import 'dart:io';

void main() {
  print("Welcome to the Budget Management Application!");
  budgetManager();
}

void budgetManager() {
  Map<String, double> expenses = {};
  double totalIncome = 0.0;

  while (true) {
    print("\nChoose an option:");
    print("1. Add Income");
    print("2. Add Expense");
    print("3. View Summary");
    print("4. Exit");

    String? choice = stdin.readLineSync();

    if (choice == "4") {
      print("Exiting the application.");
      break;
    }

    switch (choice) {
      case "1":
        print("Enter income amount:");
        double? income = double.tryParse(stdin.readLineSync() ?? "");
        if (income != null && income > 0) {
          totalIncome += income;
          print("Income added successfully.");
        } else {
          print("Invalid amount.");
        }
        break;

      case "2":
        print("Enter expense description:");
        String? name = stdin.readLineSync();
        print("Enter expense amount:");
        double? amount = double.tryParse(stdin.readLineSync() ?? "");
        if (name != null && amount != null && amount > 0) {
          expenses[name] = amount;
          print("Expense added successfully.");
        } else {
          print("Invalid input.");
        }
        break;

      case "3":
        showReport(totalIncome, expenses);
        break;

      default:
        print("Invalid option. Try again.");
    }
  }
}

void showReport(double income, Map<String, double> expenses) {
  double totalExpenses = expenses.values.fold(0.0, (sum, item) => sum + item);
  double balance = income - totalExpenses;

  print("\n--- Budget Summary ---");
  print("Total Income: \$${income.toStringAsFixed(2)}");
  print("Total Expenses: \$${totalExpenses.toStringAsFixed(2)}");
  print("Net Balance: \$${balance.toStringAsFixed(2)}");

  print("\nExpense Details:");
  expenses.forEach((key, value) {
    print("- $key: \$${value.toStringAsFixed(2)}");
  });

  if (balance < 0) {
    print("⚠ Warning: You are running a deficit!");
  } else if (balance == 0) {
    print("⚠ Warning: No remaining balance.");
  } else {
    print("✅ Your budget is in good shape.");
  }
}