/*__scenario(2)__
1- Addincome: The program should prompt the user to enter the income
description and amount.
2- Addexpense: The program should prompt the user to enter the expense
description and amount.
3- Viewnetprofit or loss: The program should calculate the total income,
total expenses, and display the net profit (income- expenses) or net
loss (if expenses exceed income).
3- Exit: The user should be able to exit the program.*/


import 'dart:io';

void main() {
  // Lists to store income and expense entries
  List<Map<String, dynamic>> incomeList = [];
  List<Map<String, dynamic>> expenseList = [];

  print("======================================");
  print("   Welcome to Budget Manager App   ");
  print("======================================");

  bool isRunning = true;

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

    stdout.write("Enter your choice (1-4): ");
    String? choice = stdin.readLineSync();

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

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

      // Input validation
      if (amount != null && amount > 0) {
        incomeList.add({
          "description": description ?? "No description",
          "amount": amount
        });
        print("Income added successfully!");
      } else {
        print("Invalid amount! Please enter a positive number.");
      }

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

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

      // Input validation
      if (amount != null && amount > 0) {
        expenseList.add({
          "description": description ?? "No description",
          "amount": amount
        });
        print("Expense added successfully!");
      } else {
        print("Invalid amount! Please enter a positive number.");
      }

    } else if (choice == "3") {
      // View Summary
      double totalIncome = 0;
      double totalExpenses = 0;

      for (var income in incomeList) {
        totalIncome += income["amount"];
      }

      for (var expense in expenseList) {
        totalExpenses += expense["amount"];
      }

      double net = totalIncome - totalExpenses;

      print("\n===== Monthly Summary =====");
      print("Total Income: \$${totalIncome.toStringAsFixed(2)}");
      print("Total Expenses: \$${totalExpenses.toStringAsFixed(2)}");

      if (net > 0) {
        print("Your net profit is \$${net.toStringAsFixed(2)}");

        // Optional Tax Calculation (15%)
        double tax = net > 0 ? net * 0.15 : 0;
        print("Tax to be paid (15%): \$${tax.toStringAsFixed(2)}");

      } else if (net < 0) {
        print("Your net loss is \$${net.abs().toStringAsFixed(2)}");
        print("No tax is required due to loss.");

      } else {
        print("You broke even this month.");
      }

    } else if (choice == "4") {
      print("Thank you for using Budget Manager App!...GB");
      isRunning = false;

    } else {
      print("Invalid choice! Please select between 1 and 4.");
    }
  }
}