import com.sun.jna.Native;
import com.sun.jna.platform.win32.User32;
import com.sun.jna.platform.win32.WinDef;
import javax.swing.*;
import java.awt.*;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

public class FocusApp {

    private static int switchCount = 0;
    private static String lastWindow = "";
    private static long lastSwitchTime = System.currentTimeMillis();

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            JFrame frame = new JFrame("Window Switch Logger");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   
            frame.setSize(400, 300);

            JTextArea logArea = new JTextArea();
            logArea.setEditable(false);
            JScrollPane scrollPane = new JScrollPane(logArea);
            frame.add(scrollPane, BorderLayout.CENTER);

            frame.setVisible(true);

            new Thread(() -> monitorWindowFocus(logArea)).start();
        });
    }

    private static void monitorWindowFocus(JTextArea logArea) {
        User32 user32 = User32.INSTANCE;
        WinDef.HWND hwnd = user32.GetForegroundWindow();
        char[] windowText = new char[512];
        user32.GetWindowText(hwnd, windowText, 512);
        lastWindow = Native.toString(windowText);

        while (true) {
            hwnd = user32.GetForegroundWindow();
            user32.GetWindowText(hwnd, windowText, 512);
            String currentWindow = Native.toString(windowText);

            if (!currentWindow.equals(lastWindow)) {
                long currentTime = System.currentTimeMillis();
                long duration = currentTime - lastSwitchTime;
                lastSwitchTime = currentTime;

                String logMessage = String.format("Window: %s (Duration: %d ms)\n", lastWindow, duration);
                lastWindow = currentWindow;
                switchCount++;
                logArea.append(logMessage);
                System.out.print(logMessage);

                try (BufferedWriter writer = new BufferedWriter(new FileWriter("window_switch_log.txt", true))) {
                    writer.write(logMessage);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            try {
                Thread.sleep(500);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}