"""Celery tasks for push notifications."""

import asyncio
from datetime import datetime, time
from zoneinfo import ZoneInfo

from sqlalchemy import select

from app.core.celery_app import celery_app
from app.core.logging import get_logger
from app.db.database import _get_session_factory
from app.db.models import PushConfig, PushEvent

logger = get_logger(__name__)

LOCAL_TZ = ZoneInfo("Asia/Shanghai")
QUIET_HOURS_START = time(21, 0)
QUIET_HOURS_END = time(9, 0)
TRIGGER_WINDOW_MINUTES = 30


@celery_app.task
def check_push_notifications() -> None:
    """Check push configs and create push events."""
    asyncio.run(_check_push_notifications())


def _is_quiet_hours(current: time) -> bool:
    if QUIET_HOURS_START < QUIET_HOURS_END:
        return QUIET_HOURS_START <= current < QUIET_HOURS_END
    return current >= QUIET_HOURS_START or current < QUIET_HOURS_END


def _within_window(current: time, target: time) -> bool:
    current_minutes = current.hour * 60 + current.minute
    target_minutes = target.hour * 60 + target.minute
    return 0 <= current_minutes - target_minutes < TRIGGER_WINDOW_MINUTES


async def _already_sent_today(
    session,
    child_profile_id: str,
    now: datetime,
) -> bool:
    start = now.replace(hour=0, minute=0, second=0, microsecond=0)
    end = now.replace(hour=23, minute=59, second=59, microsecond=999999)
    result = await session.execute(
        select(PushEvent.id).where(
            PushEvent.child_profile_id == child_profile_id,
            PushEvent.status == "sent",
            PushEvent.sent_at >= start,
            PushEvent.sent_at <= end,
        )
    )
    return result.scalar_one_or_none() is not None


async def _check_push_notifications() -> None:
    session_factory = _get_session_factory()
    now = datetime.now(LOCAL_TZ)
    current_day = now.weekday()
    current_time = now.time()

    async with session_factory() as session:
        result = await session.execute(
            select(PushConfig).where(PushConfig.enabled.is_(True))
        )
        configs = result.scalars().all()

        for config in configs:
            if not config.push_time:
                continue
            if config.push_days and current_day not in config.push_days:
                continue
            if not _within_window(current_time, config.push_time):
                continue
            if _is_quiet_hours(current_time):
                session.add(
                    PushEvent(
                        user_id=config.user_id,
                        child_profile_id=config.child_profile_id,
                        trigger_type="time",
                        status="suppressed",
                        reason="quiet_hours",
                        sent_at=now,
                    )
                )
                continue
            if await _already_sent_today(session, config.child_profile_id, now):
                continue

            session.add(
                PushEvent(
                    user_id=config.user_id,
                    child_profile_id=config.child_profile_id,
                    trigger_type="time",
                    status="sent",
                    reason=None,
                    sent_at=now,
                )
            )
            logger.info(
                "push_event_sent",
                child_profile_id=config.child_profile_id,
                user_id=config.user_id,
            )

        await session.commit()