Contract Name:
DragonCrossbreed
Contract Source Code:
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/utils/Address.sol";
import "./BaseAuctionReceiver.sol";
import "./structs/DragonInfo.sol";
import "./utils/GenesLib.sol";
import "./utils/Random.sol";
import "./DragonCreator.sol";
import "./DragonToken.sol";
contract DragonCrossbreed is BaseAuctionReceiver {
using Address for address payable;
uint constant HOURS_MAX_PERIOD = 24 * 100; //100 days
uint constant THRESHOLD_DENOMINATOR = 100*1e8;
uint[10] private _platformPrices;
uint[10] private _bonusesCommonThresholds;
uint[5] private _probabilityRareThresholds;
uint[5] private _probabilityEpicThresholds;
address private _dragonCreatorAddress;
address private _dragonRandomnessAddress;
mapping(address => uint) private _rewards;
GenesLib.GenesRange private COMMON_RANGE;
GenesLib.GenesRange private RARE_RANGE;
GenesLib.GenesRange private EPIC_RANGE;
event RewardAdded(address indexed operator, address indexed to, uint amount);
event RewardClaimed(address indexed claimer, address indexed to, uint amount);
constructor(
address accessControl,
address dragonToken,
address dragonCreator,
uint fees100) BaseAuctionReceiver(accessControl, dragonToken, fees100) {
_dragonCreatorAddress = dragonCreator;
_platformPrices = [
3*1e15, 5*1e15, 8*1e15, 10*1e15, 15*1e15,
20*1e15, 25*1e15, 30*1e15, 35*1e15, 40*1e15
];
_bonusesCommonThresholds = [
1953125, 3906250, 7812500, 15625000, 31250000,
62500000, 125000000, 250000000, 500000000, 1000000000
];
_probabilityRareThresholds = [1000000000, 500000000, 250000000, 125000000, 62500000];
_probabilityEpicThresholds = [0, 15625000, 7812500, 3906250, 1953125];
COMMON_RANGE = GenesLib.GenesRange({from: 0, to: 15});
RARE_RANGE = GenesLib.GenesRange({from: 15, to: 20});
EPIC_RANGE = GenesLib.GenesRange({from: 20, to: 25});
}
function maxTotalPeriod() internal override virtual pure returns (uint) {
return HOURS_MAX_PERIOD;
}
function numOfPriceChangesPerHour() internal override virtual pure returns (uint) {
return 30;
}
function dragonCreatorAddress() public view returns (address) {
return _dragonCreatorAddress;
}
function setDragonCreatorAddress(address newAddress) external onlyRole(CEO_ROLE) {
address previousAddress = _dragonCreatorAddress;
_dragonCreatorAddress = newAddress;
emit AddressChanged("dragonCreator", previousAddress, newAddress);
}
function platformPrice(uint genesCount) public view returns (uint) {
return _platformPrices[genesCount];
}
function setPlatformPrices(uint[10] calldata newPlatformPrices) external onlyRole(CFO_ROLE) {
_platformPrices = newPlatformPrices;
}
function bonusCommonThresholdAt(uint index) external view returns (uint) {
return _bonusesCommonThresholds[index];
}
function setBonusCommonThreshold(uint[10] calldata newBonusesCommonThresholds) external onlyRole(CFO_ROLE) {
_bonusesCommonThresholds = newBonusesCommonThresholds;
}
function probabilityRareThresholdAt(uint index) external view returns (uint) {
return _probabilityRareThresholds[index];
}
function setProbabilityRareThreshold(uint[5] calldata newProbabilityRareThresholds) external onlyRole(CFO_ROLE) {
_probabilityRareThresholds = newProbabilityRareThresholds;
}
function probabilityEpicThresholdAt(uint index) external view returns (uint) {
return _probabilityEpicThresholds[index];
}
function setProbabilityEpicThreshold(uint[5] calldata newProbabilityEpicThresholds) external onlyRole(CFO_ROLE) {
_probabilityEpicThresholds = newProbabilityEpicThresholds;
}
function crossbreedPlatformPrice(uint dragon1Id, uint dragon2Id) external view returns (uint) {
DragonToken dragonToken = DragonToken(tokenContract());
uint genes1 = dragonToken.dragonInfo(dragon1Id).genes;
uint genes2 = dragonToken.dragonInfo(dragon2Id).genes;
(uint countRare, uint countEpic) = calcCommonRareEpicGenesCount(genes1, genes2);
return platformPrice(countRare + countEpic);
}
function calcCommonRareEpicGenesCount(uint genes1, uint genes2) internal pure returns (uint, uint) {
uint mask = DragonInfo.MASK;
uint countRare = 0;
uint countEpic = 0;
for (uint i = 0; i < 10; i++) { //just Epic and Rare genes are important to count
if (genes1 & mask > 0 && genes2 & mask > 0) {
if (i < 5) {
countEpic++;
}
else {
countRare++;
}
}
mask = mask >> 4;
}
return (countRare, countEpic);
}
function processERC721(address from, uint tokenId, bytes calldata data)
internal virtual override {
DragonInfo.Details memory info = DragonToken(tokenContract()).dragonInfo(tokenId);
require(info.dragonType != DragonInfo.Types.Legendary, "DragonCrossbreed: the dragon cannot be a Legendary-type");
super.processERC721(from, tokenId, data);
}
function breed(uint myDragonId, uint anotherDragonId, uint salt) external payable {
DragonToken dragonToken = DragonToken(tokenContract());
require(
dragonToken.ownerOf(myDragonId) == _msgSender(),
"DragonCrossbreed: the caller is not an owner of the dragon"
);
require(
isLocked(anotherDragonId) || dragonToken.ownerOf(anotherDragonId) == _msgSender(),
"DragonCrossbreed: another dragon is not locked nor doesn't belong to the caller"
);
DragonInfo.Details memory parent1 = dragonToken.dragonInfo(myDragonId);
DragonInfo.Details memory parent2 = dragonToken.dragonInfo(anotherDragonId);
(uint countRare, uint countEpic) = calcCommonRareEpicGenesCount(parent1.genes, parent2.genes);
uint _platformPrice = platformPrice(countRare + countEpic);
uint _rentPrice = 0;
if (isLocked(anotherDragonId)) {
_rentPrice = priceOf(anotherDragonId);
}
require(msg.value >= (_platformPrice + _rentPrice), "DragonCrossbreed: incorrect amount sent to the contract");
uint newGenes = 0;
uint randomValue = Random.rand(salt);
uint derivedRandomValue = Random.rand(randomValue ^ salt ^ block.difficulty);
if (parent1.dragonType == DragonInfo.Types.Common && parent2.dragonType == DragonInfo.Types.Common) {
(uint y, uint z) = _randomCountOfNewRareEpic(randomValue);
if (y > 0) {
uint[] memory positions = GenesLib.randomGenePositions(RARE_RANGE, y, randomValue);
newGenes = GenesLib.randomSetGenesToPositions(newGenes, positions, randomValue, false);
}
if (z > 0) {
uint[] memory positions = GenesLib.randomGenePositions(EPIC_RANGE, z, randomValue);
newGenes = GenesLib.randomSetGenesToPositions(newGenes, positions, randomValue, false);
}
if (newGenes == 0 && _randomNewRare(0, derivedRandomValue)) { //if the bonuses above were not triggered
uint[] memory positions = GenesLib.randomGenePositions(RARE_RANGE, 1, derivedRandomValue);
newGenes = GenesLib.randomSetGenesToPositions(newGenes, positions, derivedRandomValue, false);
}
newGenes = GenesLib.randomInheritGenesInRange(newGenes, parent1.genes, parent2.genes, COMMON_RANGE, randomValue, true);
}
else if (parent1.dragonType == DragonInfo.Types.Epic20 && parent2.dragonType == DragonInfo.Types.Epic20) {
//add Epic gene
uint[] memory positions = GenesLib.randomGenePositions(EPIC_RANGE, 1, randomValue);
newGenes = GenesLib.randomSetGenesToPositions(newGenes, positions, randomValue, false);
//inherit Common
newGenes = GenesLib.randomInheritGenesInRange(newGenes, parent1.genes, parent2.genes, COMMON_RANGE, randomValue, true);
//inherit Rare
newGenes = GenesLib.randomInheritGenesInRange(newGenes, parent1.genes, parent2.genes, RARE_RANGE, randomValue, false);
}
else {
//inherit Common
newGenes = GenesLib.randomInheritGenesInRange(newGenes, parent1.genes, parent2.genes, COMMON_RANGE, randomValue, true);
//inherit Rare
newGenes = GenesLib.randomInheritGenesInRange(newGenes, parent1.genes, parent2.genes, RARE_RANGE, randomValue, false);
//inherit Epic
newGenes = GenesLib.randomInheritGenesInRange(newGenes, parent1.genes, parent2.genes, EPIC_RANGE, randomValue, false);
if (countRare < 5 && _randomNewRare(countRare, randomValue)) {
(uint count, uint[] memory positions) = GenesLib.zeroGenePositionsInRange(newGenes, RARE_RANGE);
uint pos = Random.randFrom(positions, 0, count, derivedRandomValue);
newGenes = GenesLib.setGeneLevelTo(newGenes, GenesLib.randomGeneLevel(derivedRandomValue, false), pos);
}
else if (countRare == 5 && countEpic < 5 && _randomNewEpic(countEpic, randomValue)) {
(uint count, uint[] memory positions) = GenesLib.zeroGenePositionsInRange(newGenes, EPIC_RANGE);
uint pos = Random.randFrom(positions, 0, count, derivedRandomValue);
newGenes = GenesLib.setGeneLevelTo(newGenes, GenesLib.randomGeneLevel(derivedRandomValue, false), pos);
}
}
if (_rentPrice > 0) {
payable(holderOf(anotherDragonId))
.sendValue(_rentPrice - calcFees(_rentPrice, feesPercent()));
}
DragonCreator(dragonCreatorAddress()).giveBirth(myDragonId, anotherDragonId, newGenes, _msgSender());
}
function addReward(address to, uint amount) external onlyRole(COO_ROLE) {
require(!Address.isContract(to), "DragonCrossbreed: address cannot be contract");
_rewards[to] += amount;
emit RewardAdded(_msgSender(), to, amount);
}
function claimReward(address payable to, uint amount) external {
require(!Address.isContract(to), "DragonCrossbreed: address cannot be contract");
require(amount <= _rewards[_msgSender()], "DragonCrossbreed: the given amount exceeded the allowed reward");
to.sendValue(amount);
_rewards[_msgSender()] -= amount;
emit RewardClaimed(_msgSender(), to, amount);
}
function _randomCountOfNewRareEpic(uint randomValue) internal view returns (uint, uint) {
uint r = randomValue % THRESHOLD_DENOMINATOR;
return
(r <= _bonusesCommonThresholds[0]) ? (5, 5) :
(r <= _bonusesCommonThresholds[1]) ? (5, 4) :
(r <= _bonusesCommonThresholds[2]) ? (5, 3) :
(r <= _bonusesCommonThresholds[3]) ? (5, 2) :
(r <= _bonusesCommonThresholds[4]) ? (5, 1) :
(r <= _bonusesCommonThresholds[5]) ? (5, 0) :
(r <= _bonusesCommonThresholds[6]) ? (4, 0) :
(r <= _bonusesCommonThresholds[7]) ? (3, 0) :
(r <= _bonusesCommonThresholds[8]) ? (2, 0) :
(r <= _bonusesCommonThresholds[9]) ? (1, 0) :
(0, 0);
}
function _randomNewRare(uint currentRareCount, uint randomValue) internal view returns (bool) {
uint r = randomValue % THRESHOLD_DENOMINATOR;
return r < _probabilityRareThresholds[currentRareCount];
}
function _randomNewEpic(uint currentEpicCount, uint randomValue) internal view returns (bool) {
uint r = randomValue % THRESHOLD_DENOMINATOR;
