Aerial Icons

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)

pragma solidity ^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;
        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");

        (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: SPDX-License
pragma solidity ^0.8.6;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

/*
          _____                    _____                    _____                    _____                    _____                    _____          
         /\    \                  /\    \                  /\    \                  /\    \                  /\    \                  /\    \         
        /::\    \                /::\    \                /::\    \                /::\    \                /::\    \                /::\____\        
       /::::\    \              /::::\    \              /::::\    \               \:::\    \              /::::\    \              /:::/    /        
      /::::::\    \            /::::::\    \            /::::::\    \               \:::\    \            /::::::\    \            /:::/    /         
     /:::/\:::\    \          /:::/\:::\    \          /:::/\:::\    \               \:::\    \          /:::/\:::\    \          /:::/    /          
    /:::/__\:::\    \        /:::/__\:::\    \        /:::/__\:::\    \               \:::\    \        /:::/__\:::\    \        /:::/    /           
   /::::\   \:::\    \      /::::\   \:::\    \      /::::\   \:::\    \              /::::\    \      /::::\   \:::\    \      /:::/    /            
  /::::::\   \:::\    \    /::::::\   \:::\    \    /::::::\   \:::\    \    ____    /::::::\    \    /::::::\   \:::\    \    /:::/    /             
 /:::/\:::\   \:::\    \  /:::/\:::\   \:::\    \  /:::/\:::\   \:::\____\  /\   \  /:::/\:::\    \  /:::/\:::\   \:::\    \  /:::/    /              
/:::/  \:::\   \:::\____\/:::/__\:::\   \:::\____\/:::/  \:::\   \:::|    |/::\   \/:::/  \:::\____\/:::/  \:::\   \:::\____\/:::/____/               
\::/    \:::\  /:::/    /\:::\   \:::\   \::/    /\::/   |::::\  /:::|____|\:::\  /:::/    \::/    /\::/    \:::\  /:::/    /\:::\    \               
 \/____/ \:::\/:::/    /  \:::\   \:::\   \/____/  \/____|:::::\/:::/    /  \:::\/:::/    / \/____/  \/____/ \:::\/:::/    /  \:::\    \              
          \::::::/    /    \:::\   \:::\    \            |:::::::::/    /    \::::::/    /                    \::::::/    /    \:::\    \             
           \::::/    /      \:::\   \:::\____\           |::|\::::/    /      \::::/____/                      \::::/    /      \:::\    \            
           /:::/    /        \:::\   \::/    /           |::| \::/____/        \:::\    \                      /:::/    /        \:::\    \           
          /:::/    /          \:::\   \/____/            |::|  ~|               \:::\    \                    /:::/    /          \:::\    \          
         /:::/    /            \:::\    \                |::|   |                \:::\    \                  /:::/    /            \:::\    \         
        /:::/    /              \:::\____\               \::|   |                 \:::\____\                /:::/    /              \:::\____\        
        \::/    /                \::/    /                \:|   |                  \::/    /                \::/    /                \::/    /        
         \/____/                  \/____/                  \|___|                   \/____/                  \/____/                  \/____/         
                                                                                                                                                      
          _____                    _____                   _______                   _____                    _____                                   
         /\    \                  /\    \                 /::\    \                 /\    \                  /\    \                                  
        /::\    \                /::\    \               /::::\    \               /::\____\                /::\    \                                 
        \:::\    \              /::::\    \             /::::::\    \             /::::|   |               /::::\    \                                
         \:::\    \            /::::::\    \           /::::::::\    \           /:::::|   |              /::::::\    \                               
          \:::\    \          /:::/\:::\    \         /:::/~~\:::\    \         /::::::|   |             /:::/\:::\    \                              
           \:::\    \        /:::/  \:::\    \       /:::/    \:::\    \       /:::/|::|   |            /:::/__\:::\    \                             
           /::::\    \      /:::/    \:::\    \     /:::/    / \:::\    \     /:::/ |::|   |            \:::\   \:::\    \                            
  ____    /::::::\    \    /:::/    / \:::\    \   /:::/____/   \:::\____\   /:::/  |::|   | _____    ___\:::\   \:::\    \                           
 /\   \  /:::/\:::\    \  /:::/    /   \:::\    \ |:::|    |     |:::|    | /:::/   |::|   |/\    \  /\   \:::\   \:::\    \                          
/::\   \/:::/  \:::\____\/:::/____/     \:::\____\|:::|____|     |:::|    |/:: /    |::|   /::\____\/::\   \:::\   \:::\____\                         
\:::\  /:::/    \::/    /\:::\    \      \::/    / \:::\    \   /:::/    / \::/    /|::|  /:::/    /\:::\   \:::\   \::/    /                         
 \:::\/:::/    / \/____/  \:::\    \      \/____/   \:::\    \ /:::/    /   \/____/ |::| /:::/    /  \:::\   \:::\   \/____/                          
  \::::::/    /            \:::\    \                \:::\    /:::/    /            |::|/:::/    /    \:::\   \:::\    \                              
   \::::/____/              \:::\    \                \:::\__/:::/    /             |::::::/    /      \:::\   \:::\____\                             
    \:::\    \               \:::\    \                \::::::::/    /              |:::::/    /        \:::\  /:::/    /                             
     \:::\    \               \:::\    \                \::::::/    /               |::::/    /          \:::\/:::/    /                              
      \:::\    \               \:::\    \                \::::/    /                /:::/    /            \::::::/    /                               
       \:::\____\               \:::\____\                \::/____/                /:::/    /              \::::/    /                                
        \::/    /                \::/    /                 ~~                      \::/    /                \::/    /                                 
         \/____/                  \/____/                                           \/____/                  \/____/                                  
*/

