Contract Source Code:
// contracts/Paper.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/ERC20BurnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/utils/math/SafeMathUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/token/ERC721/extensions/IERC721EnumerableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import "./IDebtCity.sol";
import "./IProperty.sol";
contract Paper is ERC20BurnableUpgradeable, OwnableUpgradeable {
/*
██████╗░░█████╗░██████╗░███████╗██████╗░
██╔══██╗██╔══██╗██╔══██╗██╔════╝██╔══██╗
██████╔╝███████║██████╔╝█████╗░░██████╔╝
██╔═══╝░██╔══██║██╔═══╝░██╔══╝░░██╔══██╗
██║░░░░░██║░░██║██║░░░░░███████╗██║░░██║
╚═╝░░░░░╚═╝░░╚═╝╚═╝░░░░░╚══════╝╚═╝░░╚═╝
*/
using SafeMathUpgradeable for uint256;
address nullAddress;
address public debtCityAddress;
address public propertyAddress;
struct Loan {
uint256 loanTime;
uint256 loanPeriod;
bool exists;
}
mapping(uint256 => uint256) internal bankerIdToTimeStamp;
mapping(uint256 => address) internal bankerIdToStaker;
mapping(address => uint256[]) internal stakerToBankerIds;
mapping(uint256 => Loan) internal bankerIdToLoanTime;
mapping(uint256 => uint256) internal propIdToTimeStamp;
mapping(uint256 => address) internal propIdToStaker;
mapping(address => uint256[]) internal stakerToPropIds;
function initialize() initializer public {
__Ownable_init();
__ERC20_init("Paper", "PAPER-DC");
nullAddress = 0x0000000000000000000000000000000000000000;
}
function setPaperAddresses(address _debtCityAddress, address _propertyAddress) public onlyOwner {
debtCityAddress = _debtCityAddress;
propertyAddress = _propertyAddress;
return;
}
/** *********************************** **/
/** ********* Helper Functions ******* **/
/** *********************************** **/
function remove(address staker, uint256 index) internal {
if (index >= stakerToBankerIds[staker].length) return;
for (uint256 i = index; i < stakerToBankerIds[staker].length - 1; i++) {
stakerToBankerIds[staker][i] = stakerToBankerIds[staker][i + 1];
}
stakerToBankerIds[staker].pop();
}
function removeBankerIdFromStaker(address staker, uint256 bankerId) internal {
for (uint256 i = 0; i < stakerToBankerIds[staker].length; i++) {
if (stakerToBankerIds[staker][i] == bankerId) {
remove(staker, i);
}
}
}
function removeProp(address staker, uint256 index) internal {
if (index >= stakerToPropIds[staker].length) return;
for (uint256 i = index; i < stakerToPropIds[staker].length - 1; i++) {
stakerToPropIds[staker][i] = stakerToPropIds[staker][i + 1];
}
stakerToPropIds[staker].pop();
}
function removePropIdFromStaker(address staker, uint256 bankerId) internal {
for (uint256 i = 0; i < stakerToPropIds[staker].length; i++) {
if (stakerToPropIds[staker][i] == bankerId) {
removeProp(staker, i);
}
}
}
/** *********************************** **/
/** ********* Staking Functions ******* **/
/** *********************************** **/
function stakePropertyByIds(uint256[] memory propIds) public {
for (uint256 i = 0; i < propIds.length; i++) {
uint256 propId = propIds[i];
require(
IERC721(propertyAddress).ownerOf(propId) == msg.sender &&
propIdToStaker[propId] == nullAddress,
"Property must be stakable by you!"
);
IERC721(propertyAddress).transferFrom(
msg.sender,
address(this),
propId
);
stakerToPropIds[msg.sender].push(propId);
propIdToTimeStamp[propId] = block.timestamp;
propIdToStaker[propId] = msg.sender;
}
}
function simpleStakeByIds(uint256[] memory bankerIds) public {
for (uint256 i = 0; i < bankerIds.length; i++) {
uint256 bankerId = bankerIds[i];
require(
IERC721(debtCityAddress).ownerOf(bankerId) == msg.sender &&
bankerIdToStaker[bankerId] == nullAddress,
"Banker must be stakable by you!"
