# Thermograph production stack: backend (FastAPI/API + TestClient(app.py)),
# frontend (the SSR content service), and TimescaleDB (PostgreSQL 18).
#
# Repo-split Stage 4: backend and frontend are two containers built from the
# SAME image (THERMOGRAPH_SERVICE_ROLE picks which process runs -- see
# Dockerfile/deploy/entrypoint.sh), not one "app" service anymore. Both get
# their own loopback-published port since prod/beta's host Caddy path-splits
# directly to each; backend also gets a reverse-proxy fallback to frontend
# (THERMOGRAPH_FRONTEND_BASE_INTERNAL) for any environment with no Caddy in
# front (LAN dev, bare-metal run.sh) -- see backend/web/app.py's
# _proxy_to_frontend and the repo-split plan's Stage 4 section.
#
#   docker compose up -d --build      # or: make up
#
# POSTGRES_PASSWORD must be set at `docker compose` time — compose reads it from
# the repo-root .env for local runs (copy .env.example -> .env), and in prod the
# systemd unit's EnvironmentFile=/etc/thermograph.env puts it in the environment
# so `docker compose up` can interpolate it. It is used BOTH to initialize the db
# container and to build backend's THERMOGRAPH_DATABASE_URL below.

services:
  db:
    # TimescaleDB on PostgreSQL 18 (the stock image already sets
    # shared_preload_libraries=timescaledb). The app's climate record — the full
    # daily archive and the hourly recent+forecast bundle — lives in hypertables
    # here (see backend/data/climate_store.py), so the DB, not the filesystem, is the
    # source of truth. The init script CREATE EXTENSIONs timescaledb on a fresh volume
    # (Alembic also does, idempotently, at app boot).
    #
    # TIMESCALEDB_TAG defaults to the floating latest-pg18 tag (today's behavior,
    # unchanged) so a plain `docker compose up` keeps working with no setup. Pin it
    # to an exact minor (e.g. 2.17.2-pg18) before any host of this stack could ever
    # replicate with another — a floating tag risks two hosts landing on different
    # extension minors, which blocks a physical replica and risks compressed-chunk
    # corruption on restore. docker-stack.yml (the Swarm interim stack) REQUIRES an
    # exact pin for exactly this reason; use the SAME tag on both once you set one.
    image: timescale/timescaledb:${TIMESCALEDB_TAG:-latest-pg18}
    environment:
      POSTGRES_USER: thermograph
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:?set POSTGRES_PASSWORD}
      POSTGRES_DB: thermograph
      # The init tuning script (deploy/db/init/20-tuning.sh) scales the Postgres +
      # DuckDB memory GUCs from this budget, matching the mem_limit below. One knob
      # per host: Terraform sets DB_MEMORY (prod 16g), local/beta default 8g.
      DB_MEMORY: ${DB_MEMORY:-8g}
    volumes:
      # Mount the volume at the PARENT of the data dir and let the image pick its own
      # PGDATA subdir under it (the timescaledb image defaults to
      # /var/lib/postgresql/data). Pinning PGDATA directly at the mountpoint trips an
      # initdb chmod on some Docker setups; the whole tree still persists this way.
      - pgdata:/var/lib/postgresql
      - ./deploy/db/init:/docker-entrypoint-initdb.d
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U thermograph -d thermograph"]
      interval: 5s
      timeout: 5s
      retries: 10
    # Give Postgres room to cache + process. mem_limit is the hard ceiling; the actual
    # budget is tuned in deploy/db/init/20-tuning.sh, which scales shared_buffers (25%),
    # effective_cache_size (75%), work_mem and maintenance_work_mem from DB_MEMORY — so
    # raising DB_MEMORY raises both the cap and the tuning together. shm_size backs
    # parallel-query shared memory (the 64MB docker default is
    # too small once shared_buffers/parallelism grow).
    # Sized via env (Terraform sets DB_CPUS/DB_MEMORY per host); defaults match the
    # historical 2 CPU / 8 GB budget so a plain `docker compose up` is unchanged.
    mem_limit: ${DB_MEMORY:-8g}
    shm_size: 1gb
    # Cap the DB at DB_CPUS CPUs. Compose v2 honors the top-level `cpus:`; the
    # deploy.resources block is the Swarm-style equivalent, kept for parity.
    cpus: ${DB_CPUS:-2}
    deploy:
      resources:
        limits:
          cpus: "${DB_CPUS:-2}"
          # Must match mem_limit above (compose rejects distinct values).
          memory: ${DB_MEMORY:-8g}
    restart: unless-stopped
    # No host port on purpose: the app reaches Postgres as db:5432 on the
    # compose network. Nothing outside the stack should touch the database.

