contract.
//@yugalabs
contract MutantBitsYachtClub is ERC721Enumerable, Ownable, ReentrancyGuard {
uint8 private constant NUM_MUTANT_TYPES = 2;
uint256 private constant MEGA_MUTATION_TYPE = 69;
uint256 public constant NUM_MEGA_MUTANTS = 8;
uint16 private constant MAX_MEGA_MUTATION_ID = 30007;
uint256 public constant SERUM_MUTATION_OFFSET = 10000;
uint256 public constant PS_MAX_MUTANT_PURCHASE = 20;
uint256 public constant PS_MAX_MUTANTS = 10000;
uint256 public mutantPrice = 10000000000000000;
uint256 public numMutantsMinted;
bool public publicSaleActive;
bool public serumMutationActive;
uint16 private currentMegaMutationId = 30000;
mapping(uint256 => uint256) private megaMutationIdsByApe;
string private baseURI;
BBYC private immutable bbyc;
BoredBitsChemistryClub private immutable bbcc;
modifier whenPublicSaleActive() {
require(publicSaleActive, "Public sale is not active");
_;
}
constructor(
string memory name,
string memory symbol,
address bbycAddress,
address bbccAddress
) ERC721(name, symbol) {
bbyc = BBYC(bbycAddress);
bbcc = BoredBitsChemistryClub(bbccAddress);
}
function withdraw() external onlyOwner {
uint256 balance = address(this).balance;
Address.sendValue(payable(owner()), balance);
}
function mintMutants(uint256 numMutants)
external
payable
whenPublicSaleActive
nonReentrant
{
require(
numMutantsMinted + numMutants <= PS_MAX_MUTANTS,
"Minting would exceed max supply"
);
require(numMutants > 0, "Must mint at least one mutant");
require(
numMutants <= PS_MAX_MUTANT_PURCHASE,
"Requested number exceeds maximum"
);
uint256 costToMint = mutantPrice * numMutants;
require(costToMint <= msg.value, "Ether value sent is not correct");
for (uint256 i = 0; i < numMutants; i++) {
uint256 mintIndex = numMutantsMinted;
if (numMutantsMinted < PS_MAX_MUTANTS) {
numMutantsMinted++;
_safeMint(msg.sender, mintIndex);
}
}
}
function mintMutantsByTeam(uint256 numMutants)
external
onlyOwner
{
require(
numMutantsMinted + numMutants <= PS_MAX_MUTANTS,
"Minting would exceed max supply"
);
require(numMutants > 0, "Must mint at least one mutant");
for (uint256 i = 0; i < numMutants; i++) {
uint256 mintIndex = numMutantsMinted;
if (numMutantsMinted < PS_MAX_MUTANTS) {
numMutantsMinted++;
_safeMint(msg.sender, mintIndex);
}
}
}
function mutateMultipleWithSerum(uint256 serumTypeId, uint256[] calldata apeIds) external nonReentrant {
require(serumMutationActive, "Serum Mutation is not active");
require(
bbcc.balanceOf(msg.sender, serumTypeId) >= apeIds.length,
"Must own at least one of this serum type to mutate"
);
for(uint i = 0; i < apeIds.length;i++) {
_mutateApeWithSerum(serumTypeId, apeIds[i]);
}
}
function mutateApeWithSerum(uint256 serumTypeId, uint256 apeId)
external
nonReentrant
{
require(serumMutationActive, "Serum Mutation is not active");
_mutateApeWithSerum(serumTypeId, apeId);
}
function _mutateApeWithSerum(uint256 serumTypeId, uint256 apeId)
internal
{
require(
bbcc.balanceOf(msg.sender, serumTypeId) > 0,
"Must own at least one of this serum type to mutate"
);
require(
bbyc.ownerOf(apeId) == msg.sender,
"Must own the ape you're attempting to mutate"
);
uint256 mutantId;
if (serumTypeId == MEGA_MUTATION_TYPE) {
require(
currentMegaMutationId <= MAX_MEGA_MUTATION_ID,
"Would exceed supply of serum-mutatable MEGA MUTANTS"
);
require(
megaMutationIdsByApe[apeId] == 0,
"Ape already mutated with MEGA MUTATION SERUM"
);
mutantId = currentMegaMutationId;
megaMutationIdsByApe[apeId] = mutantId;
currentMegaMutationId++;
} else {
mutantId = getMutantId(serumTypeId, apeId);
require(
!_exists(mutantId),
"Ape already mutated with this type of serum"
);
}
bbcc.burnSerumForAddress(serumTypeId, msg.sender);
_safeMint(msg.sender, mutantId);
}
function getMutantIdForApeAndSerumCombination(
uint256 apeId,
uint8 serumTypeId
) external view returns (uint256) {
uint256 mutantId;
if (serumTypeId == MEGA_MUTATION_TYPE) {
mutantId = megaMutationIdsByApe[apeId];
require(mutantId > 0, "Invalid MEGA Mutant Id");
} else {
mutantId = getMutantId(serumTypeId, apeId);
}
require(_exists(mutantId), "Query for nonexistent mutant");
return mutantId;
}
function hasApeBeenMutatedWithType(uint8 serumType, uint256 apeId)
external
view
returns (bool)
{
if (serumType == MEGA_MUTATION_TYPE) {
return megaMutationIdsByApe[apeId] > 0;
}
uint256 mutantId = getMutantId(serumType, apeId);
return _exists(mutantId);
}
function getMutantId(uint256 serumType, uint256 apeId)
internal
pure
returns (uint256)
{
require(
serumType != MEGA_MUTATION_TYPE,
"Mega mutant ID can't be calculated"
);
return (apeId * NUM_MUTANT_TYPES) + serumType + SERUM_MUTATION_OFFSET;
}
function isMinted(uint256 tokenId) external view returns (bool) {
require(
tokenId < MAX_MEGA_MUTATION_ID,
"tokenId outside collection bounds"
);
return _exists(tokenId);
}
function totalApesMutated() external view returns (uint256) {
return totalSupply() - numMutantsMinted;
}
function _baseURI() internal view override returns (string memory) {
return baseURI;
}
function setBaseURI(string memory uri) external onlyOwner {
baseURI = uri;
}
function togglePublicSaleActive() external onlyOwner {
publicSaleActive = !publicSaleActive;
}
function toggleSerumMutationActive() external onlyOwner {
serumMutationActive = !serumMutationActive;
}
function setMutantPrice(uint256 newPrice) external onlyOwner {
mutantPrice = newPrice;
}
}
// SPDX-License-Identifier: MIT
// ERC721A Contracts v3.3.0
// Creator: Chiru Labs
pragma solidity ^0.8.4;
import '@openzeppelin/contracts/token/ERC721/IERC721.sol';
import '@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol';
/**
* @dev Interface of an ERC721A compliant contract.