);
IERC721(debtCityAddress).transferFrom(
msg.sender,
address(this),
bankerId
);
stakerToBankerIds[msg.sender].push(bankerId);
bankerIdToTimeStamp[bankerId] = block.timestamp;
bankerIdToStaker[bankerId] = msg.sender;
bankerIdToLoanTime[bankerId] = Loan(0, 0, false);
}
}
function loanStakeByIds(uint256[] memory bankerIds, uint256 numLoanDays) public {
uint256 totalRewards = 0;
require(
numLoanDays > 0 && numLoanDays <= 5,
"Max number of loan days is 5"
);
for (uint256 i = 0; i < bankerIds.length; i++) {
uint256 bankerId = bankerIds[i];
if (IERC721(debtCityAddress).ownerOf(bankerId) == msg.sender) {
IERC721(debtCityAddress).transferFrom(
msg.sender,
address(this),
bankerId
);
stakerToBankerIds[msg.sender].push(bankerId);
bankerIdToTimeStamp[bankerId] = block.timestamp;
bankerIdToStaker[bankerId] = msg.sender;
bankerIdToLoanTime[bankerId] = Loan(0, 0, false);
}
require(
IERC721(debtCityAddress).ownerOf(bankerId) == address(this) &&
bankerIdToStaker[bankerId] == msg.sender,
"Banker must be stakable by you!"
);
require (bankerIdToLoanTime[bankerId].exists == false, "Cannot loan a banker thats already loaned out");
uint256 loanPeriod = numLoanDays;
bankerIdToLoanTime[bankerId] = Loan(block.timestamp, loanPeriod, true);
uint8 pay_rate = IDebtCity(debtCityAddress).getPayForBanker(bankerId);
totalRewards = totalRewards + ((loanPeriod) * (pay_rate * 2));
}
_mint(msg.sender, totalRewards);
}
/** *********************************** **/
/** ********* Unstake Functions ******* **/
/** *********************************** **/
function unstakeAllProps() public {
require(
stakerToPropIds[msg.sender].length > 0,
"Must have at least one property staked!"
);
uint256 totalRewards = 0;
for (uint256 i = stakerToPropIds[msg.sender].length; i > 0; i--) {
uint256 propId = stakerToPropIds[msg.sender][i - 1];
require(
propIdToStaker[propId] == msg.sender,
"Message Sender was not original property staker!"
);
uint8 pay_rate = IProperty(propertyAddress).getPayForProperty(propId);
uint256 stakeTime = block.timestamp - propIdToTimeStamp[propId];
uint256 daysStaked = stakeTime / 86400;
uint256 propReward = daysStaked * pay_rate;
IERC721(propertyAddress).transferFrom(
address(this),
msg.sender,
propId
);
totalRewards = totalRewards + propReward;
removePropIdFromStaker(msg.sender, propId);
propIdToStaker[propId] = nullAddress;
}
_mint(msg.sender, totalRewards);
}
function unstakePropsByIds(uint256[] memory propIds) public {
uint256 totalRewards = 0;
for (uint256 i = 0; i < propIds.length; i++) {
uint256 propId = propIds[i];
require(
propIdToStaker[propId] == msg.sender,
"Message Sender was not original property staker!"
);
uint8 pay_rate = IProperty(propertyAddress).getPayForProperty(propId);
uint256 stakeTime = block.timestamp - propIdToTimeStamp[propId];
uint256 daysStaked = stakeTime / 86400;
uint256 propReward = daysStaked * pay_rate;
IERC721(propertyAddress).transferFrom(
address(this),
msg.sender,
propId
);
totalRewards = totalRewards + propReward;
removePropIdFromStaker(msg.sender, propId);
propIdToStaker[propId] = nullAddress;
}
_mint(msg.sender, totalRewards);
}
function unstakeAllBankers() public {
require(
stakerToBankerIds[msg.sender].length > 0,
"Must have at least one banker staked!"
);
uint256 totalRewards = 0;
for (uint256 i = stakerToBankerIds[msg.sender].length; i > 0; i--) {
uint256 bankerId = stakerToBankerIds[msg.sender][i - 1];
require(
bankerIdToStaker[bankerId] == msg.sender,
"Message sender was not original staker!"
