version: '3.8'

services:
  # --- 1. Spring API Service (Backend) ---
  spring-api:
    build:
      context: ./backend # Path to your Spring project's root folder
      dockerfile: Dockerfile # Assumes you have a Dockerfile in ./backend
    container_name: spring-api
    ports:
      - "8080:8080" # Map host port 8080 to container port 8080
    environment:
      # These environment variables link the API to the database service defined below
      - SPRING_DATASOURCE_URL=jdbc:postgresql://db:5432/mydatabase
      - SPRING_DATASOURCE_USERNAME=myuser
      - SPRING_DATASOURCE_PASSWORD=mypassword
    depends_on:
      - db
    networks:
      - app-network

  # --- 2. Next.js App Service (Frontend) ---
  nextjs-app:
    build:
      context: ./frontend # Path to your Next.js project's root folder
      dockerfile: Dockerfile # Assumes you have a Dockerfile in ./frontend
    container_name: nextjs-app
    ports:
      - "3000:3000" # Map host port 3000 to container port 3000
    environment:
      # This variable is crucial: Next.js needs the URL for the Spring API
      # Use the Docker internal service name 'spring-api' and its port 8080
      - NEXT_PUBLIC_API_URL=http://spring-api:8080
      # For local testing, you might need the host IP for Next.js to call back
      # - NEXT_PUBLIC_API_URL_LOCAL=http://localhost:8080
    depends_on:
      - spring-api
    networks:
      - app-network

  # --- 3. PostgreSQL Database Service (Example Dependency) ---
  db:
    image: postgres:15-alpine # Lightweight and stable PostgreSQL image
    container_name: postgres-db
    environment:
      - POSTGRES_DB=mydatabase
      - POSTGRES_USER=myuser
      - POSTGRES_PASSWORD=mypassword
    volumes:
      - postgres_data:/var/lib/postgresql/data # Persist the database data
    ports:
      - "5432:5432" # Optional: Map DB port for external access (e.g., DBeaver)
    networks:
      - app-network

# --- Docker Volume for Persistent Data ---
volumes:
  postgres_data:

# --- Docker Network for Inter-Container Communication ---
networks:
  app-network:
    driver: bridge