struct FlightPass {
	bool claimed;
	bool exists;
}

struct Hookup {
	bool exists;
	uint256 price;
}

struct HookupList {
	mapping(address => Hookup) addressPriceMapping;
	uint256 addressCount;
}

struct ReserveList {
	mapping(address => bool) addressMapping;
	uint256 addressCount;
}

contract AerialIcons is ERC721, Ownable {
	address public sweetAndy = 0xBE7B3DB607525EA25956B4d28d6e552967225622;

	string public baseURI;

	uint128 public revealIndex = 0;
	uint128 public dropCount = 0;
	uint128 public dropSize = 0;
	uint128 private constant MAX_SUPPLY = 100; // Max supply
	uint256 public presalePrice = 250000000000000000; // 0.25 eth presale price
	uint256 public listPrice = 330000000000000000; // 0.33 eth list price

	mapping(uint256 => FlightPass) private flightPassMap; // mapping for winning flight path indexes
	mapping(uint256 => string) private flightPassRedemptionMap; // mapping for winning flight path indexes

	ReserveList private presale;
	HookupList private hookup;

	uint128 public currentDropReserveCount = 0;
	uint128 public currentDropReserveIndex = 0;
	mapping(uint128 => mapping(address => bool)) public currentDropReserve;

	// Keep track of state
	using Counters for Counters.Counter;
	Counters.Counter private boardingPassCounter;
	Counters.Counter private flightPassCounter;

	/**
	 * @param _baseURI base uri for tokens
	 * @param _presaleAddresses - list of presale addresses
	 */
	constructor(
		string memory _baseURI,
		address[] memory _presaleAddresses,
		uint256[] memory _flightPassIndexes
	) ERC721("AerialIcons", "AerialIcons") {
		baseURI = _baseURI;

		setPresaleAddresses(_presaleAddresses);

		for (uint128 i = 0; i < _flightPassIndexes.length; i++) {
			flightPassMap[_flightPassIndexes[i]] = FlightPass({
				claimed: false,
				exists: true
			});
		}
	}

	// General contract state
	/*------------------------------------*/

	/**
	 * Add an address to current drop.
	 */
	function reserveForCurrentDrop(address _address) public onlyOwner {
		require(
			!currentDropReserve[currentDropReserveIndex][_address],
			"ADDRESS_ALEADY_IN_DROP"
		);
		currentDropReserve[currentDropReserveIndex][_address] = true;
		currentDropReserveCount = currentDropReserveCount + 1;
	}

	/**
	 * Remove address from drop
	 */
	function removeFromCurrentDrop(address _address) public onlyOwner {
		require(
			currentDropReserve[currentDropReserveIndex][_address],
			"ADDRESS_NOT_IN_DROP"
		);
		currentDropReserve[currentDropReserveIndex][_address] = false;
		currentDropReserveCount = currentDropReserveCount - 1;
	}

	/**
	 * Set a new drop
	 */
	function handleNewDrop(
		uint128 _dropCount,
		address[] memory _reservedAddresses
	) public onlyOwner {
		dropCount = _dropCount;
		dropSize = _dropCount;
		currentDropReserveCount = 0;
		currentDropReserveIndex = currentDropReserveIndex + 1;

		for (uint128 i = 0; i < _reservedAddresses.length; i++) {
			reserveForCurrentDrop(_reservedAddresses[i]);
		}
	}

	/**
	 * Set a new drop without reserve addresses
	 */
	function handleRawNewDrop(uint128 _dropCount) public onlyOwner {
		dropCount = _dropCount;
		dropSize = _dropCount;
		currentDropReserveCount = 0;
		currentDropReserveIndex = currentDropReserveIndex + 1;
	}

