app.py

import pandas as pd
import pickle
import gradio as gr

# Define preprocessing function
def preprocess_input(data):
    df = pd.DataFrame(data, index=[0])

    # Let's find which percent are paid
    df['Percent_paid'] = df.apply(lambda row: row['Amount_paid'] / row['Transaction_Amount'] if row['Transaction_Amount'] != 0 else 0, axis=1)

    # Let's also group Vehicle_Speed, Transaction_Amount columns
    def Vehicle_Speed_group(speed):
      if speed <= 21:
        return '<= 21'
      elif speed <= 41:
        return '21-41'
      elif speed <= 93:
        return '41-93'
      elif speed <= 103:
        return '93-103'
      else:
        return '103 <'

    def Transaction_Amount_group(amount):
      if amount <= 60:
        return '<= 60'
      elif amount <= 180:
        return '60-180'
      elif amount <= 330:
        return '180-330'
      else:
        return '330 <'

    df['Vehicle_Speed_group'] = df['Vehicle_Speed'].apply(lambda x: Vehicle_Speed_group(x))
    df['Transaction_Amount_group'] = df['Transaction_Amount'].apply(lambda x: Transaction_Amount_group(x))

    # Let's encode categorical features
    df = pd.get_dummies(df, columns=['Vehicle_Type', 'Lane_Type','TollBoothID', 'Vehicle_Dimensions','Vehicle_Speed_group','Transaction_Amount_group'], drop_first=True)

    # Let's first remove unnecessary columns
    df.drop(columns = ['Transaction_ID','Timestamp','FastagID','Geographical_Location','Vehicle_Plate_Number'], inplace = True)

    # Let's convert all bool to int
    for col in df.select_dtypes(include=['bool', 'object']):
        try:
            df[col] = df[col].astype(int)
        except ValueError:
            df[col] = df[col].astype(float).round().astype(int)

    columns_to_add = ['Transaction_Amount', 'Amount_paid', 'Vehicle_Speed', 'Percent_paid',
       'Vehicle_Type_Car', 'Vehicle_Type_Motorcycle', 'Vehicle_Type_SUV',
       'Vehicle_Type_Sedan', 'Vehicle_Type_Truck', 'Vehicle_Type_Van',
       'Lane_Type_Regular', 'TollBoothID_B-102', 'TollBoothID_C-103',
       'TollBoothID_D-104', 'TollBoothID_D-105', 'TollBoothID_D-106',
       'Vehicle_Dimensions_Medium', 'Vehicle_Dimensions_Small',
       'Vehicle_Speed_group_21-41', 'Vehicle_Speed_group_41-93',
       'Vehicle_Speed_group_93-103', 'Vehicle_Speed_group_<= 21',
       'Transaction_Amount_group_330 <', 'Transaction_Amount_group_60-180',
       'Transaction_Amount_group_<= 60']

    # Add missing columns with default value of 0
    for column in columns_to_add:
        if column not in df.columns:
            df[column] = 0

    return df

# Load the trained Decision tree classification model
with open('dt_model.pkl', 'rb') as file:
    dt_model = pickle.load(file)

# Define function to detect fraud
def predict_salary(transaction_id, timestamp, vehicle_type, fastag_id, tollbooth_id, lane_type, vehicle_dimensions, transaction_amount, amount_paid, geographical_location, vehicle_speed, vehicle_plate_number):
    # Preprocess input data
    input_data = preprocess_input({
        "Transaction_ID": transaction_id,
        "Timestamp": timestamp,
        "Vehicle_Type": vehicle_type,
        "FastagID": fastag_id,
        "TollBoothID": tollbooth_id,
        "Lane_Type": lane_type,
        "Vehicle_Dimensions": vehicle_dimensions,
        "Transaction_Amount": transaction_amount,
        "Amount_paid": amount_paid,
        "Geographical_Location": geographical_location,
        "Vehicle_Speed": vehicle_speed,
        "Vehicle_Plate_Number": vehicle_plate_number
        })

    input_data = input_data[['Transaction_Amount', 'Amount_paid', 'Vehicle_Speed', 'Percent_paid',
       'Vehicle_Type_Car', 'Vehicle_Type_Motorcycle', 'Vehicle_Type_SUV',
       'Vehicle_Type_Sedan', 'Vehicle_Type_Truck', 'Vehicle_Type_Van',
       'Lane_Type_Regular', 'TollBoothID_B-102', 'TollBoothID_C-103',
       'TollBoothID_D-104', 'TollBoothID_D-105', 'TollBoothID_D-106',
       'Vehicle_Dimensions_Medium', 'Vehicle_Dimensions_Small',
       'Vehicle_Speed_group_21-41', 'Vehicle_Speed_group_41-93',
       'Vehicle_Speed_group_93-103', 'Vehicle_Speed_group_<= 21',
       'Transaction_Amount_group_330 <', 'Transaction_Amount_group_60-180',
       'Transaction_Amount_group_<= 60']]

    # Predict Fraud using the trained model
    fraud_prediction = dt_model.predict(input_data)
    fraud_prediction = ['Fraud❌' if fraud_prediction[0] == 1 else 'Not Fraud✅']
    result = f'Transaction ID {transaction_id}, the predicted fraud based on your details is {"Fraud" if fraud_prediction[0] == 1 else "Not Fraud"}'
    return result


# Define Gradio interface
interface = gr.Interface(
    fn=predict_salary,
    inputs=[
        gr.Textbox(label="Transaction ID"),
        gr.Textbox(label="Timestamp"),
        gr.Dropdown(['Bus ','Car','Motorcycle','Truck','Van','Sedan','SUV'], label="Vehicle_Type"),
        gr.Textbox(label="Fastag ID"),
        gr.Dropdown(['A-101','B-102','D-104','C-103','D-105','D-106'], label="TollBoothID"),
        gr.Dropdown(['Express','Regular'], label="Lane_Type"),
        gr.Dropdown(['Large','Small','Medium'], label="Vehicle_Dimensions"),
        gr.Number(label="Transaction Amount"),
        gr.Number(label="Amount Paid"),
        gr.Textbox(label="Geographical Location"),
        gr.Number(label="Vehicle Speed"),
        gr.Textbox(label="Vehicle Plate Number")
    ],
    outputs=gr.Textbox(label="Predicted Salary"),
    title="Fraud Detection Model",
    description="Enter details to predict salary."
)

# Launch the Gradio interface
interface.launch()