/**
* @title Waifus contract
* @dev Extends ERC721 Non-Fungible Token Standard basic implementation
*/
contract Waifus is Context, Ownable, ERC165, IWaifus, IERC721Metadata {
using SafeMath for uint256;
using Address for address;
using EnumerableSet for EnumerableSet.UintSet;
using EnumerableMap for EnumerableMap.UintToAddressMap;
using Strings for uint256;
// Public variables
// This is the provenance record of all Waifus artwork in existence
string public constant WAIFUS_PROVENANCE = "b9e2ad47185076f3f43847eeec601e7bc4a1cb51a208b34b5eb1c650cf06a546";
uint256 public constant SALE_START_TIMESTAMP = 1614624600;
// Time after which waifus are randomized and allotted
uint256 public constant REVEAL_TIMESTAMP = SALE_START_TIMESTAMP + (86400 * 14);
uint256 public constant NAME_CHANGE_PRICE = 1830 * (10 ** 18);
uint256 public constant MAX_NFT_SUPPLY = 16384;
uint256 public startingIndexBlock;
uint256 public startingIndex;
// Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
// which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;
// Mapping from holder address to their (enumerable) set of owned tokens
mapping (address => EnumerableSet.UintSet) private _holderTokens;
// Enumerable mapping from token ids to their owners
EnumerableMap.UintToAddressMap private _tokenOwners;
// Mapping from token ID to approved address
mapping (uint256 => address) private _tokenApprovals;
// Mapping from token ID to name
mapping (uint256 => string) private _tokenName;
// Mapping if certain name string has already been reserved
mapping (string => bool) private _nameReserved;
// Mapping from token ID to whether the Waifus was minted before reveal
mapping (uint256 => bool) private _mintedBeforeReveal;
// Mapping from owner to operator approvals
mapping (address => mapping (address => bool)) private _operatorApprovals;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Waifu Enhancement Token address
address private _wetAddress;
/*
* bytes4(keccak256('balanceOf(address)')) == 0x70a08231
* bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e
* bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3
* bytes4(keccak256('getApproved(uint256)')) == 0x081812fc
* bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465
* bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5
* bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd
* bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e
* bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde
*
* => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^
* 0xa22cb465 ^ 0xe985e9c5 ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd
*/
bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;
/*
* bytes4(keccak256('name()')) == 0x06fdde03
* bytes4(keccak256('symbol()')) == 0x95d89b41
*
* => 0x06fdde03 ^ 0x95d89b41 == 0x93254542
*/
bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x93254542;
/*
* bytes4(keccak256('totalSupply()')) == 0x18160ddd
* bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59
* bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7
*
* => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63
*/
bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;
// Events
event NameChange (uint256 indexed maskIndex, string newName);
/**
* @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
*/
constructor (string memory name, string memory symbol, address wetAddress) {
_name = name;
_symbol = symbol;
_wetAddress = wetAddress;
// register the supported interfaces to conform to ERC721 via ERC165
_registerInterface(_INTERFACE_ID_ERC721);
_registerInterface(_INTERFACE_ID_ERC721_METADATA);
_registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);
}
/**
* @dev See {IERC721-balanceOf}.
*/
function balanceOf(address owner) public view override returns (uint256) {
require(owner != address(0), "ERC721: balance query for the zero address");
return _holderTokens[owner].length();
}
/**
* @dev See {IERC721-ownerOf}.
*/
function ownerOf(uint256 tokenId) public view override returns (address) {
return _tokenOwners.get(tokenId, "ERC721: owner query for nonexistent token");
}
/**
* @dev See {IERC721Metadata-name}.
*/
function name() public view override returns (string memory) {
return _name;
}
/**
* @dev See {IERC721Metadata-symbol}.
*/
function symbol() public view override returns (string memory) {
return _symbol;
}
/**
* @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) public view override returns (uint256) {
return _holderTokens[owner].at(index);
}
/**
* @dev See {IERC721Enumerable-totalSupply}.
*/
function totalSupply() public view override returns (uint256) {
// _tokenOwners are indexed by tokenIds, so .length() returns the number of tokenIds
return _tokenOwners.length();
}
/**
* @dev See {IERC721Enumerable-tokenByIndex}.
*/
function tokenByIndex(uint256 index) public view override returns (uint256) {
(uint256 tokenId, ) = _tokenOwners.at(index);
return tokenId;
}
/**
* @dev Returns name of the NFT at index.
