Contract Source Code:
// contracts/DebtCity.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "./@rarible/royalties/contracts/impl/RoyaltiesV2Impl.sol";
import "./@rarible/royalties/contracts/LibPart.sol";
import "./@rarible/royalties/contracts/LibRoyaltiesV2.sol";
import "./IPaper.sol";
import "./DebtCityLibrary.sol";
contract DebtCity is ERC721Enumerable, Ownable, RoyaltiesV2Impl {
/*
██████╗░███████╗██████╗░████████╗░█████╗░██╗████████╗██╗░░░██╗
██╔══██╗██╔════╝██╔══██╗╚══██╔══╝██╔══██╗██║╚══██╔══╝╚██╗░██╔╝
██║░░██║█████╗░░██████╦╝░░░██║░░░██║░░╚═╝██║░░░██║░░░░╚████╔╝░
██║░░██║██╔══╝░░██╔══██╗░░░██║░░░██║░░██╗██║░░░██║░░░░░╚██╔╝░░
██████╔╝███████╗██████╦╝░░░██║░░░╚█████╔╝██║░░░██║░░░░░░██║░░░
╚═════╝░╚══════╝╚═════╝░░░░╚═╝░░░░╚════╝░╚═╝░░░╚═╝░░░░░░╚═╝░░░
*/
using DebtCityLibrary for uint8;
mapping(string => bool) hashToMinted;
mapping(uint256 => string) internal bankerIdToHash;
uint256 MAX_SUPPLY = 4999;
uint256 SEED_NONCE = 0;
uint256 REMAINING_BOARD_MEMBERS = 25;
uint256 REMAINING_DIRECTORS = 200;
uint256 REMAINING_VPS = 800;
uint256 REMAINING_ASSOCIATES = 1500;
uint256 REMAINING_ANALYSTS = 2474;
mapping(address => uint8) private _allowList;
bool isAllowListActive = true;
bool isMintActive = false;
address payable public payableWallet;
bytes4 private constant _INTERFACE_ID_ERC2981 = 0x2a55205a;
uint256 public ethPrice = 0.079 ether;
uint8 maxPerWallet = 2;
struct PngTrait {
string ttype;
string name;
string png;
bool on;
}
mapping(uint8 => mapping(uint8 => PngTrait)) public traitData;
uint16[][15] TIERS;
string[] LETTERS = [
"a",
"b",
"c",
"d",
"e",
"f",
"g",
"h",
"i",
"j",
"k",
"l",
"m",
"n",
"o",
"p",
"q",
"r",
"s",
"t",
"u",
"v",
"w",
"x",
"y",
"z"
];
address paperAddress;
address _owner;
constructor() ERC721("DebtCity", "BANKERS") {
_owner = msg.sender;
payableWallet = payable(address(0xBC590a5370cc163023cdC17e041967796174081B));
// 9 skin vals
TIERS[0] = [20, 1110, 1110, 1110, 1110, 1110, 1110, 1110, 1110, 1100];
// 9 eye vals
TIERS[1] = [1120, 1110, 1110, 1110, 1110, 1110, 1110, 1110, 1110];
// 4 mouth vals
TIERS[2] = [2500, 2500, 2500, 2500];
// 4 shoes vals
TIERS[3] = [2500, 2500, 2500, 2500];
// 4 pants vals
TIERS[4] = [2500, 2500, 2500, 2500];
// 8 dress shirt vals
TIERS[5] = [1250, 1250, 1250, 1250, 1250, 1250, 1250, 1250];
// 4 glasses vals
TIERS[6] = [2500, 2500, 2500, 2500];
// 10 t-shirt vals
TIERS[7] = [1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000];
// 10 polo vals
TIERS[8] = [1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000];
// 6 tie vals
TIERS[9] = [1675, 1665, 1665, 1665, 1665, 1665];
// 7 vest vals
TIERS[10] = [1432, 1428, 1428, 1428, 1428, 1428, 1428];
// 5 jacket vals
TIERS[11] = [2000, 2000, 2000, 2000, 2000];
// 6 pock square vals
TIERS[12] = [1675, 1665, 1665, 1665, 1665, 1665];
// 9 hair vals
TIERS[13] = [1120, 1110, 1110, 1110, 1110, 1110, 1110, 1110, 1110];
// 5 watch vals
TIERS[14] = [2500, 2500, 2500, 1250, 1250];
}
/** *********************************** **/
/** ********* Minting Functions ******* **/
/** *********************************** **/
function rarityGen(uint256 _randinput, uint8 _rarityTier)
internal
view
returns (uint8)
{
uint16 currentLowerBound = 0;
for (uint8 i = 0; i < TIERS[_rarityTier].length; i++) {
uint16 thisPercentage = TIERS[_rarityTier][i];
if (
_randinput >= currentLowerBound &&
_randinput < currentLowerBound + thisPercentage
) return i;
currentLowerBound = currentLowerBound + thisPercentage;
}
revert();
}
function hash(
uint256 _t,
address _a,
uint256 _c
) internal returns (string memory) {
require(_c < 10);
// This will generate a 16 character string
// The last 15 digits are random, the first is 1-5 depending on the random
// banker style assigned to the token
string memory currentHash = "";
SEED_NONCE++;
uint16 randValue = uint16(
uint256(
keccak256(
abi.encodePacked(
block.timestamp,
block.difficulty,
_t,
_a,
_c,
SEED_NONCE
)
)
)
);
uint8 bstyle = getBankerStyle(randValue); // get a random banker style
currentHash = string(abi.encodePacked(currentHash, bstyle.toString()));
uint8 pindex = 0;
bool willForceNoPolo = false;
for (uint8 i = 0; i < 15; i++) {
SEED_NONCE++;
uint16 _randinput = uint16(
uint256(
keccak256(
abi.encodePacked(
block.timestamp,
block.difficulty,
_t,
_a,
_c,
SEED_NONCE
)
)
) % 10000
);
uint8 randDigit = rarityGen(_randinput, i);
uint8 traitVal = applyBankerRules(i, bstyle, randDigit, _randinput);
if (bstyle == 1 && i == 4) pindex = traitVal; // keep track of pants colors for members
else if (bstyle == 1 && i == 12) traitVal = pindex + 1;
if (i == 7 && traitVal != 0) willForceNoPolo = true;
if (i == 8 && willForceNoPolo) traitVal = 0;
currentHash = string(
abi.encodePacked(currentHash, traitVal.toString())
);
}
if (hashToMinted[currentHash]) return hash(_t, _a, _c + 1);
return currentHash;
}
function mintInternal(uint8 quantity) internal {
uint256 _totalSupply = totalSupply();
require(_totalSupply + quantity < MAX_SUPPLY);
require(!DebtCityLibrary.isContract(msg.sender));
require(msg.value == (ethPrice * quantity));
require(
balanceOf(msg.sender) + quantity <= maxPerWallet,
"exceeds max per wallet"
);
uint8 i = 0;
uint256 newBankerId = _totalSupply;
while (i < quantity) {
uint256 bankerId = newBankerId + i;
bankerIdToHash[bankerId] = hash(bankerId, msg.sender, 0);
hashToMinted[bankerIdToHash[bankerId]] = true;
_safeMint(msg.sender, bankerId);
i ++;
}
}
function mintBanker(uint8 quantity) external payable {
require(isAllowListActive == false, "Only the allow list can mint right now");
return mintInternal(quantity);
}
function mintAllowList(uint8 quantity) external payable {
require(isAllowListActive, "Allow list is not active");
require(quantity <= _allowList[msg.sender], "Exceeded max available to purchase");
_allowList[msg.sender] -= quantity;
mintInternal(quantity);
}
function transferFrom(
address from,
address to,
uint256 tokenId
) public virtual override {
// hardcode approval so that users don't have to waste gas approving
if (_msgSender() != address(paperAddress)){
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
}
_transfer(from, to, tokenId);
}
/** *********************************** **/
/** ******* Internal Functions ******** **/
/** *********************************** **/
function applyBankerRules(uint8 i, uint8 bstyle, uint8 randDigit, uint16 bigRandom) pure internal returns (uint8) {
if (i == 6 && bigRandom % 2 == 0) randDigit = 0;
else if (i == 7 || i == 8) {
if ((bstyle == 5 && bigRandom % 2 == 0) || bstyle < 5) randDigit = 0;
}
else if (i == 9) {
if (bstyle == 5 || bstyle == 4 || (bstyle == 2 && bigRandom % 2 == 0)) randDigit = 0;
if (bstyle == 3 && randDigit == 0) randDigit = 1;
}
else if (i == 10) {
if (bstyle < 4 || bigRandom % 2 == 0) randDigit = 0;
}
else if (i == 11) {
if (bstyle > 2) randDigit = 0;
}
else if (i == 12 && bstyle > 1) randDigit = 0;
else if (i == 13 && bigRandom % 3 == 0) randDigit = 0;
else if(i == 14 && (bigRandom % 2 == 0 || bstyle == 5)) randDigit = 0;
return randDigit;
}
function getBankerStyle(uint16 rando) internal returns (uint8) {
uint16 randVal = (rando & 0xFFFF);
if (REMAINING_BOARD_MEMBERS > 0 && randVal % 200 == 0) { // ~0.5 % chance
REMAINING_BOARD_MEMBERS--;
return 1;
}
if (REMAINING_DIRECTORS > 0 && randVal % 25 == 0) { // ~4 % chance
REMAINING_DIRECTORS--;
return 2;
}
if (REMAINING_VPS > 0 && randVal % 6 == 0) { // ~16 % chance
REMAINING_VPS--;
return 3;
}
if (REMAINING_ASSOCIATES > 0 && randVal % 3 == 0) { // ~30 % chance
REMAINING_ASSOCIATES--;
return 4;
}
if (REMAINING_ANALYSTS > 0) { // assign analyst if available
REMAINING_ANALYSTS--;
return 5;
}
// else find the lowest ranking available banker type
uint8 res = getLowestType();
return res;
}
function getLowestType() internal returns (uint8) {
if (REMAINING_ANALYSTS > 0) {
REMAINING_ANALYSTS--;
return 5;
}
if (REMAINING_ASSOCIATES > 0) {
REMAINING_ASSOCIATES--;
return 4;
}
if (REMAINING_VPS > 0) {
REMAINING_VPS--;
return 3;
}
if (REMAINING_DIRECTORS > 0) {
REMAINING_DIRECTORS--;
return 2;
}