*/
interface IERC721A is IERC721, IERC721Metadata {
/**
* The caller must own the token or be an approved operator.
*/
error ApprovalCallerNotOwnerNorApproved();
/**
* The token does not exist.
*/
error ApprovalQueryForNonexistentToken();
/**
* The caller cannot approve to their own address.
*/
error ApproveToCaller();
/**
* The caller cannot approve to the current owner.
*/
error ApprovalToCurrentOwner();
/**
* Cannot query the balance for the zero address.
*/
error BalanceQueryForZeroAddress();
/**
* Cannot mint to the zero address.
*/
error MintToZeroAddress();
/**
* The quantity of tokens minted must be more than zero.
*/
error MintZeroQuantity();
/**
* The token does not exist.
*/
error OwnerQueryForNonexistentToken();
/**
* The caller must own the token or be an approved operator.
*/
error TransferCallerNotOwnerNorApproved();
/**
* The token must be owned by `from`.
*/
error TransferFromIncorrectOwner();
/**
* Cannot safely transfer to a contract that does not implement the ERC721Receiver interface.
*/
error TransferToNonERC721ReceiverImplementer();
/**
* Cannot transfer to the zero address.
*/
error TransferToZeroAddress();
/**
* The token does not exist.
*/
error URIQueryForNonexistentToken();
// Compiler will pack this into a single 256bit word.
struct TokenOwnership {
// The address of the owner.
address addr;
// Keeps track of the start time of ownership with minimal overhead for tokenomics.
uint64 startTimestamp;
// Whether the token has been burned.
bool burned;
}
// Compiler will pack this into a single 256bit word.
struct AddressData {
// Realistically, 2**64-1 is more than enough.
uint64 balance;
// Keeps track of mint count with minimal overhead for tokenomics.
uint64 numberMinted;
// Keeps track of burn count with minimal overhead for tokenomics.
uint64 numberBurned;
// For miscellaneous variable(s) pertaining to the address
// (e.g. number of whitelist mint slots used).
// If there are multiple variables, please pack them into a uint64.
uint64 aux;
}
/**
* @dev Returns the total amount of tokens stored by the contract.
*
* Burned tokens are calculated here, use `_totalMinted()` if you want to count just minted tokens.
*/
function totalSupply() external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// ERC721A Contracts v3.3.0
// Creator: Chiru Labs
pragma solidity ^0.8.4;
import './IERC721A.sol';
import '@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol';
import '@openzeppelin/contracts/utils/Address.sol';
import '@openzeppelin/contracts/utils/Context.sol';
import '@openzeppelin/contracts/utils/Strings.sol';
import '@openzeppelin/contracts/utils/introspection/ERC165.sol';
/**
* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
* the Metadata extension. Built to optimize for lower gas during batch mints.
*
* Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).
*
* Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
*
* Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
*/
contract ERC721A is Context, ERC165, IERC721A {
using Address for address;
using Strings for uint256;
// The tokenId of the next token to be minted.
uint256 internal _currentIndex;
// The number of tokens burned.
uint256 internal _burnCounter;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Mapping from token ID to ownership details
// An empty struct value does not necessarily mean the token is unowned. See _ownershipOf implementation for details.
mapping(uint256 => TokenOwnership) internal _ownerships;
// Mapping owner address to address data
mapping(address => AddressData) private _addressData;
// 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;
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
_currentIndex = _startTokenId();
}
/**
* To change the starting tokenId, please override this function.
*/
function _startTokenId() internal view virtual returns (uint256) {
return 0;
}
/**
* @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.
*/
function totalSupply() public view override returns (uint256) {
// Counter underflow is impossible as _burnCounter cannot be incremented
// more than _currentIndex - _startTokenId() times
unchecked {
return _currentIndex - _burnCounter - _startTokenId();
}
}
/**
* Returns the total amount of tokens minted in the contract.
*/
function _totalMinted() internal view returns (uint256) {
// Counter underflow is impossible as _currentIndex does not decrement,
// and it is initialized to _startTokenId()
unchecked {
return _currentIndex - _startTokenId();
}
}
/**
* @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 override returns (uint256) {
if (owner == address(0)) revert BalanceQueryForZeroAddress();
return uint256(_addressData[owner].balance);
}
/**
* Returns the number of tokens minted by `owner`.
*/
function _numberMinted(address owner) internal view returns (uint256) {
return uint256(_addressData[owner].numberMinted);
}
/**
* Returns the number of tokens burned by or on behalf of `owner`.
*/
function _numberBurned(address owner) internal view returns (uint256) {
return uint256(_addressData[owner].numberBurned);
}
/**
* Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
*/
function _getAux(address owner) internal view returns (uint64) {
return _addressData[owner].aux;
}
/**
* Sets the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
* If there are multiple variables, please pack them into a uint64.
*/
function _setAux(address owner, uint64 aux) internal {
_addressData[owner].aux = aux;
}
/**
* Gas spent here starts off proportional to the maximum mint batch size.
* It gradually moves to O(1) as tokens get transferred around in the collection over time.
*/
function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
uint256 curr = tokenId;
unchecked {
if (_startTokenId() <= curr) if (curr < _currentIndex) {
TokenOwnership memory ownership = _ownerships[curr];
if (!ownership.burned) {
if (ownership.addr != address(0)) {
return ownership;
}
// Invariant:
// There will always be an ownership that has an address and is not burned
// before an ownership that does not have an address and is not burned.
// Hence, curr will not underflow.
while (true) {
curr--;
ownership = _ownerships[curr];
if (ownership.addr != address(0)) {
return ownership;
}
}
}
}
}
revert OwnerQueryForNonexistentToken();
}
/**
* @dev See {IERC721-ownerOf}.
*/
function ownerOf(uint256 tokenId) public view override returns (address) {
return _ownershipOf(tokenId).addr;
}
/**
* @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) {
if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
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 overriden in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return '';
}
/**
* @dev See {IERC721-approve}.
*/
function approve(address to, uint256 tokenId) public override {
address owner = ERC721A.ownerOf(tokenId);
if (to == owner) revert ApprovalToCurrentOwner();
if (_msgSender() != owner) if(!isApprovedForAll(owner, _msgSender())) {
revert ApprovalCallerNotOwnerNorApproved();
}
_approve(to, tokenId, owner);
}
/**
* @dev See {IERC721-getApproved}.
