owntone-server/src/spotify_webapi.c

/*
 * Copyright (C) 2016 Espen Jürgensen <espenjurgensen@gmail.com>
 * Copyright (C) 2016 Christian Meffert <christian.meffert@googlemail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "spotify_webapi.h"

#include <event2/event.h>
#include <json.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

#include "artwork.h"
#include "cache.h"
#include "conffile.h"
#include "db.h"
#include "http.h"
#include "library.h"
#include "listener.h"
#include "logger.h"
#include "misc_json.h"
#include "spotify.h"


struct spotify_album
{
  const char *added_at;
  time_t mtime;

  const char *album_type;
  bool is_compilation;
  const char *artist;
  const char *genre;
  const char *id;
  const char *label;
  const char *name;
  const char *release_date;
  const char *release_date_precision;
  int release_year;
  const char *uri;
  const char *artwork_url;
};

struct spotify_track
{
  const char *added_at;
  time_t mtime;

  const char *album;
  const char *album_artist;
  const char *artist;
  int disc_number;
  const char *album_type;
  bool is_compilation;
  int duration_ms;
  const char *id;
  const char *name;
  int track_number;
  const char *uri;
  const char *artwork_url;

  bool is_playable;
  const char *restrictions;
  const char *linked_from_uri;
};

struct spotify_playlist
{
  const char *id;
  const char *name;
  const char *owner;
  const char *uri;

  const char *href;

  const char *tracks_href;
  int tracks_count;
};

// Credentials for the web api
static char *spotify_access_token;
static char *spotify_refresh_token;
static char *spotify_granted_scope;
static char *spotify_user_country;
static char *spotify_user;

static int32_t expires_in = 3600;
static time_t token_requested = 0;

// Mutex to avoid conflicting requests for access tokens and protects accessing the credentials from different threads
static pthread_mutex_t token_lck;


// The base playlist id for all Spotify playlists in the db
static int spotify_base_plid;
// The base playlist id for Spotify saved tracks in the db
static int spotify_saved_plid;

// Flag to avoid triggering playlist change events while the (re)scan is running
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_auth_uri      = "https://accounts.spotify.com/authorize";
static const char *spotify_token_uri     = "https://accounts.spotify.com/api/token";

static const char *spotify_playlist_uri	 = "https://api.spotify.com/v1/playlists/%s";
static const char *spotify_track_uri     = "https://api.spotify.com/v1/tracks/%s";
static const char *spotify_me_uri        = "https://api.spotify.com/v1/me";
static const char *spotify_albums_uri    = "https://api.spotify.com/v1/me/albums?limit=50";
static const char *spotify_album_uri = "https://api.spotify.com/v1/albums/%s";
static const char *spotify_album_tracks_uri = "https://api.spotify.com/v1/albums/%s/tracks";
static const char *spotify_playlists_uri = "https://api.spotify.com/v1/me/playlists?limit=50";
static const char *spotify_playlist_tracks_uri = "https://api.spotify.com/v1/playlists/%s/tracks";
static const char *spotify_artist_albums_uri = "https://api.spotify.com/v1/artists/%s/albums?include_groups=album,single";



static void
free_http_client_ctx(struct http_client_ctx *ctx)
{
  if (!ctx)
    return;

  if (ctx->input_body)
    evbuffer_free(ctx->input_body);
  if (ctx->output_headers)
    {
      keyval_clear(ctx->output_headers);
      free(ctx->output_headers);
    }
  free(ctx);
}

static bool
token_valid(void)
{
  return spotify_access_token != NULL;
}

static int
request_access_tokens(struct keyval *kv, const char **err)
{
  struct http_client_ctx ctx;
  char *param;
  char *body;
  json_object *haystack;
  const char *tmp;
  int ret;

  param = http_form_urlencode(kv);
  if (!param)
    {
      *err = "http_form_uriencode() failed";
      ret = -1;
      goto out_clear_kv;
    }

  memset(&ctx, 0, sizeof(struct http_client_ctx));
  ctx.url = (char *)spotify_token_uri;
  ctx.output_body = param;
  ctx.input_body = evbuffer_new();

  ret = http_client_request(&ctx);
  if (ret < 0)
    {
      *err = "Did not get a reply from Spotify";
      goto out_free_input_body;
    }

  // 0-terminate for safety
  evbuffer_add(ctx.input_body, "", 1);

  body = (char *)evbuffer_pullup(ctx.input_body, -1);
  if (!body || (strlen(body) == 0))
    {
      *err = "The reply from Spotify is empty or invalid";
      ret = -1;
      goto out_free_input_body;
    }

  DPRINTF(E_DBG, L_SPOTIFY, "Token reply: %s\n", body);

  haystack = json_tokener_parse(body);
  if (!haystack)
    {
      *err = "JSON parser returned an error";
      ret = -1;
      goto out_free_input_body;
    }

  free(spotify_access_token);
  spotify_access_token = NULL;

  tmp = jparse_str_from_obj(haystack, "access_token");
  if (tmp)
    spotify_access_token = strdup(tmp);

  tmp = jparse_str_from_obj(haystack, "refresh_token");
  if (tmp)
    {
      free(spotify_refresh_token);
      spotify_refresh_token = strdup(tmp);
    }

  tmp = jparse_str_from_obj(haystack, "scope");
  if (tmp)
    {
      free(spotify_granted_scope);
      spotify_granted_scope = strdup(tmp);
    }

  expires_in = jparse_int_from_obj(haystack, "expires_in");
  if (expires_in == 0)
    expires_in = 3600;

  jparse_free(haystack);

  if (!spotify_access_token)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Could not find access token in reply: %s\n", body);

      *err = "Could not find access token in Spotify reply (see log)";
      ret = -1;
      goto out_free_input_body;
    }

  token_requested = time(NULL);

  if (spotify_refresh_token)
    db_admin_set(DB_ADMIN_SPOTIFY_REFRESH_TOKEN, spotify_refresh_token);

  ret = 0;

 out_free_input_body:
  evbuffer_free(ctx.input_body);
  free(param);
 out_clear_kv:

  return ret;
}

/*
 * Request the api endpoint at 'href' and retuns the response body as
 * an allocated JSON object (must be freed by the caller) or NULL.
 *
 * @param href The spotify endpoint uri
 * @return Response as JSON object or NULL
 */
static json_object *
request_endpoint(const char *uri)
{
  struct http_client_ctx *ctx;
  char bearer_token[1024];
  char *response_body;
  json_object *json_response = NULL;
  int ret;

  ctx = calloc(1, sizeof(struct http_client_ctx));
  ctx->output_headers = calloc(1, sizeof(struct keyval));
  ctx->input_body = evbuffer_new();
  ctx->url = uri;

  snprintf(bearer_token, sizeof(bearer_token), "Bearer %s", spotify_access_token);
  if (keyval_add(ctx->output_headers, "Authorization", bearer_token) < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Add bearer_token to keyval failed for request '%s'\n", uri);
      goto out;
    }

