package invalid.lena.scrcpy;

import android.content.Context;

import java.io.File;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

// Catches uncaught exceptions on any thread, writes them as plain
// text to <externalFilesDir>/crash-<timestamp>.log, then chains to
// the system default handler so the OS crash dialog still appears.
// Testers can share the file from the app's storage instead of
// fishing for it in adb logcat.
public final class Crashlog {

    private Crashlog() {}

    public static void install(Context ctx) {
        File dir = ctx.getExternalFilesDir(null);
        if (dir == null) {
            Log.w("crashlog: no external storage, skipping install");
            return;
        }
        Thread.UncaughtExceptionHandler prev =
                Thread.getDefaultUncaughtExceptionHandler();
        Thread.setDefaultUncaughtExceptionHandler((t, e) -> {
            try {
                String ts = new SimpleDateFormat("yyyyMMdd-HHmmss",
                        Locale.ROOT).format(new Date());
                File out = new File(dir, "crash-" + ts + ".log");
                try (PrintWriter pw = new PrintWriter(new FileWriter(out))) {
                    pw.println("# " + new Date());
                    pw.println("# thread=" + t.getName());
                    pw.println();
                    e.printStackTrace(pw);
                }
                Log.e(e, "crashlog: wrote %s", out.getAbsolutePath());
            } catch (Throwable ignored) {
                // best effort - do not mask the original crash
            }
            if (prev != null) prev.uncaughtException(t, e);
        });
        Log.i("crashlog: installed -> %s", dir.getAbsolutePath());
    }
}
