import asyncio
import logging
from contextlib import suppress
from zoneinfo import ZoneInfo

from telegram.ext import Application

from .config import REMINDER_POLL_SECONDS
from .storage import AssistantStorage
from .time_utils import format_local_dt, utc_now


logger = logging.getLogger(__name__)


async def reminder_loop(application: Application) -> None:
    storage: AssistantStorage = application.bot_data["storage"]
    tz: ZoneInfo = application.bot_data["timezone"]

    while True:
        try:
            due_reminders = storage.due_reminders(utc_now())
            for reminder in due_reminders:
                await application.bot.send_message(
                    chat_id=reminder["chat_id"],
                    text=(
                        f"Напоминание #{reminder['id']} "
                        f"({format_local_dt(reminder['remind_at'], tz)}):\n"
                        f"{reminder['text']}"
                    ),
                )
                storage.mark_reminder_sent(int(reminder["id"]))
        except asyncio.CancelledError:
            raise
        except Exception:
            logger.exception("Reminder loop failed")

        await asyncio.sleep(REMINDER_POLL_SECONDS)


async def post_init(application: Application) -> None:
    application.bot_data["reminder_task"] = asyncio.create_task(
        reminder_loop(application),
        name="reminder-loop",
    )


async def post_shutdown(application: Application) -> None:
    task = application.bot_data.pop("reminder_task", None)
    if task is None:
        return

    task.cancel()
    with suppress(asyncio.CancelledError):
        await task