DiceRoller.java

// A virtual dice roller program to roll dice with a specified number of sides.

import java.util.Random;
import java.util.Scanner;
import java.util.Set;

public class DiceRoller {
    // Sets of valid inputs for yes and no responses in portuguese and english
    private static final Set<String> YES_OPTIONS = Set.of("y", "yes", "s", "sim");
    private static final Set<String> NO_OPTIONS = Set.of("n", "no", "nop", "não");

    public static void main(String[] args) {
        // Using try with resources to ensure the scanner is closed automatically
        try (Scanner scanner = new Scanner(System.in)) {
            Random random = new Random();

            // Main loop to roll dice
            while (true) {
                printDiceArtMenu();
                int sides = readPositiveInt(scanner);
                Dice dice = new Dice(sides, random);
                int result = dice.roll();
                System.out.println("You rolled a " + result + " on a " + sides + "-sided dice!!!");
                printDiceArtFinal();

                String input;
                // Loop to get a valid response for rolling again
                while (true) {
                    System.out.print("Do you want to roll again? (y/n): ");
                    input = scanner.next().trim().toLowerCase();

                    if (YES_OPTIONS.contains(input)) {
                        System.out.println("Great! Let's roll again.\n");
                        break; // sai desse loop e volta para o loop principal
                    } else if (NO_OPTIONS.contains(input)) {
                        System.out.println("Thank you for using the virtual Dice Roller :)\nGoodbye!");
                        return; // sai do main
                    } else {
                        System.out.println("Invalid input. Please type yes/y or no/n.");
                    }
                }
            }
        }
    }

    // Prints the welcome menu with ASCII art
    private static void printDiceArtMenu() {
        System.out.println("""
                ############################################
                     Welcome to the virtual DICE roller!
                ############################################
                                        _______.
                           ______      | .   . |\\
                          /      /\\    |   .   |.\\
                         /  '   /  \\   | .   . |.'|
                        /______/. . \\  |_______|.'|
                        \\ . .  \\    /  \\  ' .   \\'|
                         \\ . .  \\  /    \\____'___\\|
                          \\______\\/
                """); // pritty asciis hihi :)
    }

    // Prints the final dice ASCII art
    private static void printDiceArtFinal() {
        System.out.println("""
                \n       .-------.
                      /   o   /|
                     /_______/o|
                     | o     | |
                     |   o   |o/
                     |     o |/
                     '-------'
                """);
    }

    // Reads a positive integer from the user
    public static int readPositiveInt(Scanner scanner) {
        int value;

        while (true) {
            System.out.print("Enter the number of sides for the dice: ");

            if (scanner.hasNextInt()) {
                value = scanner.nextInt();

                if (value > 0) {
                    return value;
                }
            } else { scanner.next(); }

            System.out.println("Invalid input. Please enter a number greater than 0.");
        }
    }

    // Dice class representing a dice with a given number of sides
    public static class Dice {
        private final int sides;
        private final Random random;

        public Dice(int sides, Random random) {
            this.sides = sides;
            this.random = random;
        }

        public int roll() {
            return random.nextInt(sides) + 1;
        }
    }

}