services:
  db:
    image: postgres:16-alpine
    restart: unless-stopped
    environment:
      POSTGRES_USER: ${POSTGRES_USER}
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
      POSTGRES_DB: ${POSTGRES_DB}
    volumes:
      # Local filesystem bind mount, not a named Docker volume.
      - ./data/postgres:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER} -d ${POSTGRES_DB}"]
      interval: 5s
      timeout: 5s
      retries: 10

  app:
    build:
      context: .
      dockerfile: Dockerfile
    restart: unless-stopped
    depends_on:
      db:
        condition: service_healthy
    environment:
      # Points at the "db" service by its compose network name -- distinct
      # from the .env's localhost URL used for host-side `npm run dev`.
      DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@db:5432/${POSTGRES_DB}?schema=public
      AUTH_SECRET: ${AUTH_SECRET}
      NODE_ENV: production
    ports:
      # Host-side port only -- the container itself always listens on
      # 3000 internally (see Dockerfile's EXPOSE). Defaults to 3000 if
      # APP_PORT isn't set.
      - "${APP_PORT:-3000}:3000"