notify-bridge/packages/server/src/notify_bridge_server/services/watcher.py

"""Watcher service — orchestrates poll -> detect -> notify flow."""

from __future__ import annotations

import asyncio
import logging
from typing import Any

from sqlmodel import select
from sqlmodel.ext.asyncio.session import AsyncSession

from notify_bridge_core.models.events import ServiceEvent
from notify_bridge_core.notifications.dispatcher import NotificationDispatcher, TargetConfig
from notify_bridge_core.notifications.telegram.cache import TelegramFileCache
from notify_bridge_core.storage import JsonFileBackend

from ..database.engine import get_engine
from ..database.models import (
    EventLog,
    NotificationTracker,
    NotificationTrackerState,
    ServiceProvider,
)
from .dispatch_helpers import (
    apply_tracking_display_filters,
    event_allowed_by_config,
    get_app_timezone,
    load_link_data,
)

_LOGGER = logging.getLogger(__name__)

# Module-level Telegram file caches — shared across dispatches for reuse
_url_cache: TelegramFileCache | None = None
_asset_cache: TelegramFileCache | None = None
_cache_lock = asyncio.Lock()


async def _load_cache_settings() -> tuple[int, int]:
    """Return (url_ttl_seconds, asset_max_entries) from app settings.

    Defaults apply when the settings rows are missing. Reads in a short-lived
    session to avoid coupling to the caller's transaction.
    """
    from ..api.app_settings import get_setting
    async with AsyncSession(get_engine()) as session:
        ttl_hours_str = await get_setting(session, "telegram_cache_ttl_hours")
        max_entries_str = await get_setting(session, "telegram_asset_cache_max_entries")
    try:
        ttl_hours = int(ttl_hours_str) if ttl_hours_str else 720
    except ValueError:
        ttl_hours = 720
    try:
        max_entries = int(max_entries_str) if max_entries_str else 5000
    except ValueError:
        max_entries = 5000
    return ttl_hours * 3600, max_entries


async def _get_telegram_caches() -> tuple[TelegramFileCache | None, TelegramFileCache | None]:
    """Lazily initialize shared Telegram file caches using NOTIFY_BRIDGE_DATA_DIR.

    The URL cache runs in TTL mode (URLs aren't content-addressable); the asset
    cache runs in thumbhash mode so entries invalidate on visual change rather
    than age. Both honor an LRU size cap from settings.
    """
    global _url_cache, _asset_cache
    if _url_cache is not None:
        return _url_cache, _asset_cache
    async with _cache_lock:
        # Double-check after acquiring lock
        if _url_cache is not None:
            return _url_cache, _asset_cache
        import os
        from pathlib import Path
        data_dir = os.environ.get("NOTIFY_BRIDGE_DATA_DIR")
        if not data_dir:
            return None, None
        cache_dir = Path(data_dir) / "cache"
        ttl_seconds, max_entries = await _load_cache_settings()
        url_cache = TelegramFileCache(
            JsonFileBackend(cache_dir / "telegram_url_cache.json"),
            ttl_seconds=ttl_seconds,
            max_entries=max_entries,
        )
        asset_cache = TelegramFileCache(
            JsonFileBackend(cache_dir / "telegram_asset_cache.json"),
            use_thumbhash=True,
            max_entries=max_entries,
        )
        await url_cache.async_load()
        await asset_cache.async_load()
        _url_cache = url_cache
        _asset_cache = asset_cache
        _LOGGER.info(
            "Initialized Telegram caches in %s (url ttl=%ds, max_entries=%d, asset thumbhash mode)",
            cache_dir, ttl_seconds, max_entries,
        )
        return _url_cache, _asset_cache


async def reset_telegram_caches_in_memory() -> None:
    """Drop in-memory cache refs without touching files on disk.

    Used after settings changes so the next dispatch re-initializes caches
    with fresh parameters. Contrast with ``clear_telegram_caches`` which also
    deletes cached file_ids.
    """
    global _url_cache, _asset_cache
    async with _cache_lock:
        _url_cache = None
        _asset_cache = None
        _LOGGER.info("Reset Telegram cache refs in memory (files preserved)")


async def get_telegram_cache_stats() -> dict[str, Any]:
    """Return stats for the URL and asset Telegram caches.

