Contract Name:
BondlyLaunchPad
Contract Source Code:
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.7.3;
/////////////////////////////////////////////////
// ____ _ _ //
// | __ ) ___ _ __ __| | | | _ _ //
// | _ \ / _ \ | '_ \ / _` | | | | | | | //
// | |_) | | (_) | | | | | | (_| | | | | |_| | //
// |____/ \___/ |_| |_| \__,_| |_| \__, | //
// |___/ //
/////////////////////////////////////////////////
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";
import "@openzeppelin/contracts/token/ERC1155/IERC1155MetadataURI.sol";
contract BondlyLaunchPad is Ownable {
using Strings for string;
using SafeMath for uint256;
using Address for address;
using SafeERC20 for ERC20;
uint256 public _currentCardId = 0;
address payable public _salesperson;
bool public _saleStarted = false;
address public bccg1Address;
address public bccg2Address;
uint256[] public bccg1Ids;
uint256[] public bccg2Ids;
uint256[] times;
uint256[] limitsPerWallet;
uint8[] tiers;
struct Card {
uint256 cardId;
uint256 tokenId;
uint256 totalAmount;
uint256 currentAmount;
uint256 basePrice;
address contractAddress;
address paymentToken;
bool isFinished;
}
struct History {
mapping(uint256 => mapping(address => uint8)) purchasedHistories; // tokenId -> wallet -> amount
}
// Events
event CreateCard(
address indexed _from,
uint256 _cardId,
address indexed _contractAddress,
uint256 _tokenId,
uint256 _totalAmount,
uint256 _basePrice
);
event PurchaseCard(address indexed _from, uint256 _cardId, uint256 _amount);
event CardChanged(uint256 _cardId);
mapping(uint256 => Card) public _cards;
mapping(address => bool) public _blacklist;
mapping(address => uint8) public _whitelist; // wallet -> whitelistLevel
// whitelist level | Priority
// 0: public sale | /\
// 1: selected winners | ||
// 2: bronze | ||
// 3: silver | ||
// 4: gold | ||
// 5: platinum | ||
mapping(address => History) private _history;
constructor() {
_salesperson = msg.sender;
bccg1Address = 0x8280D56Ac92b5bFF058d60c99932FDEcDCc9441a;
bccg2Address = 0xe3782B8688ad2b0D5ba42842d400F7AdF310F88d;
bccg1Ids = [1, 2, 5, 6, 7, 8, 9, 11, 13, 14, 15, 16, 17, 18, 19];
bccg2Ids = [1, 2, 3, 4, 5, 10, 12, 13, 15, 19, 20, 21, 24, 25, 27, 28, 29, 33, 34];
}
function setSalesPerson(address payable newSalesPerson) external onlyOwner {
_salesperson = newSalesPerson;
}
function setBCCG1Address(address addr) external onlyOwner {
bccg1Address = addr;
}
function setBCCG2Address(address addr) external onlyOwner {
bccg2Address = addr;
}
function setBCCG1Ids(uint256[] calldata ids) external onlyOwner {
bccg1Ids = ids;
}
function setBCCG2Ids(uint256[] calldata ids) external onlyOwner{
bccg2Ids = ids;
}
function startSale() external onlyOwner {
_saleStarted = true;
}
function stopSale() external onlyOwner {
_saleStarted = false;
}
function createCard(
address _contractAddress,
uint256 _tokenId,
uint256 _totalAmount,
address _paymentTokenAddress,
uint256 _basePrice
) external onlyOwner {
IERC1155 _contract = IERC1155(_contractAddress);
require(
_contract.balanceOf(_salesperson, _tokenId) >= _totalAmount,
"Initial supply cannot be more than available supply"
);
require(
_contract.isApprovedForAll(_salesperson, address(this)) == true,
"Contract must be whitelisted by owner"
);
uint256 _id = _getNextCardID();
_incrementCardId();
Card memory _newCard;
_newCard.cardId = _id;
_newCard.contractAddress = _contractAddress;
_newCard.tokenId = _tokenId;
_newCard.totalAmount = _totalAmount;
_newCard.currentAmount = _totalAmount;
_newCard.basePrice = _basePrice;
_newCard.paymentToken = _paymentTokenAddress;
_newCard.isFinished = false;
_cards[_id] = _newCard;
emit CreateCard(
msg.sender,
_id,
_contractAddress,
_tokenId,
_totalAmount,
_basePrice
);
}
function isEligbleToBuy(uint256 _cardId) public view returns (uint256) {
if (_blacklist[msg.sender] == true) return 0;
if (_saleStarted == false) return 0;
Card memory _currentCard = _cards[_cardId];
if (times.length == 0) return 0;
uint8 tier = getWhitelistTier(msg.sender);