  DPRINTF(E_DBG, L_SPOTIFY, "Request Spotify API endpoint: '%s')\n", uri);

  ret = http_client_request(ctx);
  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Request for '%s' failed\n", uri);
      goto out;
    }

  // 0-terminate for safety
  evbuffer_add(ctx->input_body, "", 1);

  response_body = (char *) evbuffer_pullup(ctx->input_body, -1);
  if (!response_body || (strlen(response_body) == 0))
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Request for '%s' failed, response was empty\n", uri);
      goto out;
    }

//  DPRINTF(E_DBG, L_SPOTIFY, "Wep api response for '%s'\n%s\n", uri, response_body);

  json_response = json_tokener_parse(response_body);
  if (!json_response)
    DPRINTF(E_LOG, L_SPOTIFY, "JSON parser returned an error for '%s'\n", uri);
  else
    DPRINTF(E_DBG, L_SPOTIFY, "Spotify API endpoint request: '%s'\n", uri);

 out:
  free_http_client_ctx(ctx);

  return json_response;
}

/*
 * Request user information
 *
 * API endpoint: https://api.spotify.com/v1/me
 */
static int
request_user_info(void)
{
  json_object *response;

  free(spotify_user_country);
  spotify_user_country = NULL;
  free(spotify_user);
  spotify_user = NULL;

  response = request_endpoint(spotify_me_uri);

  if (response)
    {
      spotify_user = safe_strdup(jparse_str_from_obj(response, "id"));
      spotify_user_country = safe_strdup(jparse_str_from_obj(response, "country"));

      jparse_free(response);

      DPRINTF(E_DBG, L_SPOTIFY, "User '%s', country '%s'\n", spotify_user, spotify_user_country);
    }

  return 0;
}

/*
 * Called from the oauth callback to get a new access and refresh token
 *
 * @return 0 on success, -1 on failure
 */
static int
token_get(const char *code, const char *redirect_uri, const char **err)
{
  struct keyval kv;
  int ret;

  CHECK_ERR(L_SPOTIFY, pthread_mutex_lock(&token_lck));

  *err = "";
  memset(&kv, 0, sizeof(struct keyval));
  ret = ( (keyval_add(&kv, "grant_type", "authorization_code") == 0) &&
          (keyval_add(&kv, "code", code) == 0) &&
          (keyval_add(&kv, "client_id", spotify_client_id) == 0) &&
          (keyval_add(&kv, "client_secret", spotify_client_secret) == 0) &&
          (keyval_add(&kv, "redirect_uri", redirect_uri) == 0) );

  if (!ret)
    {
      *err = "Add parameters to keyval failed";
      ret = -1;
    }
  else
    ret = request_access_tokens(&kv, err);

  keyval_clear(&kv);

  if (ret == 0)
    request_user_info();

  CHECK_ERR(L_SPOTIFY, pthread_mutex_unlock(&token_lck));

  return ret;
}

/*
 * Get a new access token for the stored refresh token (user already granted
 * access to the web api)
 *
 * First checks if the current access token is still valid and only requests
 * a new token if not.
 *
 * @return 0 on success, -1 on failure
 */
static int
token_refresh(void)
{
  struct keyval kv;
  char *refresh_token = NULL;
  const char *err;
  int ret;

  memset(&kv, 0, sizeof(struct keyval));

  CHECK_ERR(L_SPOTIFY, pthread_mutex_lock(&token_lck));

  if (token_requested && difftime(time(NULL), token_requested) < expires_in)
    {
      DPRINTF(E_DBG, L_SPOTIFY, "Spotify token still valid\n");

      CHECK_ERR(L_SPOTIFY, pthread_mutex_unlock(&token_lck));
      return 0;
    }

  ret = db_admin_get(&refresh_token, DB_ADMIN_SPOTIFY_REFRESH_TOKEN);
  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "No spotify refresh token found\n");
      goto error;
    }

  DPRINTF(E_DBG, L_SPOTIFY, "Spotify refresh-token: '%s'\n", refresh_token);

  ret = ( (keyval_add(&kv, "grant_type", "refresh_token") == 0) &&
	  (keyval_add(&kv, "client_id", spotify_client_id) == 0) &&
	  (keyval_add(&kv, "client_secret", spotify_client_secret) == 0) &&
          (keyval_add(&kv, "refresh_token", refresh_token) == 0) );
  if (!ret)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Add parameters to keyval failed");
      goto error;
    }

  ret = request_access_tokens(&kv, &err);

  if (ret == 0)
    request_user_info();

  free(refresh_token);
  keyval_clear(&kv);

  CHECK_ERR(L_SPOTIFY, pthread_mutex_unlock(&token_lck));

  return ret;

 error:
  free(refresh_token);
  keyval_clear(&kv);

  CHECK_ERR(L_SPOTIFY, pthread_mutex_unlock(&token_lck));

  return -1;
}

/*
 * Request the api endpoint at 'href' and retuns the response body as
 * an allocated JSON object (must be freed by the caller) or NULL.
 *
 * Before making the request, the validity of the current access token
 * is checked and if necessary a token refresh request is issued before
 * requesting the given endpoint.
 *
 * @param href The spotify endpoint uri
 * @return Response as JSON object or NULL
 */
static json_object *
request_endpoint_with_token_refresh(const char *href)
{
  if (0 > token_refresh())
    {
      return NULL;
    }

  return request_endpoint(href);
}

typedef int (*paging_request_cb)(void *arg);
typedef int (*paging_item_cb)(json_object *item, int index, int total, void *arg);

/*
 * Request the spotify endpoint at 'href'
 *
 * The endpoint must return a "paging object" e. g.:
 *
 *   {
 *     "items": [ item1, item2, ... ],
 *     "limit": 50,
 *     "next": "{uri for the next set of items}",
 *     "offset": 0,
 *     "total": {total number of items},
 *   }
 *
 * The given callback is invoked for every item in the "items" array.
 * If "next" is set in the response, after processing all items, the next uri
 * is requested and the callback is invoked for every item of this request.
 * The function returns after all items are processed and there is no "next"
 * request.
 *
 * @param endpoint_uri The endpont uri
 * @param item_cb The callback function invoked for every item
 * @param pre_request_cb Callback function invoked before each request (optional)
 * @param post_request_cb Callback function invoked after each request (optional)
 * @param with_market If TRUE appends the user country as market to the request (applies track relinking)
 * @param arg User data passed to each callback
 * @return 0 on success, -1 on failure
 */
static int
request_pagingobject_endpoint(const char *href, paging_item_cb item_cb, paging_request_cb pre_request_cb, paging_request_cb post_request_cb, bool with_market, void *arg)
{
  char *next_href;
  json_object *response;
  json_object *items;
  json_object *item;
  int count;
  int i;
  int offset;
  int total;
  int ret;

  if (!with_market || !spotify_user_country)
    {
      next_href = safe_strdup(href);
    }
  else
    {
      if (strchr(href, '?'))
	next_href = safe_asprintf("%s&market=%s", href, spotify_user_country);
      else
	next_href = safe_asprintf("%s?market=%s", href, spotify_user_country);
    }

  while (next_href)
    {
      if (pre_request_cb)
	pre_request_cb(arg);

      response = request_endpoint_with_token_refresh(next_href);

      if (!response)
	{
	  DPRINTF(E_LOG, L_SPOTIFY, "Unexpected JSON: no response for paging endpoint (API endpoint: '%s')\n", next_href);

	  if (post_request_cb)
	    post_request_cb(arg);

	  free(next_href);
	  return -1;
	}

      free(next_href);
      next_href = safe_strdup(jparse_str_from_obj(response, "next"));

      offset = jparse_int_from_obj(response, "offset");
      total = jparse_int_from_obj(response, "total");

      if (jparse_array_from_obj(response, "items", &items) == 0)
        {
	  count = json_object_array_length(items);
	  for (i = 0; i < count; i++)
	    {
	      item = json_object_array_get_idx(items, i);
	      if (!item)
	        {
		  DPRINTF(E_LOG, L_SPOTIFY, "Unexpected JSON: no item at index %d in '%s' (API endpoint: '%s')\n",
			  i, json_object_to_json_string(items), href);
		  continue;
		}

	      ret = item_cb(item, (i + offset), total, arg);
	      if (ret < 0)
		{
		  DPRINTF(E_LOG, L_SPOTIFY, "Unexpected JSON: error processing item at index %d '%s' (API endpoint: '%s')\n",
			  i, json_object_to_json_string(item), href);
		}
	    }
	}

      if (post_request_cb)
	post_request_cb(arg);

      jparse_free(response);
    }

  return 0;
}

static const char *
get_album_image(json_object *jsonalbum, int max_w)
{
  json_object *jsonimages;
  json_object *jsonimage;
  int image_count;
  int index;
  const char *artwork_url;

  artwork_url = NULL;

  if (!json_object_object_get_ex(jsonalbum, "images", &jsonimages))
    {
      DPRINTF(E_DBG, L_SPOTIFY, "No images in for spotify album object found\n");
      return NULL;
    }

  // Find first image that has a smaller width than the given max_w
  // (this should avoid the need for resizing and improve performance at the cost of some quality loss)
  // Note that Spotify returns the images ordered descending by width (widest image first)
  // Special case is if no max width (max_w = 0) is given, the widest images will be used
  image_count = json_object_array_length(jsonimages);
  for (index = 0; index < image_count; index++)
    {
      jsonimage = json_object_array_get_idx(jsonimages, index);
      if (jsonimage)
	{
	  artwork_url = jparse_str_from_obj(jsonimage, "url");

	  if (max_w <= 0  || jparse_int_from_obj(jsonimage, "width") <= max_w)
	    {
	      // We have the first image that has a smaller width than the given max_w
	      break;
	    }
	}
    }

  return artwork_url;
}

static void
parse_metadata_track(json_object *jsontrack, struct spotify_track *track, int max_w)
{
  json_object *jsonalbum;
  json_object *jsonartists;
  json_object *needle;

  memset(track, 0, sizeof(struct spotify_track));

  if (json_object_object_get_ex(jsontrack, "album", &jsonalbum))
    {
      track->album = jparse_str_from_obj(jsonalbum, "name");
      if (json_object_object_get_ex(jsonalbum, "artists", &jsonartists))
	track->album_artist = jparse_str_from_array(jsonartists, 0, "name");

      track->artwork_url = get_album_image(jsonalbum, max_w);
    }

  if (json_object_object_get_ex(jsontrack, "artists", &jsonartists))
    track->artist = jparse_str_from_array(jsonartists, 0, "name");

  track->disc_number = jparse_int_from_obj(jsontrack, "disc_number");
  track->album_type = jparse_str_from_obj(jsonalbum, "album_type");
  track->is_compilation = (track->album_type && 0 == strcmp(track->album_type, "compilation"));
  track->duration_ms = jparse_int_from_obj(jsontrack, "duration_ms");
  track->name = jparse_str_from_obj(jsontrack, "name");
  track->track_number = jparse_int_from_obj(jsontrack, "track_number");
  track->uri = jparse_str_from_obj(jsontrack, "uri");
  track->id = jparse_str_from_obj(jsontrack, "id");

  // "is_playable" is only returned for a request with a market parameter, default to true if it is not in the response
  track->is_playable = true;
  if (json_object_object_get_ex(jsontrack, "is_playable", NULL))
    {
      track->is_playable = jparse_bool_from_obj(jsontrack, "is_playable");

      if (json_object_object_get_ex(jsontrack, "restrictions", &needle))
	track->restrictions = json_object_to_json_string(needle);

      if (json_object_object_get_ex(jsontrack, "linked_from", &needle))
	track->linked_from_uri = jparse_str_from_obj(needle, "uri");
    }
}

static int
get_year_from_date(const char *date)
{
  char tmp[5];
  uint32_t year = 0;

  if (date && strlen(date) >= 4)
    {
      strncpy(tmp, date, sizeof(tmp));
      tmp[4] = '\0';
      safe_atou32(tmp, &year);
    }

  return year;
}

static void
parse_metadata_album(json_object *jsonalbum, struct spotify_album *album, int max_w)
{
  json_object* jsonartists;

  memset(album, 0, sizeof(struct spotify_album));

  if (json_object_object_get_ex(jsonalbum, "artists", &jsonartists))
    album->artist = jparse_str_from_array(jsonartists, 0, "name");

  album->name = jparse_str_from_obj(jsonalbum, "name");
  album->uri = jparse_str_from_obj(jsonalbum, "uri");
  album->id = jparse_str_from_obj(jsonalbum, "id");

  album->album_type = jparse_str_from_obj(jsonalbum, "album_type");
  album->is_compilation = (album->album_type && 0 == strcmp(album->album_type, "compilation"));

  album->label = jparse_str_from_obj(jsonalbum, "label");

  album->release_date = jparse_str_from_obj(jsonalbum, "release_date");
  album->release_date_precision = jparse_str_from_obj(jsonalbum, "release_date_precision");
  album->release_year = get_year_from_date(album->release_date);

  if (max_w > 0)
    album->artwork_url = get_album_image(jsonalbum, max_w);

