#94 Downloads failing immediately correctly update UI

.tool-versions

@@ -0,0 +1 @@
+flutter 3.27.1-stable

lib/bloc/podcast/episode_bloc.dart

@@ -7,6 +7,7 @@ import 'dart:async';
 import 'package:anytime/bloc/bloc.dart';
 import 'package:anytime/entities/episode.dart';
 import 'package:anytime/services/audio/audio_player_service.dart';
+import 'package:anytime/services/download/download_service.dart';
 import 'package:anytime/services/podcast/podcast_service.dart';
 import 'package:anytime/state/bloc_state.dart';
 import 'package:logging/logging.dart';
@@ -17,6 +18,7 @@ import 'package:rxdart/rxdart.dart';
 class EpisodeBloc extends Bloc {
   final log = Logger('EpisodeBloc');
   final PodcastService podcastService;
+  final DownloadService downloadService;
   final AudioPlayerService audioPlayerService;
 
   /// Add to sink to fetch list of current downloaded episodes.
@@ -43,6 +45,7 @@ class EpisodeBloc extends Bloc {
   EpisodeBloc({
     required this.podcastService,
     required this.audioPlayerService,
+    required this.downloadService,
   }) {
     _init();
   }
@@ -65,7 +68,7 @@ class EpisodeBloc extends Bloc {
         await audioPlayerService.stop();
       }
 
-      await podcastService.deleteDownload(episode!);
+      await downloadService.deleteDownload(episode!);
 
       fetchDownloads(true);
     });

lib/bloc/podcast/podcast_bloc.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:anytime/bloc/bloc.dart';
-import 'package:anytime/entities/downloadable.dart';
 import 'package:anytime/entities/episode.dart';
 import 'package:anytime/entities/feed.dart';
 import 'package:anytime/entities/podcast.dart';
@@ -245,20 +244,9 @@ class PodcastBloc extends Bloc {
       var episode = _episodes.firstWhereOrNull((ep) => ep.guid == e.guid);
 
       if (episode != null) {
-        episode.downloadState = e.downloadState = DownloadState.queued;
-
         _refresh();
 
-        var result = await downloadService.downloadEpisode(e);
-
-        // If there was an error downloading the episode, push an error state
-        // and then restore to none.
-        if (!result) {
-          episode.downloadState = e.downloadState = DownloadState.failed;
-          _refresh();
-          episode.downloadState = e.downloadState = DownloadState.none;
-          _refresh();
-        }
+        await downloadService.downloadEpisode(e);
       }
     });
   }

lib/services/audio/default_audio_player_service.dart

@@ -15,6 +15,7 @@ import 'package:anytime/entities/sleep.dart';
 import 'package:anytime/entities/transcript.dart';
 import 'package:anytime/repository/repository.dart';
 import 'package:anytime/services/audio/audio_player_service.dart';
+import 'package:anytime/services/download/download_service.dart';
 import 'package:anytime/services/podcast/podcast_service.dart';
 import 'package:anytime/services/settings/settings_service.dart';
 import 'package:anytime/state/episode_state.dart';
@@ -37,6 +38,7 @@ class DefaultAudioPlayerService extends AudioPlayerService {
   final log = Logger('DefaultAudioPlayerService');
   final Repository repository;
   final SettingsService settingsService;
+  final DownloadService downloadService;
   final PodcastService podcastService;
 
   late AudioHandler _audioHandler;
@@ -95,6 +97,7 @@ class DefaultAudioPlayerService extends AudioPlayerService {
     required this.repository,
     required this.settingsService,
     required this.podcastService,
+    required this.downloadService,
   }) {
     AudioService.init(
       builder: () => _DefaultAudioPlayerHandler(
@@ -535,7 +538,7 @@ class DefaultAudioPlayerService extends AudioPlayerService {
         settingsService.deleteDownloadedPlayedEpisodes &&
         _currentEpisode?.downloadState == DownloadState.downloaded && !sleepy
     ) {
-      await podcastService.deleteDownload(_currentEpisode!);
+      await downloadService.deleteDownload(_currentEpisode!);
     }
 
     _stopPositionTicker();

lib/services/download/download_service.dart

@@ -5,7 +5,8 @@
 import 'package:anytime/entities/episode.dart';
 
 abstract class DownloadService {
-  Future<bool> downloadEpisode(Episode episode);
+  Future<void> downloadEpisode(Episode episode);
+  Future<void> deleteDownload(Episode episode);
 
