Contract Name:
OnchainPower
Contract Source Code:
File 1 of 1 : OnchainPower
// SPDX-License-Identifier: MIT
// File: @openzeppelin/contracts/utils/math/Math.sol
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds up instead
* of rounding down.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b - 1) / b can overflow on addition, so we distribute.
return a == 0 ? 0 : (a - 1) / b + 1;
}
/**
* @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
* @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
* with further edits by Uniswap Labs also under MIT license.
*/
function mulDiv(
uint256 x,
uint256 y,
uint256 denominator
) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
// use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = prod1 * 2^256 + prod0.
uint256 prod0; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod0 := mul(x, y)
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
return prod0 / denominator;
}
// Make sure the result is less than 2^256. Also prevents denominator == 0.
require(denominator > prod1);
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
// See https://cs.stackexchange.com/q/138556/92363.
// Does not overflow because the denominator cannot be zero at this stage in the function.
uint256 twos = denominator & (~denominator + 1);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
// that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv = 1 mod 2^4.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
// in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2^8
inverse *= 2 - denominator * inverse; // inverse mod 2^16
inverse *= 2 - denominator * inverse; // inverse mod 2^32
inverse *= 2 - denominator * inverse; // inverse mod 2^64
inverse *= 2 - denominator * inverse; // inverse mod 2^128
inverse *= 2 - denominator * inverse; // inverse mod 2^256
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
// less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(
uint256 x,
uint256 y,
uint256 denominator,
Rounding rounding
) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
function sqrt(uint256 a) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
// For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
//
// We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
// `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
//
// This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
// → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
// → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
//
// Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
uint256 result = 1 << (log2(a) >> 1);
// At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
// since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
// every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
// into the expected uint128 result.
unchecked {
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
return min(result, a / result);
}
}
/**
* @notice Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 128;
}
if (value >> 64 > 0) {
value >>= 64;
result += 64;
}
if (value >> 32 > 0) {
value >>= 32;
result += 32;
}
if (value >> 16 > 0) {
value >>= 16;
result += 16;
}
if (value >> 8 > 0) {
value >>= 8;
result += 8;
}
if (value >> 4 > 0) {
value >>= 4;
result += 4;
}
if (value >> 2 > 0) {
value >>= 2;
result += 2;
}
if (value >> 1 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10**64) {
value /= 10**64;
result += 64;
}
if (value >= 10**32) {
value /= 10**32;
result += 32;
}
if (value >= 10**16) {
value /= 10**16;
result += 16;
}
if (value >= 10**8) {
value /= 10**8;
result += 8;
}
if (value >= 10**4) {
value /= 10**4;
result += 4;
}
if (value >= 10**2) {
value /= 10**2;
result += 2;
}
if (value >= 10**1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (rounding == Rounding.Up && 10**result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256, rounded down, of a positive value.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 16;
}
if (value >> 64 > 0) {
value >>= 64;
result += 8;
}
if (value >> 32 > 0) {
value >>= 32;
result += 4;
}
if (value >> 16 > 0) {
value >>= 16;
result += 2;
}
if (value >> 8 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up && 1 << (result * 8) < value ? 1 : 0);
}
}
}
// File: @openzeppelin/contracts/utils/Strings.sol
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _SYMBOLS = "0123456789abcdef";
uint8 private constant _ADDRESS_LENGTH = 20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = Math.log10(value) + 1;
string memory buffer = new string(length);
uint256 ptr;
/// @solidity memory-safe-assembly
assembly {
ptr := add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assembly
assembly {
mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
}
value /= 10;
if (value == 0) break;
}
return buffer;
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
unchecked {
return toHexString(value, Math.log256(value) + 1);
}
}
/**
* @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] = _SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
}
// File: @openzeppelin/contracts/utils/Context.sol
// 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;
}
}
// File: @openzeppelin/contracts/access/Ownable.sol
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
/**
* @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 Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
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);
}
}
// File: @openzeppelin/contracts/utils/Address.sol
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, "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");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, 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) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, 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) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata,
string memory errorMessage
) internal view returns (bytes memory) {
if (success) {
if (returndata.length == 0) {
// only check isContract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
require(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or 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 {
_revert(returndata, errorMessage);
}
}
function _revert(bytes memory returndata, string memory errorMessage) private pure {
// 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
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)
pragma solidity ^0.8.0;
/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/
interface IERC721Receiver {
/**
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
* by `operator` from `from`, this function is called.
*
* It must return its Solidity selector to confirm the token transfer.
