Contract Name:
ImpactTheoryFoundersKey
Contract Source Code:
File 1 of 1 : ImpactTheoryFoundersKey
// File: @openzeppelin/contracts/utils/cryptography/ECDSA.sol
pragma solidity ^0.8.0;
/**
* @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
*
* These functions can be used to verify that a message was signed by the holder
* of the private keys of a given address.
*/
library ECDSA {
enum RecoverError {
NoError,
InvalidSignature,
InvalidSignatureLength,
InvalidSignatureS,
InvalidSignatureV
}
function _throwError(RecoverError error) private pure {
if (error == RecoverError.NoError) {
return; // no error: do nothing
} else if (error == RecoverError.InvalidSignature) {
revert("ECDSA: invalid signature");
} else if (error == RecoverError.InvalidSignatureLength) {
revert("ECDSA: invalid signature length");
} else if (error == RecoverError.InvalidSignatureS) {
revert("ECDSA: invalid signature 's' value");
} else if (error == RecoverError.InvalidSignatureV) {
revert("ECDSA: invalid signature 'v' value");
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature` or error string. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*
* Documentation for signature generation:
* - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
* - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
*
* _Available since v4.3._
*/
function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
// Check the signature length
// - case 65: r,s,v signature (standard)
// - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
if (signature.length == 65) {
bytes32 r;
bytes32 s;
uint8 v;
// ecrecover takes the signature parameters, and the only way to get them
// currently is to use assembly.
assembly {
r := mload(add(signature, 0x20))
s := mload(add(signature, 0x40))
v := byte(0, mload(add(signature, 0x60)))
}
return tryRecover(hash, v, r, s);
} else if (signature.length == 64) {
bytes32 r;
bytes32 vs;
// ecrecover takes the signature parameters, and the only way to get them
// currently is to use assembly.
assembly {
r := mload(add(signature, 0x20))
vs := mload(add(signature, 0x40))
}
return tryRecover(hash, r, vs);
} else {
return (address(0), RecoverError.InvalidSignatureLength);
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature`. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*/
function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, signature);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
*
* See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
*
* _Available since v4.3._
*/
function tryRecover(
bytes32 hash,
bytes32 r,
bytes32 vs
) internal pure returns (address, RecoverError) {
bytes32 s;
uint8 v;
assembly {
s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
v := add(shr(255, vs), 27)
}
return tryRecover(hash, v, r, s);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
*
* _Available since v4.2._
*/
function recover(
bytes32 hash,
bytes32 r,
bytes32 vs
) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, r, vs);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `v`,
* `r` and `s` signature fields separately.
*
* _Available since v4.3._
*/
function tryRecover(
bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internal pure returns (address, RecoverError) {
// EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
// unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
// the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
// signatures from current libraries generate a unique signature with an s-value in the lower half order.
//
// If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
// with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
// vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
// these malleable signatures as well.
if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
return (address(0), RecoverError.InvalidSignatureS);
}
if (v != 27 && v != 28) {
return (address(0), RecoverError.InvalidSignatureV);
}
// If the signature is valid (and not malleable), return the signer address
address signer = ecrecover(hash, v, r, s);
if (signer == address(0)) {
return (address(0), RecoverError.InvalidSignature);
}
return (signer, RecoverError.NoError);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `v`,
* `r` and `s` signature fields separately.
*/
function recover(
bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, v, r, s);
_throwError(error);
return recovered;
}
/**
* @dev Returns an Ethereum Signed Message, created from a `hash`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
// 32 is the length in bytes of hash,
// enforced by the type signature above
return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
}
/**
* @dev Returns an Ethereum Signed Typed Data, created from a
* `domainSeparator` and a `structHash`. This produces hash corresponding
* to the one signed with the
* https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
* JSON-RPC method as part of EIP-712.
*
* See {recover}.
*/
function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
}
}
// File: @openzeppelin/contracts/utils/math/SafeMath.sol
pragma solidity ^0.8.0;
// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.
/**
* @dev Wrappers over Solidity's arithmetic operations.
*
* NOTE: `SafeMath` is no longer needed starting with Solidity 0.8. The compiler
* now has built in overflow checking.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the substraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b > a) return (false, 0);
return (true, a - b);
}
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) return (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a / b);
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a % b);
}
}
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
return a + b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return a - b;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
return a * b;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator.