   Future<Episode?> findEpisodeByTaskId(String taskId);
 

lib/services/download/mobile_download_service.dart

@@ -13,10 +13,14 @@ import 'package:anytime/repository/repository.dart';
 import 'package:anytime/services/download/download_manager.dart';
 import 'package:anytime/services/download/download_service.dart';
 import 'package:anytime/services/podcast/podcast_service.dart';
+import 'package:anytime/services/settings/settings_service.dart';
 import 'package:collection/collection.dart' show IterableExtension;
+import 'package:flutter_downloader/flutter_downloader.dart';
 import 'package:logging/logging.dart';
 import 'package:mp3_info/mp3_info.dart';
 import 'package:rxdart/rxdart.dart';
+import 'package:synchronized/synchronized.dart';
+import 'package:uuid/uuid.dart';
 
 /// An implementation of a [DownloadService] that handles downloading
 /// of episodes on mobile.
@@ -25,23 +29,40 @@ class MobileDownloadService extends DownloadService {
 
   final log = Logger('MobileDownloadService');
   final Repository repository;
+  final SettingsService settingsService;
   final DownloadManager downloadManager;
   final PodcastService podcastService;
 
-  MobileDownloadService({required this.repository, required this.downloadManager, required this.podcastService}) {
-    downloadManager.downloadProgress.pipe(downloadProgress);
-    downloadProgress.listen((progress) {
-      _updateDownloadProgress(progress);
-    });
+  late final StreamSubscription _downloadProgressSubscription;
+
+  /// Lock ensures we wait for task creation and local save
+  /// before handling subsequent [Download update events].
+  final _downloadLock = Lock();
+
+  MobileDownloadService({
+    required this.repository,
+    required this.downloadManager,
+    required this.settingsService,
+    required this.podcastService,
+  }) {
+    _downloadProgressSubscription = downloadManager.downloadProgress.listen(
+      (progress) async => await _downloadLock.synchronized(
+        () {
+          downloadProgress.add(progress);
+          _updateDownloadProgress(progress);
+        },
+      ),
+    );
   }
 
   @override
   void dispose() {
     downloadManager.dispose();
+    _downloadProgressSubscription.cancel();
   }
 
   @override
-  Future<bool> downloadEpisode(Episode episode) async {
+  Future<void> downloadEpisode(Episode episode) async {
     try {
       final season = episode.season > 0 ? episode.season.toString() : '';
       final epno = episode.episode > 0 ? episode.episode.toString() : '';
@@ -121,28 +142,90 @@ class MobileDownloadService extends DownloadService {
           /// the URL before calling download and ensure it is https.
           var url = await resolveUrl(episode.contentUrl!, forceHttps: true);
 
-          final taskId = await downloadManager.enqueueTask(url, downloadPath, filename);
+          await _downloadLock.synchronized(() async {
+            final taskId = await downloadManager.enqueueTask(url, downloadPath, filename!);
 
-          // Update the episode with download data
-          episode.filepath = episodePath;
-          episode.filename = filename;
-          episode.downloadTaskId = taskId;
-          episode.downloadState = DownloadState.downloading;
-          episode.downloadPercentage = 0;
+            // Update the episode with download data
+            episode.filepath = episodePath;
+            episode.filename = filename;
+            episode.downloadTaskId = taskId;
+            episode.downloadState = DownloadState.downloading;
+            episode.downloadPercentage = 0;
 
-          await repository.saveEpisode(episode);
-
-          return true;
+            await repository.saveEpisode(episode);
+          });
         }
       }
-
-      return false;
     } catch (e, stack) {
       log.warning('Episode download failed (${episode.title})', e, stack);
-      return false;
+      episode.filename = null;
+      episode.filepath = null;
+      episode.downloadTaskId = null;
+      episode.downloadPercentage = 0;
+      episode.downloadState = DownloadState.none;
+
+      await repository.saveEpisode(episode);
+
+      /// If there was an error downloading the episode, push an error state
+      /// and then restore to none.
+      ///
+      /// If failure happens before download actual start, its [id] will be [null].
+      final downloadId = episode.downloadTaskId ?? const Uuid().v4();
+      downloadProgress
+        ..add(DownloadProgress(
+          downloadId,
+          0,
+          DownloadState.failed,
+        ))
+        ..add(DownloadProgress(
+          downloadId,
+          0,
+          DownloadState.none,
+        ));
     }
   }
 