if (REMAINING_BOARD_MEMBERS > 0) {
REMAINING_BOARD_MEMBERS--;
return 1;
}
return 0;
}
function getJobString(uint8 job) internal pure returns (string memory) {
if (job == 5) return "analyst";
else if (job == 4) return "associate";
else if (job == 3) return "vice_president";
else if (job == 2) return "director";
else if (job == 1) return "board_member";
return "none";
}
/** *********************************** **/
/** ********* Public Getters ********** **/
/** *********************************** **/
function getBankersRemaining() public view returns (uint256) {
return (REMAINING_BOARD_MEMBERS + REMAINING_DIRECTORS + REMAINING_VPS + REMAINING_ASSOCIATES + REMAINING_ANALYSTS);
}
function hashToMetadata(string memory _hash)
public
view
returns (string memory)
{
uint8 job = DebtCityLibrary.parseInt(
DebtCityLibrary.substring(_hash, 0, 1)
);
string memory metadataString = string(
abi.encodePacked(
'{"trait_type":"job_title","value":"',
getJobString(job), '"},'
)
);
for (uint8 i = 0; i < 15; i++) {
uint8 hashIndex = i + 1;
uint8 thisTraitIndex = DebtCityLibrary.parseInt(
DebtCityLibrary.substring(_hash, hashIndex, hashIndex + 1)
);
PngTrait memory t = traitData[i][thisTraitIndex];
if (t.on) {
if (i != 0) metadataString = string(abi.encodePacked(metadataString, ","));
metadataString = string(
abi.encodePacked(
metadataString,
'{"trait_type":"',
t.ttype,
'","value":"',
t.name,
'"}'
)
);
}
}
return string(abi.encodePacked("[", metadataString, "]"));
}
function tokenURI(uint256 _bankerId)
public
view
override
returns (string memory)
{
require(_exists(_bankerId));
string memory bankerHash = _bankerIdToHash(_bankerId);
return
string(
abi.encodePacked(
"data:application/json;base64,",
DebtCityLibrary.encode(
bytes(
string(
abi.encodePacked(
'{"name": "DebtCity #',
DebtCityLibrary.toString(_bankerId),
'", "description": "DebtCity is the first on-chain economic simulator. No IPFS, no API. Just an Ethereum blockchain simulation of finance, investment, and degeneracy", "image": "data:image/svg+xml;base64,',
DebtCityLibrary.encode(
bytes(outputFullSVG(bankerHash))
),
'","attributes":',
hashToMetadata(bankerHash),
"}"
)
)
)
)
)
);
}
function _bankerIdToHash(uint256 _bankerId)
public
view
returns (string memory)
{
return bankerIdToHash[_bankerId];
}
function getPayForBanker(uint256 _bankerId)
public
view
returns (uint8)
{
string memory bankerHash = bankerIdToHash[_bankerId];
uint8 jobVal = DebtCityLibrary.parseInt(
DebtCityLibrary.substring(bankerHash, 0, 1)
);
if (jobVal == 1) return 15;
if (jobVal == 2) return 8;
if (jobVal == 3) return 3;
if (jobVal == 4) return 2;
return 1;
}
function walletOfOwner(address _wallet)
public
view
returns (uint256[] memory)
{
uint256 bankerCount = balanceOf(_wallet);
uint256[] memory bankersId = new uint256[](bankerCount);
for (uint256 i; i < bankerCount; i++) {
bankersId[i] = tokenOfOwnerByIndex(_wallet, i);
}
return bankersId;
}
/** *********************************** **/
/** ********* Owner Functions ********* **/
/** *********************************** **/
function clearTraits() public onlyOwner {
for (uint8 i = 0; i < 15; i++) {
for (uint8 j = 0; j < 15; j++) {
delete traitData[i][i];
}
}
}
function outputFullSVG(string memory _hash) public view returns (string memory) {
string memory svgString = "";
for (uint8 i = 0; i < 15; i++) {
uint8 hashIndex = i + 1;
uint8 thisTraitIndex = DebtCityLibrary.parseInt(
DebtCityLibrary.substring(_hash, hashIndex, hashIndex + 1)
);
PngTrait memory t = traitData[i][thisTraitIndex];
if (t.on) svgString = string(abi.encodePacked(svgString, drawTrait(t)));
}
return string(abi.encodePacked(
'<svg id="banker" width="100%" height="100%" version="1.1" viewBox="0 0 40 40" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">',
svgString,
"</svg>"
));
}
function drawTrait(PngTrait memory trait) internal pure returns (string memory) {
return string(abi.encodePacked(
'<image x="4" y="4" width="32" height="32" image-rendering="pixelated" preserveAspectRatio="xMidYMid" xlink:href="data:image/png;base64,',
