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,
     104              :     List<String> completed,
     105              :   ) {
     106              :     final nextStages = <String>{};
     107            4 :     for (final flow in flows) {
     108              :       // check the flow starts with the completed stages
     109            8 :       if (flow.stages.length >= completed.length &&
     110           10 :           flow.stages.take(completed.length).toSet().containsAll(completed)) {
     111            6 :         final stages = flow.stages.skip(completed.length);
     112            6 :         if (stages.isNotEmpty) nextStages.add(stages.first);
     113              :       }
     114              :     }
     115              :     return nextStages;
     116              :   }
     117              : }