for (uint256 i = 0; i < times.length; i++) {
if (
block.timestamp >= times[i] &&
tier == tiers[i]
) {
if(tier == 1){
if(! meetsBCCGRequirement(msg.sender)){
return 0;
}
}
History storage _currentHistory =
_history[_currentCard.contractAddress];
uint256 _currentBoughtAmount =
_currentHistory.purchasedHistories[_currentCard.tokenId][
msg.sender
];
uint256 _limitPerWallet = getLimitPerWallet(_cardId);
if (_currentBoughtAmount >= _limitPerWallet) return 0;
if (
_currentCard.currentAmount <=
_limitPerWallet.sub(_currentBoughtAmount)
) return _currentCard.currentAmount;
return _limitPerWallet.sub(_currentBoughtAmount);
}
}
return 0;
}
function purchaseNFT(uint256 _cardId, uint256 _amount) external payable {
require(_blacklist[msg.sender] == false, "you are blocked");
require(_saleStarted == true, "Sale stopped");
Card memory _currentCard = _cards[_cardId];
require(_currentCard.isFinished == false, "Card is finished");
uint8 currentTier = getWhitelistTier(msg.sender);
uint256 startTime;
for (uint256 i = 0; i < tiers.length; i++) {
if (tiers[i] == currentTier) {
startTime = times[i];
}
}
require(
startTime != 0 && startTime <= block.timestamp,
"wait for sale start"
);
if(currentTier == 1){
require(meetsBCCGRequirement(msg.sender),"Must own a qualifying BCCG card");
}
IERC1155 _nftContract = IERC1155(_currentCard.contractAddress);
require(
_currentCard.currentAmount >= _amount,
"Order exceeds the max number of available NFTs"
);
History storage _currentHistory =
_history[_currentCard.contractAddress];
uint256 _currentBoughtAmount =
_currentHistory.purchasedHistories[_currentCard.tokenId][
msg.sender
];
uint256 _limitPerWallet = getLimitPerWallet(_cardId);
require(
_currentBoughtAmount < _limitPerWallet,
"Order exceeds the max limit of NFTs per wallet"
);
uint256 availableAmount = _limitPerWallet.sub(_currentBoughtAmount);
if (availableAmount > _amount) {
availableAmount = _amount;
}
uint256 _price = _currentCard.basePrice.mul(availableAmount);
require(
_currentCard.paymentToken == address(0) ||
ERC20(_currentCard.paymentToken).allowance(
msg.sender,
address(this)
) >=
_price,
"Need to Approve payment"
);
if (_currentCard.paymentToken == address(0)) {
require(msg.value >= _price, "Not enough funds to purchase");
uint256 overPrice = msg.value - _price;
_salesperson.transfer(_price);
if (overPrice > 0) msg.sender.transfer(overPrice);
} else {
ERC20(_currentCard.paymentToken).transferFrom(
msg.sender,
_salesperson,
_price
);
}
_nftContract.safeTransferFrom(
_salesperson,
msg.sender,
_currentCard.tokenId,
availableAmount,
""
);
_cards[_cardId].currentAmount = _cards[_cardId].currentAmount.sub(
availableAmount
);
_currentHistory.purchasedHistories[_currentCard.tokenId][
msg.sender
] = uint8(_currentBoughtAmount.add(availableAmount));
emit PurchaseCard(msg.sender, _cardId, availableAmount);
}
function meetsBCCGRequirement(address addr) public view returns (bool){
address[] memory bccg1Addrs = new address[](bccg1Ids.length);
for(uint256 i = 0; i < bccg1Addrs.length; i++){
bccg1Addrs[i] = addr;
}
IERC1155 bccg1 = IERC1155(bccg1Address);
uint256[] memory bccg1Quantities = bccg1.balanceOfBatch(bccg1Addrs, bccg1Ids);
for(uint256 i = 0; i < bccg1Quantities.length; i++){
if(bccg1Quantities[i] > 0){
return true;
}
}
address[] memory bccg2Addrs = new address[](bccg2Ids.length);
for(uint256 i = 0; i < bccg2Addrs.length; i++){
bccg2Addrs[i] = addr;
}
IERC1155 bccg2 = IERC1155(bccg2Address);
uint256[] memory bccg2Quantities = bccg2.balanceOfBatch(bccg2Addrs, bccg2Ids);
for(uint256 i = 0; i < bccg2Quantities.length; i++){
if(bccg2Quantities[i] > 0){
return true;
}
}
return false;
}
function _getNextCardID() private view returns (uint256) {
return _currentCardId.add(1);
}
function _incrementCardId() private {
_currentCardId++;
}
function cancelCard(uint256 _cardId) external onlyOwner {
_cards[_cardId].isFinished = true;
emit CardChanged(_cardId);
}
function _setTier(
uint8 _tier,
uint256 _startTime,
uint256 _limitPerWallet
) private {