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return a % b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b <= a, errorMessage);
return a - b;
}
}
/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b > 0, errorMessage);
return a / b;
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b > 0, errorMessage);
return a % b;
}
}
}
// File: @openzeppelin/contracts/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);
}
}
// File: @openzeppelin/contracts/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
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() {
_setOwner(_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 {
_setOwner(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");
_setOwner(newOwner);
}
function _setOwner(address newOwner) private {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// File: @openzeppelin/contracts/security/Pausable.sol
pragma solidity ^0.8.0;
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/
abstract contract Pausable is Context {
/**
* @dev Emitted when the pause is triggered by `account`.
*/
event Paused(address account);
/**
* @dev Emitted when the pause is lifted by `account`.
*/
event Unpaused(address account);
bool private _paused;
/**
* @dev Initializes the contract in unpaused state.
*/
constructor() {
_paused = false;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/
function paused() public view virtual returns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/
modifier whenNotPaused() {
require(!paused(), "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/
modifier whenPaused() {
require(paused(), "Pausable: not paused");
_;
}
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - The contract must not be paused.
*/
function _pause() internal virtual whenNotPaused {
_paused = true;
emit Paused(_msgSender());
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - The contract must be paused.
*/
function _unpause() internal virtual whenPaused {
_paused = false;
emit Unpaused(_msgSender());
}
}
// File: @openzeppelin/contracts/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);
}
}
}
}
// File: @openzeppelin/contracts/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);
}
// File: @openzeppelin/contracts/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
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
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`, 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;
}
// File: @openzeppelin/contracts/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 tokenId);
/**
* @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
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
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: 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 {
require(operator != _msgSender(), "ERC721: approve to caller");
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_msgSender(), operator, approved);
}
/**
* @dev See {IERC721-isApprovedForAll}.
*/
function isApprovedForAll(address owner, address operator) public view 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 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 {}
}
// File: @openzeppelin/contracts/token/ERC721/extensions/ERC721Pausable.sol
pragma solidity ^0.8.0;
/**
* @dev ERC721 token with pausable token transfers, minting and burning.
*
* Useful for scenarios such as preventing trades until the end of an evaluation
* period, or having an emergency switch for freezing all token transfers in the
* event of a large bug.
*/
abstract contract ERC721Pausable is ERC721, Pausable {
/**
* @dev See {ERC721-_beforeTokenTransfer}.
*
* Requirements:
*
* - the contract must not be paused.
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual override {
super._beforeTokenTransfer(from, to, tokenId);
require(!paused(), "ERC721Pausable: token transfer while paused");
}
}
// File: @openzeppelin/contracts/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 Hook that is called before any token transfer. This includes minting
* and burning.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, ``from``'s `tokenId` will be burned.
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual override {
super._beforeTokenTransfer(from, to, tokenId);
if (from == address(0)) {
_addTokenToAllTokensEnumeration(tokenId);
} else if (from != to) {
_removeTokenFromOwnerEnumeration(from, tokenId);
}
if (to == address(0)) {
_removeTokenFromAllTokensEnumeration(tokenId);
} else if (to != from) {
_addTokenToOwnerEnumeration(to, tokenId);
}
}
/**
* @dev Private function to add a token to this extension's ownership-tracking data structures.
* @param to address representing the new owner of the given token ID
* @param tokenId uint256 ID of the token to be added to the tokens list of the given address
*/
function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
uint256 length = ERC721.balanceOf(to);
_ownedTokens[to][length] = tokenId;
_ownedTokensIndex[tokenId] = length;
}
/**
* @dev Private function to add a token to this extension's token tracking data structures.
* @param tokenId uint256 ID of the token to be added to the tokens list
*/
function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
_allTokensIndex[tokenId] = _allTokens.length;
_allTokens.push(tokenId);
}
/**
* @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
* while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
* gas optimizations e.g. when performing a transfer operation (avoiding double writes).
* This has O(1) time complexity, but alters the order of the _ownedTokens array.
* @param from address representing the previous owner of the given token ID
* @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
*/
function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
// To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
uint256 tokenIndex = _ownedTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary
if (tokenIndex != lastTokenIndex) {
uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
_ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
}
// This also deletes the contents at the last position of the array
delete _ownedTokensIndex[tokenId];
delete _ownedTokens[from][lastTokenIndex];
}
/**
* @dev Private function to remove a token from this extension's token tracking data structures.
* This has O(1) time complexity, but alters the order of the _allTokens array.
