feat: Add metadata caching and proper integration for external media files

app/src/main/java/com/cappielloantonio/tempo/service/MediaManager.java

@@ -223,6 +223,25 @@ public class MediaManager {
         }
     }
 
+    public static void playDownloadedMediaItem(ListenableFuture<MediaBrowser> mediaBrowserListenableFuture, MediaItem mediaItem) {
+        if (mediaBrowserListenableFuture != null && mediaItem != null) {
+            mediaBrowserListenableFuture.addListener(() -> {
+                try {
+                    if (mediaBrowserListenableFuture.isDone()) {
+                        MediaBrowser mediaBrowser = mediaBrowserListenableFuture.get();
+                        mediaBrowser.clearMediaItems();
+                        mediaBrowser.setMediaItem(mediaItem);
+                        mediaBrowser.prepare();
+                        mediaBrowser.play();
+                        clearDatabase();
+                    }
+                } catch (ExecutionException | InterruptedException e) {
+                    e.printStackTrace();
+                }
+            }, MoreExecutors.directExecutor());
+        }
+    }
+
     public static void startRadio(ListenableFuture<MediaBrowser> mediaBrowserListenableFuture, InternetRadioStation internetRadioStation) {
         if (mediaBrowserListenableFuture != null) {
             mediaBrowserListenableFuture.addListener(() -> {

app/src/main/java/com/cappielloantonio/tempo/ui/activity/MainActivity.java

@@ -1,11 +1,14 @@
 package com.cappielloantonio.tempo.ui.activity;
 
 import android.content.Context;
+import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
+import android.net.Uri;
 import android.os.Bundle;
 import android.os.Handler;
+import android.text.TextUtils;
 import android.util.Log;
 import android.view.View;
 
@@ -13,7 +16,10 @@ import androidx.annotation.NonNull;
 import androidx.core.splashscreen.SplashScreen;
 import androidx.fragment.app.FragmentManager;
 import androidx.lifecycle.ViewModelProvider;
+import androidx.media3.common.MediaItem;
+import androidx.media3.common.MediaMetadata;
 import androidx.media3.common.Player;
+import androidx.media3.common.MimeTypes;
 import androidx.media3.common.util.UnstableApi;
 import androidx.navigation.NavController;
 import androidx.navigation.fragment.NavHostFragment;
@@ -56,6 +62,7 @@ public class MainActivity extends BaseActivity {
     private BottomSheetBehavior bottomSheetBehavior;
 
     ConnectivityStatusBroadcastReceiver connectivityStatusBroadcastReceiver;
+    private Intent pendingDownloadPlaybackIntent;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -77,6 +84,8 @@ public class MainActivity extends BaseActivity {
         checkConnectionType();
         getOpenSubsonicExtensions();
         checkTempoUpdate();
+
+        maybeSchedulePlaybackIntent(getIntent());
     }
 
     @Override
@@ -84,6 +93,7 @@ public class MainActivity extends BaseActivity {
         super.onStart();
         pingServer();
         initService();
+        consumePendingPlaybackIntent();
     }
 
     @Override
@@ -99,6 +109,14 @@ public class MainActivity extends BaseActivity {
         bind = null;
     }
 
+    @Override
+    protected void onNewIntent(Intent intent) {
+        super.onNewIntent(intent);
+        setIntent(intent);
+        maybeSchedulePlaybackIntent(intent);
+        consumePendingPlaybackIntent();
+    }
+
     @Override
     public void onBackPressed() {
         if (bottomSheetBehavior.getState() == BottomSheetBehavior.STATE_EXPANDED)
@@ -418,4 +436,68 @@ public class MainActivity extends BaseActivity {
             }
         }
     }
+
+    private void maybeSchedulePlaybackIntent(Intent intent) {
+        if (intent == null) return;
+        if (Constants.ACTION_PLAY_EXTERNAL_DOWNLOAD.equals(intent.getAction())
+                || intent.hasExtra(Constants.EXTRA_DOWNLOAD_URI)) {
+            pendingDownloadPlaybackIntent = new Intent(intent);
+        }
+    }
+
+    private void consumePendingPlaybackIntent() {
+        if (pendingDownloadPlaybackIntent == null) return;
+        Intent intent = pendingDownloadPlaybackIntent;
+        pendingDownloadPlaybackIntent = null;
+        playDownloadedMedia(intent);
+    }
+
+    private void playDownloadedMedia(Intent intent) {
+        String uriString = intent.getStringExtra(Constants.EXTRA_DOWNLOAD_URI);
+        if (TextUtils.isEmpty(uriString)) {
+            return;
+        }
+
+        Uri uri = Uri.parse(uriString);
+        String mediaId = intent.getStringExtra(Constants.EXTRA_DOWNLOAD_MEDIA_ID);
+        if (TextUtils.isEmpty(mediaId)) {
+            mediaId = uri.toString();
+        }
+
+        String title = intent.getStringExtra(Constants.EXTRA_DOWNLOAD_TITLE);
+        String artist = intent.getStringExtra(Constants.EXTRA_DOWNLOAD_ARTIST);
+        String album = intent.getStringExtra(Constants.EXTRA_DOWNLOAD_ALBUM);
+        int duration = intent.getIntExtra(Constants.EXTRA_DOWNLOAD_DURATION, 0);
+
+        Bundle extras = new Bundle();
+        extras.putString("id", mediaId);
+        extras.putString("title", title);
+        extras.putString("artist", artist);
+        extras.putString("album", album);
+        extras.putString("uri", uri.toString());
+        extras.putString("type", Constants.MEDIA_TYPE_MUSIC);
+        extras.putInt("duration", duration);
+
+        MediaMetadata.Builder metadataBuilder = new MediaMetadata.Builder()
+                .setExtras(extras)
+                .setIsBrowsable(false)
+                .setIsPlayable(true);
+
+        if (!TextUtils.isEmpty(title)) metadataBuilder.setTitle(title);
+        if (!TextUtils.isEmpty(artist)) metadataBuilder.setArtist(artist);
+        if (!TextUtils.isEmpty(album)) metadataBuilder.setAlbumTitle(album);
+
+        MediaItem mediaItem = new MediaItem.Builder()
+                .setMediaId(mediaId)
+                .setMediaMetadata(metadataBuilder.build())
+                .setUri(uri)
+                .setMimeType(MimeTypes.BASE_TYPE_AUDIO)
+                .setRequestMetadata(new MediaItem.RequestMetadata.Builder()
+                        .setMediaUri(uri)
+                        .setExtras(extras)
+                        .build())
+                .build();
+
+        MediaManager.playDownloadedMediaItem(getMediaBrowserListenableFuture(), mediaItem);
+    }
 }

