Weather App 🌤️

A weather application built with Go and Next.js that provides real-time weather data for Indian cities. Available as both a web application and CLI tool.

🌐 Web Version (v1.0)

Modern web application with Go backend and Next.js frontend.

Features

• 🎨 Modern UI: Clean, responsive design with dark mode support
• 🌡️ Real-time Weather: Temperature (°C/°F toggle), humidity, precipitation
• ⭐ Favorites: Save up to 5 cities with localStorage persistence
• 🔄 Live Updates: Weather data refreshes every 15 minutes
• ⚡ Redis Caching: Fast response times (~2ms vs ~500ms) with 15-minute cache
• 🏙️ Indian Cities: Comprehensive coverage of Indian metropolitan areas

Quick Start

Backend (Go Server)

# Optional: Start Redis for caching (improves performance)
redis-server

# Start the API server
go run server/main.go

# Server runs on http://localhost:8080

Note: Redis is optional. The server works without it but responses will be slower (when scaled).

Frontend (Next.js)

# Install dependencies
cd frontend
npm install

# Start development server
npm run dev

# Open http://localhost:3000

Project Structure

weather-cli/
├── server/                      # Go HTTP API server
│   ├── main.go
│   ├── pkg/                     # Shared Go packages
│   │   ├── cache/              # Redis caching layer
│   │   └── weather/            # Weather API client
│   └── REDIS_CACHING_GUIDE.md  # Caching implementation guide
├── frontend/                    # Next.js web application
│   ├── src/
│   │   ├── app/                # Next.js pages
│   │   ├── components/         # React components
│   │   ├── hooks/              # Custom React hooks (useFavourites)
│   │   └── types/              # TypeScript definitions
│   └── package.json
├── locations/                   # City coordinates database
│   └── cities.json
└── weather_codes/               # Weather descriptions
    └── data.json

API Endpoints

• GET /weather?city={city} - Get weather for a city

Example:

curl "http://localhost:8080/weather?city=chennai"

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💻 CLI Version (v0)

Simple command-line interface for quick weather checks.

Quick Start

cd cli
go run .

Full CLI documentation: cli/README.md

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🌍 Supported Cities

Major Indian cities including Chennai, Mumbai, Delhi, Bangalore, Hyderabad, Kolkata, Pune, Coimbatore, and more. See locations/cities.json for the complete list.

Adding New Cities

Edit locations/cities.json:

{
  "cityname": {
    "lat": 12.34,
    "lon": 56.78
  }
}

🔧 Technical Stack

Backend

• Language: Go 1.19+
• API: Open-Meteo (free, no API key required)
• Server: Native Go HTTP server with CORS
• Cache: Redis (optional, for performance optimization)
• Dependencies: github.com/redis/go-redis/v9

Frontend

• Framework: Next.js 14+ (React)
• Language: TypeScript
• Styling: Tailwind CSS
• UI Components: shadcn/ui
• State: React hooks (useState, useEffect)

📝 Environment Variables

Optional configuration for the backend server:

# Redis Configuration (optional - defaults to localhost:6379)
export REDIS_ADDR="localhost:6379"
export REDIS_PASSWORD=""  # Leave empty if no password

# Start the server
go run server/main.go

Redis Caching Benefits:

• ⚡ 250x faster responses (2ms vs 500ms)
• 💰 Reduced API calls to Open-Meteo
• 🛡️ Graceful degradation - works without Redis

🚀 Development

Backend Development

# Optional: Start Redis for development
redis-server

# Run server with auto-reload (using air)
cd server
air

# Or run directly
go run server/main.go

For detailed Redis setup and caching architecture, see server/REDIS_CACHING_GUIDE.md

Frontend Development

cd frontend
npm run dev

Building for Production

# Backend
go build -o weather-server server/main.go

# Frontend
cd frontend
npm run build
npm start

📄 License

This project is open source and available under the MIT License.

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Built with ❤️ using Go and Next.js