return r < _probabilityEpicThresholds[currentEpicCount];
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
assembly {
size := extcodesize(account)
}
return size > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value
) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/utils/math/Math.sol";
import "./utils/BytesLib.sol";
import "./LockableReceiver.sol";
abstract contract BaseAuctionReceiver is LockableReceiver {
enum PriceDirection { NONE, UP, DOWN }
struct PriceSettings {
uint startingPrice;
uint finalPrice;
uint priceChangePeriod; //in hours
uint priceChangeStep;
PriceDirection direction;
uint timestampAddedAt;
}
using SafeMath for uint;
mapping(uint => PriceSettings) internal _priceSettings;
uint private _fees100;
constructor (address accessControl, address dragonToken, uint fees100)
LockableReceiver(accessControl, dragonToken) {
_fees100 = fees100;
}
function weiMinPrice() internal virtual pure returns (uint) {
return 0;
}
function maxTotalPeriod() internal virtual pure returns (uint) {
return 0;
}
/**
* Defines how often the price is changed during 1 hour. 60 by default (every minute).
*/
function numOfPriceChangesPerHour() internal virtual pure returns (uint) {
return 60;
}
function feesPercent() public virtual view returns (uint) {
return _fees100;
}
function updateFeesPercent(uint newFees100) external virtual onlyRole(CFO_ROLE) {
_fees100 = newFees100;
}
function calcFees(uint weiAmount, uint fees100) internal virtual pure returns (uint) {
return weiAmount.div(1e4).mul(fees100);
}
function readPriceSettings(bytes calldata data) internal virtual pure returns (uint, uint, uint) {
uint weiStartingPrice = BytesLib.toUint256(data, 0);
uint weiFinalPrice = BytesLib.toUint256(data, 0x20);
uint totalPriceChangePeriod = BytesLib.toUint256(data, 0x40);
return (weiStartingPrice, weiFinalPrice, totalPriceChangePeriod);
}
function processERC721(address /*from*/, uint tokenId, bytes calldata data)
internal virtual override {
(uint weiStartingPrice, uint weiFinalPrice, uint totalPriceChangePeriod) =
readPriceSettings(data);
uint _weiMinPrice = weiMinPrice();
uint _maxTotalPeriod = maxTotalPeriod();
if (_weiMinPrice > 0) {
require(weiStartingPrice >= _weiMinPrice && weiFinalPrice >= _weiMinPrice,
"BaseAuctionReceiver: the starting price and the final price cannot be less than weiMinPrice()");
}
if (_maxTotalPeriod > 0) {
require(totalPriceChangePeriod <= _maxTotalPeriod,
"BaseAuctionReceiver: the price change period cannot exceed maxTotalPeriod()");
require(totalPriceChangePeriod >= 12 && totalPriceChangePeriod.mod(12) == 0,
"BaseAuctionReceiver: the price change period should be a multiple of 0.5 days");
}
uint step;
PriceDirection d;
(step, d) = calcPriceChangeStep(
weiStartingPrice, weiFinalPrice, totalPriceChangePeriod, numOfPriceChangesPerHour());
PriceSettings memory settings = PriceSettings ({
startingPrice: weiStartingPrice,
finalPrice: weiFinalPrice,
priceChangePeriod: totalPriceChangePeriod,
priceChangeStep: step,
direction: d,
timestampAddedAt: block.timestamp
});
_priceSettings[tokenId] = settings;
}
function priceSettingsOf(uint tokenId) public view returns (PriceSettings memory) {
return _priceSettings[tokenId];
}
function priceOf(uint tokenId) public view returns (uint) {
PriceSettings memory settings = priceSettingsOf(tokenId);
if (settings.direction == PriceDirection.NONE) {
return settings.startingPrice;
}
uint max = Math.max(settings.startingPrice, settings.finalPrice);
uint min = Math.min(settings.startingPrice, settings.finalPrice);
uint diff = max.sub(min);
uint totalNumOfPeriodsToFinalPrice = diff.div(settings.priceChangeStep);
uint numOfPeriods =
(block.timestamp - settings.timestampAddedAt).div(60)
.mul(numOfPriceChangesPerHour()).div(60);
uint result;
if (numOfPeriods > totalNumOfPeriodsToFinalPrice) {
result = settings.finalPrice;
}
else if (settings.direction == PriceDirection.DOWN) {
result = settings.startingPrice.sub(settings.priceChangeStep.mul(numOfPeriods));
}
else {
result = settings.startingPrice.add(settings.priceChangeStep.mul(numOfPeriods));
}
return result;
}
function calcPriceChangeStep(
uint weiStartingPrice,
uint weiFinalPrice,
uint totalPriceChangePeriod,
uint _numOfPriceChangesPerHour) internal virtual pure returns (uint, PriceDirection) {
if (weiStartingPrice == weiFinalPrice) {
return (0, PriceDirection.NONE);
}
uint max = Math.max(weiStartingPrice, weiFinalPrice);
uint min = Math.min(weiStartingPrice, weiFinalPrice);
uint diff = max.sub(min);
PriceDirection direction = PriceDirection.DOWN;
if (max == weiFinalPrice) {
direction = PriceDirection.UP;
}
return (diff.div(totalPriceChangePeriod.mul(_numOfPriceChangesPerHour)), direction);
}
function withdraw(uint tokenId) public virtual override onlyHolder(tokenId) {
delete _priceSettings[tokenId];
super.withdraw(tokenId);
}
}
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
library DragonInfo {
uint constant MASK = 0xF000000000000000000000000;
enum Types {
Unknown,
Common,
Rare16,
Rare17,
Rare18,
Rare19,
Epic20,
Epic21,
Epic22,
Epic23,
Epic24,
Legendary
}
struct Details {
uint genes;