  // TODO Genre is an array of strings ('genres'), but it is always empty (https://github.com/spotify/web-api/issues/157)
  //album->genre = jparse_str_from_obj(jsonalbum, "genre");
}

static void
parse_metadata_playlist(json_object *jsonplaylist, struct spotify_playlist *playlist)
{
  json_object *needle;

  memset(playlist, 0, sizeof(struct spotify_playlist));

  playlist->name = jparse_str_from_obj(jsonplaylist, "name");
  playlist->uri = jparse_str_from_obj(jsonplaylist, "uri");
  playlist->id = jparse_str_from_obj(jsonplaylist, "id");
  playlist->href = jparse_str_from_obj(jsonplaylist, "href");

  if (json_object_object_get_ex(jsonplaylist, "owner", &needle))
    playlist->owner = jparse_str_from_obj(needle, "id");

  if (json_object_object_get_ex(jsonplaylist, "tracks", &needle))
    {
      playlist->tracks_href = jparse_str_from_obj(needle, "href");
      playlist->tracks_count = jparse_int_from_obj(needle, "total");
    }
}

/*
 * Creates a new string for the playlist API endpoint for the given playist-uri.
 * The returned string needs to be freed by the caller.
 *
 * @param uri Playlist uri (e. g. "spotify:user:username:playlist:59ZbFPES4DQwEjBpWHzrtC")
 * @return Playlist endpoint uri (e. g. "https://api.spotify.com/v1/users/username/playlists/59ZbFPES4DQwEjBpWHzrtC")
 */
static int
get_id_from_uri(const char *uri, char **id)
{
  char *tmp;
  tmp = strrchr(uri, ':');
  if (!tmp)
    {
      return -1;
    }
  tmp++;

  *id = strdup(tmp);

  return 0;
}

static char *
get_playlist_endpoint_uri(const char *uri)
{
  char *endpoint_uri = NULL;
  char *id = NULL;
  int ret;

  ret = get_id_from_uri(uri, &id);
  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Error extracting owner and id from playlist uri '%s'\n", uri);
      goto out;
    }

  endpoint_uri = safe_asprintf(spotify_playlist_uri, id);

 out:
  free(id);
  return endpoint_uri;
}

static char *
get_playlist_tracks_endpoint_uri(const char *uri)
{
  char *endpoint_uri = NULL;
  char *id = NULL;
  int ret;

  ret = get_id_from_uri(uri, &id);
  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Error extracting owner and id from playlist uri '%s'\n", uri);
      goto out;
    }

  endpoint_uri = safe_asprintf(spotify_playlist_tracks_uri, id);

 out:
  free(id);
  return endpoint_uri;
}

static char *
get_album_endpoint_uri(const char *uri)
{
  char *endpoint_uri = NULL;
  char *id = NULL;
  int ret;

  ret = get_id_from_uri(uri, &id);
  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Error extracting id from uri '%s'\n", uri);
      goto out;
    }

  endpoint_uri = safe_asprintf(spotify_album_uri, id);

 out:
  free(id);
  return endpoint_uri;
}

static char *
get_album_tracks_endpoint_uri(const char *uri)
{
  char *endpoint_uri = NULL;
  char *id = NULL;
  int ret;

  ret = get_id_from_uri(uri, &id);
  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Error extracting id from uri '%s'\n", uri);
      goto out;
    }

  endpoint_uri = safe_asprintf(spotify_album_tracks_uri, id);

 out:
  free(id);
  return endpoint_uri;
}

static char *
get_track_endpoint_uri(const char *uri)
{
  char *endpoint_uri = NULL;
  char *id = NULL;
  int ret;

  ret = get_id_from_uri(uri, &id);
  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Error extracting id from track uri '%s'\n", uri);
      goto out;
    }

  endpoint_uri = safe_asprintf(spotify_track_uri, id);

 out:
  free(id);
  return endpoint_uri;
}

static char *
get_artist_albums_endpoint_uri(const char *uri)
{
  char *endpoint_uri = NULL;
  char *id = NULL;
  int ret;

  ret = get_id_from_uri(uri, &id);
  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Error extracting id from uri '%s'\n", uri);
      goto out;
    }

  endpoint_uri = safe_asprintf(spotify_artist_albums_uri, id);

 out:
  free(id);
  return endpoint_uri;
}

static json_object *
request_track(const char *path)
{
  char *endpoint_uri;
  json_object *response;

  endpoint_uri = get_track_endpoint_uri(path);
  response = request_endpoint_with_token_refresh(endpoint_uri);
  free(endpoint_uri);

  return response;
}

/* Thread: httpd */
char *
spotifywebapi_oauth_uri_get(const char *redirect_uri)
{
  struct keyval kv;
  char *param;
  char *uri;
  int uri_len;
  int ret;

  uri = NULL;
  memset(&kv, 0, sizeof(struct keyval));
  ret = ( (keyval_add(&kv, "client_id", spotify_client_id) == 0) &&
	  (keyval_add(&kv, "response_type", "code") == 0) &&
	  (keyval_add(&kv, "redirect_uri", redirect_uri) == 0) &&
	  (keyval_add(&kv, "scope", spotify_scope) == 0) &&
	  (keyval_add(&kv, "show_dialog", "false") == 0) );
  if (!ret)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Cannot display Spotify oath interface (error adding parameters to keyval)\n");
      goto out_clear_kv;
    }

  param = http_form_urlencode(&kv);
  if (param)
    {
      uri_len = strlen(spotify_auth_uri) + strlen(param) + 3;
      uri = calloc(uri_len, sizeof(char));
      snprintf(uri, uri_len, "%s/?%s", spotify_auth_uri, param);

      free(param);
    }

 out_clear_kv:
  keyval_clear(&kv);

  return uri;
}

/* Thread: httpd */
int
spotifywebapi_oauth_callback(struct evkeyvalq *param, const char *redirect_uri, char **errmsg)
{
  const char *code;
  const char *err;
  int ret;

  *errmsg = NULL;

  code = evhttp_find_header(param, "code");
  if (!code)
    {
      *errmsg = safe_asprintf("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);
  if (ret < 0)
    {
      *errmsg = safe_asprintf("Error: %s", err);
      return -1;
    }

  // Trigger scan after successful access to spotifywebapi
  spotifywebapi_fullrescan();

  listener_notify(LISTENER_SPOTIFY);

  return 0;
}

static int
transaction_start(void *arg)
{
  db_transaction_begin();
  return 0;
}

static int
transaction_end(void *arg)
{
  db_transaction_end();
  return 0;
}

static void
map_track_to_queueitem(struct db_queue_item *item, const struct spotify_track *track, const struct spotify_album *album)
{
  char virtual_path[PATH_MAX];

  memset(item, 0, sizeof(struct db_queue_item));

  item->file_id = DB_MEDIA_FILE_NON_PERSISTENT_ID;
  item->title = safe_strdup(track->name);
  item->artist = safe_strdup(track->artist);

  if (album)
    {
      item->album_artist = safe_strdup(album->artist);
      item->album = safe_strdup(album->name);
      item->artwork_url = safe_strdup(album->artwork_url);
    }
  else
    {
      item->album_artist = safe_strdup(track->album_artist);
      item->album = safe_strdup(track->album);
      item->artwork_url = safe_strdup(track->artwork_url);
    }

  item->disc = track->disc_number;
  item->song_length = track->duration_ms;
  item->track = track->track_number;

  item->data_kind = DATA_KIND_SPOTIFY;
  item->media_kind = MEDIA_KIND_MUSIC;

  item->path = safe_strdup(track->uri);

  snprintf(virtual_path, PATH_MAX, "/%s", track->uri);
  item->virtual_path = strdup(virtual_path);
}

static int
queue_add_track(const char *uri, int position, char reshuffle, uint32_t item_id, int *count, int *new_item_id)
{
  json_object *response;
  struct spotify_track track;
  struct db_queue_item item;
  struct db_queue_add_info queue_add_info;
  int ret;

  response = request_track(uri);
  if (!response)
    return -1;

  parse_metadata_track(response, &track, ART_DEFAULT_WIDTH);

