/*
 *  Copyright 2013 The WebRTC Project Authors. All rights reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

package org.appspot.apprtc;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.util.Log;
import android.util.TypedValue;
import android.widget.ScrollView;
import android.widget.TextView;

import java.io.PrintWriter;
import java.io.StringWriter;

/**
 * Singleton helper: install a default unhandled exception handler which shows
 * an informative dialog and kills the app.  Useful for apps whose
 * error-handling consists of throwing RuntimeExceptions.
 * NOTE: almost always more useful to
 * Thread.setDefaultUncaughtExceptionHandler() rather than
 * Thread.setUncaughtExceptionHandler(), to apply to background threads as well.
 */
public class UnhandledExceptionHandler implements Thread.UncaughtExceptionHandler {
    private static final String TAG = "AppRTCMobileActivity";
    private final Activity activity;

    public UnhandledExceptionHandler(final Activity activity) {
        this.activity = activity;
    }

    // Returns the Message attached to the original Cause of |t|.
    private static String getTopLevelCauseMessage(Throwable t) {
        Throwable topLevelCause = t;
        while (topLevelCause.getCause() != null) {
            topLevelCause = topLevelCause.getCause();
        }
        return topLevelCause.getMessage();
    }

    // Returns a human-readable String of the stacktrace in |t|, recursively
    // through all Causes that led to |t|.
    private static String getRecursiveStackTrace(Throwable t) {
        StringWriter writer = new StringWriter();
        t.printStackTrace(new PrintWriter(writer));
        return writer.toString();
    }

    @Override
    public void uncaughtException(Thread unusedThread, final Throwable e) {
        e.printStackTrace();
        System.out.println("UnhandledExceptionHandler.uncaughtException " + e.getMessage());
//        activity.runOnUiThread(new Runnable() {
//            @Override
//            public void run() {
//                String title = "Fatal error: " + getTopLevelCauseMessage(e);
//                String msg = getRecursiveStackTrace(e);
//                TextView errorView = new TextView(activity);
//                errorView.setText(msg);
//                errorView.setTextSize(TypedValue.COMPLEX_UNIT_SP, 8);
//                ScrollView scrollingContainer = new ScrollView(activity);
//                scrollingContainer.addView(errorView);
//                Log.e(TAG, title + "\n\n" + msg);
//                DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() {
//                    @Override
//                    public void onClick(DialogInterface dialog, int which) {
//                        dialog.dismiss();
//                        System.exit(1);
//                    }
//                };
//                AlertDialog.Builder builder = new AlertDialog.Builder(activity);
//                builder.setTitle(title)
//                        .setView(scrollingContainer)
//                        .setPositiveButton("Exit", listener)
//                        .show();
//            }
//        });
    }
}