🔨 add deposit

src/Staking.sol

@@ -2,31 +2,56 @@
 pragma solidity 0.8.20;
 
 import {IERC20, SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
 import {IStaking} from "contracts/interface/IStaking.sol";
 
-contract Staking {
+contract Staking is Ownable, IStaking {
     using SafeERC20 for IERC20;
 
-    struct StakerInfo {
-        uint256 stakedAmount;
-        uint256 debtReward;
-        uint256 accumulatedRewards;
-        uint256 lastUpdate;
-    }
-
     IERC20 public stakingToken;
     IERC20 public rewardToken;
     uint256 public ratePerSecond;
+    uint256 public lastRewardTimestamp;
+    uint256 public accRewardsPerShare;
 
     mapping(address => StakerInfo) public stakerInfo;
 
-    constructor(
-        address stakingToken_,
-        address rewardToken_,
-        uint256 ratePerSecond_
-    ) {
+    constructor(address stakingToken_, address rewardToken_, uint256 ratePerSecond_, address owner_) Ownable(owner_) {
         stakingToken = IERC20(stakingToken_);
         rewardToken = IERC20(rewardToken_);
         ratePerSecond = ratePerSecond_;
     }
+
+    function deposit(uint256 amount) external {
+        StakerInfo storage staker = stakerInfo[msg.sender];
+        _updatePool();
+        if (staker.stakedAmount > 0) {
+            uint256 pending = (staker.stakedAmount * accRewardsPerShare) - staker.rewardDebt;
+
+            staker.accRewards += pending;
+        }
+
+        stakingToken.safeTransferFrom(msg.sender, address(this), amount);
+        staker.stakedAmount += amount;
+        staker.rewardDebt = amount * (accRewardsPerShare);
+
+        emit Deposit(msg.sender, amount);
+    }
+
+    function _updatePool() private {
+        if (block.timestamp <= lastRewardTimestamp) {
+            return;
+        }
+
+        uint256 stakedAmount = stakingToken.balanceOf(address(this));
+        if (stakedAmount == 0) {
+            lastRewardTimestamp = block.timestamp;
+            return;
+        }
+
+        uint256 reward = (block.timestamp - lastRewardTimestamp) * ratePerSecond;
+
+        accRewardsPerShare += (reward / stakedAmount);
+        lastRewardTimestamp = block.timestamp;
+    }
 }

src/interface/IStaking.sol

@@ -1,4 +1,18 @@
 // SPDX-License-Identifier: MIT
 pragma solidity 0.8.20;
 
-interface IStaking {}
+interface IStaking {
+    struct StakerInfo {
+        uint256 stakedAmount;
+        uint256 rewardDebt;
+        uint256 accRewards;
+    }
+
+    event Deposit(address indexed staker, uint256 amount);
+    event Withdraw(address indexed staker, uint256 amount);
+    event Claim(address indexed staker, uint256 amount);
+    event EmergencyWithdraw(
+        address indexed user,
+        uint256 amount
+    );
+}