Staking Pool Smart Contract

A secure and efficient ERC20 token staking pool that allows users to earn rewards for staking their tokens.

Overview

The StakingPool contract enables users to:

• Stake ERC20 tokens
• Earn rewards based on staking duration
• Unstake tokens at any time
• Claim accumulated rewards

The contract includes security features like reentrancy protection and proper access control.

Features

• Token Staking: Users can stake any ERC20 token
• Reward System: Rewards accumulate based on staking duration
• Admin Controls: Contract owner can fund the reward pool and adjust reward rates
• Security: Protected against reentrancy attacks
• Events: Comprehensive event logging for all major actions

Technical Details

Contract Architecture

The contract inherits from:

• ReentrancyGuard: Prevents reentrancy attacks
• Ownable: Provides basic authorization control

Key Components

1. StakeInfo Struct

struct StakeInfo {
    uint256 amount;           // Amount of tokens staked
    uint256 timestamp;        // When the stake was made
    uint256 lastRewardTimestamp; // Last time rewards were claimed
}

2. State Variables

• stakingToken: The ERC20 token being staked
• totalStaked: Total amount of tokens staked
• rewardRate: Reward rate (tokens per day per 1000 tokens)
• rewardPool: Available rewards for distribution

Main Functions

User Functions

• stake(uint256 _amount): Stake tokens
• unstake(uint256 _amount): Unstake tokens
• claimRewards(): Claim accumulated rewards

Admin Functions

• fundRewardPool(uint256 _amount): Fund the reward pool
• setRewardRate(uint256 _newRate): Update reward rate

Events

• Staked(address indexed user, uint256 amount)
• Unstaked(address indexed user, uint256 amount)
• RewardClaimed(address indexed user, uint256 amount)
• RewardPoolFunded(uint256 amount)

Reward Calculation

Rewards are calculated using the formula:

reward = (stakedAmount * rewardRate * timeStaked) / (1000 * 1 days)

Where:

• stakedAmount: Amount of tokens staked
• rewardRate: Current reward rate
• timeStaked: Time since last reward claim

Security Features

1. Reentrancy Protection

   • All external functions are protected with nonReentrant modifier
   • Prevents reentrancy attacks during token transfers

2. Access Control

   • Admin functions restricted to contract owner
   • User functions accessible to all

3. Input Validation

   • Amount checks
   • Balance checks
   • Transfer validations

Testing

The contract includes comprehensive tests using Foundry:

1. Basic Operations

   • Staking
   • Unstaking
   • Reward claiming

2. Edge Cases

   • Insufficient stake
   • Multiple stakes
   • Reward calculations

To run tests:

forge test

Deployment

1. Deploy an ERC20 token contract
2. Deploy the StakingPool contract with the token address
3. Fund the reward pool with tokens
4. Set the initial reward rate

Usage Example

// Approve tokens
token.approve(stakingPoolAddress, amount);

// Stake tokens
stakingPool.stake(amount);

// Claim rewards
stakingPool.claimRewards();

// Unstake tokens
stakingPool.unstake(amount);

Best Practices

1. Always check token approvals before staking
2. Monitor reward pool balance
3. Consider gas costs for frequent operations
4. Keep track of reward rates

License

MIT License