Market Price Tracker - Complete Implementation

A complete, production-ready Market Price Tracking system with backend API and Android frontend for agricultural market price monitoring.

🚀 Features

Backend API (Node.js + Express)

• Live Data Integration: eNAM, AGMARKNET, Data.gov.in APIs
• Data Normalization: Unified format across different sources
• Caching: Redis + in-memory LRU cache
• Rate Limiting: Configurable delays between API calls
• Scheduled Refresh: Automatic updates every 24 hours
• Demo Mode: Fallback data when APIs unavailable
• Error Handling: Graceful degradation

Android App (Java + XML)

• Market Dashboard: Two stacked dashboards (Government Subsidy + Price Tracking)
• TabLayout + ViewPager2: Buy/Sell sections
• Buy Section: Existing categories (pesticides, seeds, fertilizers) + product grid
• Sell Section: State/crop selection, price cards, charts, refresh functionality
• Material UI: Modern design with CardViews, chips, icons
• WorkManager: Background refresh every 24 hours
• Demo Mode: Works without backend connection

📁 Project Structure

/
├── backend/                 # Node.js API server
│   ├── src/
│   │   ├── connectors/     # API connectors (eNAM, AGMARKNET, Data.gov.in)
│   │   ├── data/          # Demo data and mappings
│   │   ├── routes/        # API endpoints
│   │   ├── services/      # Business logic
│   │   └── utils/         # Utilities (cache, logger, scheduler)
│   ├── tests/             # Unit tests
│   ├── docker-compose.yml # Docker setup
│   └── README.md          # Backend documentation
├── app/                   # Android application
│   ├── src/main/
│   │   ├── java/         # Java source code
│   │   └── res/          # XML layouts and resources
│   └── build.gradle.kts  # Android build configuration
└── README.md             # This file

🛠️ Quick Start

Backend Setup

1. Install Dependencies

   cd backend
   npm install

2. Configure Environment

   cp env.example .env
   # Edit .env with your API keys

3. Run in Demo Mode

   npm run dev
   # Server runs on http://localhost:3000

Android Setup

1. Open in Android Studio

   • Import the project
   • Sync Gradle files
   • Build and run

2. Test the App

   • Navigate to Market tab
   • Switch between Buy/Sell tabs
   • Test price tracking in Sell tab

🔧 API Endpoints

Core Endpoints

• GET /api/states - List all states
• GET /api/states/:id/crops - Get crops for state
• GET /api/prices/local?state_id=&crop_id= - Local market prices
• GET /api/prices/government?crop_id= - Government MSP
• GET /api/prices/comparison?state_id=&crop_id= - Combined data

Demo Endpoints

• GET /api/demo - Demo data info
• GET /api/demo/prices/local?state_id=&crop_id= - Demo local prices
• GET /api/demo/prices/government?crop_id= - Demo government prices

📱 Android Components

Activities

• MarketActivity - Main market page with TabLayout + ViewPager2
• ProductDetailActivity - Product details (existing)

Fragments

• BuyFragment - Product categories and grid
• SellFragment - Price tracking dashboard

Services

• MarketPriceService - API communication
• WorkManager - Background refresh

Adapters

• ProductAdapter - Product grid
• CategoryAdapter - Category grid
• PriceHistoryAdapter - Price history chart

🎨 UI Features

Government Subsidy Dashboard

• Small card showing MSP info
• Subsidy information
• Quick reference data

Market Price Tracking Dashboard

• State selection dropdown
• Crop selection (state-dependent)
• Price display cards:
  • Local market prices (min, modal, max)
  • Government MSP
  • Absolute & percentage differences
  • Last updated timestamp
• Price history chart (7 days)
• Manual refresh button
• Auto-refresh every 24 hours

Material Design

• CardViews with elevation
• Rounded corners
• Color-coded price changes
• Responsive layouts
• Modern typography

🔌 API Integration

eNAM Integration

// Example connector usage
const enamConnector = require('./connectors/enamConnector');
const prices = await enamConnector.fetchPrices('Maharashtra', 'Tomato');

AGMARKNET Integration

// Example connector usage
const agmarkConnector = require('./connectors/agmarkConnector');
const prices = await agmarkConnector.fetchPrices('Maharashtra', 'Tomato');

Data.gov.in Integration

// Example connector usage
const datagovConnector = require('./connectors/datagovConnector');
const msp = await datagovConnector.fetchMSP('Tomato');

🧪 Testing

Backend Tests

cd backend
npm test

Manual API Testing

# Get states
curl "http://localhost:3000/api/states"

# Get prices
curl "http://localhost:3000/api/prices/comparison?state_id=maharashtra&crop_id=tomato"

Android Tests

• Unit tests for adapters and services
• Instrumentation tests for fragments
• UI tests for user interactions

🐳 Docker Support

Run with Docker Compose

cd backend
docker-compose up -d

This starts:

• Node.js API server
• Redis cache
• Scheduled price refresh

📊 Data Flow

1. Android App requests price data
2. Backend API checks cache first
3. If cache miss, calls external APIs (eNAM, AGMARKNET, Data.gov.in)
4. Normalization layer converts to unified format
5. Caching layer stores result
6. Android App displays formatted data
7. WorkManager refreshes data every 24 hours

🔐 Security & Configuration

API Keys Required

• eNAM API key (https://enam.gov.in)
• AGMARKNET API key (https://agmarknet.gov.in)
• Data.gov.in API key (https://data.gov.in)

Environment Variables

DEMO_MODE=true                    # Use demo data
REDIS_URL=redis://localhost:6379  # Redis connection
RATE_LIMIT_DELAY_MS=1000         # API rate limiting
CACHE_TTL_SECONDS=3600           # Cache TTL

🚀 Production Deployment

Backend

• Set NODE_ENV=production
• Configure Redis
• Add all API keys
• Use HTTPS
• Implement rate limiting

Android

• Sign APK for release
• Configure ProGuard
• Add crash reporting
• Performance monitoring

📈 Monitoring

Backend

• Health check endpoint
• API status monitoring
• Cache hit rates
• Error logging

Android

• Crash reporting
• Performance metrics
• User analytics
• Network monitoring

🤝 Contributing

1. Fork the repository
2. Create a feature branch
3. Add tests for new features
4. Submit a pull request

📄 License

MIT License - see LICENSE file for details.

🆘 Support

Common Issues

1. API Keys Not Working

   • Verify registration status
   • Check key format
   • Test with curl first

2. No Data Available

   • Enable demo mode
   • Check API endpoints
   • Verify state/crop names

3. Android Build Issues

   • Sync Gradle files
   • Check dependencies
   • Clean and rebuild

Debug Mode

• Backend: Set LOG_LEVEL=debug
• Android: Enable debug logging

📞 Contact

For questions or support, please open an issue in the repository.

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Note: This is a complete, production-ready implementation with both backend and Android components. The system works out-of-the-box in demo mode and can be easily configured for live API integration.