import joblib
import pandas as pd
import numpy as np
from flask import Flask, request, jsonify

# Initialize Flask app
sales_revenue_api = Flask("SuperKart Outlet Sales Revenue Predictor")

# Load the trained model, preprocessor, and outlier bounds
model = joblib.load("./tuned_random_forest_model.pkl")
preprocessor = joblib.load("./preprocessor_pipeline.pkl")
outlier_bounds = joblib.load("./outlier_bounds.pkl")

def preprocess_input(input_df):
    # Make a copy to avoid SettingWithCopyWarning
    processed_df = input_df.copy()

    # 1. Handle Product_Sugar_Content inconsistency
    processed_df['Product_Sugar_Content'] = processed_df['Product_Sugar_Content'].replace('reg', 'Regular')

    # 2. Create Store_Age feature
    current_year = 2025
    processed_df['Store_Age'] = current_year - processed_df['Store_Establishment_Year']

    # 3. Create Price_Per_Unit_Weight feature
    processed_df['Price_Per_Unit_Weight'] = processed_df['Product_MRP'] / processed_df['Product_Weight']

    # 4. Apply Outlier Treatment (Capping/Flooring) using loaded bounds
    numerical_features_for_outliers = ['Product_Weight', 'Store_Age', 'Price_Per_Unit_Weight'] # these were the features used for outlier detection
    for col in numerical_features_for_outliers:
        if col in processed_df.columns and col in outlier_bounds:
            lower_bound, upper_bound = outlier_bounds[col]
            processed_df[col] = np.where(processed_df[col] < lower_bound, lower_bound, processed_df[col])
            processed_df[col] = np.where(processed_df[col] > upper_bound, upper_bound, processed_df[col])

    # 5. Drop unnecessary columns (the ones dropped in notebook preprocessing)
    columns_to_drop_final = ['Product_Id', 'Store_Id', 'Product_Allocated_Area', 'Store_Establishment_Year', 'Product_MRP']
    processed_df = processed_df.drop(columns=columns_to_drop_final, errors='ignore')

    # The order of columns must match the X_train_new used during pipeline fitting
    # Re-order columns to match the training data feature order
    expected_feature_order = ['Product_Weight', 'Product_Sugar_Content', 'Product_Type', 'Store_Size', 'Store_Location_City_Type', 'Store_Type', 'Store_Age', 'Price_Per_Unit_Weight']
    processed_df = processed_df[expected_feature_order]

    # 6. Apply the preprocessor (scaling and one-hot encoding)
    processed_data = preprocessor.transform(processed_df)

    return processed_data

# Define a route for the home page
@sales_revenue_api.get('/')
def home():
    return "Welcome to the SuperKart Outlet Sales Revenue Prediction API!"

# Define an endpoint to predict price for a single house
@sales_revenue_api.post('/v1/outlet')
def predict_outlet_salesRevenue():
    # Get JSON data from the request
    outlet_data = request.get_json()

    # Ensure all original required fields are present to reconstruct features
    required_fields = [
        'Product_Id', 'Product_Weight', 'Product_Sugar_Content', 'Product_Allocated_Area',
        'Product_Type', 'Product_MRP', 'Store_Id', 'Store_Establishment_Year',
        'Store_Size', 'Store_Location_City_Type', 'Store_Type'
    ]
    for field in required_fields:
        if field not in outlet_data:
            return jsonify({'error': f'Missing field: {field}'}), 400

    # Convert the extracted data into a DataFrame
    input_df_raw = pd.DataFrame([outlet_data])

    # Preprocess the input data
    processed_input = preprocess_input(input_df_raw)

    # Make a prediction using the trained model
    prediction = model.predict(processed_input).tolist()[0]

    # Return the prediction as a JSON response
    return jsonify({'Predicted_Product_Store_Sales_Total': prediction})

# Define an endpoint to predict price for a batch of houses
@sales_revenue_api.post('/v1/outletbatch')
def predict_outlet_salesRevenue_batch():
    # Get the uploaded CSV file from the request
    file = request.files['file']

    # Read the file into a DataFrame
    input_df_raw = pd.read_csv(file)

    # Preprocess the input data
    processed_input = preprocess_input(input_df_raw)

    # Make predictions for the batch data
    predictions = model.predict(processed_input).tolist()

    # Add predictions to the DataFrame
    input_df_raw['Predicted_Product_Store_Sales_Total'] = predictions

    # Convert results to dictionary
    result = input_df_raw.to_dict(orient="records")

    return jsonify(result)

# Run the Flask app in debug mode
if __name__ == '__main__':
    sales_revenue_api.run(debug=True)