Create Crowdfunding.sol

blockchain_development_integration/pi_network/smart_contracts/Crowdfunding.sol

@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+contract Crowdfunding {
+    struct Campaign {
+        address creator;
+        uint256 goal;
+        uint256 raisedAmount;
+        uint256 deadline;
+        bool isCompleted;
+    }
+
+    mapping(uint256 => Campaign) public campaigns;
+    uint256 public campaignCount;
+
+    function createCampaign(uint256 goal, uint256 duration) external {
+        require(goal > 0, "Goal must be greater than 0");
+        campaignCount++;
+        campaigns[campaignCount] = Campaign(msg.sender, goal, 0, block.timestamp + duration, false);
+    }
+
+    function contribute(uint256 campaignId) external payable {
+        Campaign storage campaign = campaigns[campaignId];
+        require(block.timestamp < campaign.deadline, "Campaign has ended");
+        require(!campaign.isCompleted, "Campaign already completed");
+
+        campaign.raisedAmount += msg.value;
+    }
+
+    function finalizeCampaign(uint256 campaignId) external {
+        Campaign storage campaign = campaigns[campaignId];
+        require(block.timestamp >= campaign.deadline, "Campaign is still ongoing");
+        require(!campaign.isCompleted, "Campaign already completed");
+
+        campaign.isCompleted = true;
+        if (campaign.raisedAmount >= campaign.goal) {
+            payable(campaign.creator).transfer(campaign.raisedAmount);
+        }
+    }
+}