*/
function getApproved(uint256 tokenId) public view override returns (address) {
if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();
return _tokenApprovals[tokenId];
}
/**
* @dev See {IERC721-setApprovalForAll}.
*/
function setApprovalForAll(address operator, bool approved) public virtual override {
if (operator == _msgSender()) revert ApproveToCaller();
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_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 {
_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 {
_transfer(from, to, tokenId);
if (to.isContract()) if(!_checkContractOnERC721Received(from, to, tokenId, _data)) {
revert TransferToNonERC721ReceiverImplementer();
}
}
/**
* @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`),
*/
function _exists(uint256 tokenId) internal view returns (bool) {
return _startTokenId() <= tokenId && tokenId < _currentIndex && !_ownerships[tokenId].burned;
}
/**
* @dev Equivalent to `_safeMint(to, quantity, '')`.
*/
function _safeMint(address to, uint256 quantity) internal {
_safeMint(to, quantity, '');
}
/**
* @dev Safely mints `quantity` tokens and transfers them to `to`.
*
* Requirements:
*
* - If `to` refers to a smart contract, it must implement
* {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
* - `quantity` must be greater than 0.
*
* Emits a {Transfer} event.
*/
function _safeMint(
address to,
uint256 quantity,
bytes memory _data
) internal {
uint256 startTokenId = _currentIndex;
if (to == address(0)) revert MintToZeroAddress();
if (quantity == 0) revert MintZeroQuantity();
_beforeTokenTransfers(address(0), to, startTokenId, quantity);
// Overflows are incredibly unrealistic.
// balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
// updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
unchecked {
_addressData[to].balance += uint64(quantity);
_addressData[to].numberMinted += uint64(quantity);
_ownerships[startTokenId].addr = to;
_ownerships[startTokenId].startTimestamp = uint64(block.timestamp);
uint256 updatedIndex = startTokenId;
uint256 end = updatedIndex + quantity;
if (to.isContract()) {
do {
emit Transfer(address(0), to, updatedIndex);
if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {
revert TransferToNonERC721ReceiverImplementer();
}
} while (updatedIndex < end);
// Reentrancy protection
if (_currentIndex != startTokenId) revert();
} else {
do {
emit Transfer(address(0), to, updatedIndex++);
} while (updatedIndex < end);
}
_currentIndex = updatedIndex;
}
_afterTokenTransfers(address(0), to, startTokenId, quantity);
}
/**
* @dev Mints `quantity` tokens and transfers them to `to`.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `quantity` must be greater than 0.
*
* Emits a {Transfer} event.
*/
function _mint(address to, uint256 quantity) internal {
uint256 startTokenId = _currentIndex;
if (to == address(0)) revert MintToZeroAddress();
if (quantity == 0) revert MintZeroQuantity();
_beforeTokenTransfers(address(0), to, startTokenId, quantity);
// Overflows are incredibly unrealistic.
// balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
// updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
unchecked {
_addressData[to].balance += uint64(quantity);
_addressData[to].numberMinted += uint64(quantity);
_ownerships[startTokenId].addr = to;
_ownerships[startTokenId].startTimestamp = uint64(block.timestamp);
uint256 updatedIndex = startTokenId;
uint256 end = updatedIndex + quantity;
do {
emit Transfer(address(0), to, updatedIndex++);
} while (updatedIndex < end);
_currentIndex = updatedIndex;
}
_afterTokenTransfers(address(0), to, startTokenId, quantity);
}
/**
* @dev Transfers `tokenId` from `from` to `to`.
*
* 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
) private {
TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
if (prevOwnership.addr != from) revert TransferFromIncorrectOwner();
bool isApprovedOrOwner = (_msgSender() == from ||
isApprovedForAll(from, _msgSender()) ||
getApproved(tokenId) == _msgSender());
if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
if (to == address(0)) revert TransferToZeroAddress();
_beforeTokenTransfers(from, to, tokenId, 1);
// Clear approvals from the previous owner
_approve(address(0), tokenId, from);
// Underflow of the sender's balance is impossible because we check for
// ownership above and the recipient's balance can't realistically overflow.
// Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
unchecked {
_addressData[from].balance -= 1;
_addressData[to].balance += 1;
TokenOwnership storage currSlot = _ownerships[tokenId];
currSlot.addr = to;
currSlot.startTimestamp = uint64(block.timestamp);
// If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
// Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
uint256 nextTokenId = tokenId + 1;
TokenOwnership storage nextSlot = _ownerships[nextTokenId];
if (nextSlot.addr == address(0)) {
// This will suffice for checking _exists(nextTokenId),
// as a burned slot cannot contain the zero address.
if (nextTokenId != _currentIndex) {
nextSlot.addr = from;
nextSlot.startTimestamp = prevOwnership.startTimestamp;
}
}
}
emit Transfer(from, to, tokenId);
_afterTokenTransfers(from, to, tokenId, 1);
}
/**
* @dev Equivalent to `_burn(tokenId, false)`.
*/
function _burn(uint256 tokenId) internal virtual {
_burn(tokenId, false);
}
/**
* @dev Destroys `tokenId`.
* The approval is cleared when the token is burned.
*
* Requirements:
*
* - `tokenId` must exist.
*
* Emits a {Transfer} event.
*/
function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
address from = prevOwnership.addr;
if (approvalCheck) {
bool isApprovedOrOwner = (_msgSender() == from ||
isApprovedForAll(from, _msgSender()) ||
getApproved(tokenId) == _msgSender());
if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
}
_beforeTokenTransfers(from, address(0), tokenId, 1);
// Clear approvals from the previous owner
_approve(address(0), tokenId, from);
// Underflow of the sender's balance is impossible because we check for
// ownership above and the recipient's balance can't realistically overflow.
// Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
unchecked {
AddressData storage addressData = _addressData[from];
addressData.balance -= 1;
addressData.numberBurned += 1;
// Keep track of who burned the token, and the timestamp of burning.
TokenOwnership storage currSlot = _ownerships[tokenId];
currSlot.addr = from;
currSlot.startTimestamp = uint64(block.timestamp);
currSlot.burned = true;
// If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.
// Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
uint256 nextTokenId = tokenId + 1;
TokenOwnership storage nextSlot = _ownerships[nextTokenId];
if (nextSlot.addr == address(0)) {
// This will suffice for checking _exists(nextTokenId),
// as a burned slot cannot contain the zero address.
if (nextTokenId != _currentIndex) {
nextSlot.addr = from;
nextSlot.startTimestamp = prevOwnership.startTimestamp;
}
}
}
emit Transfer(from, address(0), tokenId);
_afterTokenTransfers(from, address(0), tokenId, 1);
// Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
unchecked {
_burnCounter++;
}
}
/**
* @dev Approve `to` to operate on `tokenId`
*
* Emits a {Approval} event.
*/
function _approve(
address to,
uint256 tokenId,
address owner
) private {
_tokenApprovals[tokenId] = to;
emit Approval(owner, to, tokenId);
}
/**
* @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target 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 _checkContractOnERC721Received(
address from,
address to,
uint256 tokenId,
bytes memory _data
) private returns (bool) {
try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
return retval == IERC721Receiver(to).onERC721Received.selector;
} catch (bytes memory reason) {
if (reason.length == 0) {
revert TransferToNonERC721ReceiverImplementer();
} else {
assembly {
revert(add(32, reason), mload(reason))
}
}
}
}
/**
* @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
* And also called before burning one token.
*
* startTokenId - the first token id to be transferred
* quantity - the amount to be transferred
*
* 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, `tokenId` will be burned by `from`.
* - `from` and `to` are never both zero.
*/
function _beforeTokenTransfers(
address from,
address to,
uint256 startTokenId,
uint256 quantity
) internal virtual {}
/**
* @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
* minting.
* And also called after one token has been burned.
*
* startTokenId - the first token id to be transferred
* quantity - the amount to be transferred
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
* transferred to `to`.
* - When `from` is zero, `tokenId` has been minted for `to`.
* - When `to` is zero, `tokenId` has been burned by `from`.
* - `from` and `to` are never both zero.
*/
function _afterTokenTransfers(
address from,
address to,
uint256 startTokenId,
uint256 quantity
) internal virtual {}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.6;
import "@openzeppelin/contracts/token/ERC1155/ERC1155.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
contract BoredBitsChemistryClub is ERC1155, Ownable {
using Strings for uint256;
bool public mintOpen = false;
address private mutationContract;
string private baseURI;
bytes32 public m1MerkleRoot;
bytes32 public m2MerkleRoot;
bytes32 public megaMerkleRoot;
mapping(uint256 => bool) public validSerumTypes;
mapping(uint256 => uint256) public maxSerums;
mapping(address => mapping(uint => bool)) private claimed;
mapping(uint => uint) public assetNonce;
string public name = "Bored Bits Chemistry Club";
string public symbol = "BBCC";
modifier notClaimed(uint idx){
require(!claimed[msg.sender][idx],"You cannot claim this again");
_;
}
modifier opened(){
require(mintOpen, "mint is closed");
_;
}
constructor(string memory _baseURI) ERC1155(_baseURI) {
baseURI = _baseURI;
validSerumTypes[0] = true;
validSerumTypes[1] = true;
validSerumTypes[69] = true;
maxSerums[0] = 7500;
maxSerums[1] = 2492;
maxSerums[69] = 8;
}
function setM1MerkleRoot(bytes32 root) external onlyOwner {
m1MerkleRoot = root;
}
function setM2MerkleRoot(bytes32 root) external onlyOwner {
m2MerkleRoot = root;
}
function setMegaMerkleRoot(bytes32 root) external onlyOwner {
megaMerkleRoot = root;
}
function toggleMint() external onlyOwner {
mintOpen = !mintOpen;
}
function claimM1(uint qty, bytes32[] memory proof) external opened notClaimed(0) {
require(MerkleProof.verify(proof, m1MerkleRoot, keccak256(abi.encodePacked(msg.sender, qty))), "Invalid proof");
require(assetNonce[0] + qty <= maxSerums[0], "Total exceeded");
claimed[msg.sender][0] = true;
assetNonce[0] += qty;
_mint(msg.sender, 0, qty, "");
}
function claimM2(uint qty, bytes32[] memory proof) external opened notClaimed(1) {
require(MerkleProof.verify(proof, m2MerkleRoot, keccak256(abi.encodePacked(msg.sender, qty))), "Invalid proof");
require(assetNonce[1] + qty <= maxSerums[1], "Total exceeded");
claimed[msg.sender][1] = true;
assetNonce[1] += qty;
_mint(msg.sender, 1, qty, "");
}
function claimMega(uint qty, bytes32[] memory proof) external opened notClaimed(69) {
require(MerkleProof.verify(proof, megaMerkleRoot, keccak256(abi.encodePacked(msg.sender, qty))), "Invalid proof");
require(assetNonce[69] + qty <= maxSerums[69], "Total exceeded");
claimed[msg.sender][69] = true;
assetNonce[69] += qty;
_mint(msg.sender, 69, qty, "");
}
function mintBatch(uint256[] memory ids, uint256[] memory amounts)
external
onlyOwner
{
_mintBatch(owner(), ids, amounts, "");
}
function setMutationContractAddress(address mutationContractAddress)
external
onlyOwner
{
mutationContract = mutationContractAddress;
}
function burnSerumForAddress(uint256 typeId, address burnTokenAddress)
external
{
require(msg.sender == mutationContract, "Invalid burner address");
_burn(burnTokenAddress, typeId, 1);
}
function updateBaseUri(string memory _baseURI) external onlyOwner {
baseURI = _baseURI;
}
function uri(uint256 typeId)
public
view
override
returns (string memory)
{
require(
validSerumTypes[typeId],
"URI requested for invalid serum type"
);
return
bytes(baseURI).length > 0
? string(abi.encodePacked(baseURI, typeId.toString()))
: baseURI;
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.6;
import "@openzeppelin/contracts/access/Ownable.sol";
import "./erc721a/contracts/ERC721A.sol";
import "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
contract BBYC is ERC721A, Ownable {
uint public price = 0.03 ether;
uint public maxSupply = 10000;
uint public maxTx = 20;
bytes32 public merkleRoot;
bool private mintOpen = false;
bool private presaleOpen = false;
string internal baseTokenURI = '';
constructor() ERC721A("Bored Bits Yacht Club", "BBYC") {}
function toggleMint() external onlyOwner {
mintOpen = !mintOpen;
}
function togglePresale() external onlyOwner {
presaleOpen = !presaleOpen;
}
function setPrice(uint newPrice) external onlyOwner {
price = newPrice;
}
function setBaseTokenURI(string calldata _uri) external onlyOwner {
baseTokenURI = _uri;
}
function setMerkleRoot(bytes32 root) external onlyOwner {
merkleRoot = root;
}
function setMaxSupply(uint newSupply) external onlyOwner {
maxSupply = newSupply;
}
function setMaxTx(uint newMax) external onlyOwner {
maxTx = newMax;
}
function _baseURI() internal override view returns (string memory) {
return baseTokenURI;
}
function buyTo(address to, uint qty) external onlyOwner {
_mintTo(to, qty);
}
function buy(uint qty, bytes32[] memory proof) external payable {
require(presaleOpen, "store closed");
require(verify(proof), "address not in whitelist");
_buy(qty);
}
function buy(uint qty) external payable {
require(mintOpen, "store closed");
_buy(qty);
}
function _buy(uint qty) internal {
require(qty <= maxTx && qty > 0, "TRANSACTION: qty of mints not alowed");
uint free = balanceOf(_msgSender()) == 0 ? 1 : 0;
require(msg.value >= price * (qty - free), "PAYMENT: invalid value");
_mintTo(_msgSender(), qty);
}
function mint(uint qty) external payable {
require(qty <= maxTx && qty > 0, "TRANSACTION: qty of mints not alowed");
require(msg.value >= price * qty, "PAYMENT: invalid value");
_mintTo(_msgSender(), qty);
}
function _mintTo(address to, uint qty) internal {
require(qty + totalSupply() <= maxSupply, "SUPPLY: Value exceeds totalSupply");
_mint(to, qty);
}
function withdraw() external onlyOwner {
payable(_msgSender()).transfer(address(this).balance);
}
function verify(bytes32[] memory proof) internal view returns (bool) {
bytes32 leaf = keccak256(abi.encodePacked(msg.sender));
return MerkleProof.verify(proof, merkleRoot, leaf);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/cryptography/MerkleProof.sol)
pragma solidity ^0.8.0;
/**
* @dev These functions deal with verification of Merkle Trees proofs.