for (uint256 i = 0; i < tiers.length; i++) {
if (tiers[i] == _tier) {
times[i] = _startTime;
limitsPerWallet[i] = _limitPerWallet;
return;
}
}
tiers.push(_tier);
times.push(_startTime);
limitsPerWallet.push(_limitPerWallet);
}
function setTier(
uint8 _tier,
uint256 _startTime,
uint256 _limitPerWallet
) external onlyOwner {
_setTier(_tier, _startTime, _limitPerWallet);
}
function setTiers(
uint8[] calldata _tiers,
uint256[] calldata _startTimes,
uint256[] calldata _limitsPerWallet
) external onlyOwner{
require(_tiers.length == _startTimes.length &&
_tiers.length == _limitsPerWallet.length,
"Input array lengths mismatch");
for(uint256 i = 0; i < _tiers.length; i++){
_setTier(_tiers[i], _startTimes[i], _limitsPerWallet[i]);
}
}
function resumeCard(uint256 _cardId) external onlyOwner {
_cards[_cardId].isFinished = false;
emit CardChanged(_cardId);
}
function setCardPrice(uint256 _cardId, uint256 _newPrice)
external
onlyOwner
returns (bool)
{
_cards[_cardId].basePrice = _newPrice;
emit CardChanged(_cardId);
}
function setCardPaymentToken(uint256 _cardId, address _newAddr)
external
onlyOwner
returns (bool)
{
_cards[_cardId].paymentToken = _newAddr;
emit CardChanged(_cardId);
}
function addBlackListAddress(address addr) external onlyOwner {
_blacklist[addr] = true;
}
function batchAddBlackListAddress(address[] calldata addr)
external
onlyOwner
{
for (uint256 i = 0; i < addr.length; i++) {
_blacklist[addr[i]] = true;
}
}
function removeBlackListAddress(address addr) external onlyOwner {
_blacklist[addr] = false;
}
function batchRemoveBlackListAddress(address[] calldata addr)
external
onlyOwner
{
for (uint256 i = 0; i < addr.length; i++) {
_blacklist[addr[i]] = false;
}
}
function addWhiteListAddress(
address _addr,
uint8 _tier
) external onlyOwner {
_whitelist[_addr] = _tier;
}
function batchAddWhiteListAddress(
address[] calldata _addr,
uint8 _tier
) external onlyOwner {
for (uint256 i = 0; i < _addr.length; i++) {
_whitelist[_addr[i]] = _tier;
}
}
function getLimitPerWallet(uint256 _cardId) public view returns(uint256){
uint256 limit = 0;
uint256 latestStartTime = 0;
for(uint256 i = 0; i < tiers.length; i++){
if(times[i] <= block.timestamp && times[i] > latestStartTime){
limit = limitsPerWallet[i];
latestStartTime = times[i];
}
}
return limit;
}
function getWhitelistTier(address addr) public view returns(uint8){
uint8 tier = _whitelist[addr];
if(tier != 0){
return tier;
}
for (uint256 i = 0; i < tiers.length; i++) {
if (tiers[i] == 0) {
if(block.timestamp >= times[i]){
return 0;
}
}
}
return 1;
}
function isCardCompleted(uint256 _cardId) public view returns (bool) {
return _cards[_cardId].isFinished;
}
function isCardFree(uint256 _cardId) public view returns (bool) {
return _cards[_cardId].basePrice == 0;
}
function getCardContract(uint256 _cardId) public view returns (address) {
return _cards[_cardId].contractAddress;
}
function getCardPaymentContract(uint256 _cardId)
public
view
returns (address)
{
return _cards[_cardId].paymentToken;
}
function getCardTokenId(uint256 _cardId) public view returns (uint256) {
return _cards[_cardId].tokenId;
}
function getCardTimes(uint256 _cardId)
public
view
returns (uint8[] memory, uint256[] memory)
{
return (tiers, times);
}
function getCardTime(uint256 _cardId, uint8 _tier)
public
view
returns (uint256)
{
for(uint256 i = 0; i < tiers.length; i++){
if(tiers[i] == _tier){
return times[i];
}
}
return 0;
}
function getCardLimitPerWallet(uint256 _cardId, uint8 _tier)
public
view
returns (uint256)
{
for(uint256 i = 0; i < tiers.length; i++){
if(tiers[i] == _tier){
return limitsPerWallet[i];
}
}
return 0;
}
function getCardTotalAmount(uint256 _cardId) public view returns (uint256) {
return _cards[_cardId].totalAmount;
}
function getCardCurrentAmount(uint256 _cardId)
public
view
returns (uint256)
{
return _cards[_cardId].currentAmount;
}
function getAllCardsPerContract(address _contractAddr)
public
view
returns (uint256[] memory, uint256[] memory)
{
uint256 count;
for (uint256 i = 1; i <= _currentCardId; i++) {
