import 'dart:io';

void main() {
  List<Map<String, double>> incomeList = [];
  List<Map<String, double>> expenseList = [];

  bool isRunning = true;
  print("     ===  Assalamualaikum  ===");
  print("=== Budget Management Application ===");

  while (isRunning) {
    print("\nChoose an option:");
    print("1. Add Income");
    print("2. Add Expense");
    print("3. View Net Profit/Loss");
    print("4. Exit");

    stdout.write("Enter your choice: ");
    String? choice = stdin.readLineSync();

    if (choice == null) {
      print("Invalid input.");
      continue;
    }

    if (choice == "1") {
      
      stdout.write("Enter income description: ");
      String? description = stdin.readLineSync();

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

      
      if (description != null &&
          description.isNotEmpty &&
          amount != null &&
          amount >= 0) {
        incomeList.add({description: amount});
        print("Income added successfully.");
      } else {
        print("Invalid income data. Amount must be a positive number.");
      }

    } else if (choice == "2") {
      
      stdout.write("Enter expense description: ");
      String? description = stdin.readLineSync();

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

      
      if (description != null &&
          description.isNotEmpty &&
          amount != null &&
          amount >= 0) {
        expenseList.add({description: amount});
        print("Expense added successfully.");
      } else {
        print("Invalid expense data. Amount must be a positive number.");
      }

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

      double totalIncome = 0;
      double totalExpenses = 0;

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

      
      for (var item in expenseList) {
        totalExpenses += item.values.first;
      }

      double netProfit = totalIncome - totalExpenses;

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

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

        
        double tax = netProfit > 0 ? netProfit * 0.15 : 0;
        print("Tax to be paid (15%): \$${tax}");

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

    } else if (choice == "4") {
      print("Exiting Budget Management Application...Assalamualaikum");
      isRunning = false;

    } else {
      print("Invalid choice. Please select from 1 to 4.");
    }
  }}