import json

from channels.db import database_sync_to_async
from channels.generic.websocket import AsyncWebsocketConsumer
from django.contrib.auth.models import AnonymousUser

def get_base_url(scope):
    headers = dict(scope["headers"])
    host = headers.get(b"host", b"").decode()
    scheme = "https" if scope.get("scheme") == "https" else "http"
    return f"{scheme}://{host}"

class ChatConsumer(AsyncWebsocketConsumer):
    """
    Xona asosidagi chat consumer.
    Ulanish: ws://host/ws/chat/room/{room_id}/?token=<jwt>

    Matn xabari yuborish:
        { "message_type": "text", "text": "Salom" }

    Fayl xabari (oldin REST orqali yuklab, keyin URL yuborish):
        { "message_type": "image", "file_url": "https://...", "text": "caption (ixtiyoriy)" }
    """

    async def connect(self):
        user = self.scope.get("user")
        if not user or isinstance(user, AnonymousUser):
            await self.close(code=4001)
            return

        self.room_id = self.scope["url_route"]["kwargs"]["room_id"]
        self.room_group = f"chat_room_{self.room_id}"

        await self.channel_layer.group_add(self.room_group, self.channel_name)
        await self.accept()

    async def disconnect(self, close_code):
        if hasattr(self, "room_group"):
            await self.channel_layer.group_discard(self.room_group, self.channel_name)

    async def receive(self, text_data):
        user = self.scope.get("user")
        if not user or isinstance(user, AnonymousUser):
            await self.close(code=401)
            return

        try:
            data = json.loads(text_data)
        except (json.JSONDecodeError, ValueError):
            await self.send(text_data=json.dumps({"error": "Noto'g'ri format."}))
            return

        message_type = data.get("message_type", "text")
        text = (data.get("text") or "").strip()

        if message_type == "text" and not text:
            await self.send(text_data=json.dumps({"error": "Matn bo'sh bo'lishi mumkin emas."}))
            return

        if message_type != "text":
            await self.send(
                text_data=json.dumps(
                    {"error": "Fayl xabarlarni yuklash uchun REST API dan foydalaning."}
                )
            )
            return

        await self._save_message(user, text)

    # Uz
    # Bu funksiya ishlatilmayapti, shuning uchun commentga olib qoydim, bu funksiya orniga /core/apps/chat/tasks/message.py ichida rest api yordamida message
    # yuborilsa ishlatiladigan task bor.

    # En
    # This function is not used, so I commented it out. Instead, a task is used in /core/apps/chat/tasks/message.py
    # to send message when message is added from REST API.
    
    # async def chat_message(self, event):
    #     await self.send(
    #         text_data=json.dumps(
    #             {
    #                 "id": event["id"],
    #                 "message_type": event["message_type"],
    #                 "text": event["text"],
    #                 "file_url": event["file_url"],
    #                 "sender": event["sender"],
    #                 "created_at": event["created_at"],
    #             }
    #         )
    #     )

    @database_sync_to_async
    def _save_message(self, user, text):
        from core.apps.chat.models import ChatmessageModel

        msg = ChatmessageModel.objects.create(
            room_id=self.room_id,
            sender=user,
            message_type="text",
            text=text,
        )
        full_name = user.get_full_name().strip() or str(user.phone)
        base_url = get_base_url(self.scope)

        avatar_url = (
            base_url + user.avatar.url
            if user.avatar else None
        )
        return {
            "id": msg.id,
            "message_type": msg.message_type,
            "text": msg.text,
            "file_url": None,
            "sender": {
                "id": user.id,
                "full_name": full_name,
                "role": user.role,
                "phone": user.phone,
                "avatar": avatar_url,
            },
            "created_at": msg.created_at.isoformat(),
        }