feat: add Qobuz playlist follow/unfollow (#172)

Discovered undocumented Qobuz API endpoints from bundle analysis:
- POST /playlist/subscribe { playlist_id }
- POST /playlist/unsubscribe { playlist_id }

This is the native "follow playlist" feature that syncs across all
Qobuz clients, separate from QBZ's existing "Copy to Library" (local
copy) and "Favorite" (local flag) features.

Added:
- subscribe_playlist/unsubscribe_playlist in both qbz-qobuz and legacy client
- v2_qobuz_subscribe_playlist / v2_qobuz_unsubscribe_playlist commands
- Bookmark toggle button in PlaylistDetailView (next to Copy button)
- i18n keys in all 5 locales

cc

crates/qbz-qobuz/src/client.rs

@@ -1622,6 +1622,54 @@ impl QobuzClient {
         Ok(response)
     }
 
+    /// Subscribe to a Qobuz playlist (follow it in the user's library)
+    pub async fn subscribe_playlist(&self, playlist_id: u64) -> Result<()> {
+        let url = endpoints::build_url(paths::PLAYLIST_SUBSCRIBE);
+
+        let response = self
+            .http
+            .get(&url)
+            .headers(self.authenticated_headers().await?)
+            .query(&[("playlist_id", playlist_id.to_string())])
+            .send()
+            .await?;
+
+        let status = response.status();
+        if !status.is_success() {
+            let body = response.text().await.unwrap_or_default();
+            return Err(ApiError::ApiResponse(format!(
+                "playlist/subscribe failed ({}): {}",
+                status, body
+            )));
+        }
+
+        Ok(())
+    }
+
+    /// Unsubscribe from a Qobuz playlist
+    pub async fn unsubscribe_playlist(&self, playlist_id: u64) -> Result<()> {
+        let url = endpoints::build_url(paths::PLAYLIST_UNSUBSCRIBE);
+
+        let response = self
+            .http
+            .get(&url)
+            .headers(self.authenticated_headers().await?)
+            .query(&[("playlist_id", playlist_id.to_string())])
+            .send()
+            .await?;
+
+        let status = response.status();
+        if !status.is_success() {
+            let body = response.text().await.unwrap_or_default();
+            return Err(ApiError::ApiResponse(format!(
+                "playlist/unsubscribe failed ({}): {}",
+                status, body
+            )));
+        }
+
+        Ok(())
+    }
+
     /// Add item to favorites
     pub async fn add_favorite(&self, fav_type: &str, item_id: &str) -> Result<()> {
         let url = endpoints::build_url(paths::FAVORITE_CREATE);

crates/qbz-qobuz/src/endpoints.rs

@@ -39,6 +39,8 @@ pub mod paths {
     pub const PLAYLIST_DELETE_TRACKS: &str = "/playlist/deleteTracks";
     pub const PLAYLIST_UPDATE: &str = "/playlist/update";
     pub const PLAYLIST_GET_TAGS: &str = "/playlist/getTags";
+    pub const PLAYLIST_SUBSCRIBE: &str = "/playlist/subscribe";
+    pub const PLAYLIST_UNSUBSCRIBE: &str = "/playlist/unsubscribe";
 
     // Favorites
     pub const FAVORITE_GET_USER_FAVORITES: &str = "/favorite/getUserFavorites";

src-tauri/src/api/client.rs

@@ -2076,6 +2076,34 @@ impl QobuzClient {
         Ok(())
     }
 
+    /// Subscribe to a Qobuz playlist (follow it in the user's Qobuz library)
+    pub async fn subscribe_playlist(&self, playlist_id: u64) -> Result<()> {
+        let url = endpoints::build_url(paths::PLAYLIST_SUBSCRIBE);
+
+        self.http
+            .get(&url)
+            .headers(self.authenticated_headers().await?)
+            .query(&[("playlist_id", playlist_id.to_string())])
+            .send()
+            .await?;
+
+        Ok(())
+    }
+
+    /// Unsubscribe from a Qobuz playlist
+    pub async fn unsubscribe_playlist(&self, playlist_id: u64) -> Result<()> {
+        let url = endpoints::build_url(paths::PLAYLIST_UNSUBSCRIBE);
+
+        self.http
+            .get(&url)
+            .headers(self.authenticated_headers().await?)
+            .query(&[("playlist_id", playlist_id.to_string())])
+            .send()
+            .await?;
+
+        Ok(())
+    }
+
     /// Add tracks to a playlist
     pub async fn add_tracks_to_playlist(&self, playlist_id: u64, track_ids: &[u64]) -> Result<()> {
         let url = endpoints::build_url(paths::PLAYLIST_ADD_TRACKS);

src-tauri/src/api/endpoints.rs

@@ -41,6 +41,8 @@ pub mod paths {
     pub const PLAYLIST_DELETE_TRACKS: &str = "/playlist/deleteTracks";
     pub const PLAYLIST_UPDATE: &str = "/playlist/update";
     pub const PLAYLIST_GET_TAGS: &str = "/playlist/getTags";
+    pub const PLAYLIST_SUBSCRIBE: &str = "/playlist/subscribe";
+    pub const PLAYLIST_UNSUBSCRIBE: &str = "/playlist/unsubscribe";
 
