relatica/lib/models/direct_message_thread.dart

import 'package:flutter/foundation.dart';

import 'auth/profile.dart';
import 'direct_message.dart';

class DirectMessageThread {
  final List<DirectMessage> messages;

  final List<String> participantIds;

  final String title;

  final String parentUri;

  DirectMessageThread({
    required this.messages,
    required this.participantIds,
    required this.title,
    required this.parentUri,
  });

  DirectMessageThread deepCopy() => DirectMessageThread(
        messages: List.from(messages),
        participantIds: List.from(participantIds),
        title: title,
        parentUri: parentUri,
      );

  DirectMessageThread copy({List<DirectMessage>? messages}) =>
      DirectMessageThread(
        messages: messages ?? this.messages,
        participantIds: participantIds,
        title: title,
        parentUri: parentUri,
      );

  get allSeen => messages.isEmpty
      ? false
      : messages
          .map((m) => m.seen)
          .reduce((allUnseen, thisUnseen) => allUnseen && thisUnseen);

  static List<DirectMessageThread> createThreads(
    Profile profile,
    Iterable<DirectMessage> messages,
  ) {
    final threads = <String, List<DirectMessage>>{};
    for (final m in messages) {
      final thread = threads.putIfAbsent(m.parentUri, () => []);
      thread.add(m);
    }

    final result = <DirectMessageThread>[];
    for (final t in threads.entries) {
      final parentUri = t.key;
      final threadMessages = t.value;
      final participantIds = <String>{};
      var title = '';
      threadMessages.sort((m1, m2) => m1.createdAt.compareTo(m2.createdAt));
      for (final m in threadMessages) {
        participantIds.add(m.senderId);
        participantIds.add(m.recipientId);
        if (title.isEmpty) {
          title = m.title;
        }
      }
      final thread = DirectMessageThread(
        messages: threadMessages,
        participantIds: participantIds.toList(),
        title: title,
        parentUri: parentUri,
      );
      result.add(thread);
    }

    result.sort((t1, t2) =>
        t2.messages.first.createdAt.compareTo(t1.messages.first.createdAt));

    return result;
  }

  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
      other is DirectMessageThread &&
          runtimeType == other.runtimeType &&
          title == other.title &&
          parentUri == other.parentUri &&
          listEquals(messages, other.messages) &&
          listEquals(participantIds, other.participantIds);

  @override
  int get hashCode =>
      title.hashCode ^
      parentUri.hashCode ^
      Object.hashAll(messages) ^
      Object.hashAll(participantIds);
}