* @param tokenId uint256 ID of the token to be removed from the tokens list
*/
function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
// To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = _allTokens.length - 1;
uint256 tokenIndex = _allTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
// rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
// an 'if' statement (like in _removeTokenFromOwnerEnumeration)
uint256 lastTokenId = _allTokens[lastTokenIndex];
_allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
// This also deletes the contents at the last position of the array
delete _allTokensIndex[tokenId];
_allTokens.pop();
}
}
// File: @openzeppelin/contracts/token/ERC721/extensions/ERC721Burnable.sol
pragma solidity ^0.8.0;
/**
* @title ERC721 Burnable Token
* @dev ERC721 Token that can be irreversibly burned (destroyed).
*/
abstract contract ERC721Burnable is Context, ERC721 {
/**
* @dev Burns `tokenId`. See {ERC721-_burn}.
*
* Requirements:
*
* - The caller must own `tokenId` or be an approved operator.
*/
function burn(uint256 tokenId) public virtual {
//solhint-disable-next-line max-line-length
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721Burnable: caller is not owner nor approved");
_burn(tokenId);
}
}
// File: ImpactTheoryFoundersKey.sol
pragma solidity ^0.8.0;
/**
*
* Impact Theory Founders Key
*
*/
contract ImpactTheoryFoundersKey is
Ownable,
ERC721Burnable,
ERC721Enumerable,
ERC721Pausable
{
using SafeMath for uint256;
using Strings for uint256;
using ECDSA for bytes32;
// Public tier info
struct Tier {
uint256 id;
string name;
}
// Private tier info
struct TierInfo {
Tier tier;
uint256 startingOffset;
uint256 totalSupply;
uint256 startingPrice;
uint256 endingPrice;
uint256 maxPerClosedPresale;
uint256 maxTotalMint;
bool saleEnded;
}
// Base token uri
string private baseTokenURI; // baseTokenURI can point to IPFS folder like https://ipfs.io/ipfs/{cid}/ while
string private baseTokenURIForMetadata; // baseTokenURIForMetadata should point to the raw IPFS endpoint because it will not use IPFS folders. For example: https://ipfs.io/ipfs/
// For uint to bytes32 conversion
bytes16 private constant HEX_ALPHABET = "0123456789abcdef";
string private constant IPFS_PREFIX = "f01551220"; // IPFS byte (f) + CID v1 (0x01) + raw codec (0x55) + SHA256 (0x12) + 256 bits long (0x20)
// Payment address
address private paymentAddress = 0x681EA99a65E6f392f0F5276Af396AE8CaD140E6D;
// Royalties address
address private royaltyAddress = 0x681EA99a65E6f392f0F5276Af396AE8CaD140E6D;
// Signer address
address private signerAddress = 0x4A2034e724034F31b46117d918E789c42EBE0CF2;
// Royalties basis points (percentage using 2 decimals - 10000 = 100, 0 = 0)
uint256 private royaltyBasisPoints = 1000; // 10%
// Token info
string public constant TOKEN_NAME = "Impact Theory Founder's Key";
string public constant TOKEN_SYMBOL = "ITFK";
// Sale durations
uint256 public constant CLOSED_PRESALE_DURATION = 1 days;
uint256 public constant PRESALE_DURATION = 1 days;
uint256 public constant AUCTION_DURATION = 1 days;
uint256 public constant AUCTION_PRICE_CHANGE = 1 hours;
uint256 public constant DURATION_BETWEEN_TIERS = 1 days;
// Public sale params
uint256 public publicSaleStartTime;
bool public publicSaleActive;
//-- Tiers --//
// Tier 1 - public info
Tier public tier1 = Tier({id: 1, name: "Legendary"});
// Tier 1 - private info
TierInfo private tier1Info =
TierInfo({
tier: tier1,
startingOffset: 1,
totalSupply: 2700,
startingPrice: 3 ether,
endingPrice: 1.5 ether,
maxPerClosedPresale: 1,
maxTotalMint: 4,
saleEnded: false
});
// Tier 2 - public info
Tier public tier2 = Tier({id: 2, name: "Heroic"});
// Tier 2 - private info
TierInfo private tier2Info =
TierInfo({
tier: tier2,
startingOffset: 2701,
totalSupply: 7300,
startingPrice: 1.5 ether,
endingPrice: .75 ether,
maxPerClosedPresale: 2,
maxTotalMint: 5,
saleEnded: false
});
// Tier 3 - public info
Tier public tier3 = Tier({id: 3, name: "Relentless"});
// Tier 3 - private info
TierInfo private tier3Info =
TierInfo({
tier: tier3,
startingOffset: 10001,
totalSupply: 10000,
startingPrice: .1 ether,
endingPrice: .05 ether,
maxPerClosedPresale: 1,
maxTotalMint: 5,
saleEnded: false
});
Tier[] public allTiersArray;
TierInfo[] private allTiersInfoArray;
uint256[] public allTierIds;
mapping(uint256 => Tier) public allTiers;
mapping(uint256 => TierInfo) private allTiersInfo;
mapping(uint256 => Tier) public tokenTier;
mapping(uint256 => uint256) public tokenMintedAt;
mapping(uint256 => uint256) public tokenLastTransferredAt;
mapping(uint256 => uint256) public tierCounts;
mapping(uint256 => bytes32[]) public tokenMetadata;
// Presale whitelist per tier
mapping(address => uint256[]) private presaleWhitelist;
// Used nonces for mint signatures
mapping(string => bool) private usedNonces;
//-- Events --//
event PublicSaleStart(uint256 indexed _saleStartTime);
event PublicSalePaused(uint256 indexed _timeElapsed);
event PublicSaleActive(bool indexed _publicSaleActive);
event RoyaltyBasisPoints(uint256 indexed _royaltyBasisPoints);
//-- Modifiers --//
// Public sale active modifier
modifier whenPublicSaleActive() {
require(publicSaleActive, "Public sale is not active");
_;
}
// Public sale not active modifier
modifier whenPublicSaleNotActive() {
require(
!publicSaleActive && publicSaleStartTime == 0,
"Public sale is already active"
);
_;
}
// Owner or public sale active modifier
modifier whenOwnerOrPublicSaleActive() {
require(
owner() == _msgSender() || publicSaleActive,
"Public sale is not active"
);
_;
}
// -- Constructor --//
constructor(string memory _baseTokenURI) ERC721(TOKEN_NAME, TOKEN_SYMBOL) {
baseTokenURI = _baseTokenURI;
// Setup intial tiers and tiers info
Tier[3] memory allTiersArrayMem = [tier1, tier2, tier3];
TierInfo[3] memory allTiersInfoArrayMem = [
tier1Info,
tier2Info,
tier3Info
];
for (uint256 i = 0; i < allTiersArrayMem.length; i++) {
uint256 tierId = allTiersArrayMem[i].id;
// Tier arrays
allTiersArray.push(allTiersArrayMem[i]);
allTiersInfoArray.push(allTiersInfoArrayMem[i]);
allTierIds.push(tierId);
// Tier mappings
allTiers[tierId] = allTiersArray[i];
allTiersInfo[tierId] = allTiersInfoArray[i];
}
}
// -- External Functions -- //
// Start public sale
function startPublicSale() external onlyOwner whenPublicSaleNotActive {
publicSaleStartTime = block.timestamp;
publicSaleActive = true;
emit PublicSaleStart(publicSaleStartTime);
}
// Set this value to the block.timestamp you'd like to reset to
// Created as a way to fast foward in time for tier timing unit tests
// Can also be used if needing to pause and restart public sale from original start time (returned in startPublicSale() above)
function setPublicSaleStartTime(uint256 _publicSaleStartTime)
external
onlyOwner
{
publicSaleStartTime = _publicSaleStartTime;
emit PublicSaleStart(publicSaleStartTime);
}
// Toggle public sale
function togglePublicSaleActive() external onlyOwner {
publicSaleActive = !publicSaleActive;
emit PublicSaleActive(publicSaleActive);
}
// Pause public sale
function pausePublicSale() external onlyOwner whenPublicSaleActive {
publicSaleActive = false;
emit PublicSalePaused(getElapsedSaleTime());
}
// End tier sale
function setTierSaleEnded(uint256 _tierId, bool _saleEnded)
external
onlyOwner
whenPublicSaleActive
{
allTiersInfo[_tierId].saleEnded = _saleEnded;
}
// Get all tiers
function getAllTiers() external view returns (Tier[] memory) {
return allTiersArray;
}
// Get all tiers info
function getAllTiersInfo()
external
view
onlyOwner
returns (TierInfo[] memory)
{
return allTiersInfoArray;
}
// Support royalty info - See {EIP-2981}: https://eips.ethereum.org/EIPS/eip-2981
function royaltyInfo(uint256, uint256 _salePrice)
external
view
returns (address receiver, uint256 royaltyAmount)
{
return (
royaltyAddress,
(_salePrice.mul(royaltyBasisPoints)).div(10000)
);
}
// Adds multiple address to presale whitelist for specific tier
function addToPresaleWhitelist(uint256 _tierId, address[] memory _addresses)
external
onlyOwner
{
Tier memory tier = allTiers[_tierId];