  DPRINTF(E_DBG, L_SPOTIFY, "Got track: '%s' (%s) \n", track.name, track.uri);

  map_track_to_queueitem(&item, &track, NULL);

  ret = db_queue_add_start(&queue_add_info, position);
  if (ret == 0)
    {
      ret = db_queue_add_item(&queue_add_info, &item);
      ret = db_queue_add_end(&queue_add_info, reshuffle, item_id, ret);
      if (ret == 0)
	{
	  if (count)
	    *count = queue_add_info.count;
	  if (new_item_id)
	    *new_item_id = queue_add_info.new_item_id;
	}
    }

  free_queue_item(&item, 1);
  jparse_free(response);

  return 0;
}

struct queue_add_album_param {
  struct spotify_album album;
  struct db_queue_add_info queue_add_info;
};

static int
queue_add_album_tracks(json_object *item, int index, int total, void *arg)
{
  struct queue_add_album_param *param;
  struct spotify_track track;
  struct db_queue_item queue_item;
  int ret;

  param = arg;

  parse_metadata_track(item, &track, ART_DEFAULT_WIDTH);

  if (!track.uri || !track.is_playable)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Track not available for playback: '%s' - '%s' (%s) (restrictions: %s)\n", track.artist, track.name, track.uri, track.restrictions);
      return -1;
    }

  map_track_to_queueitem(&queue_item, &track, &param->album);

  ret = db_queue_add_item(&param->queue_add_info, &queue_item);

  free_queue_item(&queue_item, 1);

  return ret;
}

static int
queue_add_album(const char *uri, int position, char reshuffle, uint32_t item_id, int *count, int *new_item_id)
{
  char *album_endpoint_uri = NULL;
  char *endpoint_uri = NULL;
  json_object *json_album;
  struct queue_add_album_param param;
  int ret;

  album_endpoint_uri = get_album_endpoint_uri(uri);
  json_album = request_endpoint_with_token_refresh(album_endpoint_uri);
  parse_metadata_album(json_album, &param.album, ART_DEFAULT_WIDTH);

  ret = db_queue_add_start(&param.queue_add_info, position);
  if (ret < 0)
    goto out;

  endpoint_uri = get_album_tracks_endpoint_uri(uri);

  ret = request_pagingobject_endpoint(endpoint_uri, queue_add_album_tracks, NULL, NULL, true, &param);

  ret = db_queue_add_end(&param.queue_add_info, reshuffle, item_id, ret);
  if (ret == 0 && count)
    *count = param.queue_add_info.count;

 out:
  free(album_endpoint_uri);
  free(endpoint_uri);
  jparse_free(json_album);

  return ret;
}

static int
queue_add_albums(json_object *item, int index, int total, void *arg)
{
  struct db_queue_add_info *param;
  struct queue_add_album_param param_add_album;
  char *endpoint_uri = NULL;
  int ret;

  param = arg;
  param_add_album.queue_add_info = *param;

  parse_metadata_album(item, &param_add_album.album, ART_DEFAULT_WIDTH);

  endpoint_uri = get_album_tracks_endpoint_uri(param_add_album.album.uri);
  ret = request_pagingobject_endpoint(endpoint_uri, queue_add_album_tracks, NULL, NULL, true, &param_add_album);

  *param = param_add_album.queue_add_info;

  free(endpoint_uri);
  return ret;

}

static int
queue_add_artist(const char *uri, int position, char reshuffle, uint32_t item_id, int *count, int *new_item_id)
{
  struct db_queue_add_info queue_add_info;
  char *endpoint_uri = NULL;
  int ret;

  ret = db_queue_add_start(&queue_add_info, position);
  if (ret < 0)
    return -1;

  endpoint_uri = get_artist_albums_endpoint_uri(uri);
  ret = request_pagingobject_endpoint(endpoint_uri, queue_add_albums, NULL, NULL, true, &queue_add_info);

  ret = db_queue_add_end(&queue_add_info, reshuffle, item_id, ret);
  if (ret == 0 && count)
    *count = queue_add_info.count;

  free(endpoint_uri);
  return ret;
}

static int
queue_add_playlist_tracks(json_object *item, int index, int total, void *arg)
{
  struct db_queue_add_info *queue_add_info;
  struct spotify_track track;
  json_object *jsontrack;
  struct db_queue_item queue_item;
  int ret;

  queue_add_info = arg;

  if (!(item && json_object_object_get_ex(item, "track", &jsontrack)))
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Unexpected JSON: missing 'track' in JSON object at index %d\n", index);
      return -1;
    }

  parse_metadata_track(jsontrack, &track, ART_DEFAULT_WIDTH);
  track.added_at = jparse_str_from_obj(item, "added_at");
  track.mtime = jparse_time_from_obj(item, "added_at");

  if (!track.uri || !track.is_playable)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Track not available for playback: '%s' - '%s' (%s) (restrictions: %s)\n", track.artist, track.name, track.uri, track.restrictions);
      return -1;
    }

  map_track_to_queueitem(&queue_item, &track, NULL);

  ret = db_queue_add_item(queue_add_info, &queue_item);

  free_queue_item(&queue_item, 1);

  return ret;
}

static int
queue_add_playlist(const char *uri, int position, char reshuffle, uint32_t item_id, int *count, int *new_item_id)
{
  char *endpoint_uri;
  struct db_queue_add_info queue_add_info;
  int ret;

  ret = db_queue_add_start(&queue_add_info, position);
  if (ret < 0)
    return -1;

  endpoint_uri = get_playlist_tracks_endpoint_uri(uri);

  ret = request_pagingobject_endpoint(endpoint_uri, queue_add_playlist_tracks, NULL, NULL, true, &queue_add_info);

  ret = db_queue_add_end(&queue_add_info, reshuffle, item_id, ret);
  if (ret == 0 && count)
    *count = queue_add_info.count;

  free(endpoint_uri);

  return ret;
}

static int
queue_item_add(const char *uri, int position, char reshuffle, uint32_t item_id, int *count, int *new_item_id)
{
  if (strncasecmp(uri, "spotify:track:", strlen("spotify:track:")) == 0)
    {
      queue_add_track(uri, position, reshuffle, item_id, count, new_item_id);
      return LIBRARY_OK;
    }
  else if (strncasecmp(uri, "spotify:artist:", strlen("spotify:artist:")) == 0)
    {
      queue_add_artist(uri, position, reshuffle, item_id, count, new_item_id);
      return LIBRARY_OK;
    }
  else if (strncasecmp(uri, "spotify:album:", strlen("spotify:album:")) == 0)
    {
      queue_add_album(uri, position, reshuffle, item_id, count, new_item_id);
      return LIBRARY_OK;
    }
  else if (strncasecmp(uri, "spotify:", strlen("spotify:")) == 0)
    {
      queue_add_playlist(uri, position, reshuffle, item_id, count, new_item_id);
      return LIBRARY_OK;
    }

  return LIBRARY_PATH_INVALID;
}


/*
 * Returns the directory id for /spotify:/<artist>/<album>, if the directory (or the parent
 * directories) does not yet exist, they will be created.
 * If an error occured the return value is -1.
 *
 * @return directory id for the given artist/album directory
 */
static int
prepare_directories(const char *artist, const char *album)
{
  int dir_id;
  char virtual_path[PATH_MAX];
  int ret;

  ret = snprintf(virtual_path, sizeof(virtual_path), "/spotify:/%s", artist);
  if ((ret < 0) || (ret >= sizeof(virtual_path)))
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Virtual path exceeds PATH_MAX (/spotify:/%s)\n", artist);
      return -1;
    }
  dir_id = db_directory_addorupdate(virtual_path, NULL, 0, DIR_SPOTIFY);
  if (dir_id <= 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Could not add or update directory '%s'\n", virtual_path);
      return -1;
    }
  ret = snprintf(virtual_path, sizeof(virtual_path), "/spotify:/%s/%s", artist, album);
  if ((ret < 0) || (ret >= sizeof(virtual_path)))
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Virtual path exceeds PATH_MAX (/spotify:/%s/%s)\n", artist, album);
      return -1;
    }
  dir_id = db_directory_addorupdate(virtual_path, NULL, 0, dir_id);
  if (dir_id <= 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Could not add or update directory '%s'\n", virtual_path);
      return -1;
    }

  return dir_id;
}

/*
 * Purges all Spotify files from the library that are not in a playlist
 * (Note: all files from saved albums are in the spotify:savedtracks playlist)
 */
static int
cleanup_spotify_files(void)
{
  struct query_params qp;
  char *path;
  int ret;

  memset(&qp, 0, sizeof(struct query_params));

  qp.type = Q_BROWSE_PATH;
  qp.sort = S_NONE;
  qp.filter = "f.path LIKE 'spotify:%%' AND NOT f.path IN (SELECT filepath FROM playlistitems)";

  ret = db_query_start(&qp);
  if (ret < 0)
    {
      db_query_end(&qp);
      return -1;
    }

  while (((ret = db_query_fetch_string(&qp, &path)) == 0) && (path))
    {
      cache_artwork_delete_by_path(path);
    }

  db_query_end(&qp);

  db_spotify_files_delete();

  return 0;
}

static void
map_track_to_mfi(struct media_file_info *mfi, const struct spotify_track *track, const struct spotify_album *album, const char *pl_name)
{
  char virtual_path[PATH_MAX];

  mfi->title = safe_strdup(track->name);
  mfi->artist = safe_strdup(track->artist);
  mfi->disc = track->disc_number;
  mfi->song_length = track->duration_ms;
  mfi->track = track->track_number;

  mfi->data_kind   = DATA_KIND_SPOTIFY;
  mfi->media_kind  = MEDIA_KIND_MUSIC;
  mfi->type        = strdup("spotify");
  mfi->codectype   = strdup("wav");
  mfi->description = strdup("Spotify audio");

  mfi->path = strdup(track->uri);
  mfi->fname = strdup(track->uri);

  mfi->time_modified = track->mtime;
  mfi->time_added = track->mtime;

  if (album)
    {
      mfi->album_artist = safe_strdup(album->artist);
      mfi->album = safe_strdup(album->name);
      mfi->genre = safe_strdup(album->genre);
      mfi->compilation = album->is_compilation;
      mfi->year = album->release_year;
    }
  else
    {
      mfi->album_artist = safe_strdup(track->album_artist);
      if (cfg_getbool(cfg_getsec(cfg, "spotify"), "album_override") && pl_name)
	mfi->album = safe_strdup(pl_name);
      else
	mfi->album = safe_strdup(track->album);

      if (cfg_getbool(cfg_getsec(cfg, "spotify"), "artist_override") && pl_name)
	mfi->compilation =  true;
      else
	mfi->compilation = track->is_compilation;
    }

  snprintf(virtual_path, PATH_MAX, "/spotify:/%s/%s/%s", mfi->album_artist, mfi->album, mfi->title);
  mfi->virtual_path = strdup(virtual_path);
}

static int
track_add(struct spotify_track *track, struct spotify_album *album, const char *pl_name, int dir_id)
{
  struct media_file_info mfi;
  int ret;

  if (!track->uri || !track->is_playable)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Track not available for playback: '%s' - '%s' (%s) (restrictions: %s)\n",
	      track->artist, track->name, track->uri, track->restrictions);
      return -1;
    }

  if (track->linked_from_uri)
    DPRINTF(E_DBG, L_SPOTIFY, "Track '%s' (%s) linked from %s\n", track->name, track->uri, track->linked_from_uri);

  ret = db_file_ping_bypath(track->uri, track->mtime);
  if (ret == 0)
    {
      DPRINTF(E_DBG, L_SPOTIFY, "Track '%s' (%s) is new or modified (mtime is %" PRIi64 ")\n",
	      track->name, track->uri, (int64_t)track->mtime);

      memset(&mfi, 0, sizeof(struct media_file_info));

      mfi.id = db_file_id_bypath(track->uri);
      mfi.directory_id = dir_id;

      map_track_to_mfi(&mfi, track, album, pl_name);

      library_media_save(&mfi);

      free_mfi(&mfi, 1);
    }

  spotify_uri_register(track->uri);

  if (album)
    cache_artwork_ping(track->uri, album->mtime, 0);
  else
    cache_artwork_ping(track->uri, 1, 0);

  return 0;
}

static int
playlist_add_or_update(struct playlist_info *pli)
{
  int pl_id;

  pl_id = db_pl_id_bypath(pli->path);
  if (pl_id < 0)
    return library_playlist_save(pli);

  pli->id = pl_id;

  db_pl_clear_items(pli->id);

  return library_playlist_save(pli);
}

/*
 * Add a saved album to the library
 */
static int
saved_album_add(json_object *item, int index, int total, void *arg)
{
  json_object *jsonalbum;
  struct spotify_album album;
  struct spotify_track track;
  json_object *needle;
  json_object *jsontracks;
  json_object *jsontrack;
  int track_count;
  int dir_id;
  int i;
  int ret;

  if (!json_object_object_get_ex(item, "album", &jsonalbum))
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Unexpected JSON: Item %d is missing the 'album' field\n", index);
      return -1;
    }
  if (!json_object_object_get_ex(jsonalbum, "tracks", &needle))
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Unexpected JSON: Item %d is missing the 'tracks' field'\n", index);
      return -1;
    }
  if (jparse_array_from_obj(needle, "items", &jsontracks) < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Unexpected JSON: Item %d has an empty 'tracks' array\n", index);
      return -1;
    }

  // Map album information
  parse_metadata_album(jsonalbum, &album, 0);
  album.added_at = jparse_str_from_obj(item, "added_at");
  album.mtime = jparse_time_from_obj(item, "added_at");

  // Now map the album tracks and insert/update them in the files database
  db_transaction_begin();

  // Get or create the directory structure for this album
  dir_id = prepare_directories(album.artist, album.name);

  track_count = json_object_array_length(jsontracks);
  for (i = 0; i < track_count; i++)
    {
      jsontrack = json_object_array_get_idx(jsontracks, i);
      if (!jsontrack)
	break;

      parse_metadata_track(jsontrack, &track, 0);
      track.mtime = album.mtime;

      ret = track_add(&track, &album, NULL, dir_id);

      if (ret == 0 && spotify_saved_plid)
	db_pl_add_item_bypath(spotify_saved_plid, track.uri);
    }

  db_transaction_end();

  if ((index + 1) >= total || ((index + 1) % 10 == 0))
    DPRINTF(E_LOG, L_SPOTIFY, "Scanned %d of %d saved albums\n", (index + 1), total);

  return 0;
}

/*
 * Thread: library
 *
 * Scan users saved albums into the library
 */
static int
scan_saved_albums()
{
  int ret;

  ret = request_pagingobject_endpoint(spotify_albums_uri, saved_album_add, NULL, NULL, true, NULL);

  return ret;
}


/*
 * Add a saved playlist tracks to the library
 */
static int
saved_playlist_tracks_add(json_object *item, int index, int total, void *arg)
{
  struct spotify_track track;
  json_object *jsontrack;
  int *plid;
  int dir_id;
  int ret;

  plid = arg;

  if (!(item && json_object_object_get_ex(item, "track", &jsontrack)))
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Unexpected JSON: missing 'track' in JSON object at index %d\n", index);
      return -1;
    }

  parse_metadata_track(jsontrack, &track, 0);
  track.added_at = jparse_str_from_obj(item, "added_at");
  track.mtime = jparse_time_from_obj(item, "added_at");

  if (!track.uri || !track.is_playable)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Track not available for playback: '%s' - '%s' (%s) (restrictions: %s)\n", track.artist, track.name, track.uri, track.restrictions);
      return 0;
    }

  dir_id = prepare_directories(track.album_artist, track.album);
  ret = track_add(&track, NULL, NULL, dir_id);
  if (ret == 0)
    db_pl_add_item_bypath(*plid, track.uri);

  return 0;
}

/* Thread: library */
static int
scan_playlist_tracks(const char *playlist_tracks_endpoint_uri, int plid)
{
  int ret;

  ret = request_pagingobject_endpoint(playlist_tracks_endpoint_uri, saved_playlist_tracks_add, transaction_start, transaction_end, true, &plid);

  return ret;
}

static void
map_playlist_to_pli(struct playlist_info *pli, struct spotify_playlist *playlist)
{
  memset(pli, 0, sizeof(struct playlist_info));

  pli->type  = PL_PLAIN;
  pli->path  = strdup(playlist->uri);
  pli->title = safe_strdup(playlist->name);

  pli->parent_id    = spotify_base_plid;
  pli->directory_id = DIR_SPOTIFY;

  if (playlist->owner)
    pli->virtual_path = safe_asprintf("/spotify:/%s (%s)", playlist->name, playlist->owner);
  else
    pli->virtual_path = safe_asprintf("/spotify:/%s", playlist->name);
}

/*
 * Add a saved playlist to the library
 */
static int
saved_playlist_add(json_object *item, int index, int total, void *arg)
{
  struct spotify_playlist playlist;
  struct playlist_info pli;
  int pl_id;

  // Map playlist information
  parse_metadata_playlist(item, &playlist);

  DPRINTF(E_DBG, L_SPOTIFY, "Got playlist: '%s' with %d tracks (%s) \n", playlist.name, playlist.tracks_count, playlist.uri);

  if (!playlist.uri || !playlist.name || playlist.tracks_count == 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Ignoring playlist '%s' with %d tracks (%s)\n", playlist.name, playlist.tracks_count, playlist.uri);
      return -1;
    }

  map_playlist_to_pli(&pli, &playlist);

  pl_id = playlist_add_or_update(&pli);

  free_pli(&pli, 1);

  if (pl_id > 0)
    scan_playlist_tracks(playlist.tracks_href, pl_id);
  else
    DPRINTF(E_LOG, L_SPOTIFY, "Error adding playlist: '%s' (%s) \n", playlist.name, playlist.uri);

  DPRINTF(E_LOG, L_SPOTIFY, "Scanned %d of %d saved playlists\n", (index + 1), total);

  return 0;
}

/*
 * Thread: library
 *
 * Scan users saved playlists into the library
 */
static int
scan_playlists()
{
  int ret;

  ret = request_pagingobject_endpoint(spotify_playlists_uri, saved_playlist_add, NULL, NULL, false, NULL);

  return ret;
}

static void
create_saved_tracks_playlist()
{
  struct playlist_info pli =
    {
      .path = strdup("spotify:savedtracks"),
      .title = strdup("Spotify Saved"),
      .virtual_path = strdup("/spotify:/Spotify Saved"),
      .type = PL_PLAIN,
      .parent_id = spotify_base_plid,
      .directory_id = DIR_SPOTIFY,
    };

  spotify_saved_plid = playlist_add_or_update(&pli);
  if (spotify_saved_plid < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Error adding playlist for saved tracks\n");
      spotify_saved_plid = 0;
    }

  free_pli(&pli, 1);
}

/*
 * Add or update playlist folder for all spotify playlists (if enabled in config)
 */
static void
create_base_playlist()
{
  cfg_t *spotify_cfg;
  struct playlist_info pli =
    {
      .path = strdup("spotify:playlistfolder"),
      .title = strdup("Spotify"),
      .type = PL_FOLDER,
    };

  spotify_base_plid = 0;
  spotify_cfg = cfg_getsec(cfg, "spotify");
  if (cfg_getbool(spotify_cfg, "base_playlist_disable"))
    {
      free_pli(&pli, 1);
      return;
    }

  spotify_base_plid = playlist_add_or_update(&pli);
  if (spotify_base_plid < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Error adding base playlist\n");
      spotify_base_plid = 0;
    }

  free_pli(&pli, 1);
}

static void
scan()
{
  time_t start;
  time_t end;

  if (!token_valid() || scanning)
    {
      DPRINTF(E_DBG, L_SPOTIFY, "No valid web api token or scan already in progress, rescan ignored\n");
      return;
    }

  start = time(NULL);
  scanning = true;

  db_directory_enable_bypath("/spotify:");
  create_base_playlist();
  create_saved_tracks_playlist();
  scan_saved_albums();
  scan_playlists();

  scanning = false;
  end = time(NULL);

  DPRINTF(E_LOG, L_SPOTIFY, "Spotify scan completed in %.f sec\n", difftime(end, start));
}

/* Thread: library */
static int
initscan()
{
  int ret;

  /* Refresh access token for the spotify webapi */
  ret =  token_refresh();
  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Spotify webapi token refresh failed. "
	"In order to use the web api, authorize forked-daapd to access "
	"your saved tracks by visiting http://forked-daapd.local:3689\n");

      db_spotify_purge();

      return 0;
    }

  spotify_saved_plid = 0;

  /*
   * Login to spotify needs to be done before scanning tracks from the web api.
   * (Scanned tracks need to be registered with libspotify 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://forked-daapd.local:3689\n");

      db_spotify_purge();

      return 0;
    }

  /*
   * Scan saved tracks from the web api
   */
  scan();

  return 0;
}

/* Thread: library */
static int
rescan()
{
  scan();
  return 0;
}

/* Thread: library */
static int
fullrescan()
{
  db_spotify_purge();
  scan();
  return 0;
}

/* Thread: library */
static enum command_state
webapi_fullrescan(void *arg, int *ret)
{
  *ret = fullrescan();
  return COMMAND_END;
}

/* Thread: library */
static enum command_state
webapi_rescan(void *arg, int *ret)
{
  *ret = rescan();
  return COMMAND_END;
}

/* Thread: library */
static enum command_state
webapi_pl_save(void *arg, int *ret)
{
  const char *uri;
  char *endpoint_uri;
  json_object *response;

  uri = arg;
  endpoint_uri = get_playlist_endpoint_uri(uri);

  response = request_endpoint_with_token_refresh(endpoint_uri);
  if (!response)
    {
      *ret = -1;
      goto out;
    }

  *ret = saved_playlist_add(response, 0, 1, NULL);

  jparse_free(response);

 out:
  free(endpoint_uri);

  return COMMAND_END;
}

/* Thread: library */
static enum command_state
webapi_pl_remove(void *arg, int *ret)
{
  const char *uri;
  struct playlist_info *pli;
  int plid;

  uri = arg;
  pli = db_pl_fetch_bypath(uri);

  if (!pli)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Playlist '%s' not found, can't delete\n", uri);

      *ret = -1;
      return COMMAND_END;
    }

  DPRINTF(E_LOG, L_SPOTIFY, "Removing playlist '%s' (%s)\n", pli->title, uri);

  plid = pli->id;

  free_pli(pli, 0);

  db_spotify_pl_delete(plid);
  cleanup_spotify_files();
  *ret = 0;

  return COMMAND_END;
}

void
spotifywebapi_fullrescan(void)
{
  library_exec_async(webapi_fullrescan, NULL);
}

void
spotifywebapi_rescan(void)
{
  library_exec_async(webapi_rescan, NULL);
}

void
spotifywebapi_pl_save(const char *uri)
{
  if (scanning || !token_valid())
    {
      DPRINTF(E_DBG, L_SPOTIFY, "Scanning spotify saved tracks still in progress, ignoring update trigger for single playlist '%s'\n", uri);
      return;
    }

  library_exec_async(webapi_pl_save, strdup(uri));
}

void
spotifywebapi_pl_remove(const char *uri)
{
  if (scanning || !token_valid())
    {
      DPRINTF(E_DBG, L_SPOTIFY, "Scanning spotify saved tracks still in progress, ignoring remove trigger for single playlist '%s'\n", uri);
      return;
    }

  library_exec_async(webapi_pl_remove, strdup(uri));
}

char *
spotifywebapi_artwork_url_get(const char *uri, int max_w, int max_h)
{
  json_object *response;
  struct spotify_track track;
  char *artwork_url;

  response = request_track(uri);
  if (!response)
    {
      return NULL;
    }

  parse_metadata_track(response, &track, max_w);

  DPRINTF(E_DBG, L_SPOTIFY, "Got track artwork url: '%s' (%s) \n", track.artwork_url, track.uri);

  artwork_url = safe_strdup(track.artwork_url);
  jparse_free(response);

  return artwork_url;
}

void
spotifywebapi_status_info_get(struct spotifywebapi_status_info *info)
{
  memset(info, 0, sizeof(struct spotifywebapi_status_info));

  CHECK_ERR(L_SPOTIFY, pthread_mutex_lock(&token_lck));

  info->token_valid = token_valid();
  if (spotify_user)
    {
      strncpy(info->user, spotify_user, (sizeof(info->user) - 1));
    }
  if (spotify_user_country)
    {
      strncpy(info->country, spotify_user_country, (sizeof(info->country) - 1));
    }
  if (spotify_granted_scope)
    {
      strncpy(info->granted_scope, spotify_granted_scope, (sizeof(info->granted_scope) - 1));
    }
  if (spotify_scope)
    {
      strncpy(info->required_scope, spotify_scope, (sizeof(info->required_scope) - 1));
    }

  CHECK_ERR(L_SPOTIFY, pthread_mutex_unlock(&token_lck));
}

void
spotifywebapi_access_token_get(struct spotifywebapi_access_token *info)
{
  token_refresh();

  memset(info, 0, sizeof(struct spotifywebapi_access_token));

  CHECK_ERR(L_SPOTIFY, pthread_mutex_lock(&token_lck));

  if (token_requested > 0)
    info->expires_in = expires_in - difftime(time(NULL), token_requested);
  else
    info->expires_in = 0;

  info->token = safe_strdup(spotify_access_token);

  CHECK_ERR(L_SPOTIFY, pthread_mutex_unlock(&token_lck));
}

static int
spotifywebapi_init()
{
  int ret;

  CHECK_ERR(L_SPOTIFY, mutex_init(&token_lck));
  ret = spotify_init();

  return ret;
}

static void
spotifywebapi_deinit()
{
  CHECK_ERR(L_SPOTIFY, pthread_mutex_destroy(&token_lck));

  spotify_deinit();

  free(spotify_access_token);
  free(spotify_refresh_token);
  free(spotify_granted_scope);
  free(spotify_user_country);
  free(spotify_user);
}

struct library_source spotifyscanner =
{
  .name = "spotifyscanner",
  .disabled = 0,
  .init = spotifywebapi_init,
  .deinit = spotifywebapi_deinit,
  .rescan = rescan,
  .metarescan = rescan,
  .initscan = initscan,
  .fullrescan = fullrescan,
  .queue_item_add = queue_item_add,
};