trait.png,
'"/>'
));
}
function uploadTraits(uint8 traitType, PngTrait[] memory traits) public onlyOwner {
for (uint8 i = 0; i < traits.length; i++) {
traitData[traitType][i] = PngTrait(
traits[i].ttype,
traits[i].name,
traits[i].png,
traits[i].on
);
}
}
function setPaperAddress(address _paperAddress) public onlyOwner {
paperAddress = _paperAddress;
}
function flipMintMode() public onlyOwner {
isMintActive = !isMintActive;
}
function flipAllowMode() public onlyOwner {
isAllowListActive = !isAllowListActive;
}
function setAllowList(address[] calldata addresses) external onlyOwner {
for (uint256 i = 0; i < addresses.length; i++) {
_allowList[addresses[i]] = 2;
}
}
function setPayableWallet(address _payableWallet) external onlyOwner {
payableWallet = payable(_payableWallet);
}
function withdraw() external onlyOwner {
uint256 balance = address(this).balance;
payable(payableWallet).transfer(balance);
}
/** *********************************** **/
/** ******* Royalties Functions ******* **/
/** *********************************** **/
function setRoyalties(uint _tokenId, address payable _royaltiesRecipientAddress, uint96 _percentageBasisPoints) public onlyOwner {
LibPart.Part[] memory _royalties = new LibPart.Part[](1);
_royalties[0].value = _percentageBasisPoints;
_royalties[0].account = _royaltiesRecipientAddress;
_saveRoyalties(_tokenId, _royalties);
}
function royaltyInfo(uint256 _tokenId, uint256 _salePrice) external view returns (address receiver,uint256 royaltyAmount) {
LibPart.Part[] memory _royalties = royalties[_tokenId];
if (_royalties.length > 0) {
return (_royalties[0].account, (_salePrice * _royalties[0].value) / 10000);
}
return (address(0), 0);
}
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
if (interfaceId == LibRoyaltiesV2._INTERFACE_ID_ROYALTIES) {
return true;
}
if (interfaceId == _INTERFACE_ID_ERC2981) {
return true;
}
return super.supportsInterface(interfaceId);
}
}
// contracts/IDebt.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
interface IPaper is IERC20 {
function burnFrom(address account, uint256 amount) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
library DebtCityLibrary {
string internal constant TABLE =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
function encode(bytes memory data) internal pure returns (string memory) {
if (data.length == 0) return "";
string memory table = TABLE;
uint256 encodedLen = 4 * ((data.length + 2) / 3);
string memory result = new string(encodedLen + 32);
assembly {
mstore(result, encodedLen)
let tablePtr := add(table, 1)
let dataPtr := data
let endPtr := add(dataPtr, mload(data))
let resultPtr := add(result, 32)
// loop over input 3 bytes at a time
for {
} lt(dataPtr, endPtr) {
} {
dataPtr := add(dataPtr, 3)
let input := mload(dataPtr)
mstore(
resultPtr,
shl(248, mload(add(tablePtr, and(shr(18, input), 0x3F))))
)
resultPtr := add(resultPtr, 1)
mstore(
resultPtr,
shl(248, mload(add(tablePtr, and(shr(12, input), 0x3F))))
)
resultPtr := add(resultPtr, 1)
mstore(
resultPtr,
shl(248, mload(add(tablePtr, and(shr(6, input), 0x3F))))
)
resultPtr := add(resultPtr, 1)
mstore(
resultPtr,
shl(248, mload(add(tablePtr, and(input, 0x3F))))
)
resultPtr := add(resultPtr, 1)
}
// padding with '='
switch mod(mload(data), 3)
case 1 {
mstore(sub(resultPtr, 2), shl(240, 0x3d3d))
}
case 2 {
mstore(sub(resultPtr, 1), shl(248, 0x3d))
}
}
return result;
}
function isContract(address account) internal view returns (bool) {
uint256 size;
assembly {
size := extcodesize(account)
}
return size > 0;
}
function parseInt(string memory _a)
internal
pure
returns (uint8 _parsedInt)
{
bytes memory bresult = bytes(_a);
uint8 mint = 0;
for (uint8 i = 0; i < bresult.length; i++) {
if (
(uint8(uint8(bresult[i])) >= 48) &&
(uint8(uint8(bresult[i])) <= 57)
) {
mint *= 10;
mint += uint8(bresult[i]) - 48;
}
}
return mint;
}
function toString(uint256 value) internal pure returns (string memory) {
if (value == 0) {
return "0";
}