require(tier.id == _tierId, "Invalid tier");
for (uint256 i = 0; i < _addresses.length; i++) {
address _address = _addresses[i];
uint256[] storage tierIds = presaleWhitelist[_address];
bool exists = false;
for (uint256 j = 0; j < tierIds.length; j++) {
if (tierIds[j] == tier.id) {
exists = true;
}
}
if (!exists) {
tierIds.push(tier.id);
}
presaleWhitelist[_address] = tierIds;
}
}
// Removes single address from whitelist for specific tier
function removeFromPresaleWhitelist(uint256 _tierId, address _address)
external
onlyOwner
{
Tier memory tier = allTiers[_tierId];
require(tier.id == _tierId, "Invalid tier");
uint256[] storage tierIds = presaleWhitelist[_address];
// Loop over each tier id
for (uint256 i = 0; i < tierIds.length; i++) {
if (tierIds[i] == tier.id) {
// If tier id is found, replace with last tier id
tierIds[i] = tierIds[tierIds.length - 1];
}
}
// Remove last tier id, since it replaced the matched tier id
tierIds.pop();
presaleWhitelist[_address] = tierIds;
}
// Get all tiers address is whitelisted for
function getPresaleWhitelist(address _address)
external
view
onlyOwner
returns (uint256[] memory)
{
return presaleWhitelist[_address];
}
//-- Public Functions --//
// Get elapsed sale time
function getElapsedSaleTime() public view returns (uint256) {
return
publicSaleStartTime > 0
? block.timestamp.sub(publicSaleStartTime)
: 0;
}
// Get remaining closed presale time
function getRemainingClosedPresaleTime(uint256 _tierId)
public
view
whenPublicSaleActive
returns (uint256)
{
Tier memory tier = allTiers[_tierId];
require(tier.id == _tierId, "Invalid tier");
// Get elapsed sale time
uint256 elapsed = getElapsedSaleTime();
// Time logic based on tier and constants
uint256 closedPresaleStart = (tier.id - 1).mul(DURATION_BETWEEN_TIERS);
uint256 closedPresaleEnd = closedPresaleStart.add(
CLOSED_PRESALE_DURATION
);
// Tier not active
require(elapsed >= closedPresaleStart, "Tier not active");
// Tier finished presale
if (elapsed >= closedPresaleEnd) {
return 0;
}
// Elasped time since presale start
uint256 elapsedSinceStart = elapsed.sub(closedPresaleStart);
// Total duration minus elapsed time since presale start
return CLOSED_PRESALE_DURATION.sub(elapsedSinceStart);
}
// Get remaining presale time
function getRemainingPresaleTime(uint256 _tierId)
public
view
whenPublicSaleActive
returns (uint256)
{
Tier memory tier = allTiers[_tierId];
require(tier.id == _tierId, "Invalid tier");
// Get elapsed sale time
uint256 elapsed = getElapsedSaleTime();
// Time logic based on tier and constants
uint256 closedPresaleStart = (tier.id - 1).mul(DURATION_BETWEEN_TIERS);
uint256 closedPresaleEnd = closedPresaleStart.add(
CLOSED_PRESALE_DURATION
);
uint256 presaleStart = closedPresaleEnd;
uint256 presaleEnd = presaleStart.add(PRESALE_DURATION);
// Tier not active
require(elapsed >= presaleStart, "Tier not active");
// Tier finished presale
if (elapsed >= presaleEnd) {
return 0;
}
// Elasped time since presale start
uint256 elapsedSinceStart = elapsed.sub(presaleStart);
// Total duration minus elapsed time since presale start
return PRESALE_DURATION.sub(elapsedSinceStart);
}
// Get remaining auction time
function getRemainingAuctionTime(uint256 _tierId)
public
view
whenPublicSaleActive
returns (uint256)
{
Tier memory tier = allTiers[_tierId];
require(tier.id == _tierId, "Invalid tier");
uint256 elapsed = getElapsedSaleTime();
// Time logic based on tier and constants
uint256 closedPresaleStart = (tier.id - 1).mul(DURATION_BETWEEN_TIERS);
uint256 closedPresaleEnd = closedPresaleStart.add(
CLOSED_PRESALE_DURATION
);
uint256 presaleStart = closedPresaleEnd;
uint256 presaleEnd = presaleStart.add(PRESALE_DURATION);
uint256 auctionStart = presaleEnd;
uint256 auctionEnd = auctionStart.add(AUCTION_DURATION);
// Tier not active
require(elapsed >= auctionStart, "Tier not active");
// Tier finished auction
if (elapsed >= auctionEnd) {
return 0;
}
// Elasped time since auction start
uint256 elapsedSinceStart = elapsed.sub(auctionStart);
// Total duration minus elapsed time since auction start
