services:
  # The PostgreSQL Database Service
  db:
    image: postgis/postgis:16-3.4-alpine
    container_name: movie_db
    # Load database credentials from the .env file.
    env_file:
      - .env
    environment:
      - POSTGRES_USER=${POSTGRES_USER}
      - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
      - POSTGRES_DB=${POSTGRES_DB}
    ports:
      # Expose the port to the host for optional direct access/debugging.
      - "5432:5432"
    volumes:
      # Persist database data on the host machine.
      - postgres-data:/var/lib/postgresql/data
    # The healthcheck ensures the 'api' service doesn't start until
    # the database is ready to accept connections. This is a critical requirement.
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER} -d ${POSTGRES_DB}"]
      interval: 10s
      timeout: 5s
      retries: 5
      start_period: 10s

  # The Go API Service
  api:
    # Build the image from the Dockerfile in the current directory.
    build: .
    container_name: movie_api
    # Load all application configuration from the .env file.
    env_file:
      - .env
    # Ensure the process runs with /app as the working directory so
    # relative path loading of .env (by the application) works.
    working_dir: /app
    # Mount the local .env into the container so the app can open it
    # (env_file injects variables but does not create the file on disk).
    volumes:
      - ./.env:/app/.env:ro
    ports:
      # Map the host port to the container port. Uses the PORT from .env.
      - "${PORT}:${PORT}"
    # This ensures the 'api' service starts only after the 'db' service is healthy.
    depends_on:
      db:
        condition: service_healthy
    healthcheck:
      test: ["CMD-SHELL", "curl -f http://localhost:${PORT}/healthz || exit 1"]
      interval: 5s
      timeout: 3s
      retries: 5
      start_period: 5s

# Define the named volume for data persistence.
volumes:
  postgres-data: