LangChain/app/api/chat.py

from fastapi import APIRouter, HTTPException, UploadFile, File, Query
from app.services.qa import get_answer, ask_rag
from app.schemas.chat import ChatRequest, ChatResponse
import time

router = APIRouter()

@router.post("/chat/")
async def chat(request: ChatRequest, session_id: str = "default_session"):
    start_time = time.time()
    
    try:
        answer = get_answer(session_id, request.message)
        latency_ms = int((time.time() - start_time) * 1000)
        return ChatResponse(answer=answer, latency_ms=latency_ms)
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Ollama call failed with error: {str(e)}")

@router.post("/ask/")
async def ask(session_id: str = Query("default_session"), question: str = Query(...), file: UploadFile = File(None)):
    start_time = time.time()
    
    try:
        file_content = None
        file_name = None
        if file:
            file_content = await file.read()
            file_name = file.filename
            if not file_name.endswith(('.txt', '.md')):
                raise HTTPException(status_code=400, detail="Only .txt or .md files are supported")
        
        result = ask_rag(session_id, question, file_content, file_name)
        latency_ms = int((time.time() - start_time) * 1000)
        return {"answer": result["answer"], "sources": result["sources"], "latency_ms": latency_ms}
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Ollama call failed with error: {str(e)}")

@router.get("/health")
async def health():
    return {"status": "healthy"}