Envelope/mobile/lib/services/conversations_service.dart

import 'dart:convert';

import 'package:Envelope/utils/storage/get_file.dart';
import 'package:http/http.dart' as http;
import 'package:pointycastle/export.dart';
import 'package:sqflite/sqflite.dart';
import 'package:uuid/uuid.dart';

import '/database/models/friends.dart';
import '/database/models/conversation_users.dart';
import '/database/models/conversations.dart';
import '/database/models/my_profile.dart';
import '/exceptions/update_data_exception.dart';
import '/utils/encryption/aes_helper.dart';
import '/utils/storage/database.dart';
import '/utils/storage/session_cookie.dart';

class _BaseConversationsResult {
  List<Conversation> conversations;
  List<String> detailIds;


  _BaseConversationsResult({
    required this.conversations,
    required this.detailIds,
  });
}

class ConversationsService {
  static Future<void> saveConversation(Conversation conversation) async {
    final db = await getDatabaseConnection();

    db.update(
      'conversations',
      conversation.toMap(),
      where: 'id = ?',
      whereArgs: [conversation.id],
    );
  }

  static Future<Conversation> addUsersToConversation(Conversation conversation, List<Friend> friends) async {
    final db = await getDatabaseConnection();

    var uuid = const Uuid();

   for (Friend friend in friends) {
      await db.insert(
        'conversation_users',
        ConversationUser(
          id: uuid.v4(),
          userId: friend.friendId,
          conversationId: conversation.id,
          username: friend.username,
          associationKey: uuid.v4(),
          publicKey: friend.publicKey,
          admin: false,
        ).toMap(),
        conflictAlgorithm: ConflictAlgorithm.replace,
      );
    }

    return conversation;
  }

  static Future<void> updateConversation(
    Conversation conversation,
    {
      includeUsers = false,
      updatedImage = false,
      saveConversation = true,
    } ) async {

    if (saveConversation) {
      await saveConversation(conversation);
    }

    String sessionCookie = await getSessionCookie();

    Map<String, dynamic> conversationJson = await conversation.payloadJson(includeUsers: includeUsers);

    var resp = await http.put(
      await MyProfile.getServerUrl('api/v1/auth/conversations'),
      headers: <String, String>{
        'Content-Type': 'application/json; charset=UTF-8',
        'cookie': sessionCookie,
      },
      body: jsonEncode(conversationJson),
    );

    if (resp.statusCode != 204) {
      throw UpdateDataException('Unable to update conversation, please try again later.');
    }

    if (!updatedImage) {
      return;
    }

    Map<String, dynamic> attachmentJson = conversation.payloadImageJson();

    resp = await http.post(
      await MyProfile.getServerUrl('api/v1/auth/conversations/${conversation.id}/image'),
      headers: <String, String>{
        'Content-Type': 'application/json; charset=UTF-8',
        'cookie': sessionCookie,
      },
      body: jsonEncode(attachmentJson),
    );

    if (resp.statusCode != 204) {
      throw UpdateDataException('Unable to update conversation image, please try again later.');
    }
  }

  static Future<_BaseConversationsResult> _getBaseConversations() async {
    RSAPrivateKey privKey = await MyProfile.getPrivateKey();

    http.Response resp = await http.get(
      await MyProfile.getServerUrl('api/v1/auth/conversations'),
      headers: {
        'cookie': await getSessionCookie(),
      }
    );

    if (resp.statusCode != 200) {
      throw Exception(resp.body);
    }

    _BaseConversationsResult result = _BaseConversationsResult(
      conversations: [],
      detailIds: []
    );

    List<dynamic> conversationsJson = jsonDecode(resp.body);

    if (conversationsJson.isEmpty) {
      return result;
    }

    for (var i = 0; i < conversationsJson.length; i++) {
      Conversation conversation = Conversation.fromJson(
        conversationsJson[i] as Map<String, dynamic>,
        privKey,
      );
      result.conversations.add(conversation);
      result.detailIds.add(conversation.id);
    }

    return result;
  }

  static Conversation _findConversationByDetailId(List<Conversation> conversations, String id) {
    for (var conversation in conversations) {
      if (conversation.id == id) {
        return conversation;
      }
    }
    // Or return `null`.
    throw ArgumentError.value(id, 'id', 'No element with that id');
  }


  static Future<void> _storeConversations(Database db, Conversation conversation, Map<String, dynamic> detailsJson) async {

    conversation.createdAt = DateTime.parse(detailsJson['created_at']);
    conversation.updatedAt = DateTime.parse(detailsJson['updated_at']);

    conversation.messageExpiryDefault = detailsJson['message_expiry'];

    conversation.twoUser = AesHelper.aesDecrypt(
      base64.decode(conversation.symmetricKey),
      base64.decode(detailsJson['two_user']),
    ) == 'true';

    if (conversation.twoUser) {
      MyProfile profile = await MyProfile.getProfile();

      final db = await getDatabaseConnection();

