from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel
import pandas as pd
import numpy as np
import joblib


# Load your trained model and encoders
xgb_model = joblib.load("xgb_model.joblib")
encoders = joblib.load("encoders.joblib")

# Function to handle unseen labels during encoding
def safe_transform(encoder, column):
    classes = encoder.classes_
    return [encoder.transform([x])[0] if x in classes else -1 for x in column]

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

# Endpoint for making predictions
@app.post("/predict")
def predict(customer_name: str,
    customer_address: str,
    customer_phone: str,
    customer_email: str,
    cod:str,
    weight: str,
    pickup_address: str,
    origin_city_name: str,
    destination_city_name: str):
    # Convert input data to DataFrame
    input_data = {
        'customer_name': customer_name,
        'customer_address': customer_address,
        'customer_phone': customer_phone,
        'customer_email': customer_email,
        'cod': float(cod),
        'weight': float(weight),
        'pickup_address':pickup_address,
        'origin_city.name':origin_city_name,
        'destination_city.name':destination_city_name
    }
    input_df = pd.DataFrame([input_data])

    # Encode categorical variables using the same encoders used during training
    for col in input_df.columns:
        if col in encoders:
            input_df[col] = safe_transform(encoders[col], input_df[col])

    # Predict and obtain probabilities
    pred = xgb_model.predict(input_df)
    pred_proba = xgb_model.predict_proba(input_df)

    # Output
    predicted_status = "Unknown" if pred[0] == -1 else encoders['status.name'].inverse_transform([pred])[0]
    probability = pred_proba[0][pred[0]] * 100 if pred[0] != -1 else "Unknown"

    if predicted_status == "RETURN TO CLIENT":
       probability = 100 - probability

    return {"Probability": round(probability,2)}