services:
  # PostgreSQL - Primary database
  postgres:
    image: postgres:16-alpine
    environment:
      POSTGRES_USER: urlshortner
      POSTGRES_PASSWORD: localdev
      POSTGRES_DB: urlshortner
    ports:
      - "5432:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data
      - ./db/init.sql:/docker-entrypoint-initdb.d/init.sql
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U urlshortner"]
      interval: 5s
      timeout: 5s
      retries: 5

  # Redis - Caching layer
  redis:
    image: redis:7-alpine
    ports:
      - "6379:6379"
    volumes:
      - redis_data:/data
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 5s
      timeout: 5s
      retries: 5

  # API Server (can scale with --scale api=3)
  api:
    build:
      context: .
      dockerfile: Dockerfile
    environment:
      DATABASE_URL: postgresql://urlshortner:localdev@postgres:5432/urlshortner
      REDIS_URL: redis://redis:6379
      MACHINE_ID: 1
    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_healthy
    ports:
      - "8000"  # Random port mapping for scaling

  # Nginx - Load balancer
  nginx:
    image: nginx:alpine
    ports:
      - "80:80"
    volumes:
      - ./nginx/nginx.conf:/etc/nginx/nginx.conf:ro
    depends_on:
      - api

volumes:
  postgres_data:
  redis_data: