version: '3.8'

services:
  # ==================== BACKEND API - Scalable Workers ====================
  backend:
    build:
      context: .
      dockerfile: Dockerfile
    restart: unless-stopped
    env_file:
      - .env
    # environment:
    #   # Core Settings
    #   - NODE_ENV=${NODE_ENV:-production}
    #   - PORT=${PORT:-3000}
    #   - API_PREFIX=${API_PREFIX:-/api}
      
    #   # Database (Cloud MongoDB Atlas)
    #   - MONGODB_URL=${MONGODB_URL}
      
    #   # Redis (Cloud Redis Labs)
    #   - REDIS_URL=${REDIS_URL}
      
    #   # JWT
    #   - JWT_SECRET=${JWT_SECRET}
      
    #   # Email
    #   - EMAIL_SERVICE=gmail
    #   - EMAIL_USER=${EMAIL_USER}
    #   - EMAIL_PASS=${EMAIL_APP_PASSWORD}
      
    #   # Frontend & CORS
    #   - ALLOWED_ORIGINS=${ALLOWED_ORIGINS}
    #   - FRONTEND_URL=${FRONTEND_URL}
      
    #   # Cloudinary
    #   - CLOUDINARY_API_KEY=${CLOUDINARY_API_KEY}
    #   - CLOUDINARY_API_SECRET=${CLOUDINARY_API_SECRET}
    #   - CLOUDINARY_CLOUD_NAME=${CLOUDINARY_CLOUD_NAME}
      
    #   # Google OAuth
    #   - GOOGLE_CLIENT_ID=${GOOGLE_CLIENT_ID}
    #   - GOOGLE_CLIENT_SECRET=${GOOGLE_CLIENT_SECRET}
      
    #   # Razorpay
    #   - RZP_KEY_ID=${RZP_KEY_ID}
    #   - RZP_KEY_SECRET=${RZP_KEY_SECRET}
      
    #   # AI API
    #   - VERMARJUN_API_KEY=${VERMARJUN_API_KEY}
    #   - VERMARJUN_BASE_URL=${VERMARJUN_BASE_URL}
    #   - VERMARJUN_MODEL_NAME=${VERMARJUN_MODEL_NAME}
      
    #   # Microservice
    #   - MICROSERVICE_URL=${MICROSERVICE_URL}
    
    healthcheck:
      test: ["CMD", "node", "-e", "require('http').get('http://localhost:3000${API_PREFIX}/health', (r) => { process.exit(r.statusCode === 200 ? 0 : 1) })"]
      interval: 30s
      timeout: 10s
      retries: 3
      start_period: 40s
    
    networks:
      - backend-network
    
    # Resource limits (adjust based on your needs)
    deploy:
      resources:
        limits:
          cpus: '0.5'
          memory: 512M
        reservations:
          cpus: '0.25'
          memory: 256M

  # ==================== NGINX - Load Balancer ====================
  nginx:
    image: nginx:alpine
    container_name: nginx
    restart: unless-stopped
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
      - ./nginx-logs:/var/log/nginx
    depends_on:
      - backend
    healthcheck:
      test: ["CMD", "wget", "--quiet", "--tries=1", "--spider", "http://localhost/api/health"]
      interval: 30s
      timeout: 10s
      retries: 3
    networks:
      - backend-network

# ==================== NETWORKS ====================
networks:
  backend-network:
    driver: bridge

# ============================================================================
# USAGE COMMANDS:
# ============================================================================
# Start with 4 backend workers:
#   docker-compose up -d --build --scale backend=4
#
# Scale to 8 workers:
#   docker-compose up -d --scale backend=8
#
# Scale down to 2 workers:
#   docker-compose up -d --scale backend=2
#
# View logs:
#   docker-compose logs -f backend
#
# View all services:
#   docker-compose ps
#
# Stop all services:
#   docker-compose down
#
# Rebuild backend after code changes:
#   docker-compose build backend
#   docker-compose up -d --scale backend=4
#
# Test health endpoint:
#   curl http://localhost/api/health
#
# Test load balancing:
#   for i in {1..20}; do curl -s http://localhost/api/health | jq -r '.instance'; done
# ============================================================================