*/
function tokenNameByIndex(uint256 index) public view returns (string memory) {
return _tokenName[index];
}
/**
* @dev Returns if the name has been reserved.
*/
function isNameReserved(string memory nameString) public view returns (bool) {
return _nameReserved[toLower(nameString)];
}
/**
* @dev Returns if the NFT has been minted before reveal phase
*/
function isMintedBeforeReveal(uint256 index) public view override returns (bool) {
return _mintedBeforeReveal[index];
}
/**
* @dev Gets current Waifus Price
*/
function getNFTPrice() public view returns (uint256) {
require(block.timestamp >= SALE_START_TIMESTAMP, "Sale has not started");
require(totalSupply() < MAX_NFT_SUPPLY, "Sale has already ended");
uint currentSupply = totalSupply();
if (currentSupply >= 16381) {
return 100000000000000000000; // 16381 - 16383 100 ETH
} else if (currentSupply >= 16000) {
return 2000000000000000000; // 16000 - 16380 2.0 ETH
} else if (currentSupply >= 15000) {
return 1300000000000000000; // 15000 - 15999 1.3 ETH
} else if (currentSupply >= 13000) {
return 1100000000000000000; // 13000 - 14999 1.1 ETH
} else if (currentSupply >= 11000) {
return 900000000000000000; // 11000 - 12999 0.9 ETH
} else if (currentSupply >= 9000) {
return 700000000000000000; // 9000 - 10999 0.7 ETH
} else if (currentSupply >= 7000) {
return 500000000000000000; // 7000 - 8999 0.5 ETH
} else if (currentSupply >= 5000) {
return 400000000000000000; // 5000 - 6999 0.4 ETH
} else if (currentSupply >= 3000) {
return 300000000000000000; // 3000 - 4999 0.3 ETH
} else if (currentSupply >= 1500) {
return 200000000000000000; // 1500 - 2999 0.2 ETH
} else {
return 100000000000000000; // 0 - 1499 0.1 ETH
}
}
/**
* @dev Mints Waifus
*/
function mintNFT(uint256 numberOfNfts) public payable {
require(totalSupply() < MAX_NFT_SUPPLY, "Sale has already ended");
require(numberOfNfts > 0, "numberOfNfts cannot be 0");
require(numberOfNfts <= 20, "You may not buy more than 20 NFTs at once");
require(totalSupply().add(numberOfNfts) <= MAX_NFT_SUPPLY, "Exceeds MAX_NFT_SUPPLY");
require(getNFTPrice().mul(numberOfNfts) == msg.value, "Ether value sent is not correct");
for (uint i = 0; i < numberOfNfts; i++) {
uint mintIndex = totalSupply();
if (block.timestamp < REVEAL_TIMESTAMP) {
_mintedBeforeReveal[mintIndex] = true;
}
_safeMint(msg.sender, mintIndex);
}
/**
* Source of randomness. Theoretical miner withhold manipulation possible but should be sufficient in a pragmatic sense
*/
if (startingIndexBlock == 0 && (totalSupply() == MAX_NFT_SUPPLY || block.timestamp >= REVEAL_TIMESTAMP)) {
startingIndexBlock = block.number;
}
}
/**
* @dev Finalize starting index
*/
function finalizeStartingIndex() public {
require(startingIndex == 0, "Starting index is already set");
require(startingIndexBlock != 0, "Starting index block must be set");
startingIndex = uint(blockhash(startingIndexBlock)) % MAX_NFT_SUPPLY;
// Just a sanity case in the worst case if this function is called late (EVM only stores last 256 block hashes)
if (block.number.sub(startingIndexBlock) > 255) {
startingIndex = uint(blockhash(block.number-1)) % MAX_NFT_SUPPLY;
}
// Prevent default sequence
if (startingIndex == 0) {
startingIndex = startingIndex.add(1);
}
}
/**
* @dev Changes the name for Waifus tokenId
*/
function changeName(uint256 tokenId, string memory newName) public {
address owner = ownerOf(tokenId);
require(_msgSender() == owner, "ERC721: caller is not the owner");
require(validateName(newName) == true, "Not a valid new name");
require(sha256(bytes(newName)) != sha256(bytes(_tokenName[tokenId])), "New name is same as the current one");
require(isNameReserved(newName) == false, "Name already reserved");
IERC20(_wetAddress).transferFrom(msg.sender, address(this), NAME_CHANGE_PRICE);
// If already named, dereserve old name
if (bytes(_tokenName[tokenId]).length > 0) {
toggleReserveName(_tokenName[tokenId], false);
}
toggleReserveName(newName, true);
_tokenName[tokenId] = newName;
IERC20(_wetAddress).burn(NAME_CHANGE_PRICE);
emit NameChange(tokenId, newName);
}
/**
* @dev Withdraw ether from this contract (Callable by owner)
*/
function withdraw() onlyOwner public {
uint balance = address(this).balance;
msg.sender.transfer(balance);
}
/**
* @dev See {IERC721-approve}.