return AUCTION_DURATION.sub(elapsedSinceStart);
}
// Mint token - requires tier and amount
function mint(
uint256 _tierId,
uint256 _amount,
bytes32 _hash,
bytes memory _signature,
string memory _nonce
) public payable whenOwnerOrPublicSaleActive {
require(
matchAddressSigner(_hash, _signature),
"Direct mint disallowed"
);
require(!usedNonces[_nonce], "Hash already used");
require(
hashTransaction(_msgSender(), _amount, _nonce) == _hash,
"Hash failed"
);
Tier memory tier = allTiers[_tierId];
TierInfo memory tierInfo = allTiersInfo[_tierId];
require(tier.id == _tierId, "Invalid tier");
// Must mint at least one
require(_amount > 0, "Must mint at least one");
// Check there enough mints left for tier
require(
getMintsLeft(tier.id).sub(_amount) >= 0,
"Minting would exceed max supply"
);
// Get current address total balance
uint256 currentTotalAmount = super.balanceOf(_msgSender());
// Loop over all tokens for address and get current tier count
uint256 currentTierAmount = 0;
for (uint256 i = 0; i < currentTotalAmount; i++) {
uint256 tokenId = super.tokenOfOwnerByIndex(_msgSender(), i);
Tier memory _tokenTier = tokenTier[tokenId];
if (_tokenTier.id == tier.id) {
currentTierAmount++;
}
}
uint256 costToMint = 0;
uint256 amount = _amount;
// Is owner
bool isOwner = owner() == _msgSender();
// If not owner, check amounts are not more than max amounts
if (!isOwner) {
// Get elapsed sale time
uint256 elapsed = getElapsedSaleTime();
// Time logic based on tier and constants
uint256 closedPresaleStart = (tier.id - 1).mul(
DURATION_BETWEEN_TIERS
);
uint256 closedPresaleEnd = closedPresaleStart.add(
CLOSED_PRESALE_DURATION
);
// If still in the closed whitelist, do not allow more than max per closed presale
if (elapsed <= closedPresaleEnd) {
require(
currentTierAmount.add(amount) <= tierInfo.maxPerClosedPresale,
"Requested amount exceeds maximum whitelist mint amount"
);
}
// Do not allow more than max total mint
require(
currentTierAmount.add(amount) <= tierInfo.maxTotalMint,
"Requested amount exceeds maximum total mint amount"
);
}
// Get cost to mint
costToMint = getMintPrice(tier.id).mul(amount);
// Check cost to mint for tier, and if enough ETH is passed to mint
require(costToMint <= msg.value, "ETH amount sent is not correct");
for (uint256 i = 0; i < amount; i++) {
// Token id is tier starting offset plus count of already minted
uint256 tokenId = tierInfo.startingOffset.add(tierCounts[tier.id]);
// Safe mint
_safeMint(_msgSender(), tokenId);
// Attribute token id with tier
tokenTier[tokenId] = tier;
// Store minted at timestamp by token id
tokenMintedAt[tokenId] = block.timestamp;
// Increment tier counter
tierCounts[tier.id] = tierCounts[tier.id].add(1);
}
usedNonces[_nonce] = true;
// Send mint cost to payment address
Address.sendValue(payable(paymentAddress), costToMint);
// Return unused value
if (msg.value > costToMint) {
Address.sendValue(payable(_msgSender()), msg.value.sub(costToMint));
}
}
// Burn multiple
function burnMultiple(uint256[] memory _tokenIds) public onlyOwner {
for (uint256 i = 0; i < _tokenIds.length; i++) {
// Token id
uint256 tokenId = _tokenIds[i];
_burn(tokenId);
}
}
// Get mint price
function getMintPrice(uint256 _tierId)
public
view
whenOwnerOrPublicSaleActive
returns (uint256)
{
Tier memory tier = allTiers[_tierId];
TierInfo memory tierInfo = allTiersInfo[_tierId];
require(tier.id == _tierId, "Invalid tier");
// Is owner
bool isOwner = owner() == _msgSender();
// If owner, cost is 0
if (isOwner) {
return 0;
}
uint256 elapsed = getElapsedSaleTime();
uint256 currentPrice = 0;
// Setup starting and ending prices
uint256 startingPrice = tierInfo.startingPrice;
uint256 endingPrice = tierInfo.endingPrice;
// Time logic based on tier and constants
uint256 closedPresaleStart = (tier.id - 1).mul(DURATION_BETWEEN_TIERS);
uint256 closedPresaleEnd = closedPresaleStart.add(
CLOSED_PRESALE_DURATION
);
uint256 presaleStart = closedPresaleEnd;
uint256 presaleEnd = presaleStart.add(PRESALE_DURATION);
