import os
import logging
from typing import Optional
from telethon import TelegramClient, events
from telethon.tl.types import MessageMediaPhoto, MessageMediaDocument
from db.repository import Repository
from core.dedup import compute_content_hash, compute_file_hash
from services.ai_processor import AIProcessor
from core.metrics import COLLECTED_POSTS_TOTAL
from core.proxy import get_telegram_proxy

logger = logging.getLogger(__name__)

SESSION_DIR = os.getenv("SESSION_DIR", "/app/sessions" if os.path.exists("/app") else "/projects/telegram-bots/copykar/sessions")
MEDIA_DIR = os.getenv("MEDIA_DIR", "/app/data/media" if os.path.exists("/app") else "/projects/telegram-bots/copykar/data/media")

class CollectorService:
    def __init__(
        self,
        repo: Repository,
        ai_processor: AIProcessor,
        api_id: Optional[int] = None,
        api_hash: Optional[str] = None,
        phone: Optional[str] = None,
        session_name: Optional[str] = None,
    ):
        self.repo = repo
        self.ai_processor = ai_processor
        self.api_id = api_id or int(os.getenv("API_ID", "0"))
        self.api_hash = api_hash or os.getenv("API_HASH", "")
        self.phone = phone or os.getenv("PHONE")
        self.session_name = session_name or os.path.join(SESSION_DIR, "collector.session")
        os.makedirs(os.path.dirname(self.session_name), exist_ok=True)
        os.makedirs(MEDIA_DIR, exist_ok=True)
        self.client = TelegramClient(self.session_name, self.api_id, self.api_hash, proxy=get_telegram_proxy())

    async def start(self):
        logger.info("Starting Collector Userbot...")
        if self.phone:
            await self.client.start(phone=self.phone)
        else:
            await self.client.start()
        logger.info("Collector Userbot connected successfully.")

        @self.client.on(events.NewMessage)
        async def on_new_message(event: events.NewMessage.Event):
            await self._handle_message(event)

    async def _handle_message(self, event: events.NewMessage.Event):
        try:
            chat_id = event.chat_id
            source = await self.repo.get_source_by_channel_id(chat_id)
            if not source or not source.is_active:
                return

            raw_text = event.raw_text or ""
            media_path = None
            media_type = None
            media_hash = None

            if event.message.media:
                if isinstance(event.message.media, MessageMediaPhoto):
                    media_type = "photo"
                elif isinstance(event.message.media, MessageMediaDocument):
                    media_type = "document"
                else:
                    media_type = "other"

                filename = f"{chat_id}_{event.message.id}"
                download_target = os.path.join(MEDIA_DIR, filename)
                downloaded_file = await event.message.download_media(file=download_target)
                if downloaded_file:
                    media_path = downloaded_file
                    media_hash = compute_file_hash(downloaded_file)

            content_hash = compute_content_hash(raw_text, media_hash)

            post_id = await self.repo.create_raw_post(
                source_channel_id=chat_id,
                source_message_id=event.message.id,
                raw_text=raw_text,
                media_path=media_path,
                media_type=media_type,
                content_hash=content_hash,
            )

            if post_id:
                COLLECTED_POSTS_TOTAL.labels(source_channel_id=str(chat_id)).inc()
                logger.info(f"Collected new post ID {post_id} from channel {chat_id}")
                await self.ai_processor.process_post(post_id)
        except Exception as e:
            logger.error(f"Error handling message from {event.chat_id}: {e}", exc_info=True)

    async def stop(self):
        if self.client.is_connected():
            await self.client.disconnect()
            logger.info("Collector Userbot disconnected.")