Fatimaalkoud_242002338_question2.

// Exam 3 - Question 2
// Budget Management Application
// Student Name: Fatima Alkoud
// University ID: 242002338

import 'dart:io';

void main() {

  // Lists to store income and expenses
  List<Map<String, double>> incomeList = [];
  List<Map<String, double>> expenseList = [];

  bool running = true;

  print("Welcome to Budget Management Application");

  // Main loop
  while (running) {

    print("\n--- Budget Menu ---");
    print("1. Add income");
    print("2. Add expense");
    print("3. View summary");
    print("4. Exit");

    String? choice = stdin.readLineSync();

    // Handle menu options using if/else
    if (choice == '1') {

      print("Enter income description:");
      String? description = stdin.readLineSync();

      print("Enter income amount:");
      String? amountInput = stdin.readLineSync();
      double? amount = double.tryParse(amountInput ?? "");

      // Validate positive amount
      if (amount != null && amount > 0) {
        incomeList.add({ description ?? "Unknown": amount });
        print("Income added successfully.");
      } else {
        print("Invalid amount. Please enter a positive number.");
      }

    } else if (choice == '2') {

      print("Enter expense description:");
      String? description = stdin.readLineSync();

      print("Enter expense amount:");
      String? amountInput = stdin.readLineSync();
      double? amount = double.tryParse(amountInput ?? "");

      // Validate positive amount
      if (amount != null && amount > 0) {
        expenseList.add({ description ?? "Unknown": amount });
        print("Expense added successfully.");
      } else {
        print("Invalid amount. Please enter a positive number.");
      }

    } else if (choice == '3') {

      double totalIncome = 0;
      double totalExpense = 0;

      // Calculate total income
      for (var item in incomeList) {
        totalIncome += item.values.first;
      }

      // Calculate total expenses
      for (var item in expenseList) {
        totalExpense += item.values.first;
      }

      double netResult = totalIncome - totalExpense;

      print("\n--- Budget Summary ---");
      print("Total Income: \$${totalIncome}");
      print("Total Expenses: \$${totalExpense}");

      if (netResult > 0) {
        print("Your net profit is \$${netResult}");

        // Calculate 15% tax only if there is profit (ternary operator)
        double tax = netResult > 0 ? netResult * 0.15 : 0;
        print("Tax to be paid (15%): \$${tax}");

      } else if (netResult < 0) {
        print("Your net loss is \$${netResult.abs()}");
      } else {
        print("You broke even. No profit, no loss.");
      }

    } else if (choice == '4') {

      running = false;
      print("Exiting application. Goodbye!");

    } else {
      print("Invalid option. Please try again.");
    }
  }
}