version: "3.8"

# ── Secrets never hardcoded. All from .env file (git-ignored). ────────────────
# Copy .env.example to .env and fill in values before running.

x-common-env: &common-env
  env_file: .env

services:

  # ── PostgreSQL ──────────────────────────────────────────────────────────────
  db:
    image: postgres:latest
    env_file: .env
    environment:
      POSTGRES_DB: ${POSTGRES_DB:-txndb}
      POSTGRES_USER: ${POSTGRES_USER:-txnuser}
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:?POSTGRES_PASSWORD must be set}
    volumes:
      - postgres_data:/var/lib/postgresql
      - ./infra/postgres/init.sql:/docker-entrypoint-initdb.d/init.sql:ro
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER:-txnuser} -d ${POSTGRES_DB:-txndb}"]
      interval: 5s
      timeout: 5s
      retries: 10
      start_period: 10s
    deploy:
      resources:
        limits:
          cpus: "1.0"
          memory: 512M
    restart: unless-stopped
    networks:
      - internal

  # ── Redis ───────────────────────────────────────────────────────────────────
  redis:
    image: redis:7-alpine
    command: >
      redis-server
      --requirepass ${REDIS_PASSWORD:?REDIS_PASSWORD must be set}
      --maxmemory 256mb
      --maxmemory-policy allkeys-lru
      --save ""
    healthcheck:
      test: ["CMD", "redis-cli", "-a", "${REDIS_PASSWORD}", "ping"]
      interval: 5s
      timeout: 3s
      retries: 10
    deploy:
      resources:
        limits:
          cpus: "0.5"
          memory: 300M
    restart: unless-stopped
    networks:
      - internal

  # ── API ─────────────────────────────────────────────────────────────────────
  api:
    build:
      context: .
      dockerfile: Dockerfile
      target: runtime
    <<: *common-env
    ports:
      - "8000:8000"
    volumes:
      - upload_data:/tmp/txn_uploads
    depends_on:
      db:
        condition: service_healthy   # waits for Postgres to accept connections
      redis:
        condition: service_healthy
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:8000/health"]
      interval: 10s
      timeout: 5s
      retries: 5
      start_period: 20s
    deploy:
      resources:
        limits:
          cpus: "1.0"
          memory: 512M
    restart: unless-stopped
    networks:
      - internal
      - external

  # ── Celery Worker (LLM queue) ────────────────────────────────────────────────
  worker:
    build:
      context: .
      dockerfile: Dockerfile
      target: runtime
    <<: *common-env
    command: >
      celery -A app.workers.celery_app.celery_app worker
      --loglevel=info
      --queues=llm,default
      --concurrency=4
      --max-tasks-per-child=100
    volumes:
      - upload_data:/tmp/txn_uploads
    depends_on:
      db:
        condition: service_healthy
      redis:
        condition: service_healthy
    healthcheck:
      test: ["CMD", "celery", "-A", "app.workers.celery_app.celery_app", "inspect", "ping"]
      interval: 30s
      timeout: 10s
      retries: 3
      start_period: 30s
    deploy:
      resources:
        limits:
          cpus: "2.0"
          memory: 1G
    restart: unless-stopped
    networks:
      - internal
      - external

  # ── Celery Beat (scheduled tasks) ────────────────────────────────────────────
  beat:
    build:
      context: .
      dockerfile: Dockerfile
      target: runtime
    <<: *common-env
    command: >
      celery -A app.workers.celery_app.celery_app beat
      --loglevel=info
    depends_on:
      redis:
        condition: service_healthy
    deploy:
      resources:
        limits:
          cpus: "0.25"
          memory: 128M
    restart: unless-stopped
    networks:
      - internal

  # ── Alembic migrations (init container pattern) ──────────────────────────────
  migrate:
    build:
      context: .
      dockerfile: Dockerfile
      target: runtime
    <<: *common-env
    command: alembic -c /app/alembic.ini upgrade head
    depends_on:
      db:
        condition: service_healthy
    restart: "no"   # run once and exit
    networks:
      - internal

volumes:
  postgres_data:
  upload_data:

networks:
  internal:
    driver: bridge
    internal: true   # DB and Redis not reachable from host
  external:
    driver: bridge   # Only API is on external network