feature/airdrop contract & scripts (#90)

* create airdrop contract & scripts
---------

Co-authored-by: Suraj Kohli <[email protected]>

.gitignore

@@ -7,4 +7,5 @@ artifacts/
 deployments/localhost/
 .vscode
 .*
-gas-report.txt
+gas-report.txt
+utils/Airdrop.xlsx

contracts/ClayDistributor.sol

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+import "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
+
+contract ClayDistributor {
+    using SafeERC20 for IERC20;
+
+    address public immutable token;
+    bytes32 public immutable merkleRoot;
+    uint256 public immutable dropAmount;
+
+    mapping(address => bool) public isClaimed;
+
+    constructor(address token_, bytes32 merkleRoot_, uint256 dropAmount_) {
+        token = token_;
+        merkleRoot = merkleRoot_;
+        dropAmount = dropAmount_;
+    }
+
+    event Claimed(address indexed user);
+
+    function claim(bytes32[] calldata merkleProof) public {
+        require(isClaimed[msg.sender] == false, "Already Claimed!");
+
+        // Verify the merkle proof.
+        bytes32 node = keccak256(abi.encodePacked(msg.sender));
+
+        require(
+            MerkleProof.verify(merkleProof, merkleRoot, node),
+            "Invalid Proof!"
+        );
+
+        // Mark it claimed and send the token.
+        isClaimed[msg.sender] = true;
+        IERC20(token).safeTransfer(msg.sender, dropAmount);
+
+        emit Claimed(msg.sender);
+    }
+}

deploy/011_deploy_clay_distributor.js

@@ -0,0 +1,25 @@
+/**
+ * This script deploys the Clay Distributor Contract
+ * 
+ */
+const func = async function (hre) {
+    const { deployments, getNamedAccounts } = hre;
+    const { deploy } = deployments;
+
+    const { deployer } = await getNamedAccounts();
+
+    const Clay = await deployments.get("ClayToken");
+    // run build-merkle task to generate Merkle Tree Root
+    const MerkleTreeRoot = "0x33ec19caac80a438ca65f6149174a5ecdc4ed6fbf4a70858405fa0cff9d58fd6";
+    const DropAmount = "100";
+    const DropAmountInWei = ethers.utils.parseUnits(DropAmount, 18);
+
+    await deploy("ClayDistributor", {
+        from: deployer,
+        args: [Clay.address, MerkleTreeRoot, DropAmountInWei],
+        log: true,
+        skipIfAlreadyDeployed: false,
+    });
+};
+module.exports = func;
+func.tags = ["ClayDistributor"];

hardhat.config.js

@@ -26,6 +26,8 @@ require("./tasks/emp-request-withdrawal");
 require("./tasks/add-impl-to-finder");
 require("./tasks/create-lp");
 require("./tasks/setup-finder");
+require("./tasks/build-merkle");
+require("./tasks/clay-claim");
 require("./tasks/transfer-clayToken-ownership");
 require("./tasks/transfer-contract-ownership");
 require("./tasks/transfer-all-ownerships");