from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.exc import SQLAlchemyError
from sqlalchemy.orm import Session

from app.api.routes.dependencies import db_error_detail, get_db
from app.api.schemas import ChatRequest, ChatResponse
from app.services.orchestration.orquestrador_service import OrquestradorService

router = APIRouter(tags=["Chat"])


@router.post("/chat", response_model=ChatResponse)
async def chat(request: ChatRequest, db: Session = Depends(get_db)):
    """Processa mensagem do usuario via orquestrador e retorna resposta do chat."""
    try:
        service = OrquestradorService(db)
        result = await service.handle_message(
            message=request.message,
            user_id=request.user_id,
        )
        return ChatResponse(response=result)
    except SQLAlchemyError as exc:
        raise HTTPException(
            status_code=503,
            detail=db_error_detail(exc),
        )
    except ValueError as exc:
        # Erros de configuracao de Vertex (regiao/projeto/modelo)
        raise HTTPException(status_code=500, detail=f"Configuracao invalida do Vertex AI: {exc}")
    except RuntimeError as exc:
        raise HTTPException(status_code=503, detail=f"Falha temporaria no LLM/Vertex AI: {exc}")