*
* The proofs can be generated using the JavaScript library
* https://github.com/miguelmota/merkletreejs[merkletreejs].
* Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
*
* See `test/utils/cryptography/MerkleProof.test.js` for some examples.
*
* WARNING: You should avoid using leaf values that are 64 bytes long prior to
* hashing, or use a hash function other than keccak256 for hashing leaves.
* This is because the concatenation of a sorted pair of internal nodes in
* the merkle tree could be reinterpreted as a leaf value.
*/
library MerkleProof {
/**
* @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
* defined by `root`. For this, a `proof` must be provided, containing
* sibling hashes on the branch from the leaf to the root of the tree. Each
* pair of leaves and each pair of pre-images are assumed to be sorted.
*/
function verify(
bytes32[] memory proof,
bytes32 root,
bytes32 leaf
) internal pure returns (bool) {
return processProof(proof, leaf) == root;
}
/**
* @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
* from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
* hash matches the root of the tree. When processing the proof, the pairs
* of leafs & pre-images are assumed to be sorted.
*
* _Available since v4.4._
*/
function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
bytes32 computedHash = leaf;
for (uint256 i = 0; i < proof.length; i++) {
bytes32 proofElement = proof[i];
if (computedHash <= proofElement) {
// Hash(current computed hash + current element of the proof)
computedHash = _efficientHash(computedHash, proofElement);
} else {
// Hash(current element of the proof + current computed hash)
computedHash = _efficientHash(proofElement, computedHash);
}
}
return computedHash;
}
function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
assembly {
mstore(0x00, a)
mstore(0x20, b)
value := keccak256(0x00, 0x40)
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
/**
* @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);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value
) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC721.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);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)
pragma solidity ^0.8.0;
import "../IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Enumerable is IERC721 {
/**
* @dev Returns the total amount of tokens stored by the contract.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns a token ID owned by `owner` at a given `index` of its token list.
* Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);
/**
* @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
* Use along with {totalSupply} to enumerate all tokens.
*/
function tokenByIndex(uint256 index) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721Enumerable.sol)
pragma solidity ^0.8.0;
import "../ERC721.sol";
import "./IERC721Enumerable.sol";
/**
* @dev This implements an optional extension of {ERC721} defined in the EIP that adds
* enumerability of all the token ids in the contract as well as all token ids owned by each
* account.
*/
abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
// Mapping from owner to list of owned token IDs
mapping(address => mapping(uint256 => uint256)) private _ownedTokens;
// Mapping from token ID to index of the owner tokens list
mapping(uint256 => uint256) private _ownedTokensIndex;
// Array with all token ids, used for enumeration
uint256[] private _allTokens;
// Mapping from token id to position in the allTokens array
mapping(uint256 => uint256) private _allTokensIndex;
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
return _ownedTokens[owner][index];
}
/**
* @dev See {IERC721Enumerable-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _allTokens.length;
}
/**
* @dev See {IERC721Enumerable-tokenByIndex}.
*/
function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
require(index < ERC721Enumerable.totalSupply(), "ERC721Enumerable: global index out of bounds");
return _allTokens[index];
}
/**
* @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` cannot be the zero address.
* - `to` cannot be the zero address.
*
* 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 override {
super._beforeTokenTransfer(from, to, tokenId);
if (from == address(0)) {
_addTokenToAllTokensEnumeration(tokenId);
} else if (from != to) {
_removeTokenFromOwnerEnumeration(from, tokenId);
}
if (to == address(0)) {
_removeTokenFromAllTokensEnumeration(tokenId);
} else if (to != from) {
_addTokenToOwnerEnumeration(to, tokenId);
}
}
/**
* @dev Private function to add a token to this extension's ownership-tracking data structures.
* @param to address representing the new owner of the given token ID
* @param tokenId uint256 ID of the token to be added to the tokens list of the given address
*/
function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
uint256 length = ERC721.balanceOf(to);
_ownedTokens[to][length] = tokenId;
_ownedTokensIndex[tokenId] = length;
}
/**
* @dev Private function to add a token to this extension's token tracking data structures.
* @param tokenId uint256 ID of the token to be added to the tokens list
*/
function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
_allTokensIndex[tokenId] = _allTokens.length;
_allTokens.push(tokenId);
}
/**
* @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
* while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
* gas optimizations e.g. when performing a transfer operation (avoiding double writes).
* This has O(1) time complexity, but alters the order of the _ownedTokens array.
