from fastapi import FastAPI, HTTPException
from fastapi.responses import JSONResponse
from fastapi.middleware.cors import CORSMiddleware
import data_collector as dc
import pandas as pd

app = FastAPI()
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

@app.post("/get_product_count_prediction")
async def get_product_count_prediction(b_id: int, product_name: str):
    try:
        # main
        data, message = dc.get_data(b_id=b_id, product_name=product_name)
        
        if message == "done":
            # Summarize the sales count per month
            data['transaction_date'] = pd.to_datetime(data['transaction_date'])
            data.set_index('transaction_date', inplace=True)
            monthly_sales = data['sell_qty'].resample('M').sum().reset_index()
            
            full_trend, forecasted_value, rounded_value = dc.forecast(monthly_sales)
            print(full_trend, forecasted_value, rounded_value)
            
            rounded_value.columns = ["next_month", "y", "predicted_count"]
            
            # Convert to dictionary
            result_dict = rounded_value.to_dict(orient="records")[0]
            
            response_content = {
                "status": "success",
                "message": "Prediction successful",
                "data": {
                    "next_month": str(result_dict["next_month"]),
                    "predicted_count": result_dict["predicted_count"]
                }
            }
            return JSONResponse(content=response_content, status_code=200)
        else:
            raise HTTPException(status_code=400, detail=message)
    except Exception as e:
        response_content = {
            "status": "error",
            "message": str(e),
            "data": None
        }
        return JSONResponse(content=response_content, status_code=500)