);
// make sure this banker isn't time locked from loan stake still
Loan memory l = bankerIdToLoanTime[bankerId];
uint256 loanTime = l.loanTime;
uint256 loanPeriod = l.loanPeriod;
// loan period is in days so we convert to seconds, (60 * 60 * 24 = 600)
uint256 loanPeriodSeconds = loanPeriod * 86400;
require(block.timestamp > (loanTime + loanPeriodSeconds), "Must have loaned banker for full loan time period");
uint256 rewardTime;
if (loanTime > 0) {
rewardTime = (loanTime - bankerIdToTimeStamp[bankerId]) + (block.timestamp - (loanTime + loanPeriodSeconds));
} else {
rewardTime = block.timestamp - bankerIdToTimeStamp[bankerId];
}
uint8 pay_rate = IDebtCity(debtCityAddress).getPayForBanker(bankerId);
uint256 rewardDays = rewardTime / 86400;
uint256 bankerReward = (rewardDays * pay_rate) - 5;
require (bankerReward > 0, "must have staked for at least a day to unstake");
IERC721(debtCityAddress).transferFrom(
address(this),
msg.sender,
bankerId
);
totalRewards = totalRewards + bankerReward;
removeBankerIdFromStaker(msg.sender, bankerId);
bankerIdToStaker[bankerId] = nullAddress;
bankerIdToLoanTime[bankerId] = Loan(0, 0, false);
}
_mint(msg.sender, totalRewards);
}
function unstakeByIds(uint256[] memory bankerIds) public {
uint256 totalRewards = 0;
for (uint256 i = 0; i < bankerIds.length; i++) {
uint256 bankerId = bankerIds[i];
require(
bankerIdToStaker[bankerId] == msg.sender,
"Message sender was not original staker!"
);
// make sure this banker isn't time locked from loan stake still
Loan memory l = bankerIdToLoanTime[bankerId];
uint256 loanTime = l.loanTime;
uint256 loanPeriod = l.loanPeriod;
// loan period is in days so we convert to seconds, (60 * 60 * 24 = 600)
uint256 loanPeriodSeconds = loanPeriod * 86400;
require(block.timestamp > (loanTime + loanPeriodSeconds), "Must have loaned banker for full loan time seconds");
uint256 rewardTime;
if (loanTime > 0) {
rewardTime = (loanTime - bankerIdToTimeStamp[bankerId]) + (block.timestamp - (loanTime + loanPeriodSeconds));
} else {
rewardTime = block.timestamp - bankerIdToTimeStamp[bankerId];
}
uint8 pay_rate = IDebtCity(debtCityAddress).getPayForBanker(bankerId);
uint256 rewardDays = rewardTime / 86400;
uint256 bankerReward = (rewardDays * pay_rate) - 5;
require (bankerReward > 0, "must have staked for at least a day to unstake");
IERC721(debtCityAddress).transferFrom(
address(this),
msg.sender,
bankerId
);
totalRewards = totalRewards + bankerReward;
removeBankerIdFromStaker(msg.sender, bankerId);
bankerIdToStaker[bankerId] = nullAddress;
bankerIdToLoanTime[bankerId] = Loan(0, 0, false);
}
_mint(msg.sender, totalRewards);
}
/** *********************************** **/
/** ********* Claiming Functions ******* **/
/** *********************************** **/
function claimBankersById(uint256[] memory bankerIds) public {
uint256 totalRewards = 0;
for (uint256 i = 0; i < bankerIds.length; i++) {
uint256 bankerId = bankerIds[i];
require(
bankerIdToStaker[bankerId] == msg.sender,
"Message sender was not original staker!"
);
// make sure this banker isn't time locked from loan stake still
Loan memory l = bankerIdToLoanTime[bankerId];
uint256 loanTime = l.loanTime;
uint256 loanPeriod = l.loanPeriod;
// loan period is in days so we convert to seconds, (60 * 60 * 24 = 600)
uint256 loanPeriodSeconds = loanPeriod * 86400;
require(block.timestamp > (loanTime + loanPeriodSeconds), "Must have loaned banker for full loan time seconds");
uint256 rewardTime;
if (loanTime > 0) {
rewardTime = (loanTime - bankerIdToTimeStamp[bankerId]) + (block.timestamp - (loanTime + loanPeriodSeconds));
} else {
rewardTime = block.timestamp - bankerIdToTimeStamp[bankerId];
}
uint8 pay_rate = IDebtCity(debtCityAddress).getPayForBanker(bankerId);
uint256 rewardDays = rewardTime / 86400;
require (rewardDays > 0, "must have staked for at least a day to claim anything");
totalRewards += (rewardDays * pay_rate);
bankerIdToTimeStamp[bankerId] = block.timestamp;
bankerIdToLoanTime[bankerId] = Loan(0, 0, false);
}
_mint(msg.sender, totalRewards);
}
function claimPropsById(uint256[] memory propIds) public {
uint256 totalRewards = 0;
for (uint256 i = 0; i < propIds.length; i++) {
uint256 propId = propIds[i];
require(
propIdToStaker[propId] == msg.sender,
"Message sender was not original staker!"