* @param from address representing the previous owner of the given token ID
* @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
*/
function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
// To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
uint256 tokenIndex = _ownedTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary
if (tokenIndex != lastTokenIndex) {
uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
_ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
}
// This also deletes the contents at the last position of the array
delete _ownedTokensIndex[tokenId];
delete _ownedTokens[from][lastTokenIndex];
}
/**
* @dev Private function to remove a token from this extension's token tracking data structures.
* This has O(1) time complexity, but alters the order of the _allTokens array.
* @param tokenId uint256 ID of the token to be removed from the tokens list
*/
function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
// To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = _allTokens.length - 1;
uint256 tokenIndex = _allTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
// rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
// an 'if' statement (like in _removeTokenFromOwnerEnumeration)
uint256 lastTokenId = _allTokens[lastTokenIndex];
_allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
// This also deletes the contents at the last position of the array
delete _allTokensIndex[tokenId];
_allTokens.pop();
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)
pragma solidity ^0.8.0;
/**
* @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);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721.sol)
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* 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 be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev 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);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/ERC721.sol)
pragma solidity ^0.8.0;
import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.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: balance query for the zero address");
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: owner query for nonexistent token");
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) {
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
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 owner nor approved for all"
);
_approve(to, tokenId);
}
/**
* @dev See {IERC721-getApproved}.
*/
function getApproved(uint256 tokenId) public view virtual override returns (address) {
require(_exists(tokenId), "ERC721: approved query for nonexistent token");
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: transfer caller is not 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: transfer caller is not 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) {
require(_exists(tokenId), "ERC721: operator query for nonexistent token");
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 a {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 a {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 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 {
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 {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC1155/extensions/IERC1155MetadataURI.sol)
pragma solidity ^0.8.0;
import "../IERC1155.sol";
/**
* @dev Interface of the optional ERC1155MetadataExtension interface, as defined
* in the https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[EIP].
*
* _Available since v3.1._
*/
interface IERC1155MetadataURI is IERC1155 {
/**
* @dev Returns the URI for token type `id`.
*
* If the `\{id\}` substring is present in the URI, it must be replaced by
* clients with the actual token type ID.
*/
function uri(uint256 id) external view returns (string memory);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC1155/IERC1155Receiver.sol)
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev _Available since v3.1._
*/
interface IERC1155Receiver is IERC165 {
/**
* @dev Handles the receipt of a single ERC1155 token type. This function is
* called at the end of a `safeTransferFrom` after the balance has been updated.
*
* NOTE: To accept the transfer, this must return
* `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
* (i.e. 0xf23a6e61, or its own function selector).
*
* @param operator The address which initiated the transfer (i.e. msg.sender)
* @param from The address which previously owned the token
* @param id The ID of the token being transferred
* @param value The amount of tokens being transferred
* @param data Additional data with no specified format
* @return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` if transfer is allowed
*/
function onERC1155Received(
address operator,
address from,
uint256 id,
uint256 value,
bytes calldata data
) external returns (bytes4);
/**
* @dev Handles the receipt of a multiple ERC1155 token types. This function
* is called at the end of a `safeBatchTransferFrom` after the balances have
* been updated.
*
* NOTE: To accept the transfer(s), this must return
* `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
* (i.e. 0xbc197c81, or its own function selector).
*
* @param operator The address which initiated the batch transfer (i.e. msg.sender)
* @param from The address which previously owned the token
* @param ids An array containing ids of each token being transferred (order and length must match values array)
* @param values An array containing amounts of each token being transferred (order and length must match ids array)
* @param data Additional data with no specified format
* @return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if transfer is allowed
*/
function onERC1155BatchReceived(
address operator,
address from,
uint256[] calldata ids,
uint256[] calldata values,
bytes calldata data
) external returns (bytes4);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC1155/IERC1155.sol)
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC1155 compliant contract, as defined in the
* https://eips.ethereum.org/EIPS/eip-1155[EIP].
*
* _Available since v3.1._
*/
interface IERC1155 is IERC165 {
/**
* @dev Emitted when `value` tokens of token type `id` are transferred from `from` to `to` by `operator`.
*/
event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);
/**
* @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
* transfers.
*/
event TransferBatch(
address indexed operator,
address indexed from,
address indexed to,
uint256[] ids,
uint256[] values
);
/**
* @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
* `approved`.
*/
event ApprovalForAll(address indexed account, address indexed operator, bool approved);
/**
* @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
*
* If an {URI} event was emitted for `id`, the standard
* https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
* returned by {IERC1155MetadataURI-uri}.
*/
event URI(string value, uint256 indexed id);
/**
* @dev Returns the amount of tokens of token type `id` owned by `account`.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function balanceOf(address account, uint256 id) external view returns (uint256);
/**
* @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}.
*
* Requirements:
*
* - `accounts` and `ids` must have the same length.
*/
function balanceOfBatch(address[] calldata accounts, uint256[] calldata ids)
external
view
returns (uint256[] memory);
/**
* @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
*
* Emits an {ApprovalForAll} event.
*
* Requirements:
*
* - `operator` cannot be the caller.
*/
function setApprovalForAll(address operator, bool approved) external;
/**
* @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
*
* See {setApprovalForAll}.
*/
function isApprovedForAll(address account, address operator) external view returns (bool);
/**
* @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
*
* Emits a {TransferSingle} event.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - If the caller is not `from`, it must be have been approved to spend ``from``'s tokens via {setApprovalForAll}.
* - `from` must have a balance of tokens of type `id` of at least `amount`.
* - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
* acceptance magic value.
*/
function safeTransferFrom(
address from,
address to,
uint256 id,
uint256 amount,
bytes calldata data
) external;
/**
* @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
*
* Emits a {TransferBatch} event.
*
* Requirements:
*
* - `ids` and `amounts` must have the same length.
* - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
* acceptance magic value.
*/
function safeBatchTransferFrom(
address from,
address to,
uint256[] calldata ids,
uint256[] calldata amounts,
bytes calldata data
) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC1155/ERC1155.sol)
pragma solidity ^0.8.0;
import "./IERC1155.sol";
import "./IERC1155Receiver.sol";
import "./extensions/IERC1155MetadataURI.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/introspection/ERC165.sol";
/**
* @dev Implementation of the basic standard multi-token.
* See https://eips.ethereum.org/EIPS/eip-1155
* Originally based on code by Enjin: https://github.com/enjin/erc-1155
*
* _Available since v3.1._
*/
contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI {
using Address for address;
// Mapping from token ID to account balances
mapping(uint256 => mapping(address => uint256)) private _balances;
// Mapping from account to operator approvals
mapping(address => mapping(address => bool)) private _operatorApprovals;
// Used as the URI for all token types by relying on ID substitution, e.g. https://token-cdn-domain/{id}.json
string private _uri;
/**
* @dev See {_setURI}.
