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

from telegram.ext import Application

from .config import REMINDER_POLL_SECONDS
from .services import SERVICES_KEY, ApplicationServices
from .telegram_utils import escape_markdown_text, markdown_code, send_markdown
from .time_utils import format_local_dt, utc_now


logger = logging.getLogger(__name__)


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

    while True:
        try:
            due_reminders = storage.due_reminders(utc_now())
            for reminder in due_reminders:
                await send_markdown(
                    application.bot,
                    chat_id=reminder["chat_id"],
                    markdown=(
                        f"**⏰ Напоминание "
                        f"{markdown_code('#' + str(reminder['id']))}**\n\n"
                        f"**Время:** "
                        f"{markdown_code(format_local_dt(reminder['remind_at'], tz))}\n"
                        f"**Задача:** {escape_markdown_text(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