);
uint8 pay_rate = IProperty(propertyAddress).getPayForProperty(propId);
uint256 claimTime = block.timestamp - propIdToTimeStamp[propId];
uint256 daysStaked = claimTime / 86400;
require (daysStaked > 0, "must have staked for at least a day to claim anything");
totalRewards = totalRewards + (daysStaked * pay_rate);
propIdToTimeStamp[propId] = block.timestamp;
}
_mint(msg.sender, totalRewards);
}
function claimAllRewards() public {
require(
stakerToBankerIds[msg.sender].length > 0 || stakerToPropIds[msg.sender].length > 0,
"Must have at least one banker or prop staked!"
);
uint256 totalRewards = 0;
for (uint256 i = stakerToBankerIds[msg.sender].length; i > 0; i--) {
uint256 bankerId = stakerToBankerIds[msg.sender][i - 1];
require(
bankerIdToStaker[bankerId] == msg.sender,
"Message sender was not original staker!"
);
Loan memory l = bankerIdToLoanTime[bankerId];
uint256 loanTime = l.loanTime;
uint256 loanPeriod = l.loanPeriod;
// loan period is in days so we convert to seconds, (60 * 60 * 24 = 600)
uint256 loanPeriodSeconds = loanPeriod * 86400;
if (block.timestamp > (loanTime + loanPeriodSeconds)) {
uint256 rewardTime;
if (loanTime > 0) {
rewardTime = (loanTime - bankerIdToTimeStamp[bankerId]) + (block.timestamp - (loanTime + loanPeriodSeconds));
} else {
rewardTime = block.timestamp - bankerIdToTimeStamp[bankerId];
}
uint8 pay_rate = IDebtCity(debtCityAddress).getPayForBanker(bankerId);
uint256 rewardDays = rewardTime / 86400;
if (rewardDays > 0) {
totalRewards = totalRewards + (rewardDays * pay_rate);
bankerIdToTimeStamp[bankerId] = block.timestamp;
bankerIdToLoanTime[bankerId] = Loan(0, 0, false);
}
}
}
for (uint256 i = stakerToPropIds[msg.sender].length; i > 0; i--) {
uint256 propId = stakerToPropIds[msg.sender][i - 1];
require(
propIdToStaker[propId] == msg.sender,
"Message sender was not original staker!"
);
uint8 pay_rate = IProperty(propertyAddress).getPayForProperty(propId);
uint256 claimTime = block.timestamp - propIdToTimeStamp[propId];
uint256 daysStaked = claimTime / 86400;
if (daysStaked > 0) {
totalRewards = totalRewards + (daysStaked * pay_rate);
propIdToTimeStamp[propId] = block.timestamp;
}
}
_mint(msg.sender, totalRewards);
}
/** *********************************** **/
/** ********* Public Getters ********** **/
/** *********************************** **/
function getBankersStaked(address staker)
public
view
returns (uint256[] memory)
{
return stakerToBankerIds[staker];
}
function getBankersLoaned(address staker)
public
view
returns (uint256[] memory)
{
uint256[] memory loanBankers = new uint256[](stakerToBankerIds[staker].length);
for (uint256 i = 0; i < stakerToBankerIds[staker].length; i++) {
uint256 bankerId = stakerToBankerIds[staker][i];
Loan memory l = bankerIdToLoanTime[bankerId];
uint256 loanTime = l.loanTime;
uint256 loanPeriod = l.loanPeriod;
if (loanTime > 0 && loanPeriod > 0) {
loanBankers[i] = bankerId;
}
}
return loanBankers;
}
function getPropsStaked(address staker)
public
view
returns (uint256[] memory)
{
return stakerToPropIds[staker];
}
function getRewardsByBankerId(uint256 bankerId)
public
view
returns (uint256)
{
require(
bankerIdToStaker[bankerId] != nullAddress,
"Banker is not staked!"
