main.py

from fastapi import FastAPI, UploadFile, Form, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import HTMLResponse, JSONResponse, FileResponse
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates
import shutil, os

app = FastAPI()

# ✅ CORS to allow frontend to access backend
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# ✅ Mount static folder (optional JS/CSS support)
app.mount("/static", StaticFiles(directory="static"), name="static")

# ✅ Set templates folder
templates = Jinja2Templates(directory="templates")

# ✅ Serve home.html
@app.get("/", response_class=HTMLResponse)
async def serve_home(request: Request):
    return templates.TemplateResponse("home.html", {"request": request})

# ✅ Backend prediction API
@app.post("/predict")
async def predict(question: str = Form(...), file: UploadFile = Form(...)):
    try:
        temp_path = f"temp_{file.filename}"
        with open(temp_path, "wb") as f:
            shutil.copyfileobj(file.file, f)

        if file.content_type.startswith("image/"):
            from appImage import answer_question_from_image
            from PIL import Image
            image = Image.open(temp_path)
            answer = answer_question_from_image(image, question)
        else:
            from app import answer_question_from_doc
            class NamedFile:
                def __init__(self, name): self.name = name
            answer = answer_question_from_doc(NamedFile(temp_path), question)

        os.remove(temp_path)
        return JSONResponse(content={"answer": answer})

    except Exception as e:
        return JSONResponse(content={"error": str(e)}, status_code=500)