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
*
* The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
*/
function onERC721Received(
address operator,
address from,
uint256 tokenId,
bytes calldata data
) external returns (bytes4);
}
// File: @openzeppelin/contracts/utils/introspection/IERC165.sol
// 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);
}
// File: @openzeppelin/contracts/utils/introspection/ERC165.sol
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
/**
* @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;
}
}
// File: @openzeppelin/contracts/token/ERC721/IERC721.sol
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC721/IERC721.sol)
pragma solidity ^0.8.0;
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes calldata data
) external;
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must 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: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
* or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
* understand this adds an external call which potentially creates a reentrancy vulnerability.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
}
// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)
pragma solidity ^0.8.0;
/**
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Enumerable is IERC721 {
/**
* @dev Returns the total amount of tokens stored by the contract.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns a token ID owned by `owner` at a given `index` of its token list.
* Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);
/**
* @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
* Use along with {totalSupply} to enumerate all tokens.
*/
function tokenByIndex(uint256 index) external view returns (uint256);
}
// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)
pragma solidity ^0.8.0;
/**
* @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);
}
// File: @openzeppelin/contracts/token/ERC721/ERC721.sol
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC721/ERC721.sol)
pragma solidity ^0.8.0;
/**
* @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: address zero is not a valid owner");
return _balances[owner];
}
/**
* @dev See {IERC721-ownerOf}.
*/
function ownerOf(uint256 tokenId) public view virtual override returns (address) {
address owner = _ownerOf(tokenId);
require(owner != address(0), "ERC721: invalid token ID");
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) {
_requireMinted(tokenId);
string memory baseURI = _baseURI();
return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
}
/**
* @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
* token will be the concatenation of the `baseURI` and the `tokenId`. Empty
* by default, can be overridden in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return "";
}
/**
* @dev See {IERC721-approve}.
*/
function approve(address to, uint256 tokenId) public virtual override {
address owner = ERC721.ownerOf(tokenId);
require(to != owner, "ERC721: approval to current owner");
require(
_msgSender() == owner || isApprovedForAll(owner, _msgSender()),
"ERC721: approve caller is not token owner or approved for all"
);
_approve(to, tokenId);
}
/**
* @dev See {IERC721-getApproved}.
*/
function getApproved(uint256 tokenId) public view virtual override returns (address) {
_requireMinted(tokenId);
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: caller is not token owner or 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: caller is not token owner or 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 the owner of the `tokenId`. Does NOT revert if token doesn't exist
*/
function _ownerOf(uint256 tokenId) internal view virtual returns (address) {
return _owners[tokenId];
}
/**
* @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 _ownerOf(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) {
address owner = ERC721.ownerOf(tokenId);
return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
}
/**
* @dev Safely mints `tokenId` and transfers it to `to`.
*
* Requirements:
*
* - `tokenId` must not exist.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function _safeMint(address to, uint256 tokenId) internal virtual {
_safeMint(to, tokenId, "");
}
/**
* @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
* forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
*/
function _safeMint(
address to,
uint256 tokenId,
bytes memory data
) internal virtual {
_mint(to, tokenId);
require(
_checkOnERC721Received(address(0), to, tokenId, data),
"ERC721: transfer to non ERC721Receiver implementer"
);
}
/**
* @dev Mints `tokenId` and transfers it to `to`.
*
* WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
*
* Requirements:
*
* - `tokenId` must not exist.
* - `to` cannot be the zero address.
*
* Emits a {Transfer} event.
*/
function _mint(address to, uint256 tokenId) internal virtual {
require(to != address(0), "ERC721: mint to the zero address");
require(!_exists(tokenId), "ERC721: token already minted");
_beforeTokenTransfer(address(0), to, tokenId, 1);
// Check that tokenId was not minted by `_beforeTokenTransfer` hook
require(!_exists(tokenId), "ERC721: token already minted");
unchecked {
// Will not overflow unless all 2**256 token ids are minted to the same owner.
// Given that tokens are minted one by one, it is impossible in practice that
// this ever happens. Might change if we allow batch minting.
// The ERC fails to describe this case.
_balances[to] += 1;
}
_owners[tokenId] = to;
emit Transfer(address(0), to, tokenId);
_afterTokenTransfer(address(0), to, tokenId, 1);
}
/**
* @dev Destroys `tokenId`.
* The approval is cleared when the token is burned.
* This is an internal function that does not check if the sender is authorized to operate on the token.
*
* Requirements:
*
* - `tokenId` must exist.
*
* Emits a {Transfer} event.
*/
function _burn(uint256 tokenId) internal virtual {
address owner = ERC721.ownerOf(tokenId);
_beforeTokenTransfer(owner, address(0), tokenId, 1);
// Update ownership in case tokenId was transferred by `_beforeTokenTransfer` hook
owner = ERC721.ownerOf(tokenId);
// Clear approvals
delete _tokenApprovals[tokenId];
unchecked {
// Cannot overflow, as that would require more tokens to be burned/transferred
// out than the owner initially received through minting and transferring in.
_balances[owner] -= 1;
}
delete _owners[tokenId];
emit Transfer(owner, address(0), tokenId);
_afterTokenTransfer(owner, address(0), tokenId, 1);
}
/**
* @dev Transfers `tokenId` from `from` to `to`.
* As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
*
* Emits a {Transfer} event.
*/
function _transfer(
address from,
address to,
uint256 tokenId
) internal virtual {
require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
require(to != address(0), "ERC721: transfer to the zero address");
_beforeTokenTransfer(from, to, tokenId, 1);
// Check that tokenId was not transferred by `_beforeTokenTransfer` hook
require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
// Clear approvals from the previous owner
delete _tokenApprovals[tokenId];
unchecked {
// `_balances[from]` cannot overflow for the same reason as described in `_burn`:
// `from`'s balance is the number of token held, which is at least one before the current
// transfer.
// `_balances[to]` could overflow in the conditions described in `_mint`. That would require
// all 2**256 token ids to be minted, which in practice is impossible.
_balances[from] -= 1;
_balances[to] += 1;
}
_owners[tokenId] = to;
emit Transfer(from, to, tokenId);
_afterTokenTransfer(from, to, tokenId, 1);
}
/**
* @dev Approve `to` to operate on `tokenId`
*
* Emits an {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 an {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 Reverts if the `tokenId` has not been minted yet.
*/
function _requireMinted(uint256 tokenId) internal view virtual {
require(_exists(tokenId), "ERC721: invalid token ID");
}
/**
* @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 {
/// @solidity memory-safe-assembly
assembly {
revert(add(32, reason), mload(reason))
}
}
}
} else {
return true;
}
}
/**
* @dev Hook that is called before any token transfer. This includes minting and burning. If {ERC721Consecutive} is
* used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s tokens will be transferred to `to`.
* - When `from` is zero, the tokens will be minted for `to`.
* - When `to` is zero, ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
* - `batchSize` is non-zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256, /* firstTokenId */
uint256 batchSize
) internal virtual {
if (batchSize > 1) {
if (from != address(0)) {
_balances[from] -= batchSize;
}
if (to != address(0)) {
_balances[to] += batchSize;
}
}
}
/**
* @dev Hook that is called after any token transfer. This includes minting and burning. If {ERC721Consecutive} is
* used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s tokens were transferred to `to`.
* - When `from` is zero, the tokens were minted for `to`.
* - When `to` is zero, ``from``'s tokens were burned.
* - `from` and `to` are never both zero.
* - `batchSize` is non-zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(
address from,
address to,
uint256 firstTokenId,
uint256 batchSize
) internal virtual {}
}
// File: @openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC721/extensions/ERC721Enumerable.sol)
pragma solidity ^0.8.0;
/**
* @dev This implements an optional extension of {ERC721} defined in the EIP that adds
* enumerability of all the token ids in the contract as well as all token ids owned by each
* account.
*/
abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
// Mapping from owner to list of owned token IDs
mapping(address => mapping(uint256 => uint256)) private _ownedTokens;
// Mapping from token ID to index of the owner tokens list
mapping(uint256 => uint256) private _ownedTokensIndex;
// Array with all token ids, used for enumeration
uint256[] private _allTokens;
// Mapping from token id to position in the allTokens array
mapping(uint256 => uint256) private _allTokensIndex;
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
return _ownedTokens[owner][index];
}
/**
* @dev See {IERC721Enumerable-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _allTokens.length;
}
/**
* @dev See {IERC721Enumerable-tokenByIndex}.
*/
function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
require(index < ERC721Enumerable.totalSupply(), "ERC721Enumerable: global index out of bounds");
return _allTokens[index];
}
/**
* @dev See {ERC721-_beforeTokenTransfer}.
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 firstTokenId,
uint256 batchSize
) internal virtual override {
super._beforeTokenTransfer(from, to, firstTokenId, batchSize);
if (batchSize > 1) {
// Will only trigger during construction. Batch transferring (minting) is not available afterwards.
revert("ERC721Enumerable: consecutive transfers not supported");
}
uint256 tokenId = firstTokenId;
if (from == address(0)) {
_addTokenToAllTokensEnumeration(tokenId);
} else if (from != to) {
_removeTokenFromOwnerEnumeration(from, tokenId);
}
if (to == address(0)) {
_removeTokenFromAllTokensEnumeration(tokenId);
} else if (to != from) {
_addTokenToOwnerEnumeration(to, tokenId);
}
}
/**
* @dev Private function to add a token to this extension's ownership-tracking data structures.
* @param to address representing the new owner of the given token ID
* @param tokenId uint256 ID of the token to be added to the tokens list of the given address
*/
function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
uint256 length = ERC721.balanceOf(to);
_ownedTokens[to][length] = tokenId;
_ownedTokensIndex[tokenId] = length;
}
/**
* @dev Private function to add a token to this extension's token tracking data structures.
* @param tokenId uint256 ID of the token to be added to the tokens list
*/
function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
_allTokensIndex[tokenId] = _allTokens.length;
_allTokens.push(tokenId);
}
/**
* @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
* while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
* gas optimizations e.g. when performing a transfer operation (avoiding double writes).
* This has O(1) time complexity, but alters the order of the _ownedTokens array.
* @param from address representing the previous owner of the given token ID
* @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
*/
function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
// To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
uint256 tokenIndex = _ownedTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary
if (tokenIndex != lastTokenIndex) {
uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
_ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
}
// This also deletes the contents at the last position of the array
delete _ownedTokensIndex[tokenId];
delete _ownedTokens[from][lastTokenIndex];
}
/**
* @dev Private function to remove a token from this extension's token tracking data structures.
* This has O(1) time complexity, but alters the order of the _allTokens array.
* @param tokenId uint256 ID of the token to be removed from the tokens list
*/
function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
// To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = _allTokens.length - 1;
uint256 tokenIndex = _allTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
// rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
// an 'if' statement (like in _removeTokenFromOwnerEnumeration)
uint256 lastTokenId = _allTokens[lastTokenIndex];
_allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
// This also deletes the contents at the last position of the array
delete _allTokensIndex[tokenId];
_allTokens.pop();
}
}
// File: contracts/OnchainPower.sol
pragma solidity >=0.8.0 <0.9.0;
library Base64 {
string internal constant TABLE = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
function encode(bytes memory data) internal pure returns (string memory) {
if (data.length == 0) return '';
// load the table into memory
string memory table = TABLE;
// multiply by 4/3 rounded up
uint256 encodedLen = 4 * ((data.length + 2) / 3);
// add some extra buffer at the end required for the writing
string memory result = new string(encodedLen + 32);
assembly {
// set the actual output length
mstore(result, encodedLen)
// prepare the lookup table
let tablePtr := add(table, 1)
// input ptr
let dataPtr := data
let endPtr := add(dataPtr, mload(data))
// result ptr, jump over length
let resultPtr := add(result, 32)
// run over the input, 3 bytes at a time
for {} lt(dataPtr, endPtr) {}
{
dataPtr := add(dataPtr, 3)
// read 3 bytes
let input := mload(dataPtr)
// write 4 characters
mstore(resultPtr, shl(248, mload(add(tablePtr, and(shr(18, input), 0x3F)))))
resultPtr := add(resultPtr, 1)
mstore(resultPtr, shl(248, mload(add(tablePtr, and(shr(12, input), 0x3F)))))
resultPtr := add(resultPtr, 1)
mstore(resultPtr, shl(248, mload(add(tablePtr, and(shr( 6, input), 0x3F)))))
resultPtr := add(resultPtr, 1)