);
Loan memory l = bankerIdToLoanTime[bankerId];
uint256 loanTime = l.loanTime;
uint256 loanPeriod = l.loanPeriod;
uint256 loanPeriodSeconds = loanPeriod * 86400;
require(block.timestamp > (loanTime + loanPeriodSeconds), "Banker is still loan time locked so there is no current rewards");
uint256 rewardTime;
if (loanTime > 0) {
rewardTime = (loanTime - bankerIdToTimeStamp[bankerId]) + (block.timestamp - (loanTime + loanPeriodSeconds));
} else {
rewardTime = block.timestamp - bankerIdToTimeStamp[bankerId];
}
uint8 pay_rate = IDebtCity(debtCityAddress).getPayForBanker(bankerId);
uint256 rewardDays = rewardTime / 86400;
uint256 totalRewards = rewardDays * pay_rate;
return totalRewards;
}
function getRewardsByPropertyId(uint256 propId)
public
view
returns (uint256)
{
require(
propIdToStaker[propId] != nullAddress,
"Property is not staked!"
);
uint256 secondsStaked = block.timestamp - propIdToTimeStamp[propId];
uint256 daysStaked = secondsStaked / 86400;
uint8 pay_rate = IProperty(propertyAddress).getPayForProperty(propId);
return (pay_rate * daysStaked);
}
function getStaker(uint256 bankerId) public view returns (address) {
return bankerIdToStaker[bankerId];
}
/**
* @dev Destroys `amount` tokens from `account`, deducting from the caller's
* allowance.
*
* See {ERC20-_burn} and {ERC20-allowance}.
*
* Requirements:
*
* - the caller must have allowance for ``accounts``'s tokens of at least
* `amount`.
*/
function burnFrom(address account, uint256 amount) public virtual override {
uint256 currentAllowance = allowance(account, _msgSender());
if (_msgSender() != address(propertyAddress)) {
require(currentAllowance >= amount, "ERC20: burn amount exceeds allowance");
}
unchecked {
_approve(account, _msgSender(), currentAllowance - amount);
}
_burn(account, amount);
}
}
// contracts/IDebtCity.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
interface IProperty is IERC721 {
function getPayForProperty(uint256 _tokenId) external view returns (uint8);
}
// contracts/IDebtCity.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
interface IDebtCity is IERC721 {
function getPayForBanker(uint256 _tokenId) external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes calldata data
) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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 generally not needed starting with Solidity 0.8, since the compiler
* now has built in overflow checking.
*/
library SafeMathUpgradeable {
/**
* @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
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165Upgradeable {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
* @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 ContextUpgradeable is Initializable {
function __Context_init() internal onlyInitializing {
}
function __Context_init_unchained() internal onlyInitializing {
}
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
/**
* @dev This empty reserved space is put in place to allow future versions to add new
* variables without shifting down storage in the inheritance chain.
* See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
*/
uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @dev Collection of functions related to the address type
*/
library AddressUpgradeable {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return 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 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: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)
pragma solidity ^0.8.0;
import "../IERC721Upgradeable.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721EnumerableUpgradeable is IERC721Upgradeable {
/**
* @dev Returns the total amount of tokens stored by the contract.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns a token ID owned by `owner` at a given `index` of its token list.
* Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);
/**
* @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
* Use along with {totalSupply} to enumerate all tokens.
*/
function tokenByIndex(uint256 index) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165Upgradeable.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721Upgradeable is IERC165Upgradeable {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes calldata data
) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20Upgradeable.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20MetadataUpgradeable is IERC20Upgradeable {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/extensions/ERC20Burnable.sol)
pragma solidity ^0.8.0;
import "../ERC20Upgradeable.sol";
import "../../../utils/ContextUpgradeable.sol";
import "../../../proxy/utils/Initializable.sol";
/**
* @dev Extension of {ERC20} that allows token holders to destroy both their own
* tokens and those that they have an allowance for, in a way that can be
* recognized off-chain (via event analysis).
*/
abstract contract ERC20BurnableUpgradeable is Initializable, ContextUpgradeable, ERC20Upgradeable {
function __ERC20Burnable_init() internal onlyInitializing {
}
function __ERC20Burnable_init_unchained() internal onlyInitializing {
}
/**
* @dev Destroys `amount` tokens from the caller.