	/**
	 * Escape hatch to update reveal index
	 */
	function handleReveal(uint128 _revealIndex) public onlyOwner {
		revealIndex = _revealIndex;
	}

	/**
	 * Escape hatch to update price.
	 */
	function setPresalePrice(uint128 _presalePrice) public onlyOwner {
		presalePrice = _presalePrice;
	}

	/**
	 * Escape hatch to update list price.
	 */
	function setListPrice(uint128 _listPrice) public onlyOwner {
		listPrice = _listPrice;
	}

	/**
	 * Escape hatch to update URI.
	 */
	function setBaseURI(string memory _baseURI) public onlyOwner {
		baseURI = _baseURI;
	}

	/**
	 * Update a flight passes redemption URI.
	 */
	function setFlightPassRedemptionURI(
		uint256 _tokenId,
		string memory _redemptionURI
	) public onlyOwner {
		flightPassRedemptionMap[_tokenId] = _redemptionURI;
	}

	/**
	 * Add flight pass for certain token index
	 */
	function setFlightPassIndex(uint256 _tokenId) public onlyOwner {
		require(!flightPassMap[_tokenId].claimed, "FLIGHT_PASS_CLAIMED");
		flightPassMap[_tokenId] = FlightPass({ exists: true, claimed: false });
	}

	/**
	 * Update sweet baby andy's address in the event of an emergency
	 */
	function setSweetAndy(address _sweetAndy) public onlyOwner {
		sweetAndy = _sweetAndy;
	}

	/*
	 * Withdraw, sends:
	 * 95% of all past sales to artist.
	 * 5% of all past sales to devs.
	 */
	function withdraw() public onlyOwner {
		// Pass collaborators their cut
		uint256 balance = address(this).balance;

		// Send devs 4.95%
		(bool success, ) = sweetAndy.call{ value: (balance * 5) / 100 }("");
		require(success, "FAILED_SEND_DEV");

		// Send owner remainder
		(success, ) = owner().call{ value: (balance * 95) / 100 }("");
		require(success, "FAILED_SEND_OWNER");
	}

	/**
	 * Add a single address to the reserve list.
	 */
	function addPresaleAddress(address _address) public onlyOwner {
		require(
			!presale.addressMapping[_address],
			"PRESALE_ADDRESS_ALREADY_EXISTS"
		);

		presale.addressMapping[_address] = true;
		presale.addressCount = presale.addressCount + 1;
	}

	/**
	 * Add addresses to presale.
	 */
	function setPresaleAddresses(address[] memory _addresses) public onlyOwner {
		for (uint128 i = 0; i < _addresses.length; i++) {
			// Do not incrememnt counter if this address already exists
			if (!presale.addressMapping[_addresses[i]]) {
				presale.addressMapping[_addresses[i]] = true;
				presale.addressCount = presale.addressCount + 1;
			}
		}
	}

	/**
	 * Remove from presale.
	 */
	function removePresaleAddress(address _address) public onlyOwner {
		require(presale.addressMapping[_address], "RESERVE_ADDRESS_DNE");
		presale.addressMapping[_address] = false;
		presale.addressCount = presale.addressCount - 1;
	}

	/**
	 * Add a single address to the hookup.
	 */
	function addHookupAddress(address _address, uint256 _price)
		public
		onlyOwner
	{
		require(
			!hookup.addressPriceMapping[_address].exists,
			"HOOKUP_ADDRESS_ALREADY_EXISTS"
		);

		hookup.addressPriceMapping[_address] = Hookup({
			exists: true,
			price: _price
		});
		hookup.addressCount = hookup.addressCount + 1;
	}

	/**
	 * Add addresses to hookup.
	 * A bit wacky, but addresses and prices are parallel arrays that
	 * compose into matching key-value pairs.
	 */
	function setHookupAddresses(
		address[] memory _addresses,
		uint256[] memory _prices
	) public onlyOwner {
		require(
			_addresses.length == _prices.length,
			"HOOKUP_ARRAYS_MUST_BE_PARALLEL"
		);

		for (uint128 i = 0; i < _addresses.length; i++) {
			// Do not incrememnt counter if this address already exists
			if (!hookup.addressPriceMapping[_addresses[i]].exists) {
				hookup.addressPriceMapping[_addresses[i]] = Hookup({
					exists: true,
					price: _prices[i]
				});
				hookup.addressCount = hookup.addressCount + 1;
			}
		}
	}