if (_cards[i].contractAddress == _contractAddr) {
count++;
}
}
uint256[] memory cardIds = new uint256[](count);
uint256[] memory tokenIds = new uint256[](count);
count = 0;
for (uint256 i = 1; i <= _currentCardId; i++) {
if (_cards[i].contractAddress == _contractAddr) {
cardIds[count] = i;
tokenIds[count] = _cards[i].tokenId;
count++;
}
}
return (cardIds, tokenIds);
}
function getActiveCardsPerContract(address _contractAddr)
public
view
returns (uint256[] memory, uint256[] memory)
{
uint256 count;
for (uint256 i = 1; i <= _currentCardId; i++) {
if (
_cards[i].contractAddress == _contractAddr &&
_cards[i].isFinished == false
) {
count++;
}
}
uint256[] memory cardIds = new uint256[](count);
uint256[] memory tokenIds = new uint256[](count);
count = 0;
for (uint256 i = 1; i <= _currentCardId; i++) {
if (
_cards[i].contractAddress == _contractAddr &&
_cards[i].isFinished == false
) {
cardIds[count] = i;
tokenIds[count] = _cards[i].tokenId;
count++;
}
}
return (cardIds, tokenIds);
}
function getClosedCardsPerContract(address _contractAddr)
public
view
returns (uint256[] memory, uint256[] memory)
{
uint256 count;
for (uint256 i = 1; i <= _currentCardId; i++) {
if (
_cards[i].contractAddress == _contractAddr &&
_cards[i].isFinished
) {
count++;
}
}
uint256[] memory cardIds = new uint256[](count);
uint256[] memory tokenIds = new uint256[](count);
count = 0;
for (uint256 i = 1; i <= _currentCardId; i++) {
if (
_cards[i].contractAddress == _contractAddr &&
_cards[i].isFinished
) {
cardIds[count] = i;
tokenIds[count] = _cards[i].tokenId;
count++;
}
}
return (cardIds, tokenIds);
}
function getCardBasePrice(uint256 _cardId) public view returns (uint256) {
return _cards[_cardId].basePrice;
}
function getCardURL(uint256 _cardId) public view returns (string memory) {
return
IERC1155MetadataURI(_cards[_cardId].contractAddress).uri(
_cards[_cardId].tokenId
);
}
function collect(address _token) external onlyOwner {
if (_token == address(0)) {
msg.sender.transfer(address(this).balance);
} else {
uint256 amount = ERC20(_token).balanceOf(address(this));
ERC20(_token).transfer(msg.sender, amount);
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <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 () internal {
address msgSender = _msgSender();
_owner = msgSender;
emit OwnershipTransferred(address(0), 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 {
emit OwnershipTransferred(_owner, address(0));
_owner = 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");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
* @dev String operations.
*/
library Strings {
/**
* @dev Converts a `uint256` to its ASCII `string` 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);
uint256 index = digits - 1;
temp = value;
while (temp != 0) {
buffer[index--] = bytes1(uint8(48 + temp % 10));
temp /= 10;
}
return string(buffer);
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.2 <0.8.0;
/**
* @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
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 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");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(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");
// solhint-disable-next-line avoid-low-level-calls
(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");
// solhint-disable-next-line avoid-low-level-calls
(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");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private 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
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
/**
* @dev Returns the substraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b > a) return (false, 0);
return (true, a - b);
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) return (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a / b);
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a % b);
}
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