*/
constructor(string memory uri_) {
_setURI(uri_);
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
return
interfaceId == type(IERC1155).interfaceId ||
interfaceId == type(IERC1155MetadataURI).interfaceId ||
super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC1155MetadataURI-uri}.
*
* This implementation returns the same URI for *all* token types. It relies
* on the token type ID substitution mechanism
* https://eips.ethereum.org/EIPS/eip-1155#metadata[defined in the EIP].
*
* Clients calling this function must replace the `\{id\}` substring with the
* actual token type ID.
*/
function uri(uint256) public view virtual override returns (string memory) {
return _uri;
}
/**
* @dev See {IERC1155-balanceOf}.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function balanceOf(address account, uint256 id) public view virtual override returns (uint256) {
require(account != address(0), "ERC1155: balance query for the zero address");
return _balances[id][account];
}
/**
* @dev See {IERC1155-balanceOfBatch}.
*
* Requirements:
*
* - `accounts` and `ids` must have the same length.
*/
function balanceOfBatch(address[] memory accounts, uint256[] memory ids)
public
view
virtual
override
returns (uint256[] memory)
{
require(accounts.length == ids.length, "ERC1155: accounts and ids length mismatch");
uint256[] memory batchBalances = new uint256[](accounts.length);
for (uint256 i = 0; i < accounts.length; ++i) {
batchBalances[i] = balanceOf(accounts[i], ids[i]);
}
return batchBalances;
}
/**
* @dev See {IERC1155-setApprovalForAll}.
*/
function setApprovalForAll(address operator, bool approved) public virtual override {
_setApprovalForAll(_msgSender(), operator, approved);
}
/**
* @dev See {IERC1155-isApprovedForAll}.
*/
function isApprovedForAll(address account, address operator) public view virtual override returns (bool) {
return _operatorApprovals[account][operator];
}
/**
* @dev See {IERC1155-safeTransferFrom}.
*/
function safeTransferFrom(
address from,
address to,
uint256 id,
uint256 amount,
bytes memory data
) public virtual override {
require(
from == _msgSender() || isApprovedForAll(from, _msgSender()),
"ERC1155: caller is not owner nor approved"
);
_safeTransferFrom(from, to, id, amount, data);
}
/**
* @dev See {IERC1155-safeBatchTransferFrom}.
*/
function safeBatchTransferFrom(
address from,
address to,
uint256[] memory ids,
uint256[] memory amounts,
bytes memory data
) public virtual override {
require(
from == _msgSender() || isApprovedForAll(from, _msgSender()),
"ERC1155: transfer caller is not owner nor approved"
);
_safeBatchTransferFrom(from, to, ids, amounts, data);
}
/**
* @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
*
* Emits a {TransferSingle} event.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `from` must have a balance of tokens of type `id` of at least `amount`.
* - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
* acceptance magic value.
*/
function _safeTransferFrom(
address from,
address to,
uint256 id,
uint256 amount,
bytes memory data
) internal virtual {
require(to != address(0), "ERC1155: transfer to the zero address");
address operator = _msgSender();
uint256[] memory ids = _asSingletonArray(id);
uint256[] memory amounts = _asSingletonArray(amount);
_beforeTokenTransfer(operator, from, to, ids, amounts, data);
uint256 fromBalance = _balances[id][from];
require(fromBalance >= amount, "ERC1155: insufficient balance for transfer");
unchecked {
_balances[id][from] = fromBalance - amount;
}
_balances[id][to] += amount;
emit TransferSingle(operator, from, to, id, amount);
_afterTokenTransfer(operator, from, to, ids, amounts, data);
_doSafeTransferAcceptanceCheck(operator, from, to, id, amount, data);
}
/**
* @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {_safeTransferFrom}.
*
* Emits a {TransferBatch} event.
*
* Requirements:
*
* - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
* acceptance magic value.
*/
function _safeBatchTransferFrom(
address from,
address to,
uint256[] memory ids,
uint256[] memory amounts,
bytes memory data
) internal virtual {
require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch");
require(to != address(0), "ERC1155: transfer to the zero address");
address operator = _msgSender();
_beforeTokenTransfer(operator, from, to, ids, amounts, data);
for (uint256 i = 0; i < ids.length; ++i) {
uint256 id = ids[i];
uint256 amount = amounts[i];
uint256 fromBalance = _balances[id][from];
require(fromBalance >= amount, "ERC1155: insufficient balance for transfer");
unchecked {
_balances[id][from] = fromBalance - amount;
}
_balances[id][to] += amount;
}
emit TransferBatch(operator, from, to, ids, amounts);
_afterTokenTransfer(operator, from, to, ids, amounts, data);
_doSafeBatchTransferAcceptanceCheck(operator, from, to, ids, amounts, data);
}
/**
* @dev Sets a new URI for all token types, by relying on the token type ID
* substitution mechanism
* https://eips.ethereum.org/EIPS/eip-1155#metadata[defined in the EIP].
*
* By this mechanism, any occurrence of the `\{id\}` substring in either the
* URI or any of the amounts in the JSON file at said URI will be replaced by
* clients with the token type ID.
*
* For example, the `https://token-cdn-domain/\{id\}.json` URI would be
* interpreted by clients as
* `https://token-cdn-domain/000000000000000000000000000000000000000000000000000000000004cce0.json`
* for token type ID 0x4cce0.
*
* See {uri}.
*
* Because these URIs cannot be meaningfully represented by the {URI} event,
* this function emits no events.
*/
function _setURI(string memory newuri) internal virtual {
_uri = newuri;
}
/**
* @dev Creates `amount` tokens of token type `id`, and assigns them to `to`.
*
* Emits a {TransferSingle} event.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
* acceptance magic value.
*/
function _mint(
address to,
uint256 id,
uint256 amount,
bytes memory data
) internal virtual {
require(to != address(0), "ERC1155: mint to the zero address");
address operator = _msgSender();
uint256[] memory ids = _asSingletonArray(id);
uint256[] memory amounts = _asSingletonArray(amount);
_beforeTokenTransfer(operator, address(0), to, ids, amounts, data);
_balances[id][to] += amount;
emit TransferSingle(operator, address(0), to, id, amount);
_afterTokenTransfer(operator, address(0), to, ids, amounts, data);
_doSafeTransferAcceptanceCheck(operator, address(0), to, id, amount, data);
}
/**
* @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {_mint}.
