import logging
import re
from datetime import datetime
from enum import Enum
from html import unescape
from typing import List, Optional

from discord import Color, Embed
from discord.ext import commands

from bot.bot import Bot
from bot.utils import LinePaginator

log = logging.getLogger(__name__)

SEARCH_API = "https://en.wikipedia.org/w/api.php?action=query&list=search&prop=info&inprop=url&utf8=& \
      format=json&origin=*&srlimit={number_of_results}&srsearch={string}"
WIKI_THUMBNAIL = "https://upload.wikimedia.org/wikipedia/en/thumb/8/80/Wikipedia-logo-v2.svg" \
                 "/330px-Wikipedia-logo-v2.svg.png"
WIKI_SNIPPET_REGEX = r'(<!--.*?-->|<[^>]*>)'
WIKI_SEARCH_RESULT = (
    "**[{name}]({url})**\n"
    "{description}\n"
)


class WikipediaSearchErrors(Enum):
    """Errors returned in wikipedia search function."""

    no_results = "Sorry, we could not find a wikipedia article using that search term."
    api_issue = "Whoops, the Wikipedia API is having some issues right now. Try again later."


class WikipediaSearch(commands.Cog):
    """Get info from wikipedia."""

    def __init__(self, bot: Bot):
        self.bot = bot

    async def wiki_request(self, ctx: commands.Context, search: str) -> Optional[List[str]]:
        """Search wikipedia search string and return formatted first 10 pages found."""
        url = SEARCH_API.format(number_of_results=10, string=search)
        async with self.bot.http_session.get(url=url) as resp:
            if resp.status == 200:
                raw_data = await resp.json()
                number_of_results = raw_data['query']['searchinfo']['totalhits']

                if number_of_results:
                    results = raw_data['query']['search']
                    lines = []

                    for article in results:
                        formatting = {
                            'name': article['title'],
                            'description': unescape(
                                re.sub(
                                    WIKI_SNIPPET_REGEX, '', article['snippet']
                                )
                            ),
                            'url': f"https://en.wikipedia.org/?curid={article['pageid']}"
                        }
                        line = WIKI_SEARCH_RESULT.format(**formatting)
                        lines.append(line)

                    return lines

                else:
                    await ctx.send(
                        WikipediaSearchErrors.no_results.value
                    )
                    return None
            else:
                await ctx.send(
                    WikipediaSearchErrors.api_issue.value
                )
                return None

    @commands.cooldown(1, 10, commands.BucketType.user)
    @commands.command(name="wikipedia", aliases=["wiki"])
    async def wikipedia_search_command(self, ctx: commands.Context, *, search: str) -> None:
        """Sends paginated top 10 results of Wikipedia search.."""
        contents = await self.wiki_request(ctx, search)

        if contents:
            embed = Embed(
                title="Wikipedia Search Results",
                colour=Color.blurple()
            )
            embed.set_thumbnail(url=WIKI_THUMBNAIL)
            embed.timestamp = datetime.utcnow()
            await LinePaginator.paginate(
                contents, ctx, embed
            )


def setup(bot: Bot) -> None:
    """Wikipedia Cog load."""
    bot.add_cog(WikipediaSearch(bot))