uint eggId;
uint parent1Id;
uint parent2Id;
uint generation;
uint strength;
Types dragonType;
}
function getDetails(uint value) internal pure returns (Details memory) {
return Details (
{
genes: uint256(uint104(value)),
parent1Id: uint256(uint32(value >> 104)),
parent2Id: uint256(uint32(value >> 136)),
generation: uint256(uint16(value >> 168)),
strength: uint256(uint16(value >> 184)),
dragonType: Types(uint16(value >> 200)),
eggId: uint256(uint32(value >> 216))
}
);
}
function getValue(Details memory details) internal pure returns (uint) {
uint result = uint(details.genes);
result |= details.parent1Id << 104;
result |= details.parent2Id << 136;
result |= details.generation << 168;
result |= details.strength << 184;
result |= uint(details.dragonType) << 200;
result |= details.eggId << 216;
return result;
}
function calcType(uint genes) internal pure returns (Types) {
uint mask = MASK;
uint numRare = 0;
uint numEpic = 0;
for (uint i = 0; i < 10; i++) { //just Rare and Epic genes are important to check
if (genes & mask > 0) {
if (i < 5) { //Epic-range
numEpic++;
}
else { //Rare-range
numRare++;
}
}
mask = mask >> 4;
}
Types result = Types.Unknown;
if (numEpic == 5 && numRare == 5) {
result = Types.Legendary;
}
else if (numEpic < 5 && numRare == 5) {
result = Types(6 + numEpic);
}
else if (numEpic == 0 && numRare < 5) {
result = Types(1 + numRare);
}
else if (numEpic == 0 && numRare == 0) {
result = Types.Common;
}
return result;
}
function calcStrength(uint genes) internal pure returns (uint) {
uint mask = MASK;
uint strength = 0;
for (uint i = 0; i < 25; i++) {
uint gLevel = (genes & mask) >> ((24 - i) * 4);
if (i < 6) { //Epic
strength += 3 * (25 - i) * gLevel;
}
else if (i < 10) { //Rare
strength += 2 * (25 - i) * gLevel;
}
else { //Common-range
if (gLevel > 0) {
strength += (25 - i) * gLevel;
}
else {
strength += (25 - i);
}
}
mask = mask >> 4;
}
return strength;
}
function calcGeneration(uint g1, uint g2) internal pure returns (uint) {
return (g1 >= g2 ? g1 : g2) + 1;
}
}
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "./Random.sol";
library GenesLib {
using SafeMath for uint;
uint private constant MAGIC_NUM = 0x123456789ABCDEF;
struct GenesRange {
uint from;
uint to;
}
function setGeneLevelTo(uint genes, uint level, uint position) internal pure returns (uint) {
return genes | uint(level << (position * 4));
}
function geneLevelAt(uint genes, uint position) internal pure returns (uint) {
return (genes >> (position * 4)) & 0xF;
}
function zeroGenePositionsInRange(uint genes, GenesRange memory range)
internal pure returns (uint, uint[] memory) {
uint[] memory zeroPositions = new uint[](range.to - range.from);
uint count = 0;
for (uint pos = range.from; pos < range.to; pos++) {
uint level = geneLevelAt(genes, pos);
if (level == 0) {
zeroPositions[count] = pos;
count++;
}
}
return (count, zeroPositions);
}
function randomGeneLevel(uint randomValue, bool includeZero) internal pure returns (uint) {
if (includeZero) {
return randomValue.mod(16);
}
else {
return 1 + randomValue.mod(15);
}
}
function randomInheritGenesInRange(uint genes, uint parent1Genes, uint parent2Genes,
GenesRange memory range, uint randomValue, bool includeZero) internal pure returns (uint) {
for (uint pos = range.from; pos < range.to; pos++) {
uint geneLevel1 = geneLevelAt(parent1Genes, pos);
uint geneLevel2 = geneLevelAt(parent2Genes, pos);
if (includeZero || (geneLevel1 > 0 && geneLevel2 > 0)) {
uint d = (pos % 2 == 0) ? ((randomValue >> pos) + (MAGIC_NUM >> pos)) : ~(randomValue >> pos);
uint r = d.mod(100);
if (r < 45) { //45%
genes = setGeneLevelTo(genes, geneLevel1, pos);
}
else if (r >= 45 && r < 90) { //45%
genes = setGeneLevelTo(genes, geneLevel2, pos);
}
else { //10%
uint level = randomGeneLevel(d, includeZero);
genes = setGeneLevelTo(genes, level, pos);
}
}
}
return genes;
}
function randomSetGenesToPositions(uint genes, uint[] memory positions, uint randomValue, bool includeZero)
internal pure returns (uint) {
for (uint i = 0; i < positions.length; i++) {
genes = setGeneLevelTo(genes, randomGeneLevel(
(i % 2 > 0) ? ((randomValue >> i) + (MAGIC_NUM >> i)) : ~(randomValue >> i),
includeZero), positions[i]);
}
return genes;
}
function randomGenePositions(GenesRange memory range, uint count, uint randomValue)
internal pure returns (uint[] memory) {
if (count > 0) {
uint[] memory shuffledRangeArray =
Random.shuffle(createOrderedRangeArray(range.from, range.to), randomValue);
uint[] memory positions = new uint[](count);
for (uint i = 0; i < count; i++) {
positions[i] = shuffledRangeArray[i];
}
return positions;
}
return new uint[](0);
}
function createOrderedRangeArray(uint from, uint to) internal pure returns (uint[] memory) {
uint[] memory rangeArray = new uint[](to - from) ;
for (uint i = 0; i < rangeArray.length; i++) {
rangeArray[i] = from + i;
}
return rangeArray;
}
}
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
library Random {
function rand(uint salt) internal view returns (uint) {
return uint(keccak256(abi.encodePacked(block.difficulty, block.timestamp, salt)));
}