app/src/main/java/com/cappielloantonio/tempo/ui/dialog/DeleteDownloadStorageDialog.java

@@ -16,6 +16,7 @@ import com.cappielloantonio.tempo.R;
 import com.cappielloantonio.tempo.databinding.DialogDeleteDownloadStorageBinding;
 import com.cappielloantonio.tempo.util.DownloadUtil;
 import com.cappielloantonio.tempo.util.ExternalAudioReader;
+import com.cappielloantonio.tempo.util.ExternalDownloadMetadataStore;
 import com.cappielloantonio.tempo.util.Preferences;
 import com.google.android.material.dialog.MaterialAlertDialogBuilder;
 
@@ -47,7 +48,10 @@ public class DeleteDownloadStorageDialog extends DialogFragment {
         if (dialog != null) {
             Button positiveButton = dialog.getButton(Dialog.BUTTON_POSITIVE);
             positiveButton.setOnClickListener(v -> {
-                DownloadUtil.getDownloadTracker(requireContext()).removeAll();
+                if (Preferences.getDownloadDirectoryUri() == null) {
+                    DownloadUtil.getDownloadTracker(requireContext()).removeAll();
+                }
+
                 String uriString = Preferences.getDownloadDirectoryUri();
                 if (uriString != null) {
                     DocumentFile directory = DocumentFile.fromTreeUri(requireContext(), Uri.parse(uriString));
@@ -57,6 +61,7 @@ public class DeleteDownloadStorageDialog extends DialogFragment {
                         }
                     }
                     ExternalAudioReader.refreshCache();
+                    ExternalDownloadMetadataStore.clear();
                 }
                 dialog.dismiss();
             });

app/src/main/java/com/cappielloantonio/tempo/ui/dialog/DownloadDirectoryPickerDialog.java

@@ -13,6 +13,7 @@ import androidx.fragment.app.DialogFragment;
 
 import com.google.android.material.dialog.MaterialAlertDialogBuilder;
 import com.cappielloantonio.tempo.R;
+import com.cappielloantonio.tempo.util.ExternalAudioReader;
 import com.cappielloantonio.tempo.util.Preferences;
 
 public class DownloadDirectoryPickerDialog extends DialogFragment {
@@ -37,6 +38,7 @@ public class DownloadDirectoryPickerDialog extends DialogFragment {
                             );
 
                             Preferences.setDownloadDirectoryUri(uri.toString());
+                            ExternalAudioReader.refreshCache();
 
                             Toast.makeText(requireContext(), "Download directory set:\n" + uri.toString(), Toast.LENGTH_LONG).show();
                         }

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/AlbumPageFragment.java

@@ -138,10 +138,7 @@ public class AlbumPageFragment extends Fragment implements ClickCallback {
                         songs.stream().map(Download::new).collect(Collectors.toList())
                     );
                 } else {
-                    MappingUtil.mapMediaItems(songs).forEach(media -> {
+                    songs.forEach(child -> ExternalAudioWriter.downloadToUserDirectory(requireContext(), child));
-                        String title = media.mediaMetadata.title != null ? media.mediaMetadata.title.toString() : media.mediaId;
-                        ExternalAudioWriter.downloadToUserDirectory(requireContext(), media, title);
-                    });
                 }
             });
             return true;

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/DirectoryFragment.java

@@ -117,10 +117,7 @@ public class DirectoryFragment extends Fragment implements ClickCallback {
                                         songs.stream().map(Download::new).collect(Collectors.toList())
                                 );
                             } else {
-                                MappingUtil.mapMediaItems(songs).forEach(media -> {
+                                songs.forEach(child -> ExternalAudioWriter.downloadToUserDirectory(requireContext(), child));
-                                    String title = media.mediaMetadata.title != null ? media.mediaMetadata.title.toString() : media.mediaId;
-                                    ExternalAudioWriter.downloadToUserDirectory(requireContext(), media, title);
-                                });
                             }
                         }
                     });

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/DownloadFragment.java

@@ -28,6 +28,7 @@ import com.cappielloantonio.tempo.subsonic.models.Child;
 import com.cappielloantonio.tempo.ui.activity.MainActivity;
 import com.cappielloantonio.tempo.ui.adapter.DownloadHorizontalAdapter;
 import com.cappielloantonio.tempo.util.Constants;
+import com.cappielloantonio.tempo.util.ExternalAudioReader;
 import com.cappielloantonio.tempo.util.Preferences;
 import com.cappielloantonio.tempo.viewmodel.DownloadViewModel;
 import com.google.android.material.appbar.MaterialToolbar;
@@ -289,6 +290,7 @@ public class DownloadFragment extends Fragment implements ClickCallback {
                         Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION
                 );
                 Preferences.setDownloadDirectoryUri(uri.toString());
+                ExternalAudioReader.refreshCache();
                 Toast.makeText(requireContext(), "Download directory set", Toast.LENGTH_SHORT).show();
             }
         }

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/PlayerCoverFragment.java

@@ -123,9 +123,7 @@ public class PlayerCoverFragment extends Fragment {
                                 new Download(song)
                         );
                     } else {
-                        MediaItem item = MappingUtil.mapMediaItem(song);
+                        ExternalAudioWriter.downloadToUserDirectory(requireContext(), song);
-                        String title = item.mediaMetadata.title != null ? item.mediaMetadata.title.toString() : item.mediaId;
-                        ExternalAudioWriter.downloadToUserDirectory(requireContext(), item, title);
                     }
                 });
 

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/PlaylistPageFragment.java

@@ -144,19 +144,16 @@ public class PlaylistPageFragment extends Fragment implements ClickCallback {
                 if (isVisible() && getActivity() != null) {
                     if (Preferences.getDownloadDirectoryUri() == null) {
                         DownloadUtil.getDownloadTracker(requireContext()).download(
-                                MappingUtil.mapDownloads(songs),
+                            MappingUtil.mapDownloads(songs),
-                                songs.stream().map(child -> {
+                            songs.stream().map(child -> {
-                                    Download toDownload = new Download(child);
+                                Download toDownload = new Download(child);
-                                    toDownload.setPlaylistId(playlistPageViewModel.getPlaylist().getId());
+                                toDownload.setPlaylistId(playlistPageViewModel.getPlaylist().getId());
-                                    toDownload.setPlaylistName(playlistPageViewModel.getPlaylist().getName());
+                                toDownload.setPlaylistName(playlistPageViewModel.getPlaylist().getName());
-                                    return toDownload;
+                                return toDownload;
-                                }).collect(Collectors.toList())
+                            }).collect(Collectors.toList())
                         );
                     } else {
-                        MappingUtil.mapMediaItems(songs).forEach(media -> {
+                        songs.forEach(child -> ExternalAudioWriter.downloadToUserDirectory(requireContext(), child));
-                            String title = media.mediaMetadata.title != null ? media.mediaMetadata.title.toString() : media.mediaId;
-                            ExternalAudioWriter.downloadToUserDirectory(requireContext(), media, title);
-                        });
                     }
                 }
             });

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/SettingsFragment.java

@@ -428,6 +428,7 @@ public class SettingsFragment extends PreferenceFragmentCompat {
                 if (current != null) {
                     Preferences.setDownloadDirectoryUri(null);
                     Preferences.setDownloadStoragePreference(0);
+                    ExternalAudioReader.refreshCache();
                     Toast.makeText(requireContext(), "Download folder cleared.", Toast.LENGTH_SHORT).show();
                     checkStorage();
                     checkDownloadDirectory();

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/bottomsheetdialog/AlbumBottomSheetDialog.java

@@ -38,6 +38,7 @@ import com.cappielloantonio.tempo.util.MappingUtil;
 import com.cappielloantonio.tempo.util.MusicUtil;
 import com.cappielloantonio.tempo.util.Preferences;
 import com.cappielloantonio.tempo.util.ExternalAudioWriter;
+import com.cappielloantonio.tempo.util.ExternalAudioReader;
 import com.cappielloantonio.tempo.viewmodel.AlbumBottomSheetViewModel;
 import com.cappielloantonio.tempo.viewmodel.HomeViewModel;
 import com.google.android.material.bottomsheet.BottomSheetDialogFragment;
@@ -167,10 +168,7 @@ public class AlbumBottomSheetDialog extends BottomSheetDialogFragment implements
                 if (Preferences.getDownloadDirectoryUri() == null) {
                     DownloadUtil.getDownloadTracker(requireContext()).download(mediaItems, downloads);
                 } else {
-                    MappingUtil.mapMediaItems(songs).forEach(media -> {
+                    songs.forEach(child -> ExternalAudioWriter.downloadToUserDirectory(requireContext(), child));
-                        String title = media.mediaMetadata.title != null ? media.mediaMetadata.title.toString() : media.mediaId;
-                        ExternalAudioWriter.downloadToUserDirectory(requireContext(), media, title);
-                    });
                 }
                 dismissBottomSheet();
             });
@@ -196,7 +194,11 @@ public class AlbumBottomSheetDialog extends BottomSheetDialogFragment implements
             List<Download> downloads = songs.stream().map(Download::new).collect(Collectors.toList());
 
             removeAll.setOnClickListener(v -> {
-                DownloadUtil.getDownloadTracker(requireContext()).remove(mediaItems, downloads);
+                if (Preferences.getDownloadDirectoryUri() == null) {
+                    DownloadUtil.getDownloadTracker(requireContext()).remove(mediaItems, downloads);
+                } else {
+                    songs.forEach(ExternalAudioReader::delete);
+                }
                 dismissBottomSheet();
             });
         });
@@ -246,8 +248,15 @@ public class AlbumBottomSheetDialog extends BottomSheetDialogFragment implements
         albumBottomSheetViewModel.getAlbumTracks().observe(getViewLifecycleOwner(), songs -> {
             List<MediaItem> mediaItems = MappingUtil.mapDownloads(songs);
 
