E2EEChat/lib/presenter/user_chat.dart

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

import 'package:dash_chat/dash_chat.dart';
import 'package:e2ee_chat/common/api.dart';
import 'package:e2ee_chat/common/global.dart';
import 'package:e2ee_chat/model/friendship.dart';
import 'package:e2ee_chat/model/message.dart';
import 'package:e2ee_chat/model/user.dart';
import 'package:e2ee_chat/objectbox.g.dart';
import 'package:e2ee_chat/presenter/login.dart';
import 'package:flutter/material.dart';
import 'package:objectbox/objectbox.dart';
import 'package:rxdart/rxdart.dart';

import 'chat_list.dart';

class UserChatPresenter extends ChatListPresenter {
  UserChatPresenter({this.to}) {
    _listener = _listenUserChat();
  }

  User? get from => LoginPresenter().user;
  User? to;

  FriendShip get friendShip => FriendShip()
    ..user0.target = from
    ..user1.target = to;

  ToMany<Message> get messages => friendShip.messages;

  List<ChatMessage>? _chatMessages;
  List<ChatMessage> get chatMessages => _chatMessages ?? [];

  bool _disposed = false;
  Future<void>? _listener;


  @override
  void dispose() {
    _disposed = true;
    _listener?.then((e) => super.dispose()) ?? super.dispose();
  }


  Future<void> _listenUserChat() async {
    while (!_disposed) {
      if (to != null) {
        if (_chatMessages == null) {
            debug("init chatMessages");
          _chatMessages = await retrieveAllChatMessages();
          notifyListeners();
        } else {
          await flushChatMessages();
        }
      }
      await Future.delayed(Duration(seconds: 1));
    }
  }

  Future<void> flushChatMessages() async {
    final _user = LoginPresenter().user;
    if (_user != null) {
      List<String>? _list = await Api().getLastMessages(_user.username);
      if (_list != null) {
        debug("flush chat message");
        for (final i in _list) {
          chatMessages.add(chatMessageFromMessagePackage(i));
        }
        notifyListeners();
      }
    }
    // messages.forEach((message) => list.add(message.chatMessage));
  }

  ChatMessage chatMessageFromMessagePackage(String encText) {
    // Map<String, dynamic> json0 = jsonDecode(s);
    // String plaintext = json0["plaintext"];
    ChatMessage? _message;
    try {
      _message = ChatMessage.fromJson(jsonDecode(encText));
    } catch (e) {
      try {

      } catch (e) {

      }
    }
    debug('plaintext: $encText');

    return ChatMessage.fromJson(jsonDecode(plaintext));
  }

  Future<List<ChatMessage>> retrieveAllChatMessages() async {
    final list = <ChatMessage>[];
    final _user = LoginPresenter().user;
    final _to = to;
    if (_user != null && _to != null) {
      List<String>? _list = await Api().getFilterMessages(_to.username);
      if (_list != null) {
        for (final i in _list) {
          list.add(chatMessageFromMessagePackage(i));
        }
      }
    }
    return list;
    // messages.forEach((message) => list.add(message.chatMessage));
  }

  Future<bool> sendMessage(ChatMessage chatMessage) async {
    debug('user chat presenter send msg begin');
    bool _result = true;
    chatMessages.add(chatMessage);
    notifyListeners();
    try {
      final plaintext = json.encode(chatMessage);
      var message = Message();
      message.from.target = from!;
      message.to.target = to!;
      message.plaintext = plaintext;
      _result = await Api().sendMessage(to!.username, json.encode(chatMessage));
    } catch (e) {
      debug(e);
      _result = false;
    }
    if (!_result) {
      debug('user chat presenter send msg failed');
    }
    return _result;
  }

  /// 消息体
  Message? get lastMessage {
    Message? message;
    try {
      message = messages.last;
    } catch (e) {
      debug("no message");
    }
    return message;
  }

  /// 未读数量
  int get unReadCount {
    // TODO: 未读消息数量
    return 0;
  }

  get chatName => to?.username;

  /// 单聊
  get isSingle => true;

  /// 群聊信息
  get isGroup => false;

  /// 消息免打扰
  get isDND => to?.isDND;

  /// 是否为置顶
  get isStick => to?.isStick;

  /// 特别关注
  get isSpecialAttention => to?.isSpecialAttention;

  // TODO: 是否 @ 你
  get isAtYou => false;

  // TODO: 是否 @ 全部
  get isAtAll => false;

  // TODO: user avatar
  get avatar => Global.defaultAvatar;
}