ui

a.java

package client;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.concurrent.BlockingQueue;

public class TerminalWhatsApp extends Thread {

  private final BlockingQueue<String> queue;
  private final List<String> messages = new ArrayList<>();
  private volatile boolean running = true;
  private String userName;

  // ANSI escape codes for color
  private static final String GREEN = "\u001B[32m";
  private static final String CYAN = "\u001B[36m";
  private static final String RESET = "\u001B[0m";

  public TerminalWhatsApp(BlockingQueue<String> queue, String userName) {
    this.queue = queue;
    this.userName = userName;
  }

  @Override
  public void run() {
    try (Scanner scanner = new Scanner(System.in)) {
      clearScreen();
      System.out.println(CYAN + "=== Welcome to Terminal WhatsApp ===" + RESET);
      System.out.println("Type your messages below. Type 'exit' to quit.\n");

      while (running) {
        redrawChat(); // Always show chat before asking input

        System.out.print("\n" + GREEN + userName + ": " + RESET);
        String input = scanner.nextLine().trim();

        if (input.isEmpty()) {
          continue; // Ignore empty messages
        }

        if ("exit".equalsIgnoreCase(input)) {
          System.out.println(CYAN + "Exiting WhatsApp..." + RESET);
          running = false;
          break;
        }

        sendMessage(input);
      }
    }
  }

  /** Add a local (user-sent) message and send it through the queue */
  private synchronized void sendMessage(String message) {
    messages.add(GREEN + userName + ": " + RESET + message);
    try {
      queue.put(message);
    } catch (InterruptedException e) {
      Thread.currentThread().interrupt();
      System.err.println("Message sending interrupted.");
    }
  }

  /** Add an incoming message (from another user) and refresh display */
  public synchronized void addIncomingMessage(String sender, String message) {
    messages.add(CYAN + sender + ": " + RESET + message);
    redrawChat(); // Redraw the chat after receiving a message
    // Always show prompt again so the user can continue typing
    System.out.print("\n" + GREEN + userName + ": " + RESET);
    System.out.flush();
  }

  /** Redraw the entire chat history */
  private synchronized void redrawChat() {
    clearScreen();
    System.out.println(CYAN + "=== Chat ===" + RESET + "\n");
    for (String msg : messages) {
      System.out.println(msg);
    }
    System.out.flush();
  }

  /** Clear the terminal screen using ANSI codes */
  private void clearScreen() {
    System.out.print("\033[H\033[2J");
    System.out.flush();
  }

  public String getUserName() {
    return userName;
  }

  public void stopChat() {
    running = false;
    this.interrupt();
  }
}