-            if (Preferences.getDownloadDirectoryUri() == null && DownloadUtil.getDownloadTracker(requireContext()).areDownloaded(mediaItems)) {
+            if (Preferences.getDownloadDirectoryUri() == null) {
-                removeAll.setVisibility(View.VISIBLE);
+                if (DownloadUtil.getDownloadTracker(requireContext()).areDownloaded(mediaItems)) {
+                    removeAll.setVisibility(View.VISIBLE);
+                } else {
+                    removeAll.setVisibility(View.GONE);
+                }
+            } else {
+                boolean hasLocal = songs.stream().anyMatch(song -> ExternalAudioReader.getUri(song) != null);
+                removeAll.setVisibility(hasLocal ? View.VISIBLE : View.GONE);
             }
         });
     }

app/src/main/java/com/cappielloantonio/tempo/ui/fragment/bottomsheetdialog/SongBottomSheetDialog.java

@@ -164,15 +164,13 @@ public class SongBottomSheetDialog extends BottomSheetDialogFragment implements
 
         TextView download = view.findViewById(R.id.download_text_view);
         download.setOnClickListener(v -> {
-            MediaItem item = MappingUtil.mapMediaItem(song);
-            String title = item.mediaMetadata.title != null ? item.mediaMetadata.title.toString() : item.mediaId;
             if (Preferences.getDownloadDirectoryUri() == null) {
                 DownloadUtil.getDownloadTracker(requireContext()).download(
                         MappingUtil.mapDownload(song),
                         new Download(song)
                 );
             } else {
-                ExternalAudioWriter.downloadToUserDirectory(requireContext(), item, title);
+                ExternalAudioWriter.downloadToUserDirectory(requireContext(), song);
             }
             dismissBottomSheet();
         });

app/src/main/java/com/cappielloantonio/tempo/util/Constants.kt

@@ -85,6 +85,13 @@ object Constants {
     const val MEDIA_LEAST_RECENTLY_STARRED = "MEDIA_LEAST_RECENTLY_STARRED"
 
     const val DOWNLOAD_URI = "rest/download"
+    const val ACTION_PLAY_EXTERNAL_DOWNLOAD = "com.cappielloantonio.tempo.action.PLAY_EXTERNAL_DOWNLOAD"
+    const val EXTRA_DOWNLOAD_URI = "EXTRA_DOWNLOAD_URI"
+    const val EXTRA_DOWNLOAD_MEDIA_ID = "EXTRA_DOWNLOAD_MEDIA_ID"
+    const val EXTRA_DOWNLOAD_TITLE = "EXTRA_DOWNLOAD_TITLE"
+    const val EXTRA_DOWNLOAD_ARTIST = "EXTRA_DOWNLOAD_ARTIST"
+    const val EXTRA_DOWNLOAD_ALBUM = "EXTRA_DOWNLOAD_ALBUM"
+    const val EXTRA_DOWNLOAD_DURATION = "EXTRA_DOWNLOAD_DURATION"
 
     const val DOWNLOAD_TYPE_TRACK = "download_type_track"
     const val DOWNLOAD_TYPE_ALBUM = "download_type_album"

app/src/main/java/com/cappielloantonio/tempo/util/ExternalAudioReader.java

@@ -10,8 +10,10 @@ import com.cappielloantonio.tempo.subsonic.models.PodcastEpisode;
 
 import java.text.Normalizer;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Set;
 
 public class ExternalAudioReader {
 
@@ -36,6 +38,7 @@ public class ExternalAudioReader {
         if (uriString == null) {
             cache.clear();
             cachedDirUri = null;
+            ExternalDownloadMetadataStore.clear();
             return;
         }
 
