// SPDX-License-Identifier: UNLICENSED // File: node_modules\@openzeppelin\contracts\GSN\Context.sol pragma solidity >=0.6.0 <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 GSN 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 payable) { return msg.sender; } function _msgData() internal view virtual returns (bytes memory) { this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 return msg.data; } } // File: @openzeppelin\contracts\access\Ownable.sol pragma solidity >=0.6.0 <0.8.0; /** * @dev Contract module which provides a basic access control mechanism, where * there is an account (an owner) that can be granted exclusive access to * specific functions. * * By default, the owner account will be the one that deploys the contract. This * can later be changed with {transferOwnership}. * * This module is used through inheritance. It will make available the modifier * `onlyOwner`, which can be applied to your functions to restrict their use to * the owner. */ abstract contract Ownable is Context { address private _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ constructor () internal { address msgSender = _msgSender(); _owner = msgSender; emit OwnershipTransferred(address(0), msgSender); } /** * @dev Returns the address of the current owner. */ function owner() public view 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 { emit OwnershipTransferred(_owner, address(0)); _owner = 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"); emit OwnershipTransferred(_owner, newOwner); _owner = newOwner; } } // File: @openzeppelin\contracts\utils\ReentrancyGuard.sol pragma solidity >=0.6.0 <0.8.0; /** * @dev Contract module that helps prevent reentrant calls to a function. * * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier * available, which can be applied to functions to make sure there are no nested * (reentrant) calls to them. * * Note that because there is a single `nonReentrant` guard, functions marked as * `nonReentrant` may not call one another. This can be worked around by making * those functions `private`, and then adding `external` `nonReentrant` entry * points to them. * * TIP: If you would like to learn more about reentrancy and alternative ways * to protect against it, check out our blog post * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul]. */ abstract contract ReentrancyGuard { // Booleans are more expensive than uint256 or any type that takes up a full // word because each write operation emits an extra SLOAD to first read the // slot's contents, replace the bits taken up by the boolean, and then write // back. This is the compiler's defense against contract upgrades and // pointer aliasing, and it cannot be disabled. // The values being non-zero value makes deployment a bit more expensive, // but in exchange the refund on every call to nonReentrant will be lower in // amount. Since refunds are capped to a percentage of the total // transaction's gas, it is best to keep them low in cases like this one, to // increase the likelihood of the full refund coming into effect. uint256 private constant _NOT_ENTERED = 1; uint256 private constant _ENTERED = 2; uint256 private _status; constructor () internal { _status = _NOT_ENTERED; } /** * @dev Prevents a contract from calling itself, directly or indirectly. * Calling a `nonReentrant` function from another `nonReentrant` * function is not supported. It is possible to prevent this from happening * by making the `nonReentrant` function external, and make it call a * `private` function that does the actual work. */ modifier nonReentrant() { // On the first call to nonReentrant, _notEntered will be true require(_status != _ENTERED, "ReentrancyGuard: reentrant call"); // Any calls to nonReentrant after this point will fail _status = _ENTERED; _; // By storing the original value once again, a refund is triggered (see // https://eips.ethereum.org/EIPS/eip-2200) _status = _NOT_ENTERED; } } // File: @openzeppelin\contracts\utils\EnumerableSet.sol pragma solidity >=0.6.0 <0.8.0; /** * @dev Library for managing * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive * types. * * Sets have the following properties: * * - Elements are added, removed, and checked for existence in constant time * (O(1)). * - Elements are enumerated in O(n). No guarantees are made on the ordering. * * ``` * contract Example { * // Add the library methods * using EnumerableSet for EnumerableSet.AddressSet; * * // Declare a set state variable * EnumerableSet.AddressSet private mySet; * } * ``` * * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`) * and `uint256` (`UintSet`) are supported. */ library EnumerableSet { // To implement this library for multiple types with as little code // repetition as possible, we write it in terms of a generic Set type with // bytes32 values. // The Set implementation uses private functions, and user-facing // implementations (such as AddressSet) are just wrappers around the // underlying Set. // This means that we can only create new EnumerableSets for types that fit // in bytes32. struct Set { // Storage of set values bytes32[] _values; // Position of the value in the `values` array, plus 1 because index 0 // means a value is not in the set. mapping(bytes32 => uint256) _indexes; } /** * @dev Add a value to a set. O(1). * * Returns true if the value was added to the set, that is if it was not * already present. */ function _add(Set storage set, bytes32 value) private returns (bool) { if (!_contains(set, value)) { set._values.push(value); // The value is stored at length-1, but we add 1 to all indexes // and use 0 as a sentinel value set._indexes[value] = set._values.length; return true; } else { return false; } } /** * @dev Removes a value from a set. O(1). * * Returns true if the value was removed from the set, that is if it was * present. */ function _remove(Set storage set, bytes32 value) private returns (bool) { // We read and store the value's index to prevent multiple reads from the same storage slot uint256 valueIndex = set._indexes[value]; if (valueIndex != 0) {// Equivalent to contains(set, value) // To delete an element from the _values array in O(1), we swap the element to delete with the last one in // the array, and then remove the last element (sometimes called as 'swap and pop'). // This modifies the order of the array, as noted in {at}. uint256 toDeleteIndex = valueIndex - 1; uint256 lastIndex = set._values.length - 1; // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement. bytes32 lastvalue = set._values[lastIndex]; // Move the last value to the index where the value to delete is set._values[toDeleteIndex] = lastvalue; // Update the index for the moved value set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based // Delete the slot where the moved value was stored set._values.pop(); // Delete the index for the deleted slot delete set._indexes[value]; return true; } else { return false; } } /** * @dev Returns true if the value is in the set. O(1). */ function _contains(Set storage set, bytes32 value) private view returns (bool) { return set._indexes[value] != 0; } /** * @dev Returns the number of values on the set. O(1). */ function _length(Set storage set) private view returns (uint256) { return set._values.length; } /** * @dev Returns the value stored at position `index` in the set. O(1). * * Note that there are no guarantees on the ordering of values inside the * array, and it may change when more values are added or removed. * * Requirements: * * - `index` must be strictly less than {length}. */ function _at(Set storage set, uint256 index) private view returns (bytes32) { require(set._values.length > index, "EnumerableSet: index out of bounds"); return set._values[index]; } // Bytes32Set struct Bytes32Set { Set _inner; } /** * @dev Add a value to a set. O(1). * * Returns true if the value was added to the set, that is if it was not * already present. */ function add(Bytes32Set storage set, bytes32 value) internal returns (bool) { return _add(set._inner, value); } /** * @dev Removes a value from a set. O(1). * * Returns true if the value was removed from the set, that is if it was * present. */ function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) { return _remove(set._inner, value); } /** * @dev Returns true if the value is in the set. O(1). */ function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) { return _contains(set._inner, value); } /** * @dev Returns the number of values in the set. O(1). */ function length(Bytes32Set storage set) internal view returns (uint256) { return _length(set._inner); } /** * @dev Returns the value stored at position `index` in the set. O(1). * * Note that there are no guarantees on the ordering of values inside the * array, and it may change when more values are added or removed. * * Requirements: * * - `index` must be strictly less than {length}. */ function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) { return _at(set._inner, index); } // AddressSet struct AddressSet { Set _inner; } /** * @dev Add a value to a set. O(1). * * Returns true if the value was added to the set, that is if it was not * already present. */ function add(AddressSet storage set, address value) internal returns (bool) { return _add(set._inner, bytes32(uint256(value))); } /** * @dev Removes a value from a set. O(1). * * Returns true if the value was removed from the set, that is if it was * present. */ function remove(AddressSet storage set, address value) internal returns (bool) { return _remove(set._inner, bytes32(uint256(value))); } /** * @dev Returns true if the value is in the set. O(1). */ function contains(AddressSet storage set, address value) internal view returns (bool) { return _contains(set._inner, bytes32(uint256(value))); } /** * @dev Returns the number of values in the set. O(1). */ function length(AddressSet storage set) internal view returns (uint256) { return _length(set._inner); } /** * @dev Returns the value stored at position `index` in the set. O(1). * * Note that there are no guarantees on the ordering of values inside the * array, and it may change when more values are added or removed. * * Requirements: * * - `index` must be strictly less than {length}. */ function at(AddressSet storage set, uint256 index) internal view returns (address) { return address(uint256(_at(set._inner, index))); } // UintSet struct UintSet { Set _inner; } /** * @dev Add a value to a set. O(1). * * Returns true if the value was added to the set, that is if it was not * already present. */ function add(UintSet storage set, uint256 value) internal returns (bool) { return _add(set._inner, bytes32(value)); } /** * @dev Removes a value from a set. O(1). * * Returns true if the value was removed from the set, that is if it was * present. */ function remove(UintSet storage set, uint256 value) internal returns (bool) { return _remove(set._inner, bytes32(value)); } /** * @dev Returns true if the value is in the set. O(1). */ function contains(UintSet storage set, uint256 value) internal view returns (bool) { return _contains(set._inner, bytes32(value)); } /** * @dev Returns the number of values on the set. O(1). */ function length(UintSet storage set) internal view returns (uint256) { return _length(set._inner); } /** * @dev Returns the value stored at position `index` in the set. O(1). * * Note that there are no guarantees on the ordering of values inside the * array, and it may change when more values are added or removed. * * Requirements: * * - `index` must be strictly less than {length}. */ function at(UintSet storage set, uint256 index) internal view returns (uint256) { return uint256(_at(set._inner, index)); } } // File: @openzeppelin\contracts\math\SafeMath.sol pragma solidity >=0.6.0 <0.8.0; /** * @dev Wrappers over Solidity's arithmetic operations with added overflow * checks. * * Arithmetic operations in Solidity wrap on overflow. This can easily result * in bugs, because programmers usually assume that an overflow raises an * error, which is the standard behavior in high level programming languages. * `SafeMath` restores this intuition by reverting the transaction when an * operation overflows. * * Using this library instead of the unchecked operations eliminates an entire * class of bugs, so it's recommended to use it always. */ library SafeMath { /** * @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) { uint256 c = a + b; require(c >= a, "SafeMath: addition overflow"); return c; } /** * @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 sub(a, b, "SafeMath: subtraction overflow"); } /** * @dev Returns the subtraction of two unsigned integers, reverting with custom message on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b <= a, errorMessage); uint256 c = a - b; return c; } /** * @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) { // 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 0; } uint256 c = a * b; require(c / a == b, "SafeMath: multiplication overflow"); return c; } /** * @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) { return div(a, b, "SafeMath: division by zero"); } /** * @dev Returns the integer division of two unsigned integers. Reverts 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) { require(b > 0, errorMessage); uint256 c = a / b; // assert(a == b * c + a % b); // There is no case in which this doesn't hold return c; } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts 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 mod(a, b, "SafeMath: modulo by zero"); } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) { require(b != 0, errorMessage); return a % b; } } // File: contracts\interfaces\IToken.sol pragma solidity ^0.7.5; interface IToken { function snapshot() external returns (uint); function totalSupplyAt(uint _snapshotId) external view returns (uint); function balanceOfAt(address _account, uint _snapshotId) external view returns (uint); } // File: contracts\Reward.sol pragma solidity ^0.7.5; contract Reward is Ownable, ReentrancyGuard { using SafeMath for uint; using EnumerableSet for EnumerableSet.AddressSet; struct EthReward { uint snapshotId; uint totalSupplyAtSnapshot; uint rewardAmount; uint claimedAmount; uint timestamp; } uint public constant CLAIM_DEADLINE = 182 days; IToken public token; EthReward[] public rewards; // not eligible for rewards EnumerableSet.AddressSet private _blacklist; // user -> reward id -> claimed mapping(address => mapping(uint => bool)) public claimedRewards; // reward id -> drained mapping(uint => bool) private drained; event NewToken(address _token, uint _timestamp); event NewReward(uint _rewardId, uint _snapshotId, uint _amount, uint _timestamp); event Claimed(address indexed _who, uint indexed _rewardId, uint _amount, uint _timestamp); event Drained(uint _rewardId, uint _amount, uint _timestamp); event Blacklisted(address _address, bool _blacklisted); constructor(address _token) { setToken(_token); } function setToken(address _token) public onlyOwner { require(_token != address(0), "Invalid address"); token = IToken(_token); emit NewToken(_token, _getNow()); } receive() external payable { deposit(); } function deposit() public payable onlyOwner { require(msg.value > 0, "Must deposit something"); uint snapshotId = token.snapshot(); uint totalSupplyAtSnapshot = token.totalSupplyAt(snapshotId); uint newId = rewards.length; // remove blacklisted balances from total supply for (uint i = 0; i < blacklistLength(); i++) { address blacklisted = blacklistAt(i); uint balanceAtSnapshot = token.balanceOfAt(blacklisted, snapshotId); totalSupplyAtSnapshot = totalSupplyAtSnapshot.sub(balanceAtSnapshot); claimedRewards[blacklisted][newId] = true; } EthReward memory newReward = EthReward({ snapshotId : snapshotId, totalSupplyAtSnapshot : totalSupplyAtSnapshot, rewardAmount : msg.value, claimedAmount : 0, timestamp : _getNow() }); rewards.push(newReward); emit NewReward(newId, snapshotId, msg.value, _getNow()); } function claim(uint _rewardId) public nonReentrant { require(!claimedRewards[_msgSender()][_rewardId], "Already claimed"); require(beforeDeadline(_rewardId), "Too late"); uint myShare = getMyShare(_rewardId); require(myShare > 0, "Nothing to claim"); EthReward storage reward = rewards[_rewardId]; reward.claimedAmount = reward.claimedAmount.add(myShare); claimedRewards[_msgSender()][_rewardId] = true; // solhint-disable-next-line avoid-low-level-calls, avoid-call-value (bool success,) = _msgSender().call{value : myShare}(""); require(success, "Claim: unable to send value, recipient may have reverted"); emit Claimed(_msgSender(), _rewardId, myShare, _getNow()); } function claimBulk(uint[] calldata _rewardIds) external { for (uint i = 0; i < _rewardIds.length; i++) { claim(_rewardIds[i]); } } function drain(uint _rewardId) public onlyOwner { require(!beforeDeadline(_rewardId), "Too early"); require(!drained[_rewardId], "Already drained"); (,, uint rewardAmount, uint claimedAmount,) = getRewardInfo(_rewardId); uint unclaimedAmount = rewardAmount.sub(claimedAmount); drained[_rewardId] = true; _msgSender().transfer(unclaimedAmount); emit Drained(_rewardId, unclaimedAmount, _getNow()); } function drainBulk(uint[] calldata _rewardIds) external { for (uint i = 0; i < _rewardIds.length; i++) { drain(_rewardIds[i]); } } function addBlacklist(address[] calldata _blacklisted) external onlyOwner { for (uint i = 0; i < _blacklisted.length; i++) { _blacklist.add(_blacklisted[i]); emit Blacklisted(_blacklisted[i], true); } } function removeBlacklist(address[] calldata _blacklisted) external onlyOwner { for (uint i = 0; i < _blacklisted.length; i++) { _blacklist.remove(_blacklisted[i]); emit Blacklisted(_blacklisted[i], false); } } function getNumberOfRewards() public view returns (uint) { return rewards.length; } function getRewardInfo(uint _rewardId) public view returns (uint snapshotId, uint totalSupplyAtSnapshot, uint rewardAmount, uint claimedAmount, uint timestamp) { require(_rewardId >= 0 && _rewardId < getNumberOfRewards(), "Invalid reward id"); EthReward memory reward = rewards[_rewardId]; snapshotId = reward.snapshotId; totalSupplyAtSnapshot = reward.totalSupplyAtSnapshot; rewardAmount = reward.rewardAmount; claimedAmount = reward.claimedAmount; timestamp = reward.timestamp; } function deadline(uint _rewardId) public view returns (uint) { (,,,, uint timestamp) = getRewardInfo(_rewardId); return timestamp + CLAIM_DEADLINE; } function beforeDeadline(uint _rewardId) public view returns (bool) { return _getNow() <= deadline(_rewardId); } function getMyShare(uint _rewardId) public view returns (uint) { return getShare(_msgSender(), _rewardId); } function getShare(address _account, uint _rewardId) public view returns (uint) { if (claimedRewards[_account][_rewardId]) { return 0; } (uint snapshotId, uint totalSupplyAtSnapshot, uint rewardAmount, ,) = getRewardInfo(_rewardId); uint balanceAtSnapshot = token.balanceOfAt(_account, snapshotId); return rewardAmount.mul(balanceAtSnapshot).div(totalSupplyAtSnapshot); } function blacklistContains(address _address) public view returns (bool) { return _blacklist.contains(_address); } function blacklistLength() public view returns (uint) { return _blacklist.length(); } function blacklistAt(uint _index) public view returns (address) { return _blacklist.at(_index); } function _getNow() internal view returns (uint) { return block.timestamp; } }