import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_broadcast_receiver/flutter_broadcast_receiver.dart';
import 'package:isar/isar.dart';
import 'package:path_provider/path_provider.dart';
import 'package:stadtbote/model/message.dart';
import 'package:stadtbote/model/task_info.dart';
import 'package:stadtbote/tools/colored_safe_area.dart';
import 'package:stadtbote/model/status.dart';
import 'package:stadtbote/tools/connection_status.dart';

import 'tools/mqtt_core.dart';
import 'content_views/main_page.dart';
import 'content_views/utils/content_view_widget.dart';
import 'content_views/utils/widget_stack.dart';
import 'model/job.dart';
import 'tools/constants.dart';
import 'tools/util.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  final dir = await getApplicationDocumentsDirectory();
  MyApp.isarInstance = await Isar.open([
    StatusSchema,
    JobSchema,
    TaskInfoSchema,
    MessageSchema,
  ], directory: dir.path);

  runZonedGuarded(() {
  }, (error, stackTrace) {
    _traceUncaughtExceptions(error, stackTrace);
  });

  MqttCore.setup();

  runApp(const MyApp());
}

void _traceUncaughtExceptions(Object error, StackTrace stackTrace) {
  Util.logException('Ein Fehler ist aufgetreten: $error');
  Util.logException('Stack-Trace: $stackTrace');
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  static late Isar isarInstance;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Stadtbote',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const Main(),
    );
  }
}

class Main extends StatefulWidget {
  const Main({super.key});

  @override
  State<Main> createState() => _MainState();
}

class _MainState extends State<Main> {
  late ContentViewWidget _currentContent;
  late WidgetStack<ContentViewWidget> contentStack = WidgetStack();

  late Widget _currentTitleWidget;

  late Widget _leftIconButton;
  late Widget _rightIconButton;

  late bool _leftButtonVisible = false;
  late bool _rightButtonVisible = false;

  late Function _rightButtonOnPressed;
  late Function _leftButtonOnPressed;

  bool _initCompleted = false;

  final ValueNotifier<bool> _connectionLostValueNotifier = ValueNotifier<bool>(true);

  @override
  void initState() {
    super.initState();

    WidgetsBinding.instance.addPostFrameCallback((_) async {
      _initMessages();

      _currentContent = MainPage();

      var headerInfo = await _currentContent.getHeaderInfo(context);
      _currentTitleWidget = headerInfo.titleWidget;

      _leftButtonVisible = false;
      _leftIconButton = const Icon(Icons.arrow_back, size: 20.0, color: Colors.white);
      _leftButtonOnPressed = () {
        _popContentView();
      };

      _rightButtonVisible = headerInfo.rightButtonVisible;
      _rightButtonOnPressed = headerInfo.rightButtonOnPressed;
      if (headerInfo.rightButtonEnabled) {
        _rightIconButton = await headerInfo.rightButtonImage as Widget;
      }

      _initCompleted = true;

      setState(() {});
    });
  }

  @override
  void dispose() {
    super.dispose();

    //_subscription.cancel();
  }

  @override
  Widget build(BuildContext context) {
    if (!_initCompleted) {
      return Util.getWaitWidget(context);
    }

    return ColoredSafeArea(
      key: GlobalKey(),
      child: WillPopScope(
        onWillPop: () async {
          if (contentStack.isNotEmpty) {
            _popContentView();