@@ -43,12 +46,36 @@ public class ExternalAudioReader {
 
         cache.clear();
         DocumentFile directory = DocumentFile.fromTreeUri(App.getContext(), Uri.parse(uriString));
+        Map<String, Long> expectedSizes = ExternalDownloadMetadataStore.snapshot();
+        Set<String> verifiedKeys = new HashSet<>();
         if (directory != null && directory.canRead()) {
             for (DocumentFile file : directory.listFiles()) {
+                if (file == null || file.isDirectory()) continue;
                 String existing = file.getName();
-                if (existing != null) {
+                if (existing == null) continue;
-                    String base = existing.replaceFirst("\\.[^\\.]+$", "");
+
-                    cache.put(normalizeForComparison(base), file);
+                String base = existing.replaceFirst("\\.[^\\.]+$", "");
+                String key = normalizeForComparison(base);
+                Long expected = expectedSizes.get(key);
+                long actualLength = file.length();
+
+                if (expected != null && expected > 0 && actualLength == expected) {
+                    cache.put(key, file);
+                    verifiedKeys.add(key);
+                } else {
+                    ExternalDownloadMetadataStore.remove(key);
+                }
+            }
+        }
+
+        if (!expectedSizes.isEmpty()) {
+            if (verifiedKeys.isEmpty()) {
+                ExternalDownloadMetadataStore.clear();
+            } else {
+                for (String key : expectedSizes.keySet()) {
+                    if (!verifiedKeys.contains(key)) {
+                        ExternalDownloadMetadataStore.remove(key);
+                    }
                 }
             }
         }
@@ -56,7 +83,6 @@ public class ExternalAudioReader {
         cachedDirUri = uriString;
     }
 
-    /** Rebuilds the cache on next access. */
     public static synchronized void refreshCache() {
         cachedDirUri = null;
         cache.clear();
@@ -96,6 +122,7 @@ public class ExternalAudioReader {
         }
         if (deleted) {
             cache.remove(key);
+            ExternalDownloadMetadataStore.remove(key);
         }
         return deleted;
     }

app/src/main/java/com/cappielloantonio/tempo/util/ExternalAudioWriter.java

@@ -12,8 +12,8 @@ import androidx.core.app.NotificationCompat;
 import androidx.documentfile.provider.DocumentFile;
 import androidx.media3.common.MediaItem;
 
-import com.cappielloantonio.tempo.util.Preferences;
+import com.cappielloantonio.tempo.subsonic.models.Child;
-import com.cappielloantonio.tempo.util.ExternalAudioReader;
+import com.cappielloantonio.tempo.ui.activity.MainActivity;
 
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -21,9 +21,19 @@ import java.net.HttpURLConnection;
 import java.net.URL;
 import java.text.Normalizer;
 import java.util.Locale;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 public class ExternalAudioWriter {
 
+    private static final ExecutorService EXECUTOR = Executors.newSingleThreadExecutor();
+    private static final int BUFFER_SIZE = 8192;
+    private static final int CONNECT_TIMEOUT_MS = 15_000;
+    private static final int READ_TIMEOUT_MS = 60_000;
+
+    private ExternalAudioWriter() {
+    }
+
     private static String sanitizeFileName(String name) {
         String sanitized = name.replaceAll("[\\/:*?\\\"<>|]", "_");
         sanitized = sanitized.replaceAll("\\s+", " ").trim();
@@ -40,6 +50,7 @@ public class ExternalAudioWriter {
     private static DocumentFile findFile(DocumentFile dir, String fileName) {
         String normalized = normalizeForComparison(fileName);
         for (DocumentFile file : dir.listFiles()) {
+            if (file.isDirectory()) continue;
             String existing = file.getName();
             if (existing != null && normalizeForComparison(existing).equals(normalized)) {
                 return file;
@@ -48,115 +59,182 @@ public class ExternalAudioWriter {
         return null;
     }
 
-    public static void downloadToUserDirectory(Context context, MediaItem mediaItem, String fallbackName) {
+    public static void downloadToUserDirectory(Context context, Child child) {
-        new Thread(() -> {
+        if (context == null || child == null) {
-            String uriString = Preferences.getDownloadDirectoryUri();
+            return;
+        }
+        Context appContext = context.getApplicationContext();
+        MediaItem mediaItem = MappingUtil.mapDownload(child);
+        String fallbackName = child.getTitle() != null ? child.getTitle() : child.getId();
+        EXECUTOR.execute(() -> performDownload(appContext, mediaItem, fallbackName, child));
+    }
 
-            if (uriString == null) {
+    private static void performDownload(Context context, MediaItem mediaItem, String fallbackName, Child child) {
-                notifyUnavailable(context);
+        String uriString = Preferences.getDownloadDirectoryUri();
+        if (uriString == null) {
+            notifyUnavailable(context);
+            return;
+        }
+
+        DocumentFile directory = DocumentFile.fromTreeUri(context, Uri.parse(uriString));
+        if (directory == null || !directory.canWrite()) {
+            notifyFailure(context, "Cannot write to folder.");
+            return;
+        }
+
+        String artist = child.getArtist() != null ? child.getArtist() : "";
+        String title = child.getTitle() != null ? child.getTitle() : fallbackName;
+        String album = child.getAlbum() != null ? child.getAlbum() : "";
+        String baseName = artist.isEmpty() ? title : artist + " - " + title;
+        if (!album.isEmpty()) baseName += " (" + album + ")";
+        if (baseName.isEmpty()) {
+            baseName = fallbackName != null ? fallbackName : "download";
+        }
+        String metadataKey = normalizeForComparison(baseName);
+
+        Uri mediaUri = mediaItem != null && mediaItem.requestMetadata != null
+                ? mediaItem.requestMetadata.mediaUri
+                : null;
+        if (mediaUri == null) {
+            notifyFailure(context, "Invalid media URI.");
+            ExternalDownloadMetadataStore.remove(metadataKey);
+            return;
+        }
+        String scheme = mediaUri.getScheme();
+        if (scheme == null || (!scheme.equalsIgnoreCase("http") && !scheme.equalsIgnoreCase("https"))) {
+            notifyFailure(context, "Unsupported media URI.");
+            ExternalDownloadMetadataStore.remove(metadataKey);
+            return;
+        }
+
+        HttpURLConnection connection = null;
+        DocumentFile targetFile = null;
+        try {
+            connection = (HttpURLConnection) new URL(mediaUri.toString()).openConnection();
+            connection.setConnectTimeout(CONNECT_TIMEOUT_MS);
+            connection.setReadTimeout(READ_TIMEOUT_MS);
+            connection.setRequestProperty("Accept-Encoding", "identity");
+            connection.connect();
+
+            int responseCode = connection.getResponseCode();
+            if (responseCode >= HttpURLConnection.HTTP_BAD_REQUEST) {
+                notifyFailure(context, "Server returned " + responseCode);
+                ExternalDownloadMetadataStore.remove(metadataKey);
                 return;
             }
 
-            Uri treeUri = Uri.parse(uriString);
+            String mimeType = connection.getContentType();
-            DocumentFile directory = DocumentFile.fromTreeUri(context, treeUri);
+            if (mimeType == null || mimeType.isEmpty()) {
-            if (directory == null || !directory.canWrite()) {
+                mimeType = "application/octet-stream";
-                notifyFailure(context, "Cannot write to folder.");
+            }
+
+            String extension = MimeTypeMap.getSingleton().getExtensionFromMimeType(mimeType);
+            if (extension == null || extension.isEmpty()) {
+                String suffix = child.getSuffix();
+                if (suffix != null && !suffix.isEmpty()) {
+                    extension = suffix;
+                } else {
+                    extension = "bin";
+                }
+            }
+
+            String sanitized = sanitizeFileName(baseName);
+            if (sanitized.isEmpty()) sanitized = sanitizeFileName(fallbackName);
+            if (sanitized.isEmpty()) sanitized = "download";
+            String fileName = sanitized + "." + extension;
+
+            DocumentFile existingFile = findFile(directory, fileName);
+            long remoteLength = connection.getContentLengthLong();
+            Long recordedSize = ExternalDownloadMetadataStore.getSize(metadataKey);
+            if (existingFile != null && existingFile.exists()) {
+                long localLength = existingFile.length();
+                boolean matches = false;
+                if (remoteLength > 0 && localLength == remoteLength) {
+                    matches = true;
+                } else if (remoteLength <= 0 && recordedSize != null && localLength == recordedSize) {
+                    matches = true;
+                }
+                if (matches) {
+                    ExternalDownloadMetadataStore.recordSize(metadataKey, localLength);
+                    ExternalAudioReader.refreshCache();
+                    notifyExists(context, fileName);
+                    return;
+                } else {
+                    existingFile.delete();
+                    ExternalDownloadMetadataStore.remove(metadataKey);
+                }
+            }
+
+            targetFile = directory.createFile(mimeType, fileName);
+            if (targetFile == null) {
+                notifyFailure(context, "Failed to create file.");
                 return;
             }
 
-            try {
+            Uri targetUri = targetFile.getUri();
-                Uri mediaUri = mediaItem.requestMetadata.mediaUri;
+            try (InputStream in = connection.getInputStream();
-                if (mediaUri == null) {
+                 OutputStream out = context.getContentResolver().openOutputStream(targetUri)) {
-                    notifyFailure(context, "Invalid media URI.");
+                if (out == null) {
+                    notifyFailure(context, "Cannot open output stream.");
+                    targetFile.delete();
                     return;
                 }
 
-                String scheme = mediaUri.getScheme();
+                byte[] buffer = new byte[BUFFER_SIZE];
-                if (scheme == null || (!scheme.equals("http") && !scheme.equals("https"))) {
+                int len;
-                    notifyExists(context, fallbackName);
+                long total = 0;
+                while ((len = in.read(buffer)) != -1) {
+                    out.write(buffer, 0, len);
+                    total += len;
+                }
+                out.flush();
+
+                if (total <= 0) {
+                    targetFile.delete();
+                    ExternalDownloadMetadataStore.remove(metadataKey);
+                    notifyFailure(context, "Empty download.");
                     return;
                 }
 
-                HttpURLConnection connection = (HttpURLConnection) new URL(mediaUri.toString()).openConnection();
+                if (remoteLength > 0 && total != remoteLength) {
-                connection.connect();
+                    targetFile.delete();
-
+                    ExternalDownloadMetadataStore.remove(metadataKey);
-                String mimeType = connection.getContentType();
+                    notifyFailure(context, "Incomplete download.");
-                if (mimeType == null) mimeType = "application/octet-stream";
-
-                String extension = MimeTypeMap.getSingleton().getExtensionFromMimeType(mimeType);
-                if (extension == null) extension = "bin";
-
-                String artist = mediaItem.mediaMetadata.artist != null ? mediaItem.mediaMetadata.artist.toString() : "";
-                String title = mediaItem.mediaMetadata.title != null ? mediaItem.mediaMetadata.title.toString() : fallbackName;
-                String album = mediaItem.mediaMetadata.albumTitle != null ? mediaItem.mediaMetadata.albumTitle.toString() : "";
-                String name = artist.isEmpty() ? title : artist + " - " + title;
-                if (!album.isEmpty()) name += " (" + album + ")";
-
-                String sanitized = sanitizeFileName(name);
-                String fullName = sanitized + "." + extension;
-
-                DocumentFile existingFile = findFile(directory, fullName);
-                long remoteLength = connection.getContentLengthLong();
-                if (existingFile != null && existingFile.exists()) {
-                    long localLength = existingFile.length();
-                    if (remoteLength > 0 && localLength == remoteLength) {
-                        notifyExists(context, fullName);
-                        return;
-                    } else {
-                        existingFile.delete();
-                    }
-                }
-
-                DocumentFile targetFile = directory.createFile(mimeType, fullName);
-                if (targetFile == null) {
-                    notifyFailure(context, "Failed to create file.");
                     return;
                 }
 