*
* See {ERC20-_burn}.
*/
function burn(uint256 amount) public virtual {
_burn(_msgSender(), amount);
}
/**
* @dev Destroys `amount` tokens from `account`, deducting from the caller's
* allowance.
*
* See {ERC20-_burn} and {ERC20-allowance}.
*
* Requirements:
*
* - the caller must have allowance for ``accounts``'s tokens of at least
* `amount`.
*/
function burnFrom(address account, uint256 amount) public virtual {
_spendAllowance(account, _msgSender(), amount);
_burn(account, amount);
}
/**
* @dev This empty reserved space is put in place to allow future versions to add new
* variables without shifting down storage in the inheritance chain.
* See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
*/
uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20Upgradeable {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 amount
) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20Upgradeable.sol";
import "./extensions/IERC20MetadataUpgradeable.sol";
import "../../utils/ContextUpgradeable.sol";
import "../../proxy/utils/Initializable.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20Upgradeable is Initializable, ContextUpgradeable, IERC20Upgradeable, IERC20MetadataUpgradeable {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* The default value of {decimals} is 18. To select a different value for
* {decimals} you should overload it.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
function __ERC20_init(string memory name_, string memory symbol_) internal onlyInitializing {
__ERC20_init_unchained(name_, symbol_);
}
function __ERC20_init_unchained(string memory name_, string memory symbol_) internal onlyInitializing {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless this function is
* overridden;
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual override returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_approve(owner, spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
* - the caller must have allowance for ``from``'s tokens of at least
* `amount`.
*/
function transferFrom(
address from,
address to,
uint256 amount
) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, _allowances[owner][spender] + addedValue);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
address owner = _msgSender();
uint256 currentAllowance = _allowances[owner][spender];
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `sender` to `recipient`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
*/
function _transfer(
address from,
address to,
uint256 amount
) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
}
_balances[to] += amount;
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
_balances[account] += amount;
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
}
_totalSupply -= amount;
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(
address owner,
address spender,
uint256 amount
) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Spend `amount` form the allowance of `owner` toward `spender`.
*
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Might emit an {Approval} event.
*/
function _spendAllowance(
address owner,
address spender,
uint256 amount
) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
unchecked {
_approve(owner, spender, currentAllowance - amount);
}
}
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been 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 _afterTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
/**
* @dev This empty reserved space is put in place to allow future versions to add new
* variables without shifting down storage in the inheritance chain.
* See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
*/
uint256[45] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/utils/Initializable.sol)
pragma solidity ^0.8.0;
import "../../utils/AddressUpgradeable.sol";
/**
* @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
* behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
* external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
* function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
*
* TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
* possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
*
* CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
* that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
*
* [CAUTION]
* ====
* Avoid leaving a contract uninitialized.
*
* An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
* contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
* initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
*
* [.hljs-theme-light.nopadding]
* ```
* /// @custom:oz-upgrades-unsafe-allow constructor
* constructor() initializer {}
* ```
* ====
*/
abstract contract Initializable {
/**
* @dev Indicates that the contract has been initialized.
*/
bool private _initialized;
/**
* @dev Indicates that the contract is in the process of being initialized.
*/
bool private _initializing;
/**
* @dev Modifier to protect an initializer function from being invoked twice.
*/
modifier initializer() {
// If the contract is initializing we ignore whether _initialized is set in order to support multiple
// inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
// contract may have been reentered.
require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");
bool isTopLevelCall = !_initializing;
if (isTopLevelCall) {
_initializing = true;
_initialized = true;
}
_;
if (isTopLevelCall) {
_initializing = false;
}
}
/**
* @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
* {initializer} modifier, directly or indirectly.
*/
modifier onlyInitializing() {
require(_initializing, "Initializable: contract is not initializing");
_;
}
function _isConstructor() private view returns (bool) {
return !AddressUpgradeable.isContract(address(this));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
function __Ownable_init() internal onlyInitializing {
__Ownable_init_unchained();
}
function __Ownable_init_unchained() internal onlyInitializing {
_transferOwnership(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
/**
* @dev This empty reserved space is put in place to allow future versions to add new
* variables without shifting down storage in the inheritance chain.
* See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
*/
uint256[49] private __gap;
}