    Loads caches lazily if they haven't been touched by a dispatch yet.
    Returns zero-counts when ``NOTIFY_BRIDGE_DATA_DIR`` is not configured.
    """
    url_cache, asset_cache = await _get_telegram_caches()
    empty = {"count": 0, "total_size_bytes": 0, "oldest": None, "newest": None}
    return {
        "url": url_cache.stats() if url_cache else empty,
        "asset": asset_cache.stats() if asset_cache else empty,
    }


async def clear_telegram_caches() -> dict[str, Any]:
    """Delete both Telegram file caches from disk and reset in-memory state.

    Next dispatch re-initializes the caches via `_get_telegram_caches()`.
    Returns a summary with the paths that were removed.
    """
    global _url_cache, _asset_cache
    async with _cache_lock:
        removed: list[str] = []
        for cache, label in ((_url_cache, "url"), (_asset_cache, "asset")):
            if cache is not None:
                await cache.async_remove()
                removed.append(label)

        # Also remove files from disk in case caches were never initialized
        # in this process (data_dir set but dispatch never ran).
        import os
        from pathlib import Path
        data_dir = os.environ.get("NOTIFY_BRIDGE_DATA_DIR")
        if data_dir:
            cache_dir = Path(data_dir) / "cache"
            for name in ("telegram_url_cache.json", "telegram_asset_cache.json"):
                path = cache_dir / name
                if path.exists():
                    try:
                        path.unlink()
                    except OSError as e:
                        _LOGGER.warning("Failed to remove %s: %s", path, e)

        _url_cache = None
        _asset_cache = None
        _LOGGER.info("Cleared Telegram file caches: %s", removed or "none in memory")
        return {"cleared": True, "removed": removed}


async def check_tracker(tracker_id: int) -> dict[str, Any]:
    """Poll a tracker's provider for changes and dispatch notifications."""
    engine = get_engine()

    # Load all DB data eagerly before entering aiohttp context
    async with AsyncSession(engine) as session:
        tracker = await session.get(NotificationTracker, tracker_id)
        if not tracker or not tracker.enabled:
            return {"status": "skipped", "reason": "disabled or not found"}

        provider = await session.get(ServiceProvider, tracker.provider_id)
        if not provider:
            return {"status": "error", "reason": "provider not found"}

        # Load tracker state
        result = await session.exec(
            select(NotificationTrackerState).where(NotificationTrackerState.tracker_id == tracker_id)
        )
        states = result.all()
        state_dict: dict[str, Any] = {}
        for s in states:
            state_dict[s.collection_id] = {
                "name": s.collection_name or "",
                "asset_ids": s.asset_ids,
                "pending_asset_ids": s.pending_asset_ids,
                "shared": bool(s.shared),
                "meta_fingerprint": s.meta_fingerprint or {},
            }

        # Snapshot the original fingerprint per collection so we can skip the
        # (expensive) asset_ids rewrite when nothing changed. For a 200k-asset
        # album this avoids a ~7 MB JSON write to the state row every tick.
        original_fingerprints: dict[str, dict[str, Any]] = {
            cid: dict(cstate.get("meta_fingerprint") or {})
            for cid, cstate in state_dict.items()
        }

        # Load tracker-target links
        link_data = await load_link_data(session, tracker_id)

        # Load app-level timezone for quiet-hours evaluation.
        app_tz = await get_app_timezone(session)

        # Snapshot the data we need
        provider_type = provider.type
        provider_config = dict(provider.config)
        provider_name = provider.name
        tracker_name = tracker.name
        tracker_filters = dict(tracker.filters) if tracker.filters else {}
        collection_ids = list(tracker.collection_ids or [])