-                try (InputStream in = connection.getInputStream();
+                ExternalDownloadMetadataStore.recordSize(metadataKey, total);
-                OutputStream out = context.getContentResolver().openOutputStream(targetFile.getUri())) {
+                notifySuccess(context, fileName, child, targetUri);
-                    if (out == null) {
+                ExternalAudioReader.refreshCache();
-                        notifyFailure(context, "Cannot open output stream.");
-                        return;
-                    }
-
-                    byte[] buffer = new byte[8192];
-                    int len;
-                    long total = 0;
-                    while ((len = in.read(buffer)) != -1) {
-                        out.write(buffer, 0, len);
-                        total += len;
-                    }
-
-                    if (remoteLength > 0 && total != remoteLength) {
-                        targetFile.delete();
-                        notifyFailure(context, "Incomplete download.");
-                    } else {
-                        notifySuccess(context, fullName);
-                        ExternalAudioReader.refreshCache();
-                    }
-                }
-            } catch (Exception e) {
-                notifyFailure(context, e.getMessage());
             }
-        }).start();
+        } catch (Exception e) {
+            if (targetFile != null) {
+                targetFile.delete();
+            }
+            ExternalDownloadMetadataStore.remove(metadataKey);
+            notifyFailure(context, e.getMessage() != null ? e.getMessage() : "Download failed");
+        } finally {
+            if (connection != null) {
+                connection.disconnect();
+            }
+        }
     }
 
     private static void notifyUnavailable(Context context) {
         NotificationManager manager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
         Intent settingsIntent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS,
-            Uri.fromParts("package", context.getPackageName(), null));
+                Uri.fromParts("package", context.getPackageName(), null));
         PendingIntent openSettings = PendingIntent.getActivity(context, 0, settingsIntent,
-            PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE);
+                PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE);
 
         NotificationCompat.Builder builder = new NotificationCompat.Builder(context, DownloadUtil.DOWNLOAD_NOTIFICATION_CHANNEL_ID)
-            .setContentTitle("No download folder set")
+                .setContentTitle("No download folder set")
-            .setContentText("Tap to set one in settings")
+                .setContentText("Tap to set one in settings")
-            .setSmallIcon(android.R.drawable.stat_notify_error)
+                .setSmallIcon(android.R.drawable.stat_notify_error)
-            .setPriority(NotificationCompat.PRIORITY_LOW)
+                .setPriority(NotificationCompat.PRIORITY_LOW)
-            .setSilent(true)
+                .setSilent(true)
-            .setContentIntent(openSettings)
+                .setContentIntent(openSettings)
-            .setAutoCancel(true);
+                .setAutoCancel(true);
 
         manager.notify(1011, builder.build());
     }
@@ -164,30 +242,63 @@ public class ExternalAudioWriter {
     private static void notifyFailure(Context context, String message) {
         NotificationManager manager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
         NotificationCompat.Builder builder = new NotificationCompat.Builder(context, DownloadUtil.DOWNLOAD_NOTIFICATION_CHANNEL_ID)
-            .setContentTitle("Download failed")
+                .setContentTitle("Download failed")
-            .setContentText(message)
+                .setContentText(message)
-            .setSmallIcon(android.R.drawable.stat_notify_error)
+                .setSmallIcon(android.R.drawable.stat_notify_error)
-            .setAutoCancel(true);
+                .setAutoCancel(true);
         manager.notify((int) System.currentTimeMillis(), builder.build());
     }
 
-    private static void notifySuccess(Context context, String name) {
+    private static void notifySuccess(Context context, String name, Child child, Uri fileUri) {
         NotificationManager manager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
         NotificationCompat.Builder builder = new NotificationCompat.Builder(context, DownloadUtil.DOWNLOAD_NOTIFICATION_CHANNEL_ID)
-            .setContentTitle("Download complete")
+                .setContentTitle("Download complete")
-            .setContentText(name)
+                .setContentText(name)
-            .setSmallIcon(android.R.drawable.stat_sys_download_done)
+                .setSmallIcon(android.R.drawable.stat_sys_download_done)
-            .setAutoCancel(true);
+                .setAutoCancel(true);
+
+        PendingIntent playIntent = buildPlayIntent(context, child, fileUri);
+        if (playIntent != null) {
+            builder.setContentIntent(playIntent);
+        }
+
         manager.notify((int) System.currentTimeMillis(), builder.build());
     }
 
