"""
ویوهای RAG — چت با استریم
"""
from django.http import StreamingHttpResponse
from rest_framework import status
from rest_framework.request import Request
from rest_framework.response import Response
from rest_framework.views import APIView

from .chat import chat_rag_stream


class ChatView(APIView):
    """
    چت RAG با استریم.
    POST با {"message": "متن سوال"} یا query param message
    """

    def post(self, request: Request):
        message = request.data.get("message") or request.query_params.get("message")
        if not message or not isinstance(message, str):
            return Response(
                {"code": 400, "msg": "پارامتر message الزامی است."},
                status=status.HTTP_400_BAD_REQUEST,
            )
        message = str(message).strip()
        if not message:
            return Response(
                {"code": 400, "msg": "پیام نباید خالی باشد."},
                status=status.HTTP_400_BAD_REQUEST,
            )

        def generate():
            try:
                for chunk in chat_rag_stream(message):
                    yield chunk
            except Exception as e:
                yield f"\n[خطا: {e}]"

        return StreamingHttpResponse(
            generate(),
            content_type="text/plain; charset=utf-8",
        )