stadtbote-app/lib/content_views/messages_page.dart

import 'package:flutter/material.dart';
import 'package:flutter_chat_ui/flutter_chat_ui.dart';
import 'package:flutter_chat_types/flutter_chat_types.dart' as types;
import 'package:isar/isar.dart';
import 'package:mqtt_client/mqtt_client.dart';
import 'package:stadtbote/content_views/utils/content_view_widget.dart';
import 'package:stadtbote/content_views/utils/header_info.dart';
import 'package:stadtbote/main.dart';
import 'package:stadtbote/model/message.dart' as sbmessage;
import 'package:stadtbote/model/message.dart';
import 'package:stadtbote/model/session_status.dart';
import 'package:stadtbote/tools/constants.dart';
import 'package:stadtbote/tools/message_service.dart';
import 'package:stadtbote/tools/messages/publish_payload_message.dart';

import '../tools/util.dart';

class MessagesPage extends ContentViewWidget {
  const MessagesPage({super.key});

  @override
  State<MessagesPage> createState() => _MessagesPageState();

  @override
  Future<HeaderInfo> getHeaderInfo(BuildContext context) async {
    return HeaderInfo(
        titleWidget: const Text(
          'Nachrichten',
          style: TextStyle(
            color: Colors.white,
            fontSize: 20.0,
          ),
        ),
        rightButtonEnabled: true,
        rightButtonVisible: true,
        rightButtonImage: Util.fetchFutureIcon(const Icon(Icons.help_outline, size: 20.0, color: Colors.white)),
        rightButtonOnPressed: () async {
          await Util.startBrowser('https://app.assecutor.de/help/sb/app/context/003/index.html');
        });
  }
}

class _MessagesPageState extends State<MessagesPage> {
  bool _initCompleted = false;

  late String _sid;

  late final List<types.Message> _messages = [];

  final _user = const types.User(
    id: '82091008-a484-4a89-ae75-a22bf8d6f3ac',
  );

  final _central = const types.User(
    id: '82091008-a484-4a89-ae75-a22bf8d6f3ad',
  );

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

    Future.delayed(const Duration(seconds: 0), () async {
      var status = await MyApp.isarInstance.sessionStatus.where().findFirst();
      _sid = status != null ? status.sid : 'Unbekannt';

      await _fetchMessages();

      _initCompleted = true;

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

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

    return Stack(
      children: [
        Chat(
          messages: _messages,
          textMessageOptions:const TextMessageOptions(isTextSelectable:false),
          onSendPressed: _handleSendPressed,
          showUserAvatars: false,
          showUserNames: false,
          user: _user,
          onMessageTap: (context, message) => {
            _showDeleteMessageDialog(context, message)
          },
        ),
      ],
    );
  }

  void _handleSendPressed(types.PartialText text) async {
    var now = DateTime.now();

    var message = sbmessage.Message();
    message.text = text.text;
    message.from = _sid;
    message.subj = '';
    message.time = now.toUtc().toIso8601String();
    message.read = true;
    message.id = await sbmessage.Message.getNextId();

    await MyApp.isarInstance.writeTxn(() async {
      await MyApp.isarInstance.messages.put(message);
    });

    MessageService().publish<PublishPayloadMessage>(Constants.messageTopicPublishPayload, arguments: PublishPayloadMessage(topic: "message", message: message.toJson(), qos: MqttQos.exactlyOnce));

    _messages.insert(0, types.TextMessage(
      author: _user,
      createdAt: now.millisecondsSinceEpoch,
      id: message.id.toString(),
      text: text.text,
    ));

    setState(() {});
  }

  Future<void> _fetchMessages() async {
    _messages.clear();

    var messages = await MyApp.isarInstance.messages.where().findAll();
    for (var message in messages) {
      _messages.add(types.TextMessage(
        author: message.from == _sid ? _user : _central,
        createdAt: DateTime.parse(message.time).toLocal().millisecondsSinceEpoch,
        id: message.id.toString(),
        text: "${message.subj}\n${message.text}",
      ));

      _messages.sort((a, b) => b.createdAt! > a.createdAt! ? 1 : 0);

      message.read = true;
      await MyApp.isarInstance.writeTxn(() async {
        await MyApp.isarInstance.messages.put(message);
      });
    }

    setState(() {});
  }

  _showDeleteMessageDialog(BuildContext context, types.Message message) async {
    await showDialog<void>(
        context: context,
        builder: (BuildContext context) {
          return AlertDialog(
              contentPadding: EdgeInsets.zero,
              shadowColor: Colors.transparent,
              backgroundColor: Colors.white,
              content: StatefulBuilder(builder: (BuildContext context, StateSetter setState) {
                return SizedBox(
                    key: GlobalKey(),
                    height: 120,
                    width: MediaQuery
                        .of(context)
                        .size
                        .width * 1.2,
                    child: Padding(
                      padding: const EdgeInsets.all(8.0),
                      child: Container(
                        height: 100,
                        padding: const EdgeInsets.all(5),
                        child: Column(
                          children: [
                            const Text('Soll die Nachricht gelöscht werden?'),
                            const SizedBox(height: 20),
                            Row(children: [
                              Expanded(
                                child: getDefaultButton('Nein', () => {Navigator.of(context).pop()}),
                              ),
                              const SizedBox(width: 20),
                              Expanded(
                                child: getDefaultButton('Ja', () async => {
                                await MyApp.isarInstance.writeTxn(() async => { await MyApp.isarInstance.messages.delete(int.parse(message.id))}),

                                _fetchMessages(),

                                setState(() {}),

                                Navigator.of(context).pop()
                              }),
                              )
                            ])
                          ],
                        ),
                      ),
                    )
                );
              })
          );
        });
  }
}