import 'dart:async';
import 'dart:convert';
import 'dart:io';

import 'package:flutter/material.dart';
import 'package:one_key/utils/event_bus.dart';
import 'package:one_key/widgets/app_bar.dart';
import 'package:one_key/widgets/system_app_bar.dart';
import 'package:webview_flutter/webview_flutter.dart';

class WebViewPage extends StatefulWidget {
  @override
  _WebViewPageState createState() => _WebViewPageState();
}

class _WebViewPageState extends State<WebViewPage> {
  final Completer<WebViewController> _controller =
      Completer<WebViewController>();

  @override
  void initState() {
    super.initState();
    // Enable hybrid composition.
    if (Platform.isAndroid) WebView.platform = SurfaceAndroidWebView();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      // We're using a Builder here so we have a context that is below the Scaffold
      // to allow calling Scaffold.of(context) so we can show a snackbar.
      appBar: SystemAppBar(
        '一键订',
        onTap: () {
          EventBus().emit('changeStatusColor');
          Navigator.of(context).pop();
        },
      ),
      body: Builder(builder: (BuildContext context) {
        return WebView(
          initialUrl: "https://support.qq.com/product/152856",
          javascriptMode: JavascriptMode.unrestricted,
          onWebViewCreated: (WebViewController webViewController) {
            _controller.complete(webViewController);
          },
          // TODO(iskakaushik): Remove this when collection literals makes it to stable.
          // ignore: prefer_collection_literals
          javascriptChannels: <JavascriptChannel>[
            _toasterJavascriptChannel(context),
          ].toSet(),
          navigationDelegate: (NavigationRequest request) {
            if (request.url.startsWith('https://www.youtube.com/')) {
              print('blocking navigation to $request}');
              return NavigationDecision.prevent;
            }
            print('allowing navigation to $request');
            return NavigationDecision.navigate;
          },
          onPageStarted: (String url) {
            print('Page started loading: $url');
          },
          onPageFinished: (String url) {
            print('Page finished loading: $url');
          },
          gestureNavigationEnabled: true,
        );
      }),
    );
  }

  JavascriptChannel _toasterJavascriptChannel(BuildContext context) {
    return JavascriptChannel(
        name: 'Toaster',
        onMessageReceived: (JavascriptMessage message) {
          Scaffold.of(context).showSnackBar(
            SnackBar(content: Text(message.message)),
          );
        });
  }
}