import logging
import re
from random import randint
from typing import Optional, Union

from discord import Embed
from discord.ext import tasks
from discord.ext.commands import Cog, Context, command

from bot.bot import Bot
from bot.constants import Colours

log = logging.getLogger(__name__)

COMIC_FORMAT = re.compile(r"latest|[0-9]+")
BASE_URL = "https://xkcd.com"


class XKCD(Cog):
    """Retrieving XKCD comics."""

    def __init__(self, bot: Bot):
        self.bot = bot
        self.latest_comic_info: dict[str, Union[str, int]] = {}
        self.get_latest_comic_info.start()

    def cog_unload(self) -> None:
        """Cancels refreshing of the task for refreshing the most recent comic info."""
        self.get_latest_comic_info.cancel()

    @tasks.loop(minutes=30)
    async def get_latest_comic_info(self) -> None:
        """Refreshes latest comic's information ever 30 minutes. Also used for finding a random comic."""
        async with self.bot.http_session.get(f"{BASE_URL}/info.0.json") as resp:
            if resp.status == 200:
                self.latest_comic_info = await resp.json()
            else:
                log.debug(f"Failed to get latest XKCD comic information. Status code {resp.status}")

    @command(name="xkcd")
    async def fetch_xkcd_comics(self, ctx: Context, comic: Optional[str]) -> None:
        """
        Getting an xkcd comic's information along with the image.

        To get a random comic, don't type any number as an argument. To get the latest, type 'latest'.
        """
        embed = Embed(title=f"XKCD comic '{comic}'")

        embed.colour = Colours.soft_red

        if comic and (comic := re.match(COMIC_FORMAT, comic)) is None:
            embed.description = "Comic parameter should either be an integer or 'latest'."
            await ctx.send(embed=embed)
            return

        comic = randint(1, self.latest_comic_info["num"]) if comic is None else comic.group(0)

        if comic == "latest":
            info = self.latest_comic_info
        else:
            async with self.bot.http_session.get(f"{BASE_URL}/{comic}/info.0.json") as resp:
                if resp.status == 200:
                    info = await resp.json()
                else:
                    embed.title = f"XKCD comic #{comic}"
                    embed.description = f"{resp.status}: Could not retrieve xkcd comic #{comic}."
                    log.debug(f"Retrieving xkcd comic #{comic} failed with status code {resp.status}.")
                    await ctx.send(embed=embed)
                    return

        embed.title = f"XKCD comic #{info['num']}"
        embed.description = info["alt"]
        embed.url = f"{BASE_URL}/{info['num']}"

        if info["img"][-3:] in ("jpg", "png", "gif"):
            embed.set_image(url=info["img"])
            date = f"{info['year']}/{info['month']}/{info['day']}"
            embed.set_footer(text=f"{date} - #{info['num']}, \'{info['safe_title']}\'")
            embed.colour = Colours.soft_green
        else:
            embed.description = (
                "The selected comic is interactive, and cannot be displayed within an embed.\n"
                f"Comic can be viewed [here](https://xkcd.com/{info['num']})."
            )

        await ctx.send(embed=embed)


def setup(bot: Bot) -> None:
    """Load the XKCD cog."""
    bot.add_cog(XKCD(bot))