"""
youtube - A maubot plugin to display YouTube video information
Copyright (C) 2025  L. Bradley LaBoon

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License version 3 as
published by the Free Software Foundation.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.
"""
import re
from typing import Type
from yarl import URL

from maubot import Plugin, MessageEvent
from maubot.handlers import event
from mautrix.types import TextMessageEventContent, MessageType, Format, EventType
from mautrix.util.config import BaseProxyConfig, ConfigUpdateHelper

class Config(BaseProxyConfig):
    def do_update(self, helper: ConfigUpdateHelper) -> None:
        helper.copy("api_key")

class YouTube(Plugin):
    async def start(self) -> None:
        self.config.load_and_update()

    @classmethod
    def get_config_class(cls) -> Type[BaseProxyConfig]:
        return Config

    # Fetch an image URL, upload it to the matrix media store, and return the mcx:// address
    async def upload_img(self, link: str) -> str:
        image_req = await self.http.get(link)
        if (image_req.status < 400):
            image = await image_req.read()
            mxc = await self.client.upload_media(image, filename=image_req.url.name)
            return mxc
        return ""

    # Listen to all messages passively instead of requiring a command
    @event.on(EventType.ROOM_MESSAGE)
    async def handle_message(self, evt: MessageEvent) -> None:
        # Ignore messages from the bot itself to prevent infinite loops
        if evt.sender == self.client.mxid or not evt.content.body:
            return
            
        # Only process standard text messages or notices
        if evt.content.msgtype not in (MessageType.TEXT, MessageType.NOTICE):
            return

        # Find all youtube URLs in the message body using regex
        # The regex avoids matching trailing markdown brackets/parentheses
        urls = re.findall(r'(https?://(?:www\.)?(?:youtube\.com|youtu\.be)[^\s\]\)\>]+)', evt.content.body)
        
        if not urls:
            return

        for video_url_str in urls:
            video_url = URL(video_url_str)
            video_params = video_url.query
            video_id = None
            offset = ""

            # Handle URLs
            if video_url.host in ("youtube.com", "www.youtube.com"):
                if "shorts" in video_url.parts:
                    video_id = video_url.name
                else:
                    if "v" in video_params:
                        video_id = video_params["v"]
                    if "t" in video_params:
                        offset = f"&t={video_params['t']}"
            elif video_url.host == "youtu.be":
                video_id = video_url.name
                if "t" in video_params:
                    offset = f"&t={video_params['t']}"
            
            # If we couldn't extract a video_id (e.g., they linked to a channel page), skip silently
            if not video_id:
                continue

            # Fetch video info
            params = {
                "key": self.config["api_key"],
                "part": "snippet",
                "id": video_id
            }
            async with self.http.get("https://www.googleapis.com/youtube/v3/videos", params=params) as response:
                videos = await response.json()
                if "error" in videos:
                    self.log.error(f"GET {str(response.url)}: {response.status} {videos['error']['message']}")
                    continue
                elif response.status >= 400:
                    self.log.error(f"GET {str(response.url)}: {response.status}")
                    continue

            # If video is private, deleted, or wrong ID, skip silently
            if len(videos.get("items", [])) < 1:
                continue

            video = videos["items"][0]

            # Fix KeyError: 'maxres' by gracefully falling back to available resolutions
            thumbnails = video["snippet"]["thumbnails"]
            thumb_url = ""
            for res in ["maxres", "high", "standard", "medium", "default"]:
                if res in thumbnails:
                    thumb_url = thumbnails[res]["url"]
                    break

            # Upload thumbnail
            img_html = ""
            if thumb_url:
                mxc = await self.upload_img(thumb_url)
                if mxc:
                    img_html = f"<img width=400 src='{mxc}' />"

            # Construct and send response
            content = TextMessageEventContent(
                msgtype=MessageType.NOTICE,
                format=Format.HTML,
                body=f"> YouTube\n> [{video['snippet']['channelTitle']}](https://www.youtube.com/channel/{video['snippet']['channelId']})\n> **[{video['snippet']['title']}](https://www.youtube.com/watch?v={video['id']}{offset})**",
                formatted_body=f"<blockquote><h5>YouTube<br><br><a href='https://www.youtube.com/channel/{video['snippet']['channelId']}'><span data-mx-color='#FFFFFF'>{video['snippet']['channelTitle']}</span></a></h5><h4><a href='https://www.youtube.com/watch?v={video['id']}{offset}'>{video['snippet']['title']}</a></h4>{img_html}</blockquote>"
            )
            await evt.respond(content)