import 'dart:io';

void main() {
  List<Map<String, double>> incomeList = [];
  List<Map<String, double>> expenseList = [];
  
  print("Welcome to the Budget Management Application!\n");
  
  bool exitProgram = false;
  
  while (!exitProgram) {
    print("Please choose an option:");
    print("1. Add income");
    print("2. Add expense");
    print("3. View summary");
    print("4. Exit");
    stdout.write("Enter your choice: ");
    
    String? choice = stdin.readLineSync();
    
    if (choice != null) {
      if (choice == '1') {
        addEntry(incomeList, "income");
        
      } else if (choice == '2') {
        addEntry(expenseList, "expense");
        
      } else if (choice == '3') {
        displaySummary(incomeList, expenseList);
        
      } else if (choice == '4') {
        exitProgram = true;
        print("Exiting the application. Goodbye!");
        
      } else {
        print("Invalid choice! Please select 1-4.");
      }
    }
  }
}

void addEntry(List<Map<String, double>> list, String entryType) {
  stdout.write("Enter $entryType description: ");
  String? description = stdin.readLineSync();
  
  if (description != null && description.isNotEmpty) {
    stdout.write("Enter $entryType amount: ");
    String? amountInput = stdin.readLineSync();
    
    if (amountInput != null) {
      double? amount = double.tryParse(amountInput);
      
      if (amount != null && amount > 0) {
        list.add({description: amount});
        print("$entryType added!");
      } else {
        print("Invalid amount! Please enter a positive number.");
      }
    }
  } else {
    print("Description cannot be empty!");
  }
}

void displaySummary(List<Map<String, double>> incomeList, List<Map<String, double>> expenseList) {
  double totalIncome = 0;
  double totalExpense = 0;
  
  print("\nIncome Entries:");
  if (incomeList.isEmpty) {
    print("- No income entries");
  } else {
    for (var entry in incomeList) {
      entry.forEach((description, amount) {
        print("- $description: \$${amount.toStringAsFixed(2)}");
        totalIncome += amount;
      });
    }
  }
  
  print("\nExpense Entries:");
  if (expenseList.isEmpty) {
    print("- No expense entries");
  } else {
    for (var entry in expenseList) {
      entry.forEach((description, amount) {
        print("- $description: \$${amount.toStringAsFixed(2)}");
        totalExpense += amount;
      });
    }
  }
  
  double netProfit = totalIncome - totalExpense;
  
  print("\nSummary:");
  print("Total income: \$${totalIncome.toStringAsFixed(2)}");
  print("Total expenses: \$${totalExpense.toStringAsFixed(2)}");
  
  if (netProfit >= 0) {
    print("Net profit: \$${netProfit.toStringAsFixed(2)}");
    
    double tax = netProfit > 0 ? netProfit * 0.15 : 0;
    if (tax > 0) {
      print("Tax to be paid (15%): \$${tax.toStringAsFixed(2)}");
    }
  } else {
    print("Net loss: \$${(-netProfit).toStringAsFixed(2)}");
  }
}