            return false;
          } else {
            return true;
          }
        },
        child: Scaffold(
          appBar: PreferredSize(
            preferredSize: const Size.fromHeight(100),
            child: ColoredSafeArea(
                key: const Key("appBar"),
                child: SizedBox(
                  height: 100,
                  child: Padding(
                    padding: const EdgeInsets.all(8),
                    child: Stack(
                      alignment: Alignment.center,
                      children: [
                        Row(
                          mainAxisAlignment: MainAxisAlignment.spaceBetween,
                          children: [
                            Visibility(
                              visible: _leftButtonVisible,
                              child: Container(
                                width: 60,
                                height: 60,
                                decoration: const BoxDecoration(
                                  shape: BoxShape.circle,
                                  color: Colors.white,
                                ),
                                child: FittedBox(
                                  child: GestureDetector(
                                    onTap: () async {
                                      _leftButtonOnPressed();
                                    },
                                    child: CircleAvatar(
                                      radius: 15,
                                      backgroundColor: Constants.colorPrimary,
                                      child: Padding(padding: const EdgeInsets.all(1.0), child: _leftIconButton),
                                    ),
                                  ),
                                ),
                              ),
                            ),
                            Visibility(
                              visible: _rightButtonVisible,
                              child: Container(
                                width: 60,
                                height: 60,
                                decoration: const BoxDecoration(
                                  shape: BoxShape.circle,
                                  color: Colors.red,
                                ),
                                child: FittedBox(
                                  child: GestureDetector(
                                    onTap: () async {
                                      _rightButtonOnPressed();
                                    },
                                    child: CircleAvatar(
                                      backgroundColor: Constants.colorPrimary,
                                      radius: 15,
                                      child: Padding(padding: const EdgeInsets.all(1.0), child: _rightIconButton),
                                    ),
                                  ),
                                ),
                              ),
                            ),
                          ],
                        ),
                        SizedBox(
                          height: 100,
                          width: 300,
                          child: Center(
                            heightFactor: 1,
                            child: _currentTitleWidget),
                        ),
                      ],
                    ),
                  ),
                )),
          ),
          body: Column(
            children: [
              ValueListenableBuilder<bool>(
                valueListenable: _connectionLostValueNotifier,
                builder: (context, value, child) {
                  return Visibility(
                    visible: value,
                    child: Container(
                      width: MediaQuery.of(context).size.width,
                      height: 30,
                      color: Colors.red,
                      child: const Center(
                        child: Text("*** OFFLINE ***",
                          style: TextStyle(
                            color: Colors.white,
                            fontSize: 15.0,
                          ),),
                      ),
                    ),
                  );
                },
              ),
              Expanded(child: _currentContent),
            ],
          ),// This trailing comma makes auto-formatting nicer for build methods.
        ),
      ),
    );
  }

  void _initMessages() {
    BroadcastReceiver().subscribe<ContentViewWidget>(Constants.messageTopicPushContentView, (ContentViewWidget widget) {
      _pushContentView(widget);
    });
    BroadcastReceiver().subscribe<ContentViewWidget>(Constants.messageTopicPopContentView, (ContentViewWidget widget) {
      _popContentView();
    });
    BroadcastReceiver().subscribe<ContentViewWidget>(Constants.messageTopicReplaceContentView, (ContentViewWidget widget) {
      _replaceContentView(widget);
    });
    BroadcastReceiver().subscribe<bool>(Constants.messageTopicHideRightButton, (hideButton) {
      _hideRightButton(hideButton);
    });
    BroadcastReceiver().subscribe<ConnectionStatus>(Constants.messageTopicConnectionStatusChanged, (ConnectionStatus connectionStatus) {
      _connectionStatusChanged(connectionStatus);
    });
  }

  void _replaceContentView(ContentViewWidget widget) async {
    Future.delayed(const Duration(seconds: 0), () async {
      contentStack.clear();

      setState(() {
        _currentContent = widget;
      });

      var headerInfo = await _currentContent.getHeaderInfo(context);
      _currentTitleWidget = headerInfo.titleWidget;
      _rightButtonVisible = headerInfo.rightButtonVisible;
      _rightButtonOnPressed = headerInfo.rightButtonOnPressed;

      if (headerInfo.rightButtonEnabled) {
        _rightIconButton = await headerInfo.rightButtonImage as Widget;
      }

      _leftButtonVisible = false;

      setState(() {});
    });
  }

  void _popContentView() {
    Future.delayed(const Duration(seconds: 0), () async {
      var previousContentView = contentStack.pop();

      _currentContent = previousContentView;

      var headerInfo = await _currentContent.getHeaderInfo(context);
      _currentTitleWidget = headerInfo.titleWidget;
      _rightButtonVisible = headerInfo.rightButtonVisible;
      _rightButtonOnPressed = headerInfo.rightButtonOnPressed;

      if (headerInfo.rightButtonEnabled) {
        _rightIconButton = await headerInfo.rightButtonImage as Widget;
      }

      if (contentStack.isEmpty) {
        _leftButtonVisible = false;
      }

      setState(() {});
    });
  }

  void _pushContentView(ContentViewWidget widget) {
    Future.delayed(const Duration(seconds: 0), () async {
      contentStack.push(_currentContent);

      _currentContent = widget;

      var headerInfo = await _currentContent.getHeaderInfo(context);

      _currentTitleWidget = headerInfo.titleWidget;
      _rightButtonVisible = headerInfo.rightButtonVisible;
      _rightButtonOnPressed = headerInfo.rightButtonOnPressed;

      if (headerInfo.rightButtonEnabled) {
        _rightIconButton = await headerInfo.rightButtonImage as Widget;
      }

      _leftButtonVisible = true;

      setState(() {});
    });
  }

  void _hideRightButton(bool hideButton) {
    setState(() {
      _rightButtonVisible = !hideButton;
    });
  }

  void _connectionStatusChanged(ConnectionStatus connectionStatus) {
    _connectionLostValueNotifier.value = connectionStatus.status == ConnectionStatusEnum.notConnected;
  }
}