Merge pull request #1 from darwinia-network/changes

Contract changes

src/KTONStakingRewards.sol

@@ -16,11 +16,10 @@ contract StakingRewards is IStakingRewards, RewardsDistributionRecipient, Reentr
 
     /* ========== STATE VARIABLES ========== */
 
-    IERC20 public rewardsToken;
     IERC20 public stakingToken;
     uint256 public periodFinish = 0;
     uint256 public rewardRate = 0;
-    uint256 public rewardsDuration = 60 days;
+    uint256 public rewardsDuration = 7200;
     uint256 public lastUpdateTime;
     uint256 public rewardPerTokenStored;
 
@@ -34,10 +33,8 @@ contract StakingRewards is IStakingRewards, RewardsDistributionRecipient, Reentr
 
     constructor(
         address _rewardsDistribution,
-        address _rewardsToken,
         address _stakingToken
     ) public {
-        rewardsToken = IERC20(_rewardsToken);
         stakingToken = IERC20(_stakingToken);
         rewardsDistribution = _rewardsDistribution;
     }
@@ -76,18 +73,6 @@ contract StakingRewards is IStakingRewards, RewardsDistributionRecipient, Reentr
 
     /* ========== MUTATIVE FUNCTIONS ========== */
 
-    function stakeWithPermit(uint256 amount, uint deadline, uint8 v, bytes32 r, bytes32 s) external nonReentrant updateReward(msg.sender) {
-        require(amount > 0, "Cannot stake 0");
-        _totalSupply = _totalSupply.add(amount);
-        _balances[msg.sender] = _balances[msg.sender].add(amount);
-
-        // permit
-        IUniswapV2ERC20(address(stakingToken)).permit(msg.sender, address(this), amount, deadline, v, r, s);
-
-        stakingToken.safeTransferFrom(msg.sender, address(this), amount);
-        emit Staked(msg.sender, amount);
-    }
-
     function stake(uint256 amount) external nonReentrant updateReward(msg.sender) {
         require(amount > 0, "Cannot stake 0");
         _totalSupply = _totalSupply.add(amount);
@@ -108,7 +93,8 @@ contract StakingRewards is IStakingRewards, RewardsDistributionRecipient, Reentr
         uint256 reward = rewards[msg.sender];
         if (reward > 0) {
             rewards[msg.sender] = 0;
-            rewardsToken.safeTransfer(msg.sender, reward);
+            (bool success, ) = msg.sender.call.value(reward)("");
+            require(success, "Transfer failed");
             emit RewardPaid(msg.sender, reward);
         }
     }
@@ -133,7 +119,7 @@ contract StakingRewards is IStakingRewards, RewardsDistributionRecipient, Reentr
         // This keeps the reward rate in the right range, preventing overflows due to
         // very high values of rewardRate in the earned and rewardsPerToken functions;
         // Reward + leftover must be less than 2^256 / 10^18 to avoid overflow.
-        uint balance = rewardsToken.balanceOf(address(this));
+        uint balance = address(this).balance;
         require(rewardRate <= balance.div(rewardsDuration), "Provided reward too high");
 
         lastUpdateTime = block.timestamp;
@@ -161,6 +147,3 @@ contract StakingRewards is IStakingRewards, RewardsDistributionRecipient, Reentr
     event RewardPaid(address indexed user, uint256 reward);
 }
 
-interface IUniswapV2ERC20 {
-    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
-}