    # Now create aiohttp session and poll
    events: list[ServiceEvent] = []
    new_state: dict[str, Any] = {}

    if provider_type == "immich":
        from notify_bridge_core.providers.immich import ImmichServiceProvider
        from .http_session import get_http_session
        http_session = await get_http_session()
        immich = ImmichServiceProvider(
            http_session,
            provider_config.get("url", ""),
            provider_config.get("api_key", ""),
            provider_config.get("external_domain"),
            provider_name,
        )
        connected = await immich.connect()
        if not connected:
            return {"status": "error", "reason": "failed to connect to provider"}

        events, new_state = await immich.poll(collection_ids, state_dict)
    elif provider_type == "gitea":
        # Gitea is webhook-based — events arrive via /api/webhooks/gitea endpoint.
        # The scheduler still calls check_tracker but there's nothing to poll.
        return {"status": "ok", "events_detected": 0, "collections_checked": 0}
    elif provider_type == "planka":
        # Planka is webhook-based — events arrive via /api/webhooks/planka endpoint.
        return {"status": "ok", "events_detected": 0, "collections_checked": 0}
    elif provider_type == "scheduler":
        from notify_bridge_core.providers.scheduler import SchedulerServiceProvider
        custom_vars = tracker_filters.get("custom_variables", {})
        sched = SchedulerServiceProvider(
            name=provider_name,
            tracker_name=tracker_name,
            custom_variables=custom_vars,
            timezone_name=app_tz,
        )
        events, new_state = await sched.poll(collection_ids, state_dict)
    elif provider_type == "nut":
        from notify_bridge_core.providers.nut import NutServiceProvider
        nut = NutServiceProvider(
            host=provider_config.get("host", "localhost"),
            port=provider_config.get("port", 3493),
            username=provider_config.get("username"),
            password=provider_config.get("password"),
            name=provider_name,
        )
        events, new_state = await nut.poll(collection_ids, state_dict)
    elif provider_type == "google_photos":
        from notify_bridge_core.providers.google_photos import GooglePhotosServiceProvider
        from .http_session import get_http_session
        http_session = await get_http_session()
        gp = GooglePhotosServiceProvider(
            http_session,
            provider_config.get("client_id", ""),
            provider_config.get("client_secret", ""),
            provider_config.get("refresh_token", ""),
            provider_name,
        )
        connected = await gp.connect()
        if not connected:
            return {"status": "error", "reason": "failed to connect to Google Photos"}
        events, new_state = await gp.poll(collection_ids, state_dict)
    elif provider_type == "webhook":
        # Webhook providers receive events via inbound HTTP; no polling needed.
        return {"status": "ok", "events_detected": 0, "collections_checked": 0}
    else:
        return {"status": "error", "reason": f"unsupported provider type: {provider_type}"}

    # Save updated state and log events
    async with AsyncSession(engine) as session:
        for cid, cstate in new_state.items():
            existing = None
            for s in states:
                if s.collection_id == cid:
                    existing = s
                    break

            current_fingerprint = dict(cstate.get("meta_fingerprint") or {})
            prior_fingerprint = original_fingerprints.get(cid, {})
            # Skip the DB update when the provider reported no meaningful
            # change. ``existing`` is None on first-ever fetch for a
            # collection — that path always writes so the row gets created.
            if existing is not None and current_fingerprint == prior_fingerprint:
                continue

            if existing:
                existing.asset_ids = cstate.get("asset_ids", [])
                existing.pending_asset_ids = cstate.get("pending_asset_ids", [])
                existing.collection_name = cstate.get("name", "")
                existing.shared = cstate.get("shared", False)
                existing.meta_fingerprint = current_fingerprint
                session.add(existing)
            else:
                new_ts = NotificationTrackerState(
                    tracker_id=tracker_id,
                    collection_id=cid,
                    collection_name=cstate.get("name", ""),
                    shared=cstate.get("shared", False),
                    asset_ids=cstate.get("asset_ids", []),
                    pending_asset_ids=cstate.get("pending_asset_ids", []),
                    meta_fingerprint=current_fingerprint,
                )
                session.add(new_ts)