uint256 auctionStart = presaleEnd;
uint256 auctionEnd = auctionStart.add(AUCTION_DURATION);
// Tier not active
require(elapsed >= closedPresaleStart, "Tier not active");
// Closed presale - starting price
if ((elapsed >= closedPresaleStart) && (elapsed < presaleStart)) {
// Must be in presale whitelist to get price and mint
uint256[] memory whitelistedTiers = presaleWhitelist[_msgSender()];
bool isWhitelisted = false;
for (uint256 i = 0; i < whitelistedTiers.length; i++) {
if (whitelistedTiers[i] == tier.id) {
isWhitelisted = true;
}
}
require(isWhitelisted, "Tier not active, not whitelisted");
currentPrice = startingPrice;
// Presale - starting price
} else if ((elapsed >= presaleStart) && (elapsed < presaleEnd)) {
currentPrice = startingPrice;
// Dutch Auction - price descreses dynamically for duration
} else if ((elapsed >= auctionStart) && (elapsed < auctionEnd)) {
uint256 elapsedSinceAuctionStart = elapsed.sub(auctionStart); // Elapsed time since auction start
uint256 totalPriceDiff = startingPrice.sub(endingPrice); // Total price diff between starting and ending price
uint256 numPriceChanges = AUCTION_DURATION.div(
AUCTION_PRICE_CHANGE
).sub(1); // Amount of price changes in the auction
uint256 priceChangeAmount = totalPriceDiff.div(numPriceChanges); // Amount of price change per instance of price change
uint256 elapsedRounded = elapsedSinceAuctionStart.div(
AUCTION_PRICE_CHANGE
); // Elapsed time since auction start rounded to auction price change variable
uint256 totalPriceChangeAmount = priceChangeAmount.mul(
elapsedRounded
); // Total amount of price change based on time
currentPrice = startingPrice.sub(totalPriceChangeAmount); // Starting price minus total price change
// Post auction - ending price
} else if (elapsed >= auctionEnd) {
// Check if tier ended
require(!tierInfo.saleEnded, "Tier not active");
currentPrice = endingPrice;
}
// Double check current price is not lower than ending price
return currentPrice < endingPrice ? endingPrice : currentPrice;
}
// Get mints left for tier
function getMintsLeft(uint256 _tierId)
public
view
whenOwnerOrPublicSaleActive
returns (uint256)
{
Tier memory tier = allTiers[_tierId];
TierInfo memory tierInfo = allTiersInfo[_tierId];
require(tier.id == _tierId, "Invalid tier");
// Get tier total supplys and counts
uint256 tierSupply = tierInfo.totalSupply;
uint256 tierCount = tierCounts[tier.id];
return tierSupply.sub(tierCount);
}
function setPaymentAddress(address _address) public onlyOwner {
paymentAddress = _address;
}
function setSignerAddress(address _address) public onlyOwner {
signerAddress = _address;
}
// Set royalty wallet address
function setRoyaltyAddress(address _address) public onlyOwner {
royaltyAddress = _address;
}
// Set royalty basis points
function setRoyaltyBasisPoints(uint256 _basisPoints) public onlyOwner {
royaltyBasisPoints = _basisPoints;
emit RoyaltyBasisPoints(_basisPoints);
}
// Set base URI
function setBaseURI(string memory _uri) public onlyOwner {
baseTokenURI = _uri;
}
function setBaseURIForMetadata(string memory _uri) public onlyOwner {
baseTokenURIForMetadata = _uri;
}
// Append token metadata
function appendTokenMetadata(uint256 _tokenId, bytes32 _metadataHash)
public
onlyOwner
{
require(_exists(_tokenId), "Nonexistent token");
tokenMetadata[_tokenId].push(_metadataHash);
}
// Get all token metadata changes
function getTokenMetadata(uint256 _tokenId)
public
view
returns (bytes32[] memory)
{
require(_exists(_tokenId), "Nonexistent token");
return tokenMetadata[_tokenId];
}
// Token URI (baseTokenURI + tokenId)
function tokenURI(uint256 _tokenId)
public
view
virtual
override
returns (string memory)
{
require(_exists(_tokenId), "Nonexistent token");
uint256 tokenMetadataLength = tokenMetadata[_tokenId].length;
if (tokenMetadataLength > 0) {
uint256 _lastMetadataHash = uint256(
tokenMetadata[_tokenId][tokenMetadataLength - 1]
);
// IPFS CID V1 is too long for Solidity byte32 but it contains the same prefix "f01551220" if it was added to IPFS with the same codec and hash function.
