from typing import Optional, Callable, List
from telethon import events
from telethon.tl.types import Message

from config import BOT_USERNAME
from telegram.client import TelegramClientWrapper
from models.schemas import MessageResponse


class BotChatManager:
    def __init__(self, client_wrapper: TelegramClientWrapper):
        self.client_wrapper = client_wrapper
        self.bot_entity = None
        self._message_callback: Optional[Callable] = None

    async def init_bot_chat(self):
        """Initialize chat with the bot"""
        client = self.client_wrapper.client
        if not client:
            raise RuntimeError("Client not initialized")

        # Resolve bot entity
        self.bot_entity = await client.get_entity(BOT_USERNAME)

        # Set up event handler for all messages in bot chat (incoming and outgoing)
        @client.on(events.NewMessage(chats=self.bot_entity))
        async def handle_bot_message(event: events.NewMessage):
            if self._message_callback:
                msg = event.message
                response = MessageResponse(
                    id=msg.id,
                    text=msg.text,
                    date=msg.date,
                    is_outgoing=msg.out,
                    sender_name="You" if msg.out else BOT_USERNAME
                )
                await self._message_callback(response)

        return self.bot_entity

    def set_message_callback(self, callback: Callable):
        """Set callback for incoming messages"""
        self._message_callback = callback

    async def send_message(self, text: str) -> MessageResponse:
        """Send message to the bot"""
        client = self.client_wrapper.client
        if not client or not self.bot_entity:
            raise RuntimeError("Bot chat not initialized")

        msg = await client.send_message(self.bot_entity, text)
        return MessageResponse(
            id=msg.id,
            text=msg.text,
            date=msg.date,
            is_outgoing=True,
            sender_name="You"
        )

    async def get_history(self, limit: int = 50) -> List[MessageResponse]:
        """Get chat history with the bot"""
        client = self.client_wrapper.client
        if not client or not self.bot_entity:
            raise RuntimeError("Bot chat not initialized")

        messages = []
        async for msg in client.iter_messages(self.bot_entity, limit=limit):
            messages.append(MessageResponse(
                id=msg.id,
                text=msg.text,
                date=msg.date,
                is_outgoing=msg.out,
                sender_name="You" if msg.out else BOT_USERNAME
            ))

        # Return in chronological order
        return list(reversed(messages))