mstore(resultPtr, shl(248, mload(add(tablePtr, and( input, 0x3F)))))
resultPtr := add(resultPtr, 1)
}
// padding with '='
switch mod(mload(data), 3)
case 1 { mstore(sub(resultPtr, 2), shl(240, 0x3d3d)) }
case 2 { mstore(sub(resultPtr, 1), shl(248, 0x3d)) }
}
return result;
}
function buildImage(string memory _bgHue, string memory _eyesHue, string memory _pukeHue) internal pure returns(string memory) {
return encode(bytes(abi.encodePacked(
'<?xml version="1.0" encoding="utf-8"?><svg version="1.0" xmlns="http://www.w3.org/2000/svg" width="1024px" height="1024px" viewBox="0 0 1024 1024" preserveAspectRatio="xMidYMid meet">',
'<g fill="hsl(', _bgHue, ',100%,80%)"><path d="M0 512 l0 -512 512 0 512 0 0 512 0 512 -512 0 -512 0 0 -512z m513.7 403.9 c3 -1.1 8.8 -6.3 10.4 -9.2 0.6 -1 1.9 -5.1 3 -9.2 1 -4.1 3.2 -9.6 4.7 -12.2 3.5 -6 6.2 -6.5 14.6 -2.7 15.6 7.1 35.3 -0.3 43.3 -16.1 3.3 -6.5 6.3 -23.9 6.4 -37.5 0 -5.8 0.6 -20.1 1.2 -31.8 l1.2 -21.4 6.7 -2.3 c43.6 -15.2 79.2 -44.7 109.4 -90.5 22.7 -34.4 35.7 -72.7 34 -100 -1.3 -20.8 -9.2 -39.4 -22.2 -52.4 -14.8 -14.8 -33.6 -22 -57.4 -21.9 -11.5 0.1 -13.5 0.4 -24.5 3.8 -8.3 2.5 -17 6.3 -28.5 12.2 -40.9 21.3 -49.1 25.1 -64.8 30.2 -31 9.8 -43.1 11.5 -80.7 11.6 -42.6 0 -52.9 -2.1 -112 -22.7 -25.8 -9.1 -52.2 1.2 -69 26.7 -5.9 9 -10.6 21.4 -12.4 32.5 -7.1 43.8 24.5 96.3 82.4 136.7 24 16.7 49.3 29.7 78 40 l8 2.9 -0.1 3.9 c0 2.2 -0.5 8.9 -1.2 14.9 -0.7 6 -1.2 18.5 -1.2 27.7 0 25.5 2.5 35.5 11.4 44.7 7 7.4 10.2 8.5 23 8.1 l11 -0.4 0.9 4 c0.4 2.2 1.2 6.9 1.8 10.4 1.6 10.1 5.1 15.6 12.4 19.4 3.6 1.9 6.4 2.1 10.2 0.6z m-144.6 -485.5 c37.8 -6.1 67.4 -28.2 82.9 -61.8 8.5 -18.4 12.2 -36.9 12.3 -61.6 0.1 -16.2 -0.1 -18.3 -2.7 -28.5 -4.6 -17.6 -11.6 -30.5 -23 -42.4 -18.6 -19.3 -45.1 -30.4 -72.6 -30.4 -12.1 -0.1 -16.7 0.7 -32 5.5 -40.1 12.5 -66.1 38.4 -76.7 76.3 -2.7 9.5 -2.8 11 -2.7 30.5 0.1 21.2 1.1 29.4 5.6 45.9 10.3 37.7 33.8 60.5 68.8 66.5 15.9 2.7 23.7 2.7 40.1 0z m261.2 0 c12.7 -2.4 25.2 -7.3 39.1 -15.4 11.3 -6.5 18.2 -11.7 26.9 -20.3 29.7 -29.3 38.3 -66.7 25 -109.2 -9.2 -29.3 -29.6 -54.6 -56.3 -69.7 -18.8 -10.6 -44 -15.5 -64 -12.4 -13 2 -18.9 3.7 -31.3 8.8 -38.7 16 -61.8 50.7 -66.8 100.3 -1.9 19.3 -0.3 37 5.1 56 7.7 27.2 28 48 55.5 56.8 21.9 7 46.7 8.9 66.8 5.1z"/></g>',
'<g fill="#5c2929"><path d="M494.5 784.3 c-12.2 -0.7 -28.5 -2.6 -33.5 -3.8 -15.1 -3.6 -26.4 -7 -34.5 -10.2 -34.3 -13.6 -68.3 -34.5 -92 -56.5 -24.3 -22.5 -36.5 -39.3 -45.4 -62.2 -5.1 -13.2 -6.5 -22.9 -5.8 -41.5 0.7 -20.3 4.7 -31.8 15.6 -44.8 10.4 -12.5 23.7 -18.3 41.6 -18.3 11.3 0 12.8 0.4 41.6 10.3 33.2 11.5 53 15.6 79.9 16.4 34.9 1.1 68.1 -4.7 102 -17.7 7.9 -3 19.6 -8.9 54 -26.8 22.7 -11.8 36.2 -15 58 -13.8 14.1 0.8 22.2 2.6 32 7.3 14.1 6.7 26.9 22.8 31.7 39.5 2 7.4 2.9 33.4 1.3 43.9 -2.4 17.1 -7.3 31.8 -16.7 50.4 -7.6 15.2 -7.4 14.9 -13.6 24.4 -19 29.1 -46.9 57.3 -68.8 69.6 -14.2 7.9 -19.7 10.5 -22.5 