// IPFS CID V1 Multihash example: bafkreif7gr5yvy5p65nbozy7o3f7m2tt2jkyhp5fgpd4cg5ljl4e7ohxxq
// Explorer: https://cid.ipfs.io/#bafkreif7gr5yvy5p65nbozy7o3f7m2tt2jkyhp5fgpd4cg5ljl4e7ohxxq
// It's prefix (f01551220) + SHA256 hash (BF347B8AE3AFF75A17671F76CBF66A73D25583BFA533C7C11BAB4AF84FB8F7BC)
// List of codes: https://github.com/multiformats/multicodec/blob/master/table.csv
// Prefix format: IPFS specific byte (f) + CID V1 (01) + multicodec code (0x55 for raw) + hash function code (0x12 for SHA256) + length (0x20 for 256-bits)
// Final: f017012200C39FEAEE65382EFEDE80ED763CC922B280AE2A2A403C24FEE73B36D8A6AC7F7
// Addressable as usual: http://ipfs.io/ipfs/f015512200874F3B3FEE8BFE197A86AB9F676F6246248B8FFE1F81111D1C44B11D41173CD
// That way we can strip meaningless for blockchain "f01701220" and save huge amount of gas by storing it efficiently in byte32.
// IMPORTANT: JSON files up to 256KB always have 0x55 (raw) codec.
return
string(
abi.encodePacked(
abi.encodePacked(baseTokenURIForMetadata, IPFS_PREFIX),
uintToHexString(_lastMetadataHash, 32)
)
);
}
return
string(abi.encodePacked(_baseURI(), "token/", _tokenId.toString()));
}
// Contract metadata URI - Support for OpenSea: https://docs.opensea.io/docs/contract-level-metadata
function contractURI() public view returns (string memory) {
return string(abi.encodePacked(_baseURI(), "contract"));
}
// Override supportsInterface - See {IERC165-supportsInterface}
function supportsInterface(bytes4 _interfaceId)
public
view
virtual
override(ERC721, ERC721Enumerable)
returns (bool)
{
return super.supportsInterface(_interfaceId);
}
// Pauses all token transfers - See {ERC721Pausable}
function pause() public virtual onlyOwner {
_pause();
}
// Unpauses all token transfers - See {ERC721Pausable}
function unpause() public virtual onlyOwner {
_unpause();
}
//-- Private Functions --/
// Hash transaction
function hashTransaction(
address _sender,
uint256 _amount,
string memory _nonce
) private pure returns (bytes32) {
bytes32 hash = keccak256(
abi.encodePacked(
"\x19Ethereum Signed Message:\n32",
keccak256(abi.encodePacked(_sender, _amount, _nonce))
)
);
return hash;
}
// Match address signer
function matchAddressSigner(bytes32 _hash, bytes memory _signature)
private
view
returns (bool)
{
return signerAddress == _hash.recover(_signature);
}
//-- Internal Functions --//
// Get base URI
function _baseURI() internal view override returns (string memory) {
return baseTokenURI;
}
// Before all token transfer
function _beforeTokenTransfer(
address _from,
address _to,
uint256 _tokenId
) internal virtual override(ERC721, ERC721Enumerable, ERC721Pausable) {
// Store token last transfer timestamp by id
tokenLastTransferredAt[_tokenId] = block.timestamp;
super._beforeTokenTransfer(_from, _to, _tokenId);
}
// Uint to hex string
function uintToHexString(uint256 value, uint256 length)
internal
pure
returns (string memory)
{
bytes memory buffer = new bytes(2 * length);
for (uint256 i = 2 * length; i > 0; --i) {
buffer[i - 1] = HEX_ALPHABET[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
}