+  @override
+  Future<void> deleteDownload(Episode episode) async => _downloadLock.synchronized(() async {
+        // If this episode is currently downloading, cancel the download first.
+        if (episode.downloadState == DownloadState.downloaded) {
+          if (settingsService.markDeletedEpisodesAsPlayed) {
+            episode.played = true;
+          }
+        } else if (episode.downloadState == DownloadState.downloading && episode.downloadPercentage! < 100) {
+          await FlutterDownloader.cancel(taskId: episode.downloadTaskId!);
+        }
+
+        episode.downloadTaskId = null;
+        episode.downloadPercentage = 0;
+        episode.position = 0;
+        episode.downloadState = DownloadState.none;
+
+        if (episode.transcriptId != null && episode.transcriptId! > 0) {
+          await repository.deleteTranscriptById(episode.transcriptId!);
+        }
+
+        await repository.saveEpisode(episode);
+
+        if (await hasStoragePermission()) {
+          final f = File.fromUri(Uri.file(await resolvePath(episode)));
+
+          log.fine('Deleting file ${f.path}');
+
+          if (await f.exists()) {
+            f.delete();
+          }
+        }
+
+        // downloadProgress.add(DownloadProgress(
+        //   episode.downloadTaskId!,
+        //   0,
+        //   DownloadState.none,
+        // ));
+
+        return;
+      });
+
   @override
   Future<Episode?> findEpisodeByTaskId(String taskId) {
     return repository.findEpisodeByTaskId(taskId);

lib/services/podcast/mobile_podcast_service.dart

@@ -8,7 +8,6 @@ import 'dart:io';
 import 'package:anytime/api/podcast/podcast_api.dart';
 import 'package:anytime/core/utils.dart';
 import 'package:anytime/entities/chapter.dart';
-import 'package:anytime/entities/downloadable.dart';
 import 'package:anytime/entities/episode.dart';
 import 'package:anytime/entities/funding.dart';
 import 'package:anytime/entities/person.dart';
@@ -20,7 +19,6 @@ import 'package:anytime/state/episode_state.dart';
 import 'package:collection/collection.dart' show IterableExtension;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_downloader/flutter_downloader.dart';
 import 'package:intl/intl.dart';
 import 'package:logging/logging.dart';
 import 'package:path/path.dart';
@@ -507,41 +505,6 @@ class MobilePodcastService extends PodcastService {
     return repository.findAllEpisodes();
   }
 
-  @override
-  Future<void> deleteDownload(Episode episode) async {
-    // If this episode is currently downloading, cancel the download first.
-    if (episode.downloadState == DownloadState.downloaded) {
-      if (settingsService.markDeletedEpisodesAsPlayed) {
-        episode.played = true;
-      }
-    } else if (episode.downloadState == DownloadState.downloading && episode.downloadPercentage! < 100) {
-      await FlutterDownloader.cancel(taskId: episode.downloadTaskId!);
-    }
-
-    episode.downloadTaskId = null;
-    episode.downloadPercentage = 0;
-    episode.position = 0;
-    episode.downloadState = DownloadState.none;
-
-    if (episode.transcriptId != null && episode.transcriptId! > 0) {
-      await repository.deleteTranscriptById(episode.transcriptId!);
-    }
-
-    await repository.saveEpisode(episode);
-
-    if (await hasStoragePermission()) {
-      final f = File.fromUri(Uri.file(await resolvePath(episode)));
-
-      log.fine('Deleting file ${f.path}');
-
-      if (await f.exists()) {
-        f.delete();
-      }
-    }
-
-    return;
-  }
-
   @override
   Future<void> toggleEpisodePlayed(Episode episode) async {
     episode.played = !episode.played;

lib/services/podcast/podcast_service.dart

@@ -202,8 +202,6 @@ abstract class PodcastService {
 
   Future<Transcript> loadTranscriptByUrl({required TranscriptUrl transcriptUrl});
 
-  Future<void> deleteDownload(Episode episode);
-
   Future<void> toggleEpisodePlayed(Episode episode);
 
   Future<List<Podcast>> subscriptions();