main.py

from fastapi import FastAPI
from pydantic import BaseModel
import requests
import os

app = FastAPI()

# --- Gemini API key ---
GEMINI_API_KEY = "AIzaSyApC_u1SScesLRbTfdz5lEcQExDaX-5IwQ"  # Replace this with your real key
GEMINI_URL = (
    "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent"
)

# --- Static prompt ---
STATIC_INSTRUCTION = (
    "Reply with a short, well-written summary in 2 to 3 sentences. "
    "Be clear and concise. Avoid unnecessary explanations."
)

# --- Input schema ---
class ChatRequest(BaseModel):
    query: str

# --- Output schema (optional) ---
class ChatResponse(BaseModel):
    reply: str

# --- Endpoint ---
@app.post("/chat", response_model=ChatResponse)
def chat(req: ChatRequest):
    try:
        # Combine prompt and query as a single user message
        full_prompt = f"{STATIC_INSTRUCTION}\n\nUser question: {req.query}"

        contents = [
            {"role": "user", "parts": [{"text": full_prompt}]}
        ]

        response = requests.post(
            GEMINI_URL,
            headers={
                "Content-Type": "application/json",
                "x-goog-api-key": GEMINI_API_KEY
            },
            json={"contents": contents}
        )

        response.raise_for_status()  # raise exception if status != 200

        data = response.json()
        reply = (
            data.get("candidates", [{}])[0]
                .get("content", {}).get("parts", [{}])[0]
                .get("text", "No reply")
        )

        return {"reply": reply.strip()}

    except Exception as e:
        return {"reply": f"Error: {e}"}