// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/// Whitebox integration/end-to-end test of Try Dart! site.
///
/// This test opens Try Dart! in an iframe.  When opened the first time, Try
/// Dart! will display a simple hello-world example, color tokens, compile the
/// example, and run the result.  We've instrumented Try Dart! to use
/// window.parent.postMessage when the running program prints anything. So this
/// test just waits for a "Hello, World!" message.
library trydart.end_to_end_test;

import 'dart:html';
import 'dart:async';

// TODO(ahe): Remove this import if issue 17936 is fixed.
import 'dart:js' as hack;

import 'package:async_helper/async_helper.dart';

void onError(String message, String filename, int lineno, [int colno, error]) {
  if (filename != null && filename != "" && lineno != 0) {
    if (colno != null && colno != 0) {
      message = '$filename:$lineno:$colno $message';
    } else {
      message = '$filename:$lineno: $message';
    }
  }
  if (error != null) {
    // See:
    // https://mikewest.org/2013/08/debugging-runtime-errors-with-window-onerror
    var stack = error['stack'];
    if (stack != null) {
      message += '\n$stack';
    }
  }
  message = "Error occurred in Try Dart iframe: $message";

  // Synchronous, easier to read when running the browser manually.
  window.console.log(message);

  new Future(() {
    // Browsers ignore errors throw in event listeners (or from
    // window.onerror).
    throw message;
  });
}

void installErrorHandlerOn(IFrameElement iframe) {
  // This method uses dart:js to install an error event handler on the content
  // window of [iframe]. This is a workaround for http://dartbug.com/17936.
  var iframeProxy = new hack.JsObject.fromBrowserObject(iframe);
  var contentWindowProxy = iframeProxy['contentWindow'];
  if (contentWindowProxy == null) {
    print('No contentWindow in iframe');
    throw 'No contentWindow in iframe';
  }

  // Note: we have two options, use "iframe.contentWindow.onerror = ..." or
  // "iframe.contentWindow.addEventListener('error', ...)".  The former seems
  // to provide more details on both Chrome and Firefox (which provides no
  // information at all in error events).
  contentWindowProxy['onerror'] = onError;
}

void onIframeLoaded(Event event) {
  installErrorHandlerOn(event.target);
}

void main() {
  asyncStart();
  window.onMessage.listen((MessageEvent e) {
    if (e.data == 'Hello, World!\n') {
      // Clear the DOM to work around a bug in test.dart.
      document.body.nodes.clear();

      // Clean up after ourselves.
      window.localStorage.clear();

      asyncEnd();
    }
  });

  // Clearing localStorage makes Try Dart! think it is opening for the first
  // time.
  window.localStorage.clear();

  IFrameElement iframe = new IFrameElement()
      ..src = '/root_build/try_dartlang_org/index.html'
      ..style.width = '90vw'
      ..style.height = '90vh'
      ..onLoad.listen(onIframeLoaded);
  document.body.append(iframe);
  // Install an error handler both on the new iframe element, and when it has
  // fired the load event.  That seems to matter according to some sources on
  // stackoverflow.
  installErrorHandlerOn(iframe);
}