     // Favorites
     pub const FAVORITE_GET_USER_FAVORITES: &str = "/favorite/getUserFavorites";

src-tauri/src/commands_v2.rs

@@ -11296,6 +11296,36 @@ pub async fn v2_subscribe_playlist(
         .map_err(|e| format!("Failed to fetch created playlist: {}", e))
 }
 
+/// Subscribe to a Qobuz playlist (follow it in the user's Qobuz library).
+/// Unlike v2_subscribe_playlist which copies tracks locally, this calls the
+/// Qobuz API so the playlist appears in the user's account on all Qobuz clients.
+#[tauri::command]
+pub async fn v2_qobuz_subscribe_playlist(
+    playlist_id: u64,
+    state: State<'_, AppState>,
+) -> Result<(), String> {
+    log::info!("Command: v2_qobuz_subscribe_playlist {}", playlist_id);
+    let client = state.client.read().await;
+    client
+        .subscribe_playlist(playlist_id)
+        .await
+        .map_err(|e| format!("Failed to subscribe to playlist: {}", e))
+}
+
+/// Unsubscribe from a Qobuz playlist.
+#[tauri::command]
+pub async fn v2_qobuz_unsubscribe_playlist(
+    playlist_id: u64,
+    state: State<'_, AppState>,
+) -> Result<(), String> {
+    log::info!("Command: v2_qobuz_unsubscribe_playlist {}", playlist_id);
+    let client = state.client.read().await;
+    client
+        .unsubscribe_playlist(playlist_id)
+        .await
+        .map_err(|e| format!("Failed to unsubscribe from playlist: {}", e))
+}
+
 #[tauri::command]
 #[allow(non_snake_case)]
 pub async fn v2_share_track_songlink(

src-tauri/src/lib.rs

@@ -1448,6 +1448,8 @@ pub fn run() {
             commands_v2::v2_save_image_url_to_file,
             commands_v2::v2_show_track_notification,
             commands_v2::v2_subscribe_playlist,
+            commands_v2::v2_qobuz_subscribe_playlist,
+            commands_v2::v2_qobuz_unsubscribe_playlist,
             commands_v2::v2_cache_track_for_offline,
             commands_v2::v2_cache_tracks_batch_for_offline,
             commands_v2::v2_start_legacy_migration,

src/lib/components/views/PlaylistDetailView.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { ArrowLeft, Play, Shuffle, ListMusic, Search, X, ChevronDown, ChevronRight, ChevronUp, ImagePlus, Edit3, BarChart2, Heart, CloudDownload, ListPlus, GripVertical, CheckSquare } from 'lucide-svelte';
+  import { ArrowLeft, Play, Shuffle, ListMusic, Search, X, ChevronDown, ChevronRight, ChevronUp, ImagePlus, Edit3, BarChart2, Heart, CloudDownload, ListPlus, GripVertical, CheckSquare, Bookmark } from 'lucide-svelte';
   import AlbumMenu from '../AlbumMenu.svelte';
   import PlaylistCollage from '../PlaylistCollage.svelte';
   import PlaylistModal from '../PlaylistModal.svelte';
@@ -339,6 +339,12 @@
   // Show copy button only if: not own playlist AND not already copied
   let showCopyButton = $derived(!isOwnPlaylist && playlist !== null && !isCopied);
 
+  // Qobuz follow state (subscribe to playlist on Qobuz account)
+  let isFollowing = $state(false);
+  let isFollowBusy = $state(false);
+  // Show follow button only for non-owned playlists
+  let showFollowButton = $derived(!isOwnPlaylist && playlist !== null);
+
   async function scrollToTrack(trackId: number) {
     await tick();
     // With virtualized list, find track index and scroll to its computed position
@@ -908,6 +914,24 @@
     }
   }
 
