// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:ui';

import 'package:flutter/material.dart';
import 'package:flutter_localizations/flutter_localizations.dart';
import 'package:fuchsia_scenic_flutter/child_view.dart' show ChildView;
import 'package:internationalization/localizations_delegate.dart'
    as localizations;
import 'package:internationalization/strings.dart';
import 'package:internationalization/supported_locales.dart'
    as supported_locales;
import 'package:intl/intl.dart';
import 'package:simple_browser/src/blocs/webpage_bloc.dart';
import 'src/models/app_model.dart';
import 'src/widgets/error_page.dart';
import 'src/widgets/navigation_bar.dart';
import 'src/widgets/tabs_widget.dart';

// TODO(fxb/45264): Replace these with colors from the central Ermine styles.
const _kErmineColor100 = Color(0xFFE5E5E5);
const _kErmineColor200 = Color(0xFFBDBDBD);
const _kErmineColor300 = Color(0xFF282828);
const _kErmineColor400 = Color(0xFF0C0C0C);

const _kTextStyle = TextStyle(color: _kErmineColor400, fontSize: 14.0);

class App extends StatelessWidget {
  final AppModel model;

  const App(this.model);

  @override
  Widget build(BuildContext context) {
    return FutureBuilder(
      future: model.localeStream.first,
      builder: (context, snapshot) => snapshot.hasData
          ? StreamBuilder<Locale>(
              stream: model.localeStream,
              initialData: snapshot.data,
              builder: (context, snapshot) {
                final locale = snapshot.data;
                Intl.defaultLocale = locale.toString();
                return MaterialApp(
                  title: Strings.browser,
                  theme: ThemeData(
                    fontFamily: 'RobotoMono',
                    textSelectionColor: _kErmineColor200,
                    textSelectionHandleColor: _kErmineColor400,
                    hintColor: _kErmineColor400,
                    cursorColor: _kErmineColor400,
                    primaryColor: _kErmineColor100,
                    canvasColor: _kErmineColor100,
                    accentColor: _kErmineColor400,
                    buttonColor: _kErmineColor300,
                    textTheme: TextTheme(
                      bodyText2: _kTextStyle,
                      subtitle1: _kTextStyle,
                    ),
                  ),
                  locale: locale,
                  localizationsDelegates: [
                    localizations.delegate(),
                    GlobalMaterialLocalizations.delegate,
                    GlobalWidgetsLocalizations.delegate,
                  ],
                  supportedLocales: supported_locales.locales,
                  home: Scaffold(
                    body: Column(
                      children: <Widget>[
                        AnimatedBuilder(
                          animation: model.tabsBloc.currentTabNotifier,
                          builder: (_, __) => NavigationBar(
                              bloc: model.tabsBloc.currentTab,
                              newTab: model.newTab),
                        ),
                        TabsWidget(bloc: model.tabsBloc),
                        Expanded(child: _buildContent()),
                      ],
                    ),
                  ),
                );
              },
            )
          : Offstage(),
    );
  }

  Widget _buildContent() => AnimatedBuilder(
        animation: model.tabsBloc.currentTabNotifier,
        builder: (_, __) => model.tabsBloc.currentTab == null
            // hide if no tab selected
            ? _buildEmptyPage()
            : AnimatedBuilder(
                animation: model.tabsBloc.currentTab.pageTypeNotifier,
                builder: (_, __) =>
                    _buildPage(model.tabsBloc.currentTab.pageType),
              ),
      );

  Widget _buildPage(PageType pageType) {
    switch (pageType) {
      case PageType.normal:
        return _buildNormalPage();
      case PageType.error:
        // show error for error state
        return _buildErrorPage();
      default:
        // hide if no content in tab
        return _buildEmptyPage();
    }
  }

  Widget _buildNormalPage() =>
      ChildView(connection: model.tabsBloc.currentTab.childViewConnection);
  Widget _buildErrorPage() => ErrorPage();
  Widget _buildEmptyPage() => Container();
}