	/**
	 * Remove from hookup list
	 */
	function removeFromHookup(address _address) public onlyOwner {
		require(
			hookup.addressPriceMapping[_address].exists,
			"HOOKUP_ADDRESS_DNE"
		);

		delete hookup.addressPriceMapping[_address];
		hookup.addressCount = hookup.addressCount - 1;
	}

	function getTotalReserved() private view returns (uint256) {
		return (presale.addressCount + hookup.addressCount);
	}

	function isAddressReserved(address _address) private view returns (bool) {
		return
			presale.addressMapping[_address] ||
			hookup.addressPriceMapping[_address].exists;
	}

	// Minting
	/*------------------------------------*/

	function handleDropCount() private {
		dropCount = dropCount - 1;
		if (dropCount == 0) {
			revealIndex = revealIndex + dropSize;
		}
	}

	/**
	 * Mint boarding pass
	 */
	function handleBoardingPass() private {
		_safeMint(msg.sender, boardingPassCounter.current());

		handleDropCount();
		boardingPassCounter.increment();
	}

	/**
	 * Mint flight pass
	 */
	function handleFlightPass() private {
		_safeMint(msg.sender, MAX_SUPPLY - (flightPassCounter.current() + 1));

		flightPassCounter.increment();
		flightPassMap[boardingPassCounter.current()].claimed = true;
		handleDropCount();
	}

	/**
	 * Mint
	 */
	function mint(uint128 purchaseCount) public payable {
		uint256 finalPrice = listPrice;

		if (hookup.addressPriceMapping[msg.sender].exists) {
			finalPrice = hookup.addressPriceMapping[msg.sender].price;
		} else if (presale.addressMapping[msg.sender]) {
			finalPrice = presalePrice;
		}

		require(
			msg.value >= finalPrice + (listPrice * (purchaseCount - 1)),
			"LOW_ETH"
		);

		require(
			(currentDropReserve[currentDropReserveIndex][msg.sender] &&
				dropCount + 1 >= purchaseCount + currentDropReserveCount) ||
				dropCount >= (purchaseCount + currentDropReserveCount),
			"DROP_SUPPLY_REACHED"
		);
		require(
			isAddressReserved(msg.sender) ||
				boardingPassCounter.current() +
					flightPassCounter.current() +
					getTotalReserved() +
					purchaseCount -
					1 <
				MAX_SUPPLY,
			"MAX_SUPPLY_REACHED"
		);

		if (currentDropReserve[currentDropReserveIndex][msg.sender]) {
			delete currentDropReserve[currentDropReserveIndex][msg.sender];
			currentDropReserveCount = currentDropReserveCount - 1;
		}

		for (uint256 i = 0; i < purchaseCount; i++) {
			uint256 nextTokenId = boardingPassCounter.current();
			FlightPass memory flightPass = flightPassMap[nextTokenId];

			if (flightPass.exists && !flightPass.claimed) {
				handleFlightPass();
			} else {
				handleBoardingPass();
			}
		}
	}

	// ERC721 Things
	/*------------------------------------*/

	/**
	 * Get total token supply
	 */
	function totalSupply() public view returns (uint256) {
		return boardingPassCounter.current() + flightPassCounter.current();
	}

	/**
	 * Get token URI
	 */
	function tokenURI(uint256 _tokenId)
		public
		view
		override
		returns (string memory)
	{
		require(_exists(_tokenId), "TOKEN_DNE");

		if (_tokenId >= MAX_SUPPLY - flightPassCounter.current()) {
			if (bytes(flightPassRedemptionMap[_tokenId]).length != 0) {
				return flightPassRedemptionMap[_tokenId];
			} else {
				return string(abi.encodePacked(baseURI, "flight_pass"));
			}
		} else if (_tokenId + flightPassCounter.current() + 1 > revealIndex) {
			return string(abi.encodePacked(baseURI, "boarding_pass"));
		}

		return string(abi.encodePacked(baseURI, Strings.toString(_tokenId)));
	}
}

// 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 v4.4.1 (utils/Counters.sol)

pragma solidity ^0.8.0;

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 */
library Counters {
    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }

    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }

    function increment(Counter storage counter) internal {
        unchecked {
            counter._value += 1;
        }
    }

    function decrement(Counter storage counter) internal {
        uint256 value = counter._value;
        require(value > 0, "Counter: decrement overflow");
        unchecked {
            counter._value = value - 1;
        }
    }

    function reset(Counter storage counter) internal {
        counter._value = 0;
    }
}

// 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 (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);
    }

    /**
     * @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);
    }

    /**
     * @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 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);

        _balances[from] -= 1;
        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(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 {}
}

// 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 (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 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 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 (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);
    }
}

// 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);
    }
}

{
  "compilationTarget": {
    "contracts/AerialIcons.sol": "AerialIcons"
  },
  "evmVersion": "london",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}