        for event in events:
            assets_count = event.added_count or event.removed_count or 0
            details: dict[str, Any] = {
                "added_count": event.added_count,
                "removed_count": event.removed_count,
                "provider_type": event.provider_type.value,
            }
            # Scheduler/periodic events carry the schedule context in ``extra``
            # (cron expression, interval, timezone, fire count). Surface that
            # in the event log so the dashboard and audit queries can show
            # *why* the event fired, not just that it did.
            if event.event_type.value == "scheduled_message":
                sched_type = tracker_filters.get("schedule_type", "interval")
                details["schedule_type"] = sched_type
                if sched_type == "cron":
                    details["cron_expression"] = tracker_filters.get("cron_expression", "")
                else:
                    details["interval_seconds"] = tracker.scan_interval
                details["timezone"] = app_tz
                fire_count = event.extra.get("fire_count") if event.extra else None
                if fire_count is not None:
                    details["fire_count"] = fire_count
            log = EventLog(
                user_id=tracker.user_id,
                tracker_id=tracker_id,
                tracker_name=tracker.name,
                provider_id=provider.id,
                provider_name=provider_name,
                event_type=event.event_type.value,
                collection_id=event.collection_id,
                collection_name=event.collection_name,
                assets_count=assets_count,
                details=details,
            )
            session.add(log)

        await session.commit()

    # Dispatch notifications — per-link config resolution
    # Filter out empty events (e.g. assets_added with 0 added)
    events = [
        e for e in events
        if not (e.event_type.value == "assets_added" and e.added_count == 0)
        and not (e.event_type.value == "assets_removed" and e.removed_count == 0)
    ]

    _LOGGER.info(
        "Tracker %d: %d events after filter, %d links",
        tracker_id, len(events), len(link_data),
    )

    if events and link_data:
        url_cache, asset_cache = await _get_telegram_caches()
        from .http_session import get_http_session
        shared_session = await get_http_session()
        dispatcher = NotificationDispatcher(
            url_cache=url_cache,
            asset_cache=asset_cache,
            session=shared_session,
        )
        for event in events:
            _LOGGER.info(
                "Dispatching event %s for %s (added=%d removed=%d)",
                event.event_type.value, event.collection_name,
                event.added_count, event.removed_count,
            )
            # Group targets by tracking-config identity so each unique TC
            # gets one event-transform pass; targets sharing a TC dispatch
            # together (preserves the gather-fan-out inside the dispatcher).
            groups: dict[int, tuple[Any, list[TargetConfig]]] = {}
            for ld in link_data:
                tc = ld["tracking_config"]
                if tc and not event_allowed_by_config(event, tc, app_tz):
                    _LOGGER.info("  Skipped by tracking config filter")
                    continue

                tmpl = ld["template_config"]
                target_cfg = TargetConfig(
                    type=ld["target_type"],
                    config=ld["target_config"],
                    template_slots=ld["template_slots"],
                    date_format=tmpl.date_format if tmpl else "%d.%m.%Y, %H:%M UTC",
                    date_only_format=tmpl.date_only_format if tmpl and tmpl.date_only_format else "%d.%m.%Y",
                    provider_api_key=provider_config.get("api_key"),
                    provider_internal_url=provider_config.get("url", ""),
                    provider_external_url=provider_config.get("external_domain", ""),
                    receivers=ld["receivers"],
                )
                key = id(tc) if tc is not None else 0
                if key not in groups:
                    groups[key] = (tc, [])
                groups[key][1].append(target_cfg)

            for tc, target_configs in groups.values():
                if not target_configs:
                    continue
                shaped_event = apply_tracking_display_filters(event, tc)
                if shaped_event is None:
                    _LOGGER.info(
                        "  Event suppressed by display filters (favorites_only)",
                    )
                    continue
                results = await dispatcher.dispatch(shaped_event, target_configs)
                for r in results:
                    if r.get("success"):
                        _LOGGER.info("  Notification sent successfully")
                    else:
                        _LOGGER.error("  Notification failed: %s", r.get("error", "unknown"))

    return {
        "status": "ok",
        "events_detected": len(events),
        "collections_checked": len(collection_ids),
    }