      List<Map<String, dynamic>> maps = await db.query(
        'conversation_users',
        where: 'conversation_id = ? AND user_id != ?',
        whereArgs: [ conversation.id, profile.id ],
      );

      if (maps.length != 1) {
        conversation.name = 'TODO: Fix this';
      } else {
        conversation.name = maps[0]['username'];
      }

    } else {
      conversation.name = AesHelper.aesDecrypt(
        base64.decode(conversation.symmetricKey),
        base64.decode(detailsJson['name']),
      );
    }

    if (detailsJson['attachment_id'] != null) {
      conversation.icon = await getFile(
        '$defaultServerUrl/files/${detailsJson['attachment']['image_link']}',
        conversation.id,
        conversation.symmetricKey,
      ).catchError((dynamic) async {});
    }

    await db.insert(
      'conversations',
      conversation.toMap(),
      conflictAlgorithm: ConflictAlgorithm.replace,
    );

    List<dynamic> usersData = detailsJson['users'];

    for (var i = 0; i < usersData.length; i++) {
      ConversationUser conversationUser = ConversationUser.fromJson(
        usersData[i] as Map<String, dynamic>,
        base64.decode(conversation.symmetricKey),
      );

      await db.insert(
        'conversation_users',
        conversationUser.toMap(),
        conflictAlgorithm: ConflictAlgorithm.replace,
      );
    }
  }

  static Future<void> updateConversations({DateTime? updatedAt}) async {
    _BaseConversationsResult baseConvs = await _getBaseConversations();

    if (baseConvs.detailIds.isEmpty) {
      return;
    }

    Map<String, String> params = {};

    if (updatedAt != null) {
      params['updated_at'] = updatedAt.toIso8601String();
    }

    params['conversation_detail_ids'] = baseConvs.detailIds.join(',');
    var uri = await MyProfile.getServerUrl('api/v1/auth/conversation_details');
    uri = uri.replace(queryParameters: params);

    http.Response resp = await http.get(
      uri,
      headers: {
        'cookie': await getSessionCookie(),
      }
    );

    if (resp.statusCode != 200) {
      throw Exception(resp.body);
    }

    final db = await getDatabaseConnection();

    List<dynamic> conversationsDetailsJson = jsonDecode(resp.body);
    for (var i = 0; i < conversationsDetailsJson.length; i++) {
        Map<String, dynamic> detailsJson = conversationsDetailsJson[i] as Map<String, dynamic>;
        Conversation conversation = _findConversationByDetailId(baseConvs.conversations, detailsJson['id']);
        await _storeConversations(db, conversation, detailsJson);
    }
  }

  static Future<void> uploadConversation(Conversation conversation) async {
    String sessionCookie = await getSessionCookie();

    Map<String, dynamic> conversationJson = await conversation.payloadJson();

    var resp = await http.post(
      await MyProfile.getServerUrl('api/v1/auth/conversations'),
      headers: <String, String>{
        'Content-Type': 'application/json; charset=UTF-8',
        'cookie': sessionCookie,
      },
      body: jsonEncode(conversationJson),
    );

    if (resp.statusCode != 204) {
      throw Exception('Failed to create conversation');
    }
  }

  static Future<void> updateMessageExpiry(String id, String messageExpiry) async {
    http.Response resp = await http.post(
      await MyProfile.getServerUrl(
        'api/v1/auth/conversations/$id/message_expiry'
      ),
      headers: {
        'cookie': await getSessionCookie(),
      },
      body: jsonEncode({
        'message_expiry': messageExpiry,
      }),
    );

    if (resp.statusCode == 204) {
      return;
    }

    throw Exception('Cannot set message expiry for conversation');
  }
}