import uuid
import logging
from typing import Optional
from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel
from sqlalchemy.orm import Session

from backend.database.db import get_db
from backend.services.eval_service import run_full_pipeline, generate_response, evaluate_response

router = APIRouter(prefix="/chat", tags=["chat"])
logger = logging.getLogger(__name__)


class ChatRequest(BaseModel):
    query: str
    session_id: Optional[str] = None
    prompt_version: Optional[str] = "standard"
    auto_evaluate: Optional[bool] = True
    auto_retry: Optional[bool] = True


class QuickChatRequest(BaseModel):
    query: str
    session_id: Optional[str] = None


@router.post("/message")
async def send_message(
    request: ChatRequest,
    db: Session = Depends(get_db)
):

    if not request.query.strip():
        raise HTTPException(
            status_code=400,
            detail="Query cannot be empty"
        )

    session_id = request.session_id or str(uuid.uuid4())

    try:

        if request.auto_evaluate:

            result = run_full_pipeline(
                query=request.query,
                session_id=session_id,
                db=db
            )

            return result

        else:

            gen = generate_response(
                query=request.query,
                prompt_version=request.prompt_version or "standard",
                db=db,
                session_id=session_id
            )

            return gen

    except Exception as e:

        logger.error(
            f"Chat API error: {e}",
            exc_info=True
        )

        return {
            "session_id": session_id,
            "query": request.query,
            "response": (
                "System is temporarily busy. "
                "Please try again in a few seconds."
            ),
            "evaluation": None,
            "error": str(e)
        }