# Example docker-compose for running the Spanglish API as multiple replicas
# behind nginx, with Redis for shared state and Postgres as the database.
#
# This is a starting point, not a turnkey production setup. It expects a
# Dockerfile at backend/Dockerfile that builds the API and runs it on PORT.
#
# Bring it up with N API replicas:
#   docker compose -f deploy/docker-compose.scale.yml up --build --scale api=3
#
# No em dashes are used in this file by design.

services:
  postgres:
    image: postgres:16-alpine
    environment:
      POSTGRES_USER: spanglish
      POSTGRES_PASSWORD: spanglish
      POSTGRES_DB: spanglish
    # Raise max_connections if DB_POOL_MAX * replicas approaches the default 100.
    command: ["postgres", "-c", "max_connections=200"]
    volumes:
      - pgdata:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U spanglish"]
      interval: 5s
      timeout: 3s
      retries: 10

  redis:
    image: redis:7-alpine
    # noeviction is deliberate: rate-limit, lock, and lockout keys must never
    # be evicted for correctness. The cache workload is a single short-TTL key,
    # so memory pressure is negligible; if caching ever grows, revisit this or
    # move the cache to its own DB index.
    command:
      [
        "redis-server",
        "--appendonly", "yes",
        "--requirepass", "${REDIS_PASSWORD:-change-me-redis-password}",
        "--maxmemory", "256mb",
        "--maxmemory-policy", "noeviction",
      ]
    environment:
      REDISCLI_AUTH: "${REDIS_PASSWORD:-change-me-redis-password}"
    volumes:
      - redisdata:/data
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 5s
      timeout: 3s
      retries: 10

  api:
    build:
      context: ../backend
    environment:
      NODE_ENV: production
      PORT: "3001"
      DB_TYPE: postgres
      DATABASE_URL: postgresql://spanglish:spanglish@postgres:5432/spanglish
      DB_POOL_MAX: "15"
      REDIS_URL: "redis://:${REDIS_PASSWORD:-change-me-redis-password}@redis:6379"
      JWT_SECRET: change-me-to-a-strong-secret
      FRONTEND_URL: http://localhost:8080
      # Optional S3-compatible storage so uploads are shared across replicas.
      # If you omit these, mount a shared volume at /app/uploads on every replica.
      # S3_ENDPOINT: http://garage:3900
      # S3_REGION: garage
      # S3_BUCKET: spanglish-media
      # S3_ACCESS_KEY_ID: ""
      # S3_SECRET_ACCESS_KEY: ""
      # S3_PUBLIC_URL: http://localhost:8080/media
    expose:
      - "3001"
    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_healthy

  # Load balancer across the scaled api replicas. nginx resolves the "api"
  # service name via Docker's embedded DNS, which round-robins across replicas.
  lb:
    image: nginx:alpine
    ports:
      - "8080:80"
    volumes:
      - ./nginx.scale.conf:/etc/nginx/conf.d/default.conf:ro
    depends_on:
      - api

volumes:
  pgdata:
  redisdata: