Line data    Source code

       1             : /*
       2             :  *   Famedly Matrix SDK
       3             :  *   Copyright (C) 2020, 2021 Famedly GmbH
       4             :  *
       5             :  *   This program is free software: you can redistribute it and/or modify
       6             :  *   it under the terms of the GNU Affero General Public License as
       7             :  *   published by the Free Software Foundation, either version 3 of the
       8             :  *   License, or (at your option) any later version.
       9             :  *
      10             :  *   This program is distributed in the hope that it will be useful,
      11             :  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
      12             :  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
      13             :  *   GNU Affero General Public License for more details.
      14             :  *
      15             :  *   You should have received a copy of the GNU Affero General Public License
      16             :  *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
      17             :  */
      18             : 
      19             : import 'package:matrix/matrix.dart';
      20             : 
      21             : enum UiaRequestState {
      22             :   /// The request is done
      23             :   done,
      24             : 
      25             :   /// The request has failed
      26             :   fail,
      27             : 
      28             :   /// The request is currently loading
      29             :   loading,
      30             : 
      31             :   /// The request is waiting for user interaction
      32             :   waitForUser,
      33             : }
      34             : 
      35             : /// Wrapper to handle User interactive authentication requests
      36             : class UiaRequest<T> {
      37             :   void Function(UiaRequestState state)? onUpdate;
      38             :   final Future<T> Function(AuthenticationData? auth) request;
      39             :   String? session;
      40             :   UiaRequestState _state = UiaRequestState.loading;
      41             :   T? result;
      42             :   Exception? error;
      43             :   Set<String> nextStages = <String>{};
      44             :   Map<String, dynamic> params = <String, dynamic>{};
      45             : 
      46           6 :   UiaRequestState get state => _state;
      47             : 
      48           3 :   set state(UiaRequestState newState) {
      49           6 :     if (_state == newState) return;
      50           3 :     _state = newState;
      51           6 :     onUpdate?.call(newState);
      52             :   }
      53             : 
      54           3 :   UiaRequest({this.onUpdate, required this.request}) {
      55             :     // ignore: discarded_futures
      56           3 :     _run();
      57             :   }
      58             : 
      59           3 :   Future<T?> _run([AuthenticationData? auth]) async {
      60           3 :     state = UiaRequestState.loading;
      61             :     try {
      62           6 :       final res = await request(auth);
      63           3 :       state = UiaRequestState.done;
      64           3 :       result = res;
      65             :       return res;
      66           2 :     } on MatrixException catch (err) {
      67           2 :       if (err.session == null) {
      68           0 :         error = err;
      69           0 :         state = UiaRequestState.fail;
      70             :         return null;
      71             :       }
      72           4 :       session ??= err.session;
      73           2 :       final completed = err.completedAuthenticationFlows;
      74           2 :       final flows = err.authenticationFlows ?? <AuthenticationFlow>[];
      75           4 :       params = err.authenticationParams ?? <String, dynamic>{};
      76           4 :       nextStages = getNextStages(flows, completed);
      77           4 :       if (nextStages.isEmpty) {
      78           0 :         error = err;
      79           0 :         state = UiaRequestState.fail;
      80             :         return null;
      81             :       }
      82             :       return null;
      83             :     } catch (err) {
      84           4 :       error = err is Exception ? err : Exception(err);
      85           2 :       state = UiaRequestState.fail;
      86             :       return null;
      87             :     } finally {
      88           6 :       if (state == UiaRequestState.loading) {
      89           2 :         state = UiaRequestState.waitForUser;
      90             :       }
      91             :     }
      92             :   }
      93             : 
      94           4 :   Future<T?> completeStage(AuthenticationData auth) => _run(auth);
      95             : 
      96             :   /// Cancel this uia request for example if the app can not handle this stage.
      97           0 :   void cancel([Exception? err]) {
      98           0 :     error = err ?? Exception('Request has been canceled');
      99           0 :     state = UiaRequestState.fail;
     100             :   }
     101             : 
     102           2 :   Set<String> getNextStages(
     103             :       List<AuthenticationFlow> flows, List<String> completed) {
     104             :     final nextStages = <String>{};
     105           4 :     for (final flow in flows) {
     106             :       // check the flow starts with the completed stages
     107           8 :       if (flow.stages.length >= completed.length &&
     108          10 :           flow.stages.take(completed.length).toSet().containsAll(completed)) {
     109           6 :         final stages = flow.stages.skip(completed.length);
     110           6 :         if (stages.isNotEmpty) nextStages.add(stages.first);
     111             :       }
     112             :     }
     113             :     return nextStages;
     114             :   }
     115             : }