10.5 -2.8 0 -3.3 -0.5 -4.9 -4.7 -5 -13.5 -13.9 -31.5 -21.9 -44.1 -2.9 -4.7 -18.5 -23 -23.7 -27.9 -8.9 -8.4 -34.6 -22.7 -46.4 -25.8 -10.5 -2.8 -18.2 -3 -25.8 -0.7 -9.8 2.9 -13.2 5.6 -17 13.2 -2.7 5.4 -3.2 7.6 -3.1 13 0.1 7.6 5 24.3 12 40.7 2.4 5.7 4.4 10.5 4.4 10.8 0 0.4 0.8 2.5 1.9 4.8 1 2.3 3.8 9.4 6.1 15.7 2.4 6.3 4.7 12.1 5.3 12.8 0.5 0.7 1.2 4.6 1.5 8.7 l0.5 7.5 -4.4 -0.2 c-2.4 -0.1 -6.6 -0.3 -9.4 -0.5z"/><path d="M685.4 230.6 c-0.3 -0.8 -0.4 -2.6 -0.2 -4.1 l0.3 -2.6 4 4 3.9 4.1 -3.7 0 c-2.3 0 -4 -0.5 -4.3 -1.4z"/></g>',
'<g fill="hsl(', _eyesHue, ',100%,92%)"><path d="M328.5 428.3 c-25.4 -5.6 -39.6 -13.8 -50.9 -29.2 -13.1 -17.9 -20.6 -47.5 -20.6 -81.6 0 -46.9 17.6 -77.3 55.4 -96 20 -9.9 35.4 -13 59.9 -12.2 26.7 0.8 44.2 7.6 62.5 24.3 18.8 17 28 42.8 26.9 75.4 -0.8 22.5 -2.6 34.6 -7.7 50.1 -6.7 20.5 -18.6 37.4 -34.3 49.1 -9.2 6.8 -22.9 13.7 -31.7 15.8 -16.9 4.2 -22.7 4.9 -40 4.9 -9.6 -0.1 -18.4 -0.3 -19.5 -0.6z m-21.8 -124.8 c1.9 -0.8 5.9 -1.5 8.7 -1.5 5.5 0 8.7 -1.2 6.6 -2.5 -0.7 -0.4 -1 -2.7 -0.9 -5.9 0.1 -2.8 -0.3 -6.1 -0.9 -7.3 -0.7 -1.2 -1.2 -3.2 -1.2 -4.4 0 -3.9 -2.8 -5.9 -8.1 -5.9 -3.7 0 -5.3 0.5 -6.9 2.2 -1.1 1.2 -2 2.5 -2 3 0 0.4 -1.8 2 -4 3.4 -2.2 1.5 -4 3.1 -4 3.7 0 0.6 1.1 2.5 2.5 4.3 1.4 1.8 2.5 4.6 2.5 6.3 0 2.5 2.1 6.1 3.6 6.1 0.3 0 2.1 -0.7 4.1 -1.5z"/><path d="M582.5 427.5 c-26.2 -4.2 -42.1 -11.6 -55.1 -25.9 -7.3 -8 -14.1 -20.7 -17.4 -32.6 -9.7 -35 -4.5 -86.9 11.6 -114.3 12.8 -21.8 31.7 -36.3 57.4 -44.1 12.2 -3.6 19.6 -4.6 36.2 -4.6 20.1 0 33.9 3 49.2 10.7 19.3 9.7 38.7 30.3 48.3 51 7.2 15.7 9.8 25.9 11.2 44.9 2.4 31.4 -4.4 54.2 -22.3 74.9 -8.7 10.1 -12.9 13.8 -23.6 20.9 -14.8 9.8 -27.9 15.6 -43.7 19 -8.9 2 -39.8 2 -51.8 0.1z m84.9 -128.5 c2.3 0 4.7 -0.5 5.4 -1.2 1.9 -1.9 1.4 -5.3 -1.3 -7.8 -1.4 -1.3 -2.5 -3.4 -2.5 -4.6 0 -1.3 -0.6 -2.8 -1.2 -3.3 -7.9 -6.5 -7.7 -6.4 -10.2 -4.8 -1.3 0.9 -4.5 1.7 -7.2 1.9 l-4.9 0.3 -0.3 5 c-0.2 2.7 -0.8 5.5 -1.4 6.2 -1.5 1.8 -0.2 3.2 5.5 5.7 2.9 1.3 6.3 3.6 7.6 5.1 l2.4 2.8 1.9 -2.6 c1.6 -2.2 2.8 -2.7 6.2 -2.7z"/></g>',
'<g fill="#010101">',
'<path d="M500.5 918.3 c-7.3 -3.8 -10.8 -9.3 -12.4 -19.4 -0.6 -3.5 -1.4 -8.1 -1.8 -10.3 l-0.8 -3.9 -11.2 0.2 c-12.9 0.2 -16 -0.9 -22.9 -8.1 -9.2 -9.5 -11.4 -18.9 -11.4 -47.7 0 -15.7 1.1 -35.1 2.3 -42.5 0.1 -0.5 -3.4 -2.3 -7.8 -3.9 -69.1 -25.1 -125.3 -69.3 -149.2 -117.2 -16.9 -33.7 -16.4 -71.2 1.2 -98 9.2 -14 20.1 -22.4 36 -28.1 3.7 -1.3 8.1 -1.8 17.5 -1.8 11.5 0 13.2 0.2 21.5 3.1 36.2 12.8 56.4 18.6 74.5 21.5 5.6 0.8 17.5 1.3 34.5 1.3 34.3 -0.1 47.4 -2 77.7 -11.6 15.7 -5.1 23.9 -8.9 64.8 -30.2 11.4 -5.9 20.2 -9.7 28.5 -12.3 11.4 -3.5 12.7 -3.7 27 -3.8 16.1 -0.1 24.8 1.3 36.5 5.9 39.6 15.5 56.4 61.2 41.5 113 -6 20.7 -15.7 41.5 -28.9 61.5 -30.2 45.8 -65.8 75.3 -109.4 90.5 l-6.7 2.3 -1.2 21.4 c-0.6 11.7 -1.2 26 -1.2 31.8 -0.1 13.6 -3.1 31 -6.4 37.5 -3.4 6.9 -11 13.7 -18.3 16.5 -4.6 1.9 -7.9 2.4 -15.4 2.4 -8.3 0.1 -10.2 -0.3 -15.3 -2.6 l-5.7 -2.7 -1.5 2.5 c-0.8 1.3 -2.2 3.5 -3 4.8 -0.8 1.3 -2.3 5.8 -3.4 10 -1.1 4.1 -2.4 8.3 -3 9.3 -1.6 2.9 -7.4 8.1 -10.4 9.2 -4.1 1.6 -12.7 1.3 -16.2 -0.6z m13.4 -13 c1.8 -1.9 3.3 -5.1 4.5 -9.7 5.4 -21.8 15.9 -29.3 30.3 -21.6 6.5 3.5 10.3 3.7 17.8 1.1 7.2 -2.6 11.6 -6.1 14.8 -12 4.4 -7.9 4.5 -9.1 7.4 -64.8 0.3 -6.2 0.4 -11.3 0.2 -11.3 -0.2 0 -9.8 1.9 -21.4 4.1 -42.8 8.4 -64.9 9.4 -98.7 4.3 -5.7 -0.8 -11.3 -1.7 -12.4 -2 -2.5 -0.6 -2.7 0.2 -4.4 16.6 -2.1 20.6 -0.6 40.6 3.7 50.3 1.9 4.2 4 6.9 7.2 9.4 4.5 3.4 4.8 3.5 11.6 2.9 3.9 -0.3 9.1 -0.8 11.6 -1.2 4.2 -0.5 4.8 -0.3 7.2 2.5 2.7 3.3 5.3 10.9 6.8 20.5 1.2 7 2 8.8 5.5 11.5 3.5 2.8 5 2.6 8.3 -0.6z m-9.3 -127.9 c-0.3 -2.6 -1 -5.2 -1.5 -5.8 -0.4 -0.6 -2.7 -6.3 -5.1 -12.6 -2.3 -6.3 -5.1 -13.4 -6.1 -15.7 -1.1 -2.3 -1.9 -4.4 -1.9 -4.8 0 -0.3 -2 -5.1 -4.4 -10.8 -2.4 -5.6 -6.1 -15.6 -8.2 -22.2 -3.3 -10.4 -3.8 -13.3 -3.9 -21.5 0 -8.7 0.3 -10.1 3.2 -16 3.9 -7.8 7 -10.1 17.9 -13.5 7.2 -2.2 8.6 -2.4 16.4 -1.5 4.7 0.5 11.2 1.7 14.5 2.5 11.7 3.1 37.4 17.4 46.4 25.8 5.2 4.9 20.8 23.2 23.7 27.9 8 12.6 16.9 30.6 21.9 44 l1.7 4.6 3.8 -1.6 c6.6 -3 21 -11.5 28.4 -16.9 19.2 -14.1 40.8 -37.7 56.3 -61.4 6.2 -9.5 6 -9.2 13.6 -24.4 9.4 -18.6 14.3 -33.3 16.8 -50.4 1.4 -10.1 0.7 -30.2 -1.5 -37.9 -4.6 -16.6 -17.5 -32.8 -31.6 -39.5 -18.2 -8.7 -42.4 -9.9 -62.9 -3.1 -4.2 1.4 -13.7 5.7 -21.1 9.6 -52.2 27.2 -59.9 30.5 -87.2 37.2 -24.9 6.1 -43.8 8 -71.7 7.3 -29.8 -0.7 -48.4 -4.4 -83 -16.4 -27 -9.3 -30.7 -10.3 -38.6 -10.3 -23.5 0 -44 16.9 -52 43 -2.2 7.5 -3.1 26.6 -1.6 37.1 2.9 19.7 15.4 43.6 33.1 63.2 23.5 25.9 54.7 48.8 88.2 64.6 21.5 10.2 32 13.9 55.8 19.6 5 1.2 21.3 3.1 33.5 3.8 2.8 0.2 5.6 0.4 6.4 0.5 1.1 0.2 1.2 -0.8 0.7 -4.4z m39.4 -2.3 c5.2 -1 13.6 -2.7 18.5 -3.6 21.5 -4.1 43.5 -10.8 43.5 -13.2 0 -2 -9 -21.8 -13.6 -29.9 -8.7 -15.6 -15.2 -24 -27.4 -35.7 -16.8 -16.2 -32.7 -24.8 -50.6 -27.7 -6.9 -1.1 -10.3 -0.5 -17.4 3 -4.3 2.2 -8.9 10.6 -8.9 16.5 -0.1 4.2 6.6 27.8 10 35.5 1.1 2.5 4.3 10.6 7 18 2.8 7.4 6.7 17.8 8.8 23 2.1 5.2 4.2 11.3 4.6 13.4 l0.6 3.9 7.7 -0.6 c4.2 -0.3 12 -1.5 17.2 -2.6z"/>',
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'</g><g fill="hsl(', _pukeHue, ', 60%, 40%)"><path d="M501.5 907.7 c-2.5 -2.5 -3.5 -4.5 -4 -8.3 -0.4 -2.7 -1.4 -7.6 -2.2 -10.9 -3 -11.2 -6.2 -15.3 -10.7 -13.5 -1.5 0.5 -6.7 1 -11.5 1 -8.5 0 -9 -0.1 -13.3 -3.4 -9.3 -7.1 -12.6 -22.2 -11.5 -52.1 0.6 -14.3 1.9 -27.9 3.1 -31.2 0.4 -0.9 1.6 -0.8 4.8 0.2 5.9 1.7 23.7 4.3 37.8 5.4 11.2 0.9 27.6 0.2 42.5 -1.8 8.2 -1 46.4 -8.5 51.5 -10 1.9 -0.6 3.7 -1.1 3.9 -1.1 1 0 -2.4 66.2 -3.9 73.9 -1.3 6.9 -5.4 14.4 -9.7 17.7 -5 3.8 -13.3 6.4 -20.6 6.4 -5.2 0 -7.5 -0.6 -12.2 -3.1 -3.8 -2 -6.5 -2.9 -8 -2.5 -6.4 1.6 -12.9 11.4 -16.1 24.2 -2.3 9.2 -5.4 12.4 -11.9 12.4 -4 0 -5.2 -0.5 -8 -3.3z"/></g><g fill="#b64949"><path d="M515.5 777.4 c-0.4 -2.2 -2.5 -8.2 -4.6 -13.4 -2.1 -5.2 -6 -15.6 -8.8 -23 -2.7 -7.4 -5.9 -15.5 -7 -18 -1.1 -2.5 -3.8 -10.6 -6 -18 -3.2 -10.5 -4.1 -15.1 -4 -20.5 0.1 -21.4 17.1 -28.6 45 -19.2 14.1 4.8 24.4 11.4 37.9 24.4 12.2 11.7 18.7 20.1 27.4 35.7 5 8.7 15.6 32.6 15.6 35 0 2.7 -23.2 9.9 -45.5 14.1 -4.9 0.9 -13.3 2.6 -18.5 3.7 -5.2 1.1 -14.3 2.2 -20.2 2.5 l-10.7 0.6 -0.6 -3.9z"/></g>',
