import json
import re
import typing

import httpx
from pathlib import Path
import niobot

if typing.TYPE_CHECKING:
    from ..main import NonsenseBot


class MSCGetter(niobot.Module):
    bot: "NonsenseBot"

    def __init__(self, bot):
        super().__init__(bot)
        self.latest_msc = None
        self.msc_cache = Path.cwd() / ".msc-cache"
        self.msc_cache.mkdir(parents=True, exist_ok=True)

    async def get_msc_with_cache(self, number: int):
        if number not in range(1, 10_000):
            return {"error": "Invalid MSC ID"}

        file = self.msc_cache / ("%d.json" % number)
        content = None
        if file.exists():
            try:
                content = json.loads(file.read_text("utf-8", "replace"))
            except json.JSONDecodeError:
                file.unlink()

        if content:
            return content

        async with httpx.AsyncClient() as client:
            response = await client.get(
                "https://api.github.com/repos/matrix-org/matrix-spec-proposals/pulls/%d"
                % number
            )
            if response.status_code != 200:
                return {"error": "HTTP %d" % response.status_code}
            content = response.json()
            file.write_text(json.dumps(content))
            return content

    @niobot.event("message")
    async def on_message(self, room: niobot.MatrixRoom, message: niobot.RoomMessage):
        if self.bot.is_old(message):
            return
        if message.sender == self.bot.user:
            return
        if not isinstance(message, niobot.RoomMessageText):
            return
        if "m.in_reply_to" in message.source.get("m.relates_to", []):
            return
        if await self.bot.redis.get(
            self.bot.redis_key(room.room_id, "auto_msc.enabled")
        ):
            matches = re.finditer("[MmSsCc]\W?([0-9]{1,4})", message.body)

            lines = []
            for m in matches:
                no = m.group(1)
                if no:
                    data = await self.get_msc_with_cache(int(no))
                    if data.get("error"):
                        continue
                    lines.append(f"[{data['title']}]({data['html_url']})")
            if lines:
                return await self.bot.send_message(
                    room, "\n".join((f"* {ln}" for ln in lines)), reply_to=message
                )

    @niobot.command()
    async def msc(self, ctx: niobot.Context, number: str):
        """Fetches the given MSC"""
        if number.startswith("msc"):
            number = number[3:]
        elif number.startswith("#"):
            number = number[1:]
        if not number.isdigit() or len(number) != 4:
            return await ctx.respond("Invalid MXC number.")

        data: dict = await self.get_msc_with_cache(int(number))
        if data.get("error"):
            return await ctx.respond(data["error"])
        return await ctx.respond(f"[{data['title']}]({data['html_url']})")

    @niobot.command("automsc.enable")
    async def auto_msc_enable(self, ctx: niobot.Context):
        """Automatically enables MSC linking. Requires a power level of at least 50."""
        if (sp := ctx.room.power_levels.users.get(ctx.message.sender, -999)) < 50:
            return await ctx.respond("You need to have at least a power level of 50 to use this.")
        key = self.bot.redis_key(ctx.room.room_id, "auto_msc.enabled")
        exists = await self.bot.redis.get(key)
        if exists:
            return await ctx.respond("AutoMSC is already enabled in this room.")
        await self.bot.redis.set(key, 1)
        await self.bot.redis.save()
        return await self.bot.add_reaction(
            ctx.room, ctx.message, "\N{WHITE HEAVY CHECK MARK}"
        )

    @niobot.command("automsc.disable")
    async def auto_msc_disable(self, ctx: niobot.Context):
        """Disables automatic MSC linking. Requires a power level of at least 50."""
        if (sp := ctx.room.power_levels.users.get(ctx.message.sender, -999)) < 50:
            return await ctx.respond("You need to have at least a power level of 50 to use this.")
        key = self.bot.redis_key(ctx.room.room_id, "auto_msc.enabled")
        exists = await self.bot.redis.get(key)
        if exists:
            await self.bot.redis.delete(key)
            await self.bot.redis.save()
            await self.bot.add_reaction(
                ctx.room, ctx.message, "\N{WHITE HEAVY CHECK MARK}"
            )
        else:
            return await ctx.respond("AutoMSC is already disabled in this room.")