FriendListMaintance

package MidExam_8;

import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;

public class Exercise_02 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        List<String> names = Arrays.stream(scanner.nextLine()
                        .split(", "))
                .collect(Collectors.toList());
        String command = scanner.nextLine();

        int blacklisted = 0;
        int lostNames = 0;
        while (!command.equals("Report")) {
            String[] commandParts = command.split(" ");
            String commandName = commandParts[0];

            switch (commandName) {
                case "Blacklist":
                    String name = commandParts[1];
                    //   int indexOfName = names.indexOf(name);

                    if (names.contains(name)) {
                        int indexOfName = names.indexOf(name);
                        blacklisted++;
                        names.set(indexOfName, "Blacklisted");
                        System.out.printf("%s was blacklisted.%n", name);
                    } else {
                        System.out.printf("%s was not found.%n", name);
                    }
                    break;
                case "Error":
                    int index = Integer.parseInt(commandParts[1]);
                    if (index >= 0 && index < names.size()) {
                        String nameAtTheIndex = names.get(index);
                        if (!nameAtTheIndex.equals("Lost") && !nameAtTheIndex.equals("Blacklisted")) {
                            names.set(index, "Lost");
                            lostNames++;
                            System.out.printf("%s was lost due to an error.%n", nameAtTheIndex);
                        }
                    }
                    break;
                case "Change":
                    int currentIndex = Integer.parseInt(commandParts[1]);
                    if (currentIndex >= 0 && currentIndex < names.size()) {
                        String newName = commandParts[2];
                        String writtenName = names.get(currentIndex);
                        names.set(currentIndex, newName);
                            System.out.printf("%s changed his username to %s.%n", writtenName, newName);
                        break;
                    }
            }
            command = scanner.nextLine();
        }

        System.out.printf("Blacklisted names: %d%n", blacklisted);
        System.out.printf("Lost names: %d%n", lostNames);
        System.out.println(String.join(" ", names));
    }

}