UMBRA/backend/app/jobs/notifications.py

"""
Background notification dispatch job.
Runs every 60 seconds via APScheduler (registered in main.py lifespan).

DATETIME NOTE: All comparisons use datetime.now() without timezone info.
The DB uses TIMESTAMP WITHOUT TIME ZONE (naive datetimes). The Docker container
runs UTC. datetime.now() inside the container returns UTC, which matches the
naive datetimes stored in the DB. Do NOT use datetime.now(timezone.utc) here —
that would produce a timezone-aware object that cannot be compared with naive DB values.
"""
import logging
from datetime import datetime, timedelta

from sqlalchemy import select, delete, and_
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import selectinload

from app.database import AsyncSessionLocal
from app.models.settings import Settings
from app.models.reminder import Reminder
from app.models.calendar_event import CalendarEvent
from app.models.todo import Todo
from app.models.project import Project
from app.models.ntfy_sent import NtfySent
from app.models.totp_usage import TOTPUsage
from app.models.session import UserSession
from app.services.ntfy import send_ntfy_notification
from app.services.ntfy_templates import (
    build_event_notification,
    build_reminder_notification,
    build_todo_notification,
    build_project_notification,
)

logger = logging.getLogger(__name__)

UMBRA_URL = "http://10.0.69.35"


# ── Dedup helpers ─────────────────────────────────────────────────────────────

async def _already_sent(db: AsyncSession, key: str) -> bool:
    result = await db.execute(
        select(NtfySent).where(NtfySent.notification_key == key)
    )
    return result.scalar_one_or_none() is not None


async def _mark_sent(db: AsyncSession, key: str) -> None:
    db.add(NtfySent(notification_key=key))
    await db.commit()


# ── Dispatch functions ────────────────────────────────────────────────────────

async def _dispatch_reminders(db: AsyncSession, settings: Settings, now: datetime) -> None:
    """Send notifications for reminders that are currently due and not dismissed/snoozed."""
    # Mirror the filter from /api/reminders/due
    result = await db.execute(
        select(Reminder).where(
            and_(
                Reminder.remind_at <= now,
                Reminder.is_dismissed == False,  # noqa: E712
                Reminder.is_active == True,  # noqa: E712
            )
        )
    )
    reminders = result.scalars().all()
    today = now.date()

    for reminder in reminders:
        if reminder.snoozed_until and reminder.snoozed_until > now:
            continue  # respect snooze

        # Key ties notification to the specific day to handle re-fires after midnight
        key = f"reminder:{reminder.id}:{reminder.remind_at.date()}"
        if await _already_sent(db, key):
            continue

        payload = build_reminder_notification(
            title=reminder.title,
            remind_at=reminder.remind_at,
            today=today,
            description=reminder.description,
        )
        sent = await send_ntfy_notification(
            settings=settings,
            click_url=UMBRA_URL,
            **payload,
        )
        if sent:
            await _mark_sent(db, key)


async def _dispatch_events(db: AsyncSession, settings: Settings, now: datetime) -> None:
    """Send notifications for calendar events within the configured lead time window."""
    lead_minutes = settings.ntfy_event_lead_minutes
    # Window: events starting between now and (now + lead_minutes)
    window_end = now + timedelta(minutes=lead_minutes)

    result = await db.execute(
        select(CalendarEvent).where(
            and_(
                CalendarEvent.start_datetime >= now,
                CalendarEvent.start_datetime <= window_end,
                # Exclude recurring parent templates — they duplicate the child instance rows.
                # Parent templates have recurrence_rule set but no parent_event_id.
                ~and_(
                    CalendarEvent.recurrence_rule != None,  # noqa: E711
                    CalendarEvent.parent_event_id == None,  # noqa: E711
                ),
            )
        ).options(selectinload(CalendarEvent.location))
    )
    events = result.scalars().all()
    today = now.date()

    for event in events:
        # Key includes the minute-precision start to avoid re-firing during the window
        key = f"event:{event.id}:{event.start_datetime.strftime('%Y-%m-%dT%H:%M')}"
        if await _already_sent(db, key):
            continue

        payload = build_event_notification(
            title=event.title,
            start_datetime=event.start_datetime,
            all_day=event.all_day,
            today=today,
            location_name=event.location.name if event.location else None,
            description=event.description,
            is_starred=event.is_starred,
        )
        sent = await send_ntfy_notification(
            settings=settings,
            click_url=UMBRA_URL,
            **payload,
        )
        if sent:
            await _mark_sent(db, key)