*/
function approve(address to, uint256 tokenId) public virtual override {
address owner = 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 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 {
require(operator != _msgSender(), "ERC721: approve to caller");
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_msgSender(), operator, approved);
}
/**
* @dev See {IERC721-isApprovedForAll}.
*/
function isApprovedForAll(address owner, address operator) public view 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 returns (bool) {
return _tokenOwners.contains(tokenId);
}
/**
* @dev Returns whether `spender` is allowed to manage `tokenId`.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {
require(_exists(tokenId), "ERC721: operator query for nonexistent token");
address owner = ownerOf(tokenId);
return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
}
/**
* @dev Safely mints `tokenId` and transfers it to `to`.
*
* Requirements:
d*
* - `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 {
require(totalSupply() < 16385);
_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(totalSupply() < 16385);
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);
_holderTokens[to].add(tokenId);
_tokenOwners.set(tokenId, to);
emit Transfer(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 = ownerOf(tokenId);
_beforeTokenTransfer(owner, address(0), tokenId);
// Clear approvals
_approve(address(0), tokenId);
_holderTokens[owner].remove(tokenId);
_tokenOwners.remove(tokenId);
emit Transfer(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(ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
require(to != address(0), "ERC721: transfer to the zero address");
_beforeTokenTransfer(from, to, tokenId);
// Clear approvals from the previous owner
_approve(address(0), tokenId);
_holderTokens[from].remove(tokenId);
_holderTokens[to].add(tokenId);
_tokenOwners.set(tokenId, to);
emit Transfer(from, to, tokenId);
}
/**
* @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()) {
return true;
}
bytes memory returndata = to.functionCall(abi.encodeWithSelector(
IERC721Receiver(to).onERC721Received.selector,
_msgSender(),
from,
tokenId,
_data
), "ERC721: transfer to non ERC721Receiver implementer");
bytes4 retval = abi.decode(returndata, (bytes4));
return (retval == _ERC721_RECEIVED);
}
function _approve(address to, uint256 tokenId) private {
_tokenApprovals[tokenId] = to;
emit Approval(ownerOf(tokenId), to, tokenId);
}
/**
* @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 { }
/**
* @dev Reserves the name if isReserve is set to true, de-reserves if set to false
*/
function toggleReserveName(string memory str, bool isReserve) internal {
_nameReserved[toLower(str)] = isReserve;
}
/**
* @dev Check if the name string is valid (Alphanumeric and spaces without leading or trailing space)
*/
function validateName(string memory str) public pure returns (bool){
bytes memory b = bytes(str);
if(b.length < 1) return false;
if(b.length > 25) return false; // Cannot be longer than 25 characters
if(b[0] == 0x20) return false; // Leading space
if (b[b.length - 1] == 0x20) return false; // Trailing space
bytes1 lastChar = b[0];
for(uint i; i<b.length; i++){
bytes1 char = b[i];
if (char == 0x20 && lastChar == 0x20) return false; // Cannot contain continous spaces
if(
!(char >= 0x30 && char <= 0x39) && //9-0
!(char >= 0x41 && char <= 0x5A) && //A-Z
!(char >= 0x61 && char <= 0x7A) && //a-z
!(char == 0x20) //space
)
return false;
lastChar = char;
}
return true;
}
/**
* @dev Converts the string to lowercase
*/
function toLower(string memory str) public pure returns (string memory){
bytes memory bStr = bytes(str);
bytes memory bLower = new bytes(bStr.length);
for (uint i = 0; i < bStr.length; i++) {
// Uppercase character
if ((uint8(bStr[i]) >= 65) && (uint8(bStr[i]) <= 90)) {
bLower[i] = bytes1(uint8(bStr[i]) + 32);
} else {
bLower[i] = bStr[i];
}
}
return string(bLower);
}
}