function randFrom(uint[] memory array, uint from, uint to, uint randomValue)
internal pure returns (uint) {
uint count = to - from;
return array[from + randomValue % count];
}
function shuffle(uint[] memory array, uint randomValue) internal pure returns (uint[] memory) {
for (uint i = 0; i < array.length; i++) {
uint n = i + randomValue % (array.length - i);
uint temp = array[n];
array[n] = array[i];
array[i] = temp;
}
return array;
}
}
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/utils/Address.sol";
import "./structs/DragonInfo.sol";
import "./access/BaseAccessControl.sol";
import "./DragonToken.sol";
contract DragonCreator is BaseAccessControl {
using Address for address;
address private _tokenContractAddress;
mapping(DragonInfo.Types => uint) private _zeroDragonsIssueLimits;
mapping(address => bool) private _giveBirthCallers;
bool private _isChangeOfIssueLimitsAllowed;
event DragonCreated(
uint dragonId,
uint eggId,
uint parent1Id,
uint parent2Id,
uint generation,
DragonInfo.Types t,
uint genes,
address indexed creator,
address indexed to);
constructor(address accessControl, address tknContract) BaseAccessControl(accessControl) {
_tokenContractAddress = tknContract;
_isChangeOfIssueLimitsAllowed = true;
}
function tokenContract() public view returns (address) {
return _tokenContractAddress;
}
function setTokenContract(address newAddress) external onlyRole(CEO_ROLE) {
address previousAddress = _tokenContractAddress;
_tokenContractAddress = newAddress;
emit AddressChanged("tokenContract", previousAddress, newAddress);
}
function isChangeOfIssueLimitsAllowed() public view returns (bool) {
return _isChangeOfIssueLimitsAllowed;
}
function currentIssueLimitFor(DragonInfo.Types _dragonType) external view returns (uint) {
return _zeroDragonsIssueLimits[_dragonType];
}
function updateIssueLimitFor(DragonInfo.Types _dragonType, uint newValue) external onlyRole(CEO_ROLE) {
require(isChangeOfIssueLimitsAllowed(),
"DragonCreator: updating the issue limits is not allowed anymore");
_zeroDragonsIssueLimits[_dragonType] = newValue;
}
function blockUpdatingIssueLimitsForever() external onlyRole(CEO_ROLE) {
_isChangeOfIssueLimitsAllowed = false;
}
function setGiveBirthCallers(address[] calldata callers, bool value) external onlyRole(CEO_ROLE) {
for (uint i = 0; i < callers.length; i++) {
bool previousValue = _giveBirthCallers[callers[i]];
_giveBirthCallers[callers[i]] = value;
emit BoolValueChanged(string(abi.encodePacked("giveBirthCallers.", callers[i])), previousValue, value);
}
}
function issue(uint genes, address to) external onlyRole(CEO_ROLE) returns (uint) {
DragonInfo.Types dragonType = DragonInfo.calcType(genes);
uint currentLimit = _zeroDragonsIssueLimits[dragonType];
require(dragonType != DragonInfo.Types.Unknown, "DragonCreator: unable to identify a type of the given dragon");
require(currentLimit > 0, "DragonCreator: the issue limit has exceeded");
_zeroDragonsIssueLimits[dragonType] = currentLimit - 1;
return _createDragon(0, 0, 0, genes, dragonType, to);
}
function giveBirth(uint eggId, uint genes, address to) external returns (uint) {
require(_giveBirthCallers[_msgSender()], "DragonCreator: not enough privileges to call the method");
return _createDragon(eggId, 0, 0, genes, DragonInfo.Types.Unknown, to);
}
function giveBirth(uint parent1Id, uint parent2Id, uint genes, address to) external returns (uint) {
require(_giveBirthCallers[_msgSender()], "DragonCreator: not enough privileges to call the method");
return _createDragon(0, parent1Id, parent2Id, genes, DragonInfo.Types.Unknown, to);
}
function _createDragon(uint _eggId, uint _parent1Id, uint _parent2Id, uint _genes, DragonInfo.Types _dragonType, address to)
internal returns (uint) {
DragonToken dragonToken = DragonToken(tokenContract());
DragonInfo.Details memory parent1Details = dragonToken.dragonInfo(_parent1Id);
DragonInfo.Details memory parent2Details = dragonToken.dragonInfo(_parent2Id);
if (_parent1Id > 0 && _parent2Id > 0) { //if not 1st-generation dragons
require(_parent1Id != _parent2Id, "DragonCreator: parent dragons must be different");
require(
parent1Details.dragonType != DragonInfo.Types.Legendary
&& parent2Details.dragonType != DragonInfo.Types.Legendary,
"DragonCreator: neither of the parent dragons can be of Legendary-type"
);
require(!dragonToken.isSiblings(_parent1Id, _parent2Id), "DragonCreator: the parent dragons must not be siblings");
require(
!dragonToken.isParent(_parent1Id, _parent2Id) && !dragonToken.isParent(_parent2Id, _parent1Id),
"DragonCreator: neither of the parent dragons must be a parent or child of another"
);
}
DragonInfo.Details memory info = DragonInfo.Details({
eggId: _eggId,
parent1Id: _parent1Id,
parent2Id: _parent2Id,
generation: DragonInfo.calcGeneration(parent1Details.generation, parent2Details.generation),
dragonType: (_dragonType == DragonInfo.Types.Unknown) ? DragonInfo.calcType(_genes) : _dragonType,
strength: 0, //DragonInfo.calcStrength(_genes),
genes: _genes
});
uint newDragonId = dragonToken.mint(to, info);
emit DragonCreated(
newDragonId, info.eggId,
info.parent1Id, info.parent2Id,
info.generation, info.dragonType,
info.genes, _msgSender(), to);
return newDragonId;
}
}
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
import "./access/BaseAccessControl.sol";
import "./structs/DragonInfo.sol";
contract DragonToken is ERC721, BaseAccessControl {
using Address for address;
using Counters for Counters.Counter;
Counters.Counter private _dragonIds;
// Mapping token id to dragon details
mapping(uint => uint) private _info;
// Mapping token id to cid
mapping(uint => string) private _cids;
string private _defaultMetadataCid;
address private _dragonCreator;
constructor(string memory defaultCid, address accessControl)
ERC721("CryptoDragons", "CD")
BaseAccessControl(accessControl) {
_defaultMetadataCid = defaultCid;
}
function approveAndCall(address spender, uint256 tokenId, bytes calldata extraData) external returns (bool success) {
_approve(spender, tokenId);
(bool _success, ) =
spender.call(
abi.encodeWithSignature("receiveApproval(address,uint256,address,bytes)",
_msgSender(),
tokenId,
address(this),
extraData)
);
if(!_success) {
revert("DragonToken: spender internal error");
}
return true;
}
function tokenURI(uint tokenId) public view virtual override returns (string memory) {
string memory cid = _cids[tokenId];
return string(abi.encodePacked("ipfs://", (bytes(cid).length > 0) ? cid : defaultMetadataCid()));
}
function dragonCreatorAddress() public view returns(address) {
return _dragonCreator;
}
function setDragonCreatorAddress(address newAddress) external onlyRole(CEO_ROLE) {
address previousAddress = _dragonCreator;
_dragonCreator = newAddress;
emit AddressChanged("dragonCreator", previousAddress, newAddress);
}
function hasMetadataCid(uint tokenId) public view returns(bool) {
return bytes(_cids[tokenId]).length > 0;
}
function setMetadataCid(uint tokenId, string calldata cid) external onlyRole(COO_ROLE) {
require(bytes(cid).length >= 46, "DragonToken: bad CID");
require(!hasMetadataCid(tokenId), "DragonToken: CID is already set");
_cids[tokenId] = cid;
}
function defaultMetadataCid() public view returns (string memory){
return _defaultMetadataCid;
}
function setDefaultMetadataCid(string calldata newDefaultCid) external onlyRole(COO_ROLE) {
_defaultMetadataCid = newDefaultCid;
}
function dragonInfo(uint dragonId) public view returns (DragonInfo.Details memory) {
return DragonInfo.getDetails(_info[dragonId]);
}
function strengthOf(uint dragonId) external view returns (uint) {
DragonInfo.Details memory details = dragonInfo(dragonId);
return details.strength > 0 ? details.strength : DragonInfo.calcStrength(details.genes);
}
function isSiblings(uint dragon1Id, uint dragon2Id) external view returns (bool) {
DragonInfo.Details memory info1 = dragonInfo(dragon1Id);
DragonInfo.Details memory info2 = dragonInfo(dragon2Id);
return
(info1.generation > 1 && info2.generation > 1) && //the 1st generation of dragons doesn't have siblings
(info1.parent1Id == info2.parent1Id || info1.parent1Id == info2.parent2Id ||
info1.parent2Id == info2.parent1Id || info1.parent2Id == info2.parent2Id);
}
function isParent(uint dragon1Id, uint dragon2Id) external view returns (bool) {
DragonInfo.Details memory info = dragonInfo(dragon1Id);
return info.parent1Id == dragon2Id || info.parent2Id == dragon2Id;
}
function mint(address to, DragonInfo.Details calldata info) external returns (uint) {
require(_msgSender() == dragonCreatorAddress(), "DragonToken: not enough privileges to call the method");
_dragonIds.increment();
uint newDragonId = uint(_dragonIds.current());
_info[newDragonId] = DragonInfo.getValue(info);
_mint(to, newDragonId);
return newDragonId;
}
function setStrength(uint dragonId) external returns (uint) {
DragonInfo.Details memory details = dragonInfo(dragonId);
if (details.strength == 0) {
details.strength = DragonInfo.calcStrength(details.genes);
_info[dragonId] = DragonInfo.getValue(details);
}
return details.strength;
}
}
// SPDX-License-Identifier: MIT
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;
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
/**
* @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 / b + (a % b == 0 ? 0 : 1);
}
}
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
library BytesLib {
function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
address tempAddress;
assembly {
tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
}
return tempAddress;
}
function toUint256(bytes memory _bytes, uint _start) internal pure returns (uint) {
require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
uint tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0x20), _start))
}
return tempUint;
}
function toTuple128(bytes memory _bytes, uint256 _start) internal pure returns (uint, uint) {
require(_bytes.length >= _start + 32, "toTuple16_outOfBounds");
uint tempUint;
uint n1;
uint n2;
assembly {
tempUint := mload(add(add(_bytes, 0x20), _start))
n1 := and(shr(0x80, tempUint), 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)
n2 := and(tempUint, 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)