async def _dispatch_todos(db: AsyncSession, settings: Settings, today) -> None:
    """Send notifications for incomplete todos due within the configured lead days."""
    from datetime import date as date_type
    lead_days = settings.ntfy_todo_lead_days
    cutoff = today + timedelta(days=lead_days)

    result = await db.execute(
        select(Todo).where(
            and_(
                Todo.completed == False,  # noqa: E712
                Todo.due_date != None,  # noqa: E711
                Todo.due_date <= cutoff,
            )
        )
    )
    todos = result.scalars().all()

    for todo in todos:
        key = f"todo:{todo.id}:{today}"
        if await _already_sent(db, key):
            continue

        payload = build_todo_notification(
            title=todo.title,
            due_date=todo.due_date,
            today=today,
            priority=todo.priority,
            category=todo.category,
        )
        sent = await send_ntfy_notification(
            settings=settings,
            click_url=UMBRA_URL,
            **payload,
        )
        if sent:
            await _mark_sent(db, key)


async def _dispatch_projects(db: AsyncSession, settings: Settings, today) -> None:
    """Send notifications for projects with deadlines within the configured lead days."""
    lead_days = settings.ntfy_project_lead_days
    cutoff = today + timedelta(days=lead_days)

    result = await db.execute(
        select(Project).where(
            and_(
                Project.due_date != None,  # noqa: E711
                Project.due_date <= cutoff,
                Project.status != "completed",
            )
        )
    )
    projects = result.scalars().all()

    for project in projects:
        key = f"project:{project.id}:{today}"
        if await _already_sent(db, key):
            continue

        payload = build_project_notification(
            name=project.name,
            due_date=project.due_date,
            today=today,
            status=project.status,
        )
        sent = await send_ntfy_notification(
            settings=settings,
            click_url=UMBRA_URL,
            **payload,
        )
        if sent:
            await _mark_sent(db, key)


async def _purge_old_sent_records(db: AsyncSession) -> None:
    """Remove ntfy_sent entries older than 7 days to keep the table lean."""
    # See DATETIME NOTE at top of file re: naive datetime usage
    cutoff = datetime.now() - timedelta(days=7)
    await db.execute(delete(NtfySent).where(NtfySent.sent_at < cutoff))
    await db.commit()


async def _purge_totp_usage(db: AsyncSession) -> None:
    """Remove TOTP usage records older than 5 minutes — they serve no purpose beyond replay prevention."""
    cutoff = datetime.now() - timedelta(minutes=5)
    await db.execute(delete(TOTPUsage).where(TOTPUsage.used_at < cutoff))
    await db.commit()


async def _purge_expired_sessions(db: AsyncSession) -> None:
    """Remove expired UserSession rows to keep the sessions table lean."""
    await db.execute(delete(UserSession).where(UserSession.expires_at < datetime.now()))
    await db.commit()


# ── Entry point ───────────────────────────────────────────────────────────────

async def run_notification_dispatch() -> None:
    """
    Main dispatch function called by APScheduler every 60 seconds.
    Uses AsyncSessionLocal directly — not the get_db() request-scoped dependency.
    """
    try:
        async with AsyncSessionLocal() as db:
            result = await db.execute(select(Settings))
            settings = result.scalar_one_or_none()

            if not settings or not settings.ntfy_enabled:
                return

            # See DATETIME NOTE at top of file re: naive datetime usage
            now = datetime.now()
            today = now.date()

            if settings.ntfy_reminders_enabled:
                await _dispatch_reminders(db, settings, now)
            if settings.ntfy_events_enabled:
                await _dispatch_events(db, settings, now)
            if settings.ntfy_todos_enabled:
                await _dispatch_todos(db, settings, today)
            if settings.ntfy_projects_enabled:
                await _dispatch_projects(db, settings, today)

            # Daily housekeeping: purge stale dedup records
            await _purge_old_sent_records(db)

        # Security housekeeping runs every cycle regardless of ntfy_enabled
        async with AsyncSessionLocal() as db:
            await _purge_totp_usage(db)
            await _purge_expired_sessions(db)

    except Exception:
        # Broad catch: job failure must never crash the scheduler or the app
        logger.exception("ntfy dispatch job encountered an unhandled error")