+  async function toggleFollowOnQobuz() {
+    if (isFollowBusy || !playlist) return;
+    isFollowBusy = true;
+    try {
+      if (isFollowing) {
+        await invoke('v2_qobuz_unsubscribe_playlist', { playlistId: playlist.id });
+        isFollowing = false;
+      } else {
+        await invoke('v2_qobuz_subscribe_playlist', { playlistId: playlist.id });
+        isFollowing = true;
+      }
+    } catch (err) {
+      console.error('Failed to toggle Qobuz follow:', err);
+    } finally {
+      isFollowBusy = false;
+    }
+  }
+
   async function selectSort(field: SortField) {
     // Default and custom don't have direction toggles
     if (field === 'default' || field === 'custom') {
@@ -2150,11 +2174,26 @@
               class:is-loading={isCopying}
               onclick={copyPlaylistToLibrary}
               disabled={isCopying}
-              title="Copy to My Library"
+              title={$t('playlist.copyToLibrary')}
             >
               <ListPlus size={18} />
             </button>
           {/if}
+          {#if showFollowButton}
+            <button
+              class="action-btn-circle"
+              class:is-loading={isFollowBusy}
+              onclick={toggleFollowOnQobuz}
+              disabled={isFollowBusy}
+              title={isFollowing ? $t('playlist.unfollowOnQobuz') : $t('playlist.followOnQobuz')}
+            >
+              <Bookmark
+                size={18}
+                color={isFollowing ? 'var(--accent-primary)' : 'currentColor'}
+                fill={isFollowing ? 'var(--accent-primary)' : 'none'}
+              />
+            </button>
+          {/if}
           <AlbumMenu
             onPlayNext={handlePlayAllNext}
             onPlayLater={handlePlayAllLater}

src/lib/i18n/locales/de.json

@@ -388,6 +388,8 @@
     "newPlaylist": "Neue Playlist",
     "editPlaylist": "Playlist bearbeiten",
     "addToPlaylist": "Zur Playlist hinzufügen",
+    "followOnQobuz": "Auf Qobuz folgen",
+    "unfollowOnQobuz": "Auf Qobuz entfolgen",
     "enterName": "Bitte gib einen Playlist-Namen ein",
     "selectPlaylist": "Bitte wähle eine Playlist",
     "duplicates": {

src/lib/i18n/locales/en.json

@@ -410,6 +410,8 @@
     "makeOfflineConfirmDesc": "This will cache {count} tracks for offline listening. This may use significant disk space and take a while to complete.",
     "preparingPlaylistOffline": "Preparing {count} tracks from \"{name}\" for offline listening...",
     "copyToLibrary": "Copy to library",
+    "followOnQobuz": "Follow on Qobuz",
+    "unfollowOnQobuz": "Unfollow on Qobuz",
     "enterName": "Please enter a playlist name",
     "selectPlaylist": "Please select a playlist",
     "duplicates": {

src/lib/i18n/locales/es.json

@@ -410,6 +410,8 @@
     "makeOfflineConfirmDesc": "Esto almacenará {count} pistas para escuchar sin conexión. Puede usar espacio significativo en disco y tomar un tiempo en completarse.",
     "preparingPlaylistOffline": "Preparando {count} pistas de \"{name}\" para escuchar sin conexión...",
     "copyToLibrary": "Copiar a mi biblioteca",
+    "followOnQobuz": "Seguir en Qobuz",
+    "unfollowOnQobuz": "Dejar de seguir en Qobuz",
     "enterName": "Ingresa un nombre para la lista",
     "selectPlaylist": "Selecciona una lista",
     "duplicates": {

src/lib/i18n/locales/fr.json

@@ -388,6 +388,8 @@
     "newPlaylist": "Nouvelle playlist",
     "editPlaylist": "Modifier la playlist",
     "addToPlaylist": "Ajouter à la playlist",
+    "followOnQobuz": "Suivre sur Qobuz",
+    "unfollowOnQobuz": "Ne plus suivre sur Qobuz",
     "enterName": "Veuillez entrer un nom de playlist",
     "selectPlaylist": "Veuillez sélectionner une playlist",
     "duplicates": {

src/lib/i18n/locales/pt.json

@@ -410,6 +410,8 @@
     "makeOfflineConfirmDesc": "Isso armazenará {count} faixas em cache para ouvir offline. Pode usar bastante espaço em disco e levar algum tempo para concluir.",
     "preparingPlaylistOffline": "Preparando {count} faixas de \"{name}\" para ouvir offline...",
     "copyToLibrary": "Copiar para biblioteca",
+    "followOnQobuz": "Seguir no Qobuz",
+    "unfollowOnQobuz": "Deixar de seguir no Qobuz",
     "enterName": "Por favor, insira um nome para a playlist",
     "selectPlaylist": "Por favor, selecione uma playlist",
     "duplicates": {