}
return (n1, n2);
}
}
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "./access/BaseAccessControl.sol";
abstract contract LockableReceiver is BaseAccessControl, IERC721Receiver {
using Address for address payable;
address private _tokenContractAddress;
mapping(uint => address) private _lockedTokens;
event TokenLocked(uint tokenId, address indexed holder);
event TokenWithdrawn(uint tokenId, address indexed holder);
event EthersWithdrawn(address indexed operator, address indexed to, uint amount);
constructor (address accessControl, address tokenContractAddress)
BaseAccessControl(accessControl) {
_tokenContractAddress = tokenContractAddress;
}
modifier whenLocked(uint tokenId) {
require(isLocked(tokenId), "LockableReceiver: token must be locked");
_;
}
modifier onlyHolder(uint tokenId) {
require(holderOf(tokenId) == _msgSender(), "LockableReceiver: caller is not the token holder");
_;
}
function onERC721Received(address operator, address /*from*/, uint /*tokenId*/, bytes calldata /*data*/)
external virtual override returns (bytes4) {
require(operator == address(this), "LockableReceiver: the caller is not a valid operator");
return this.onERC721Received.selector;
}
function receiveApproval(address sender, uint tokenId, address _tokenContract, bytes calldata data) external virtual {
require(tokenContract() == _msgSender(), "LockableReceiver: not enough privileges to call the method");
require(_tokenContract == tokenContract(), "LockableReceiver: unable to receive the given token");
IERC721(tokenContract()).safeTransferFrom(sender, address(this), tokenId, data);
_lock(tokenId, sender);
processERC721(sender, tokenId, data);
}
function processERC721(address from, uint tokenId, bytes calldata data) internal virtual {
}
function _lock(uint tokenId, address holder) internal {
_lockedTokens[tokenId] = holder;
emit TokenLocked(tokenId, holder);
}
function _unlock(uint tokenId) internal {
delete _lockedTokens[tokenId];
}
function tokenContract() public view returns (address) {
return _tokenContractAddress;
}
function setTokenContract(address newAddress) external onlyRole(CEO_ROLE) {
address previousAddress = _tokenContractAddress;
_tokenContractAddress = newAddress;
emit AddressChanged("tokenContract", previousAddress, newAddress);
}
function isLocked(uint tokenId) public view returns (bool) {
return _lockedTokens[tokenId] != address(0);
}
function holderOf(uint tokenId) public view returns (address) {
return _lockedTokens[tokenId];
}
function withdrawEthers(uint amount, address payable to) external virtual onlyRole(CFO_ROLE) {
to.sendValue(amount);
emit EthersWithdrawn(_msgSender(), to, amount);
}
function withdraw(uint tokenId) public virtual onlyHolder(tokenId) {
_transferTokenToHolder(tokenId);
emit TokenWithdrawn(tokenId, _msgSender());
}
function _transferTokenToHolder(uint tokenId) internal virtual {
address holder = holderOf(tokenId);
if (holder != address(0)) {
IERC721(tokenContract()).safeTransferFrom(address(this), holder, tokenId);
_unlock(tokenId);
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/
interface IERC721Receiver {
/**
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
* by `operator` from `from`, this function is called.
*
* It must return its Solidity selector to confirm the token transfer.
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
*
* The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
*/
function onERC721Received(
address operator,
address from,
uint256 tokenId,
bytes calldata data
) external returns (bytes4);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes calldata data
) external;
}
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/access/IAccessControl.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "../interfaces/IChangeableVariables.sol";
abstract contract BaseAccessControl is Context, IChangeableVariables {
bytes32 public constant CEO_ROLE = keccak256("CEO");
bytes32 public constant CFO_ROLE = keccak256("CFO");
bytes32 public constant COO_ROLE = keccak256("COO");
address private _accessControl;
modifier onlyRole(bytes32 role) {
_checkRole(role, _msgSender());
_;
}
constructor (address accessControl) Context() {
_accessControl = accessControl;
}
function accessControlAddress() public view returns (address) {
return _accessControl;
}
function setAccessControlAddress(address newAddress) external onlyRole(CEO_ROLE) {
address previousAddress = _accessControl;
_accessControl = newAddress;
emit AddressChanged("accessControl", previousAddress, newAddress);
}
function hasRole(bytes32 role, address account) public view returns (bool) {
return IAccessControl(accessControlAddress()).hasRole(role, account);
}
function _checkRole(bytes32 role, address account) internal view {
if (!hasRole(role, account)) {
revert(
string(
abi.encodePacked(
"AccessControl: account ",
Strings.toHexString(uint160(account), 20),
" is missing role ",
Strings.toHexString(uint256(role), 32)
)
)
);
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev External interface of AccessControl declared to support ERC165 detection.
