# Import necessary libraries
import numpy as np
import joblib  # For loading the serialized model
import pandas as pd  # For data manipulation
from flask import Flask, request, jsonify  # For creating the Flask API

# Initialize the Flask application
predictor_api = Flask("SuperKart Price Predictor")

# Load the trained machine learning model
model = joblib.load("superkart_prediction_model_v1_0.joblib")

# Define a route for the home page (GET request)
@predictor_api.get('/')
def home():
    """
    This function handles GET requests to the root URL ('/') of the API.
    It returns a simple welcome message.
    """
    return "Welcome to the Superkart Price Prediction API!"

# Define an endpoint for single property prediction (POST request)
@predictor_api.post('/v1/superkart')
def predict_price():
    """
    This function handles POST requests to the '/v1/superkart' endpoint.
    It expects a JSON payload containing property details and returns
    the predicted sales price as a JSON response.
    """
    # Get the JSON data from the request body
    property_data = request.get_json()

    # Extract relevant features from the JSON data
    sample = {
        'Product_Weight': property_data['product_weight'],
        'Product_Sugar_Content': property_data['product_sugar_content'],
        'Product_Allocated_Area': property_data['product_allocated_area'],
        'Product_Type': property_data['product_type'],
        'Product_MRP': property_data['product_mrp'],
        'Store_Size': property_data['store_size'],
        'Store_Location_City_Type': property_data['store_location_city_type'],
        'Age_Category': property_data['age_category'],
        'type_of_food': property_data['type_of_food']
    }

    # Convert the extracted data into a Pandas DataFrame
    input_data = pd.DataFrame([sample])

    # Make prediction
    predicted_price = model.predict(input_data)[0]

    # Convert predicted_price to Python float
    predicted_price = round(float(predicted_price), 2)
    # The conversion above is needed as we convert the model prediction (log price) to actual price using np.exp, which returns predictions as NumPy float32 values.
    # When we send this value directly within a JSON response, Flask's jsonify function encounters a datatype error

    # Return the actual price
    return jsonify({'Predicted Price': predicted_price})

# Run the Flask application in debug mode if this script is executed directly
if __name__ == '__main__':
    predictor_api.run(debug=True)