Merge pull request #62 from onelove-dev/feature/blockchain-event-listener-service

Blockchain Event Listener Service

Author: SudiptaPaul-31

app/login/page.tsx

@@ -166,7 +166,7 @@ export default function LoginPage() {
               </Button>
 
               <p className="text-xs text-muted-foreground pt-4 border-t border-border/40">
-                By connecting a wallet, you agree to TaskChain's Terms of Service and Privacy Policy.
+                By connecting a wallet, you agree to TaskChain&apos;s Terms of Service and Privacy Policy.
               </p>
             </div>
           )}

components/navbar.tsx

@@ -13,10 +13,11 @@ export function Navbar() {
 
   useEffect(() => {
     const savedAddress = localStorage.getItem('stellar_wallet_address')
-    if (savedAddress) {
+    if (savedAddress && savedAddress !== address) {
+      // eslint-disable-next-line react-hooks/set-state-in-effect
       setAddress(savedAddress)
     }
-  }, [])
+  }, [address])
 
   const formatAddress = (addr: string) => {
     if (!addr || addr.length <= 10) return addr;

docs/blockchain_listener_implementation.md

@@ -0,0 +1,39 @@
+# Blockchain Event Listener Service
+
+## Overview
+Implemented a background worker service that subscribes to Stellar blockchain events to keep the application state in sync. The service handles escrow deposits, releases, and refunds for both entire jobs and individual milestones.
+
+## Key Components
+
+### 1. Database Schema Extensions
+- **Milestones Table (`scripts/004-milestones.sql`)**: Stores milestone-level progress, linked to jobs.
+- **Notifications Table (`scripts/005-notifications.sql`)**: Stores platform-wide notifications for users.
+
+### 2. Upgraded Background Worker (`scripts/worker.ts`)
+- **Stellar Horizon Streaming**: Subscribes to payments for the platform escrow account.
+- **Memo-based Logic**: Distinguishes between Job-level (`JOB-{id}`) and Milestone-level (`MIL-{id}`) operations using transaction memos.
+- **Role-aware Processing**: Fetches client and freelancer wallet addresses to automatically identify whether a payment from escrow is a **Release** (to freelancer) or a **Refund** (to client).
+- **Idempotency**: Checks `escrow_transactions` before processing to prevent duplicate updates from the same blockchain transaction.
+- **Automatic Job Completion**: Synchronizes the main Job status to `completed` once all associated milestones have been released.
+- **Real Notifications**: Inserts notification records directly into the database during event processing.
+
+## How to Run
+1. Ensure the new SQL migrations are applied to your database:
+   ```bash
+   # Run these in your Neon console or via psql
+   scripts/004-milestones.sql
+   scripts/005-notifications.sql
+   ```
+2. Set the necessary environment variables in `.env`:
+   - `DATABASE_URL`: Your Postgres connection string.
+   - `ESCROW_ACCOUNT_ID`: The Stellar account monitoring for escrow payments.
+   - `STELLAR_HORIZON_URL`: (Optional) Defaults to Testnet.
+3. Start the worker:
+   ```bash
+   npm run worker
+   ```
+
+## Design Decisions
+- **Separation of Concerns**: Kept the worker as a separate script to avoid blocking Next.js API routes.
+- **Resilience**: Implemented `SIGINT` handling for graceful shutdown and used SDK streaming for automatic reconnection.
+- **Scalability**: Used async/await and non-blocking SQL queries to handle concurrent events.

package-lock.json

@@ -39,13 +39,13 @@
     "@radix-ui/react-toggle": "1.1.1",
     "@radix-ui/react-toggle-group": "1.1.1",
     "@radix-ui/react-tooltip": "1.1.6",
+    "@stellar/freighter-api": "^6.0.1",
     "@stellar/stellar-sdk": "^14.5.0",
     "@vercel/analytics": "1.3.1",
     "autoprefixer": "^10.4.20",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "cmdk": "1.0.4",
-    "date-fns": "^4.1.0",
     "date-fns": "4.1.0",
     "dotenv": "^17.3.1",
     "embla-carousel-react": "8.5.1",
@@ -80,4 +80,4 @@
     "tw-animate-css": "1.3.3",
     "typescript": "^5"
   }
-}
+}

package.json

@@ -0,0 +1,15 @@
+-- Create milestones table
+CREATE TABLE IF NOT EXISTS milestones (
+  id SERIAL PRIMARY KEY,
+  job_id INTEGER NOT NULL REFERENCES jobs(id) ON DELETE CASCADE,
+  title VARCHAR(255) NOT NULL,
+  description TEXT,
+  amount DECIMAL(10, 2) NOT NULL,
+  status VARCHAR(20) NOT NULL DEFAULT 'pending' CHECK (status IN ('pending', 'in_progress', 'completed', 'released')),
+  due_date TIMESTAMP,
+  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX IF NOT EXISTS idx_milestones_job ON milestones(job_id);
+CREATE INDEX IF NOT EXISTS idx_milestones_status ON milestones(status);

scripts/004-milestones.sql

@@ -0,0 +1,13 @@
+-- Create notifications table
+CREATE TABLE IF NOT EXISTS notifications (
+  id SERIAL PRIMARY KEY,
+  user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+  title VARCHAR(255) NOT NULL,
+  message TEXT NOT NULL,
+  type VARCHAR(50) DEFAULT 'info',
+  is_read BOOLEAN DEFAULT FALSE,
+  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX IF NOT EXISTS idx_notifications_user ON notifications(user_id);
+CREATE INDEX IF NOT EXISTS idx_notifications_created_at ON notifications(created_at);