uint256 temp = value;
uint256 digits;
while (temp != 0) {
digits++;
temp /= 10;
}
bytes memory buffer = new bytes(digits);
while (value != 0) {
digits -= 1;
buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
value /= 10;
}
return string(buffer);
}
function substring(
string memory str,
uint256 startIndex,
uint256 endIndex
) internal pure returns (string memory) {
bytes memory strBytes = bytes(str);
bytes memory result = new bytes(endIndex - startIndex);
for (uint256 i = startIndex; i < endIndex; i++) {
result[i - startIndex] = strBytes[i];
}
return string(result);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./AbstractRoyalties.sol";
import "../RoyaltiesV2.sol";
contract RoyaltiesV2Impl is AbstractRoyalties, RoyaltiesV2 {
function getRaribleV2Royalties(uint256 id) override external view returns (LibPart.Part[] memory) {
return royalties[id];
}
function _onRoyaltiesSet(uint256 id, LibPart.Part[] memory _royalties) override internal {
emit RoyaltiesSet(id, _royalties);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../LibPart.sol";
abstract contract AbstractRoyalties {
mapping (uint256 => LibPart.Part[]) internal royalties;
function _saveRoyalties(uint256 id, LibPart.Part[] memory _royalties) internal {
uint256 totalValue;
for (uint i = 0; i < _royalties.length; i++) {
require(_royalties[i].account != address(0x0), "Recipient should be present");
require(_royalties[i].value != 0, "Royalty value should be positive");
totalValue += _royalties[i].value;
royalties[id].push(_royalties[i]);
}
require(totalValue < 10000, "Royalty total value should be < 10000");
_onRoyaltiesSet(id, _royalties);
}
function _updateAccount(uint256 _id, address _from, address _to) internal {
uint length = royalties[_id].length;
for(uint i = 0; i < length; i++) {
if (royalties[_id][i].account == _from) {
royalties[_id][i].account = payable(address(uint160(_to)));
}
}
}
function _onRoyaltiesSet(uint256 id, LibPart.Part[] memory _royalties) virtual internal;
}
pragma solidity ^0.8.0;
pragma abicoder v2;
import "./LibPart.sol";
interface RoyaltiesV2 {
event RoyaltiesSet(uint256 tokenId, LibPart.Part[] royalties);
function getRaribleV2Royalties(uint256 id) external view returns (LibPart.Part[] memory);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
library LibRoyaltiesV2 {
/*
* bytes4(keccak256('getRaribleV2Royalties(uint256)')) == 0xcad96cca
*/
bytes4 constant _INTERFACE_ID_ROYALTIES = 0xcad96cca;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
library LibPart {
bytes32 public constant TYPE_HASH = keccak256("Part(address account,uint96 value)");
struct Part {
address payable account;
uint96 value;
}
function hash(Part memory part) internal pure returns (bytes32) {
return keccak256(abi.encode(TYPE_HASH, part.account, part.value));
}
}
// 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 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 v4.4.1 (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 `IERC721.onERC721Received.selector`.
*/
function onERC721Received(
address operator,
address from,
uint256 tokenId,
bytes calldata data
) external returns (bytes4);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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`, 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 Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @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 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);
/**
* @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;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (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 overriden 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 || getApproved(tokenId) == spender || isApprovedForAll(owner, 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 (last updated v4.5.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 amount
) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
// 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);
}
}