*
* Requirements:
*
* - `ids` and `amounts` must have the same length.
* - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
* acceptance magic value.
*/
function _mintBatch(
address to,
uint256[] memory ids,
uint256[] memory amounts,
bytes memory data
) internal virtual {
require(to != address(0), "ERC1155: mint to the zero address");
require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch");
address operator = _msgSender();
_beforeTokenTransfer(operator, address(0), to, ids, amounts, data);
for (uint256 i = 0; i < ids.length; i++) {
_balances[ids[i]][to] += amounts[i];
}
emit TransferBatch(operator, address(0), to, ids, amounts);
_afterTokenTransfer(operator, address(0), to, ids, amounts, data);
_doSafeBatchTransferAcceptanceCheck(operator, address(0), to, ids, amounts, data);
}
/**
* @dev Destroys `amount` tokens of token type `id` from `from`
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `from` must have at least `amount` tokens of token type `id`.
*/
function _burn(
address from,
uint256 id,
uint256 amount
) internal virtual {
require(from != address(0), "ERC1155: burn from the zero address");
address operator = _msgSender();
uint256[] memory ids = _asSingletonArray(id);
uint256[] memory amounts = _asSingletonArray(amount);
_beforeTokenTransfer(operator, from, address(0), ids, amounts, "");
uint256 fromBalance = _balances[id][from];
require(fromBalance >= amount, "ERC1155: burn amount exceeds balance");
unchecked {
_balances[id][from] = fromBalance - amount;
}
emit TransferSingle(operator, from, address(0), id, amount);
_afterTokenTransfer(operator, from, address(0), ids, amounts, "");
}
/**
* @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {_burn}.
*
* Requirements:
*
* - `ids` and `amounts` must have the same length.
*/
function _burnBatch(
address from,
uint256[] memory ids,
uint256[] memory amounts
) internal virtual {
require(from != address(0), "ERC1155: burn from the zero address");
require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch");
address operator = _msgSender();
_beforeTokenTransfer(operator, from, address(0), ids, amounts, "");
for (uint256 i = 0; i < ids.length; i++) {
uint256 id = ids[i];
uint256 amount = amounts[i];
uint256 fromBalance = _balances[id][from];
require(fromBalance >= amount, "ERC1155: burn amount exceeds balance");
unchecked {
_balances[id][from] = fromBalance - amount;
}
}
emit TransferBatch(operator, from, address(0), ids, amounts);
_afterTokenTransfer(operator, from, address(0), ids, amounts, "");
}
/**
* @dev Approve `operator` to operate on all of `owner` tokens
*
* Emits a {ApprovalForAll} event.
*/
function _setApprovalForAll(
address owner,
address operator,
bool approved
) internal virtual {
require(owner != operator, "ERC1155: setting approval status for self");
_operatorApprovals[owner][operator] = approved;
emit ApprovalForAll(owner, operator, approved);
}
/**
* @dev Hook that is called before any token transfer. This includes minting
* and burning, as well as batched variants.
*
* The same hook is called on both single and batched variants. For single
* transfers, the length of the `id` and `amount` arrays will be 1.
*
* Calling conditions (for each `id` and `amount` pair):
*
* - When `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* of token type `id` will be transferred to `to`.
* - When `from` is zero, `amount` tokens of token type `id` will be minted
* for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens of token type `id`
* will be burned.
* - `from` and `to` are never both zero.
* - `ids` and `amounts` have the same, non-zero length.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address operator,
address from,
address to,
uint256[] memory ids,
uint256[] memory amounts,
bytes memory data
) internal virtual {}
/**
* @dev Hook that is called after any token transfer. This includes minting
* and burning, as well as batched variants.
*
* The same hook is called on both single and batched variants. For single
* transfers, the length of the `id` and `amount` arrays will be 1.
*
* Calling conditions (for each `id` and `amount` pair):
*
* - When `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* of token type `id` will be transferred to `to`.
* - When `from` is zero, `amount` tokens of token type `id` will be minted
* for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens of token type `id`
* will be burned.
* - `from` and `to` are never both zero.
* - `ids` and `amounts` have the same, non-zero length.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(
address operator,
address from,
address to,
uint256[] memory ids,
uint256[] memory amounts,
bytes memory data
) internal virtual {}
function _doSafeTransferAcceptanceCheck(
address operator,
address from,
address to,
uint256 id,
uint256 amount,
bytes memory data
) private {
if (to.isContract()) {
try IERC1155Receiver(to).onERC1155Received(operator, from, id, amount, data) returns (bytes4 response) {
if (response != IERC1155Receiver.onERC1155Received.selector) {
revert("ERC1155: ERC1155Receiver rejected tokens");
}
} catch Error(string memory reason) {
revert(reason);
} catch {
revert("ERC1155: transfer to non ERC1155Receiver implementer");
}
}
}
function _doSafeBatchTransferAcceptanceCheck(
address operator,
address from,
address to,
uint256[] memory ids,
uint256[] memory amounts,
bytes memory data
) private {
if (to.isContract()) {
try IERC1155Receiver(to).onERC1155BatchReceived(operator, from, ids, amounts, data) returns (
bytes4 response
) {
if (response != IERC1155Receiver.onERC1155BatchReceived.selector) {
revert("ERC1155: ERC1155Receiver rejected tokens");
}
} catch Error(string memory reason) {
revert(reason);
} catch {
revert("ERC1155: transfer to non ERC1155Receiver implementer");
}
}
}
function _asSingletonArray(uint256 element) private pure returns (uint256[] memory) {
uint256[] memory array = new uint256[](1);
array[0] = element;
return array;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
/**
* @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;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/
abstract contract Pausable is Context {
/**
* @dev Emitted when the pause is triggered by `account`.
*/
event Paused(address account);
/**
* @dev Emitted when the pause is lifted by `account`.
*/
event Unpaused(address account);
bool private _paused;
/**
* @dev Initializes the contract in unpaused state.
*/
constructor() {
_paused = false;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/
function paused() public view virtual returns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/
modifier whenNotPaused() {
require(!paused(), "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/
modifier whenPaused() {
require(paused(), "Pausable: not paused");
_;
}
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - The contract must not be paused.
*/
function _pause() internal virtual whenNotPaused {
_paused = true;
emit Paused(_msgSender());
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - The contract must be paused.
*/
function _unpause() internal virtual whenPaused {
_paused = false;
emit Unpaused(_msgSender());
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../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.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}