  backend:
    build: .
    # Named so `docker compose pull` can fetch a prebuilt tag instead of
    # `--build`ing in place (repo-split Stage 6's registry-pull cutover --
    # deploy.sh/Terraform set IMAGE_TAG to the SHA build-push.yml just pushed
    # for the branch being deployed). Harmless default for local/CI
    # `--build` usage, which never needs to resolve this against the
    # registry -- `build:` + `image:` together just tag the local build.
    image: ${REGISTRY_HOST:-git.thermograph.org}/${IMAGE_PATH:-emi/thermograph/app}:${IMAGE_TAG:-local}
    depends_on:
      db:
        condition: service_healthy
    environment:
      # Built from POSTGRES_PASSWORD; this `environment` value wins over anything
      # in env_file, so the URL always matches the db container's password.
      THERMOGRAPH_DATABASE_URL: postgresql+asyncpg://thermograph:${POSTGRES_PASSWORD}@db:5432/thermograph
      THERMOGRAPH_BASE: /
      PORT: 8137
      THERMOGRAPH_SERVICE_ROLE: backend
      # Docker's built-in service-name DNS -- reachable only inside the compose
      # network. See backend/web/app.py's _proxy_to_frontend.
      THERMOGRAPH_FRONTEND_BASE_INTERNAL: http://frontend:8080
      # Worker count is env-driven so Terraform can raise it on a bigger host;
      # defaults to 4 to keep a plain `docker compose up` identical to before.
      WORKERS: ${WORKERS:-4}
      # One worker wins this lock and runs the subscription notifier / homepage
      # sweep; it lives on the appdata volume so it's shared across workers.
      THERMOGRAPH_SINGLETON_LOCK: /app/data/notifier.lock
    # Prod secrets live in /etc/thermograph.env: POSTGRES_PASSWORD,
    # THERMOGRAPH_AUTH_SECRET, THERMOGRAPH_VAPID_PRIVATE_KEY/_PUBLIC_KEY,
    # THERMOGRAPH_COOKIE_SECURE=1, mail/Discord keys, ... (see
    # deploy/thermograph.env.example). `required: false` so local `docker compose
    # up` works without that file — it reads POSTGRES_PASSWORD from repo-root .env.
    env_file:
      - path: /etc/thermograph.env
        required: false
    volumes:
      # Parquet cache, notifier.lock, homepage.json, vapid.json persist here.
      - appdata:/app/data
      - applogs:/app/logs
    # No compose-level healthcheck override -- the image's own Dockerfile
    # HEALTHCHECK (port-aware via ${PORT}) already covers this, and frontend's
    # depends_on below reads it the same way.
    # Sized via env (Terraform sets APP_CPUS per host); defaults to 4 CPUs. The
    # deploy.resources block mirrors the top-level `cpus:` for Swarm parity; the
    # dev overlay drops both so dev runs uncapped.
    cpus: ${APP_CPUS:-4}
    deploy:
      resources:
        limits:
          cpus: "${APP_CPUS:-4}"
    ports:
      # Loopback only — host Caddy terminates TLS and reverse-proxies to this
      # (and, in prod/beta, directly to frontend's own port below too).
      - "127.0.0.1:8137:8137"
    restart: unless-stopped

  frontend:
    build: .
    # Same image as backend (see backend's `image:` comment above) --
    # THERMOGRAPH_SERVICE_ROLE below is what picks the process.
    image: ${REGISTRY_HOST:-git.thermograph.org}/${IMAGE_PATH:-emi/thermograph/app}:${IMAGE_TAG:-local}
    # Its own register() fetches the IndexNow key from backend at boot -- must
    # wait for a real, healthy backend, not just a started container.
    depends_on:
      backend:
        condition: service_healthy
    environment:
      THERMOGRAPH_BASE: /
      PORT: 8080
      THERMOGRAPH_SERVICE_ROLE: frontend
      THERMOGRAPH_API_BASE_INTERNAL: http://backend:8137
    # No volumes -- stateless, holds no data of its own.
    cpus: ${FRONTEND_CPUS:-2}
    deploy:
      resources:
        limits:
          cpus: "${FRONTEND_CPUS:-2}"
    ports:
      - "127.0.0.1:8080:8080"
    restart: unless-stopped

volumes:
  pgdata: {}
  appdata: {}
  applogs: {}