Add RewardsDistribution contract

src/RewardsDistribution.sol

@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.25;
+
+import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import {Ownable2StepUpgradeable} from "@openzeppelin-upgradeable/contracts/access/Ownable2StepUpgradeable.sol";
+import {SafeTransferLib} from "@solmate/utils/SafeTransferLib.sol";
+
+interface IRewardsDistributor {
+    function distributeRewards() external;
+}
+
+// TODO should be pausable?
+contract RewardsDistributor is Ownable2StepUpgradeable {
+    /*//////////////////////////////////////////////////////////////
+                               LIBRARIES
+    //////////////////////////////////////////////////////////////*/
+    using SafeTransferLib for ERC20;
+
+    /*//////////////////////////////////////////////////////////////
+                                 STRUCTS
+    //////////////////////////////////////////////////////////////*/
+
+    /// @notice the reward configuration
+    struct RewardConfiguration {
+        ERC20 token; // the reward token
+        uint256 emissionRate; // emission per second
+        uint256 lastUpdate; // last update timestamp
+    }
+
+    /// @notice reward configurations
+    mapping(address receiver => RewardConfiguration[])
+        public rewardConfigurations;
+
+    mapping(address receiver => mapping(ERC20 => uint256 id))
+        public rewardConfigurationsIds;
+
+    /// @notice Ensure logic contract is unusable
+    constructor() {
+        _disableInitializers();
+    }
+
+    /// @notice Initialize the contract
+    /// @param newOwner The owner of the contract, i.e. the DAO contract address
+    function initialize(address newOwner) public initializer {
+        __Ownable2Step_init();
+
+        // Transfer ownership to the DAO contract
+        transferOwnership(newOwner);
+    }
+
+    /// @notice Add a reward configuration
+    /// @param receiver The receiver of the rewards
+    /// @param token The reward token
+    /// @param emissionRate The emission rate
+    function addRewardConfiguration(
+        address receiver,
+        ERC20 token,
+        uint256 emissionRate
+    ) external onlyOwner {
+        rewardConfigurations[receiver].push(
+            RewardConfiguration(token, emissionRate, block.timestamp)
+        );
+
+        rewardConfigurationsIds[receiver][token] = rewardConfigurations[
+            receiver
+        ].length;
+    }
+
+    /// @notice Update the emission rate of a reward configuration
+    /// @param receiver The receiver of the rewards
+    /// @param token The reward token
+    /// @param emissionRate The new emission rate
+    /// @dev set the emission rate to 0 to stop the rewards
+    function updateEmissonRate(
+        address receiver,
+        ERC20 token,
+        uint256 emissionRate
+    ) external onlyOwner {
+        uint256 id = rewardConfigurationsIds[receiver][token];
+        require(
+            rewardConfigurations[receiver].length > 0 && id > 0,
+            "No reward configuration found"
+        );
+
+        // index is always 1 less than the id
+        rewardConfigurations[receiver][id - 1].emissionRate = emissionRate;
+    }
+
+    /// @notice Distribute rewards to receiver
+    /// @param token The reward token
+    function distributeReward(ERC20 token) external {
+        uint256 id = rewardConfigurationsIds[msg.sender][token];
+
+        require(
+            rewardConfigurations[msg.sender].length > 0 && id > 0,
+            "No reward configuration found"
+        );
+
+        RewardConfiguration storage rewardConfiguration = rewardConfigurations[
+            msg.sender
+        ][id - 1];
+
+        // difference in time since last update
+        uint256 timeDelta = block.timestamp - rewardConfiguration.lastUpdate;
+
+        if (timeDelta == 0) {
+            // nothing to do
+            return;
+        }
+
+        uint256 reward = rewardConfiguration.emissionRate * timeDelta;
+
+        // update the last update timestamp
+        rewardConfiguration.lastUpdate = block.timestamp;
+
+        // transfer the reward
+        token.safeTransfer(msg.sender, reward);
+    }
+}

src/Staking.sol

@@ -170,8 +170,8 @@ contract Staking is ERC20VotesUpgradeable, Ownable2StepUpgradeable {
         emit Staked(keyper, amount, sharesToMint, lockPeriod);
     }
 
-    //function unstakeAll();
-    // function claimRewardsAndUnstake();
+    // TODO function unstakeAll();
+    // TODO function claimRewardsAndUnstake();
 
     /// @notice Unstake SHU
     ///          - If caller is a keyper only them can unstake