require(b <= a, "SafeMath: subtraction overflow");
return a - b;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) return 0;
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
require(b > 0, "SafeMath: division by zero");
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
require(b > 0, "SafeMath: modulo by zero");
return a % b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
return a - b;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryDiv}.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
return a % b;
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../../utils/Context.sol";
import "./IERC20.sol";
import "../../math/SafeMath.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin guidelines: functions revert instead
* of returning `false` on failure. This behavior is nonetheless conventional
* and does not conflict with the expectations of ERC20 applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20 {
using SafeMath for uint256;
mapping (address => uint256) private _balances;
mapping (address => mapping (address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
uint8 private _decimals;
/**
* @dev Sets the values for {name} and {symbol}, initializes {decimals} with
* a default value of 18.
*
* To select a different value for {decimals}, use {_setupDecimals}.
*
* All three of these values are immutable: they can only be set once during
* construction.
*/
constructor (string memory name_, string memory symbol_) public {
_name = name_;
_symbol = symbol_;
_decimals = 18;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5,05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
* called.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual returns (uint8) {
return _decimals;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/
function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(address sender, address recipient, uint256 amount) internal virtual {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
_balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `to` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
_balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(address owner, address spender, uint256 amount) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Sets {decimals} to a value other than the default one of 18.
*
* WARNING: This function should only be called from the constructor. Most
* applications that interact with token contracts will not expect
* {decimals} to ever change, and may work incorrectly if it does.
*/
function _setupDecimals(uint8 decimals_) internal virtual {
_decimals = decimals_;
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be to transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens 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 amount) internal virtual { }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using SafeMath for uint256;
using Address for address;
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(IERC20 token, address spender, uint256 value) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
// solhint-disable-next-line max-line-length
require((value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).add(value);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length > 0) { // Return data is optional
// solhint-disable-next-line max-line-length
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.2 <0.8.0;
import "../../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
pragma solidity >=0.6.2 <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
pragma solidity >=0.6.0 <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 GSN 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 payable) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <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 `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, 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
pragma solidity >=0.6.0 <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);
}