"""JARVIS reminders."""
import asyncio
import logging
from datetime import datetime, timedelta
from typing import Optional

import pytz
from beanie.operators import LTE, NotIn
from croniter import croniter
from interactions import Client
from interactions.models.discord.channel import GuildText
from interactions.models.discord.embed import Embed
from interactions.models.discord.user import User
from jarvis_core.db.models import Reminder

from jarvis_tasks.prometheus.stats import reminder_count
from jarvis_tasks.util import build_embed, runat

queue = []
logger = logging.getLogger(__name__)


async def _remind(
    user: User,
    reminder: Reminder,
    embed: Embed,
    channel: Optional[GuildText] = None,
) -> None:
    delete = True
    reminded = False
    try:
        await user.send(embed=embed)
        reminded = True
        logger.debug(f"Reminder {reminder.id} sent to user")
    except Exception:
        logger.debug("Failed to DM user, falling back to channel")
        if channel:
            member = await channel.guild.fetch_member(user.id)
            if not member:
                logger.debug("User no longer in origin guild")
            else:
                if channel and not reminder.private:
                    await channel.send(f"{member.mention}", embed=embed)
                    reminded = True
                    logger.debug(f"Reminder {reminder.id} sent to origin channel")
                elif channel:
                    await channel.send(
                        f"{member.mention}, you had a private reminder set for now,"
                        " but I couldn't send it to you.\n"
                        f"Use `/reminder fetch {str(reminder.id)}` to view"
                    )
                    reminded = True
                    logger.debug(
                        f"Reminder {reminder.id} private, sent notification to origin channel"
                    )
                    reminder.active = False
                    await reminder.save()
                    delete = False
                else:
                    logger.warning(f"Reminder {reminder.id} failed, no way to contact user.")
    if reminder.repeat:
        now = datetime.now(tz=pytz.timezone(reminder.timezone))
        cron = croniter(reminder.repeat, now)
        reminder.remind_at = cron.next(datetime)
        reminder.total_reminders += 1
        delete = False
    if delete:
        await reminder.delete()
    else:
        await reminder.save()
    if reminded:
        guild_id = channel.guild.id if channel.guild else user.id
        guild_name = channel.guild.name if channel.guild else user.username
        count = reminder_count.labels(guild_id=guild_id, guild_name=guild_name)
        count.inc()
    queue.remove(reminder.id)


async def remind(bot: Client) -> None:
    """
    Run reminders in the background.

    Args:
        bot: Client instance
    """
    logger.debug("Starting Task-remind")
    while True:
        max_ts = datetime.now(tz=pytz.utc) + timedelta(seconds=5)
        reminders = Reminder.find(
            NotIn(Reminder.id, queue),
            LTE(Reminder.remind_at, max_ts),
            Reminder.active == True,
        )

        async for reminder in reminders:
            if reminder.id in queue:
                logger.debug(f"Reminder {reminder.id} was found despite filter")
                continue
            user = await bot.fetch_user(reminder.user)
            if not user:
                logger.warning(f"Failed to get user with ID {reminder.user}")
                await reminder.delete()
                continue

            embed = build_embed(
                title="You have a reminder!", description=reminder.message, fields=[]
            )
            embed.set_author(
                name=user.username + "#" + user.discriminator, icon_url=user.avatar.url
            )

            embed.set_thumbnail(url=user.avatar.url)

            channel = await bot.fetch_channel(reminder.channel)
            coro = _remind(user, reminder, embed, channel)
            asyncio.create_task(runat(reminder.remind_at, coro, logger))
            queue.append(reminder.id)

        # Check every 5 seconds
        await asyncio.sleep(5)