*/
interface IAccessControl {
/**
* @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
*
* `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
* {RoleAdminChanged} not being emitted signaling this.
*
* _Available since v3.1._
*/
event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
/**
* @dev Emitted when `account` is granted `role`.
*
* `sender` is the account that originated the contract call, an admin role
* bearer except when using {AccessControl-_setupRole}.
*/
event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
/**
* @dev Emitted when `account` is revoked `role`.
*
* `sender` is the account that originated the contract call:
* - if using `revokeRole`, it is the admin role bearer
* - if using `renounceRole`, it is the role bearer (i.e. `account`)
*/
event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
/**
* @dev Returns `true` if `account` has been granted `role`.
*/
function hasRole(bytes32 role, address account) external view returns (bool);
/**
* @dev Returns the admin role that controls `role`. See {grantRole} and
* {revokeRole}.
*
* To change a role's admin, use {AccessControl-_setRoleAdmin}.
*/
function getRoleAdmin(bytes32 role) external view returns (bytes32);
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function grantRole(bytes32 role, address account) external;
/**
* @dev Revokes `role` from `account`.
*
* If `account` had been granted `role`, emits a {RoleRevoked} event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function revokeRole(bytes32 role, address account) external;
/**
* @dev Revokes `role` from the calling account.
*
* Roles are often managed via {grantRole} and {revokeRole}: this function's
* purpose is to provide a mechanism for accounts to lose their privileges
* if they are compromised (such as when a trusted device is misplaced).
*
* If the calling account had been granted `role`, emits a {RoleRevoked}
* event.
*
* Requirements:
*
* - the caller must be `account`.
*/
function renounceRole(bytes32 role, address account) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
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);
}
}
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
interface IChangeableVariables {
event AddressChanged(string fieldName, address previousAddress, address newAddress);
event ValueChanged(string fieldName, uint previousValue, uint newValue);
event BoolValueChanged(string fieldName, bool previousValue, bool newValue);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";
/**
* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
* the Metadata extension, but not including the Enumerable extension, which is available separately as
* {ERC721Enumerable}.
*/
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
using Address for address;
using Strings for uint256;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Mapping from token ID to owner address
mapping(uint256 => address) private _owners;
// Mapping owner address to token count
mapping(address => uint256) private _balances;
// Mapping from token ID to approved address
mapping(uint256 => address) private _tokenApprovals;
// Mapping from owner to operator approvals
mapping(address => mapping(address => bool)) private _operatorApprovals;
/**
* @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
return
interfaceId == type(IERC721).interfaceId ||
interfaceId == type(IERC721Metadata).interfaceId ||
super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721-balanceOf}.
*/
function balanceOf(address owner) public view virtual override returns (uint256) {
require(owner != address(0), "ERC721: balance query for the zero address");
return _balances[owner];
}
/**
* @dev See {IERC721-ownerOf}.
*/
function ownerOf(uint256 tokenId) public view virtual override returns (address) {
address owner = _owners[tokenId];
require(owner != address(0), "ERC721: owner query for nonexistent token");
return owner;
}
/**
* @dev See {IERC721Metadata-name}.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev See {IERC721Metadata-symbol}.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev See {IERC721Metadata-tokenURI}.
*/
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
string memory baseURI = _baseURI();
return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
}
/**
* @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
* token will be the concatenation of the `baseURI` and the `tokenId`. Empty
* by default, can be overriden in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return "";
}
/**
* @dev See {IERC721-approve}.
*/
function approve(address to, uint256 tokenId) public virtual override {
address owner = ERC721.ownerOf(tokenId);
require(to != owner, "ERC721: approval to current owner");
require(
_msgSender() == owner || isApprovedForAll(owner, _msgSender()),
"ERC721: approve caller is not owner nor approved for all"
);
_approve(to, tokenId);
}
/**
* @dev See {IERC721-getApproved}.
*/
function getApproved(uint256 tokenId) public view virtual override returns (address) {
require(_exists(tokenId), "ERC721: approved query for nonexistent token");
return _tokenApprovals[tokenId];
}
/**
* @dev See {IERC721-setApprovalForAll}.
*/
function setApprovalForAll(address operator, bool approved) public virtual override {
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 {}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @title Counters
* @author Matt Condon (@shrugs)
* @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
* of elements in a mapping, issuing ERC721 ids, or counting request ids.
*
* Include with `using Counters for Counters.Counter;`
*/
library Counters {
struct Counter {
// This variable should never be directly accessed by users of the library: interactions must be restricted to
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
// this feature: see https://github.com/ethereum/solidity/issues/4637
uint256 _value; // default: 0
}
function current(Counter storage counter) internal view returns (uint256) {
return counter._value;
}
function increment(Counter storage counter) internal {
unchecked {
counter._value += 1;
}
}
function decrement(Counter storage counter) internal {
uint256 value = counter._value;
require(value > 0, "Counter: decrement overflow");
unchecked {
counter._value = value - 1;
}
}
function reset(Counter storage counter) internal {
counter._value = 0;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Metadata is IERC721 {
/**
* @dev Returns the token collection name.
*/
function name() external view returns (string memory);
/**
* @dev Returns the token collection symbol.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
*/
function tokenURI(uint256 tokenId) external view returns (string memory);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}