[spotify] Reintroduce libspotify support, change spotifyc to librespot-c

Select use of either libspotify or librespot-c as streaming backend via config
option.

librespot-c (renamed/improved spotifyc) impl has the following:
- sync interface
- seek support
- honor bitrate config, set client and thread name
- use web access token with "streaming" scope for login
- fix issue with podcast playback

Also say goodbye to file-based Spotify login.

src/library/filescanner.c

@@ -67,9 +67,6 @@
 #ifdef LASTFM
 # include "lastfm.h"
 #endif
-#ifdef SPOTIFY
-# include "spotify.h"
-#endif
 
 
 #define F_SCAN_BULK    (1 << 0)
@@ -95,7 +92,6 @@ enum file_type {
   FILE_CTRL_REMOTE,
   FILE_CTRL_RAOP_VERIFICATION,
   FILE_CTRL_LASTFM,
-  FILE_CTRL_SPOTIFY,
   FILE_CTRL_INITSCAN,
   FILE_CTRL_METASCAN, // forced scan for meta, preserves existing db records
   FILE_CTRL_FULLSCAN,
@@ -350,9 +346,6 @@ file_type_get(const char *path) {
   if (strcasecmp(ext, ".lastfm") == 0)
     return FILE_CTRL_LASTFM;
 
-  if (strcasecmp(ext, ".spotify") == 0)
-    return FILE_CTRL_SPOTIFY;
-
   if (strcasecmp(ext, ".init-rescan") == 0)
     return FILE_CTRL_INITSCAN;
 
@@ -700,17 +693,6 @@ process_file(char *file, struct stat *sb, enum file_type file_type, int scan_typ
 #endif
 	break;
 
-      case FILE_CTRL_SPOTIFY:
-#ifdef SPOTIFY
-	if (flags & F_SCAN_BULK)
-	  DPRINTF(E_LOG, L_SCAN, "Bulk scan will ignore '%s' (to process, add it after startup)\n", file);
-	else
-	  kickoff(spotify_login, file, 2);
-#else
-	DPRINTF(E_LOG, L_SCAN, "Found '%s', but this version was built without Spotify support\n", file);
-#endif
-	break;
-
       case FILE_CTRL_INITSCAN:
 	if (flags & F_SCAN_BULK)
 	  break;

src/library/spotify_webapi.c

@@ -35,6 +35,7 @@
 #include "listener.h"
 #include "logger.h"
 #include "misc_json.h"
+#include "inputs/spotify.h"
 
 
 enum spotify_request_type {
@@ -134,7 +135,7 @@ static bool scanning;
 // Endpoints and credentials for the web api
 static const char *spotify_client_id     = "0e684a5422384114a8ae7ac020f01789";
 static const char *spotify_client_secret = "232af95f39014c9ba218285a5c11a239";
-static const char *spotify_scope         = "playlist-read-private playlist-read-collaborative user-library-read user-read-private";
+static const char *spotify_scope         = "playlist-read-private playlist-read-collaborative user-library-read user-read-private streaming";
 
 static const char *spotify_auth_uri      = "https://accounts.spotify.com/authorize";
 static const char *spotify_token_uri     = "https://accounts.spotify.com/api/token";
@@ -974,10 +975,9 @@ spotifywebapi_oauth_uri_get(const char *redirect_uri)
 
 /* Thread: httpd */
 int
-spotifywebapi_oauth_callback(struct evkeyvalq *param, const char *redirect_uri, char **errmsg)
+spotifywebapi_oauth_callback(struct evkeyvalq *param, const char *redirect_uri, const char **errmsg)
 {
   const char *code;
-  const char *err;
   int ret;
 
   *errmsg = NULL;
@@ -985,18 +985,19 @@ spotifywebapi_oauth_callback(struct evkeyvalq *param, const char *redirect_uri,
   code = evhttp_find_header(param, "code");
   if (!code)
     {
-      *errmsg = safe_asprintf("Error: Didn't receive a code from Spotify");
+      *errmsg = "Error: Didn't receive a code from Spotify";
       return -1;
     }
 
   DPRINTF(E_DBG, L_SPOTIFY, "Received OAuth code: %s\n", code);
 