'</svg>'
)));
}
}
contract OnchainPower is ERC721Enumerable, Ownable {
using Strings for uint256;
uint256 public cost = 0.00023 ether;
struct ItemData {
string name;
string description;
string bgHue;
string eyesHue;
string pukeHue;
}
mapping (uint256 => ItemData) public itemsData;
constructor() ERC721("Onchain Power", "POWER") {}
function randomNum(uint256 _minNumber, uint256 _maxNumber, uint256 startAddressIndex, uint256 _salt) private view returns(uint256) {
uint endAddressIndex = startAddressIndex + 8;
bytes memory addressBytes = abi.encodePacked(msg.sender);
bytes memory addressRandomnessSeed = new bytes(endAddressIndex - startAddressIndex);
for(uint i = startAddressIndex; i < endAddressIndex; i++) {
addressRandomnessSeed[i-startAddressIndex] = addressBytes[i];
}
uint256 randomNumberModule = _maxNumber - _minNumber;
uint256 randomNumber = _minNumber + uint256(keccak256(abi.encodePacked(block.timestamp, msg.sender, addressRandomnessSeed, _salt))) % randomNumberModule;
return randomNumber;
}
function mint(uint256 _mintAmount) public payable {
require(_mintAmount > 0, "Need to mint at least 1 NFT");
require(msg.value >= cost * _mintAmount, "Insufficient funds");
uint256 supply = totalSupply();
for (uint256 i = 1; i <= _mintAmount; i++) {
ItemData memory newItemData = ItemData(
string(abi.encodePacked('Onchain Power #', uint256(supply + i).toString())),
"Awesome onchain NFT collection that can help you test new blockchain projects.",
randomNum(10, 350, 4, supply + i).toString(),
randomNum(10, 350, 8, supply + i).toString(),
randomNum(10, 350, 12, supply + i).toString());
itemsData[supply + i] = newItemData;
_safeMint(msg.sender, supply + i);
}
}
function buildMetadata(uint256 _tokenId) private view returns(string memory) {
ItemData memory currentItemData = itemsData[_tokenId];
return string(abi.encodePacked(
'data:application/json;base64,', Base64.encode(bytes(abi.encodePacked(
'{"name":"',
currentItemData.name,
'", "description":"',
currentItemData.description,
'", "image": "',
'data:image/svg+xml;base64,',
Base64.buildImage(currentItemData.bgHue, currentItemData.eyesHue, currentItemData.pukeHue),
'"}')))));
}
function tokenURI(uint256 _tokenId) public view virtual override returns (string memory) {
require(_exists(_tokenId),"ERC721Metadata: URI query for nonexistent token");
return buildMetadata(_tokenId);
}
function withdraw() public payable onlyOwner {
(bool os, ) = payable(owner()).call{value: address(this).balance}("");
require(os, "Failed to send Ether");
}
}