     private static void notifyExists(Context context, String name) {
         NotificationManager manager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
         NotificationCompat.Builder builder = new NotificationCompat.Builder(context, DownloadUtil.DOWNLOAD_NOTIFICATION_CHANNEL_ID)
-            .setContentTitle("Already downloaded")
+                .setContentTitle("Already downloaded")
-            .setContentText(name)
+                .setContentText(name)
-            .setSmallIcon(android.R.drawable.stat_sys_warning)
+                .setSmallIcon(android.R.drawable.stat_sys_warning)
-            .setAutoCancel(true);
+                .setAutoCancel(true);
         manager.notify((int) System.currentTimeMillis(), builder.build());
     }
+
+    private static PendingIntent buildPlayIntent(Context context, Child child, Uri fileUri) {
+        if (fileUri == null) return null;
+        Intent intent = new Intent(context, MainActivity.class)
+                .setAction(Constants.ACTION_PLAY_EXTERNAL_DOWNLOAD)
+                .putExtra(Constants.EXTRA_DOWNLOAD_URI, fileUri.toString())
+                .putExtra(Constants.EXTRA_DOWNLOAD_MEDIA_ID, child.getId())
+                .putExtra(Constants.EXTRA_DOWNLOAD_TITLE, child.getTitle())
+                .putExtra(Constants.EXTRA_DOWNLOAD_ARTIST, child.getArtist())
+                .putExtra(Constants.EXTRA_DOWNLOAD_ALBUM, child.getAlbum())
+                .putExtra(Constants.EXTRA_DOWNLOAD_DURATION, child.getDuration() != null ? child.getDuration() : 0)
+                .addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP);
+
+        int requestCode;
+        if (child.getId() != null) {
+            requestCode = Math.abs(child.getId().hashCode());
+        } else {
+            requestCode = Math.abs(fileUri.toString().hashCode());
+        }
+
+        return PendingIntent.getActivity(
+                context,
+                requestCode,
+                intent,
+                PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE
+        );
+    }
 }

app/src/main/java/com/cappielloantonio/tempo/util/ExternalDownloadMetadataStore.java

@@ -0,0 +1,123 @@
+package com.cappielloantonio.tempo.util;
+
+import android.content.SharedPreferences;
+
+import androidx.annotation.Nullable;
+
+import com.cappielloantonio.tempo.App;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+
+public final class ExternalDownloadMetadataStore {
+
+    private static final String PREF_KEY = "external_download_metadata";
+
+    private ExternalDownloadMetadataStore() {
+    }
+
+    private static SharedPreferences preferences() {
+        return App.getInstance().getPreferences();
+    }
+
+    private static JSONObject readAll() {
+        String raw = preferences().getString(PREF_KEY, "{}");
+        try {
+            return new JSONObject(raw);
+        } catch (JSONException e) {
+            return new JSONObject();
+        }
+    }
+
+    private static void writeAll(JSONObject object) {
+        preferences().edit().putString(PREF_KEY, object.toString()).apply();
+    }
+
+    public static synchronized void clear() {
+        writeAll(new JSONObject());
+    }
+
+    public static synchronized void recordSize(String key, long size) {
+        if (key == null || size <= 0) {
+            return;
+        }
+        JSONObject object = readAll();
+        try {
+            object.put(key, size);
+        } catch (JSONException ignored) {
+        }
+        writeAll(object);
+    }
+
+    public static synchronized void remove(String key) {
+        if (key == null) {
+            return;
+        }
+        JSONObject object = readAll();
+        object.remove(key);
+        writeAll(object);
+    }
+
+    @Nullable
+    public static synchronized Long getSize(String key) {
+        if (key == null) {
+            return null;
+        }
+        JSONObject object = readAll();
+        if (!object.has(key)) {
+            return null;
+        }
+        long size = object.optLong(key, -1L);
+        return size > 0 ? size : null;
+    }
+
+    public static synchronized Map<String, Long> snapshot() {
+        JSONObject object = readAll();
+        if (object.length() == 0) {
+            return Collections.emptyMap();
+        }
+        Map<String, Long> sizes = new HashMap<>();
+        Iterator<String> keys = object.keys();
+        while (keys.hasNext()) {
+            String key = keys.next();
+            long size = object.optLong(key, -1L);
+            if (size > 0) {
+                sizes.put(key, size);
+            }
+        }
+        return sizes;
+    }
+
+    public static synchronized void retainOnly(Set<String> keysToKeep) {
+        if (keysToKeep == null || keysToKeep.isEmpty()) {
+            clear();
+            return;
+        }
+        JSONObject object = readAll();
+        if (object.length() == 0) {
+            return;
+        }
+        Set<String> keys = new HashSet<>();
+        Iterator<String> iterator = object.keys();
+        while (iterator.hasNext()) {
+            keys.add(iterator.next());
+        }
+        boolean changed = false;
+        for (String key : keys) {
+            if (!keysToKeep.contains(key)) {
+                object.remove(key);
+                changed = true;
+            }
+        }
+        if (changed) {
+            writeAll(object);
+        }
+    }
+}

app/src/main/java/com/cappielloantonio/tempo/util/Preferences.kt

@@ -460,6 +460,10 @@ object Preferences {
 
     @JvmStatic
     fun setDownloadDirectoryUri(uri: String?) {
+        val current = App.getInstance().preferences.getString(DOWNLOAD_DIRECTORY_URI, null)
+        if (current != uri) {
+            ExternalDownloadMetadataStore.clear()
+        }
         App.getInstance().preferences.edit().putString(DOWNLOAD_DIRECTORY_URI, uri).apply()
     }