-  ret = token_get(code, redirect_uri, &err);
+  ret = token_get(code, redirect_uri, errmsg);
   if (ret < 0)
-    {
-      *errmsg = safe_asprintf("Error: %s", err);
-      return -1;
-    }
+    return -1;
+
+  ret = spotify_login_token(spotify_credentials.user, spotify_credentials.access_token, errmsg);
+  if (ret < 0)
+    return -1;
 
   // Trigger scan after successful access to spotifywebapi
   spotifywebapi_fullrescan();
@@ -1470,6 +1471,9 @@ track_add(struct spotify_track *track, struct spotify_album *album, const char *
       free_mfi(&mfi, 1);
     }
 
+  // This is only required for the libspotify backend
+  spotify_uri_register(track->uri);
+
   if (album && album->uri)
     cache_artwork_ping(track->uri, album->mtime, 0);
   else
@@ -1709,7 +1713,7 @@ scan_playlists(enum spotify_request_type request_type)
 }
 
 static void
-create_saved_tracks_playlist()
+create_saved_tracks_playlist(void)
 {
   struct playlist_info pli =
     {
@@ -1735,7 +1739,7 @@ create_saved_tracks_playlist()
  * Add or update playlist folder for all spotify playlists (if enabled in config)
  */
 static void
-create_base_playlist()
+create_base_playlist(void)
 {
   cfg_t *spotify_cfg;
   struct playlist_info pli =
@@ -1792,17 +1796,17 @@ scan(enum spotify_request_type request_type)
 
 /* Thread: library */
 static int
-initscan()
+initscan(void)
 {
   int ret;
 
   /* Refresh access token for the spotify webapi */
-  ret =  token_refresh();
+  ret = token_refresh();
   if (ret < 0)
     {
       DPRINTF(E_LOG, L_SPOTIFY, "Spotify webapi token refresh failed. "
-	"In order to use the web api, authorize the server to access "
-	"your saved tracks by visiting http://owntone.local:3689\n");
+	"In order to use Spotify, authorize the server to access your saved "
+	"tracks by visiting http://owntone.local:3689\n");
 
       db_spotify_purge();
 
@@ -1811,6 +1815,21 @@ initscan()
 
   spotify_saved_plid = 0;
 
+  /*
+   * libspotify needs to be logged in before before scanning tracks from the web
+   * since scanned tracks need to be registered for playback
+   */
+  ret = spotify_relogin();
+  if (ret < 0)
+    {
+      DPRINTF(E_LOG, L_SPOTIFY, "libspotify-login failed. In order to use Spotify, "
+	"provide valid credentials for libspotify by visiting http://owntone.local:3689\n");
+
+      db_spotify_purge();
+
+      return 0;
+    }
+
   /*
    * Scan saved tracks from the web api
    */
@@ -1821,7 +1840,7 @@ initscan()
 
 /* Thread: library */
 static int
-rescan()
+rescan(void)
 {
   scan(SPOTIFY_REQUEST_TYPE_RESCAN);
   return 0;
@@ -1829,7 +1848,7 @@ rescan()
 
 /* Thread: library */
 static int
-metarescan()
+metarescan(void)
 {
   scan(SPOTIFY_REQUEST_TYPE_METARESCAN);
   return 0;
@@ -1837,7 +1856,7 @@ metarescan()
 
 /* Thread: library */
 static int
-fullrescan()
+fullrescan(void)
 {
   db_spotify_purge();
   scan(SPOTIFY_REQUEST_TYPE_RESCAN);
@@ -2050,7 +2069,8 @@ spotifywebapi_init()
 {
   CHECK_ERR(L_SPOTIFY, mutex_init(&token_lck));
 
-  return 0;
+  // Required for libspotify backend
+  return spotify_init();
 }
 
 static void
@@ -2058,6 +2078,8 @@ spotifywebapi_deinit()
 {
   CHECK_ERR(L_SPOTIFY, pthread_mutex_destroy(&token_lck));
 
+  spotify_deinit();
+
   free_credentials();
 }
 

src/library/spotify_webapi.h

@@ -45,7 +45,7 @@ struct spotifywebapi_access_token
 char *
 spotifywebapi_oauth_uri_get(const char *redirect_uri);
 int
-spotifywebapi_oauth_callback(struct evkeyvalq *param, const char *redirect_uri, char **errmsg);
+spotifywebapi_oauth_callback(struct evkeyvalq *param, const char *redirect_uri, const char **errmsg);
 
 void
 spotifywebapi_fullrescan(void);