from __future__ import annotations

import asyncio
import re
from io import BytesIO
from textwrap import dedent
from typing import Annotated

import discord
import sympy
from aiohttp import ClientSession
from discord.ext import commands
from PIL import Image

# https://github.com/python-discord/bot-core/blob/main/pydis_core/utils/regex.py#L29
FORMATTED_CODE_REGEX = re.compile(
    r"(?P<delim>(?P<block>```)|``?)"
    r"(?(block)(?:(?P<lang>[a-z]+)\n)?)"
    r"(?:[ \t]*\n)*"
    r"(?P<code>.*?)"
    r"\s*"
    r"(?P=delim)",
    flags=re.DOTALL | re.IGNORECASE,
)

# https://github.com/python-discord/bot-core/blob/main/pydis_core/utils/regex.py#L44C1-L49C2
RAW_CODE_REGEX = re.compile(r"^(?:[ \t]*\n)*" r"(?P<code>.*?)" r"\s*$", flags=re.DOTALL)


async def threads(channel: discord.TextChannel):
    for t in channel.threads:
        yield t
    async for t in channel.archived_threads():
        yield t


# https://github.com/python-discord/bot/blob/main/bot/exts/utils/snekbox/_cog.py#L97
class CodeblockConverter(commands.Converter):
    @classmethod
    async def convert(cls, ctx: commands.Context, code: str) -> list[str]:
        if match := list(FORMATTED_CODE_REGEX.finditer(code)):
            blocks = [block for block in match if block.group("block")]

            if len(blocks) > 1:
                codeblocks = [block.group("code") for block in blocks]
                info = "several code blocks"
            else:
                match = match[0] if len(blocks) == 0 else blocks[0]
                code, block, lang, delim = match.group("code", "block", "lang", "delim")
                codeblocks = [dedent(code)]
                if block:
                    info = (f"'{lang}' highlighted" if lang else "plain") + " code block"
                else:
                    info = f"{delim}-enclosed inline code"
        else:
            m = RAW_CODE_REGEX.fullmatch(code)
            if m is None:
                raise RuntimeError("what")
            codeblocks = [dedent(m.group("code"))]
            info = "unformatted or badly formatted code"

        code = "\n".join(codeblocks)
        print(f"Extracted {info} for evaluation:\n{code}")
        return codeblocks


class Night(commands.Cog):
    @commands.hybrid_command()
    @commands.is_owner()
    async def reload(self, ctx: commands.Context):
        print("reload")
        bot: commands.Bot = ctx.bot
        try:
            await bot.reload_extension("nightly.night")
        except commands.ExtensionNotLoaded:
            await ctx.reply("not loaded")
        print("reloaded")
        await ctx.reply("reloaded")

    @commands.hybrid_command()
    @commands.is_owner()
    async def sync(self, ctx: commands.Context):
        await ctx.bot.tree.sync()
        print("synced")
        await ctx.reply("synced")

    async def leetcode_one(self, ctx: commands.Context, /, url: str):
        match = re.search(r"/problems/([a-z0-9\-]*)", url)
        if not match:
            await ctx.reply("invalid url")
            return
        name = match.group(1)
        async with ClientSession() as session:
            async with session.post(
                "https://leetcode.com/graphql/",
                json={
                    "query": "\n    query consolePanelConfig($titleSlug: String!) {\n  question(titleSlug: $titleSlug) {\n    questionId\n    questionFrontendId\n    questionTitle\n    enableDebugger\n    enableRunCode\n    enableSubmit\n    enableTestMode\n    exampleTestcaseList\n    metaData\n  }\n}\n    ",
                    "variables": {"titleSlug": name},
                    "operationName": "consolePanelConfig",
                },
            ) as response:
                if not response.ok:
                    await ctx.reply("error (idk)")
                    return
                match await response.json():
                    case {"data": {"question": {"questionFrontendId": qfi, "questionTitle": qt}}}:
                        title = f"{qfi}. {qt}"
                        print(title)
                    case _:
                        await ctx.reply("error (leetcode format wrong)")
                        return
                if not isinstance(ctx.channel, discord.TextChannel):
                    await ctx.reply("not available outside text channels")
                    return
                async for thread in threads(ctx.channel):
                    if thread.name == title:
                        message = await ctx.reply(f"exists: {thread.jump_url}", delete_after=60)
                        return
                thread = await ctx.channel.create_thread(name=title, type=discord.ChannelType.public_thread)
                message = await thread.send(f"https://leetcode.com/problems/{name}/")
                if not ctx.bot_permissions.manage_messages:
                    await ctx.reply("cannot pin messages (missing permissions)", mention_author=False)
                    return
                await message.pin()

    @commands.command(aliases=["lc"])
    async def leetcode(self, ctx: commands.Context, *urls: str):
        async with asyncio.TaskGroup() as tg:
            for url in urls:
                tg.create_task(self.leetcode_one(ctx, url))

    @commands.command()
    @commands.is_owner()
    async def lc_cleanup(self, ctx: commands.Context):
        async for message in ctx.channel.history(limit=1000):
            if message.author == ctx.me and message.content.startswith("exists:"):
                await message.delete()
        await ctx.reply("done")

    @commands.hybrid_command()
    async def tex(self, ctx: commands.Context, *, code: Annotated[list[str], CodeblockConverter]):
        print(code)
        buf = BytesIO()

        def preview():
            sympy.preview(
                code[0],
                viewer="BytesIO",
                euler=False,
                outputbuffer=buf,
                dvioptions=["-fg", "White", "-bg", "Black", "-D", "200"],
                extra_preamble=r"""
\usepackage{xcolor}
\color{white}
""",
            )

        await asyncio.to_thread(preview)
        buf.seek(0)
        im0 = Image.open(buf)
        print(im0.size)
        im1 = Image.new(im0.mode, (im0.width + 40, im0.height + 40))
        im1.paste(im0, (20, 20))
        buf = BytesIO()
        im1.save(buf, format="png")
        buf.seek(0)
        await ctx.reply(file=discord.File(buf, filename="tex.png"))


async def setup(bot: commands.Bot):
    global cog
    cog = Night()
    await bot.add_cog(cog)


async def teardown(bot: commands.Bot):
    global cog
    await bot.remove_cog(cog.qualified_name)
    del cog
    print("torn down")