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 "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;
};

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;

  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;
};

struct spotify_request
{
  struct http_client_ctx *ctx;
  char *response_body;
  json_object *haystack;
  json_object *items;
  int count;
  int total;
  const char *next_uri;

  int index;
};


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


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

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_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/users/%s/playlists/%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_playlists_uri = "https://api.spotify.com/v1/me/playlists?limit=50";


static int
spotifywebapi_token_get(const char *code, const char *redirect_uri, char **user, const char **err);
static int
spotifywebapi_token_refresh(char **user);
static enum command_state
webapi_fullrescan(void *arg, int *ret);



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

/*--------------------- HELPERS FOR SPOTIFY WEB API -------------------------*/
/*                 All the below is in the httpd thread                      */

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 int
request_uri(struct spotify_request *request, const char *uri)
{
  char bearer_token[1024];
  int ret;

  memset(request, 0, sizeof(struct spotify_request));

  if (0 > spotifywebapi_token_refresh(NULL))
    {
      return -1;
    }

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

  snprintf(bearer_token, sizeof(bearer_token), "Bearer %s", spotify_access_token);
  if (keyval_add(request->ctx->output_headers, "Authorization", bearer_token) < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Add bearer_token to keyval failed\n");
      return -1;
    }

  ret = http_client_request(request->ctx);
  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Request for saved tracks/albums failed\n");
      return -1;
    }

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

  request->response_body = (char *) evbuffer_pullup(request->ctx->input_body, -1);
  if (!request->response_body || (strlen(request->response_body) == 0))
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Request for saved tracks/albums failed, response was empty\n");
      return -1;
    }

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

  request->haystack = json_tokener_parse(request->response_body);
  if (!request->haystack)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "JSON parser returned an error\n");
      return -1;
    }

  DPRINTF(E_DBG, L_SPOTIFY, "Got response for '%s'\n", uri);
  return 0;
}

static void
spotifywebapi_request_end(struct spotify_request *request)
{
  free_http_client_ctx(request->ctx);
  jparse_free(request->haystack);
}

static int
spotifywebapi_request_next(struct spotify_request *request, const char *uri, bool append_market)
{
  char *next_uri;
  int ret;

  if (request->ctx && !request->next_uri)
    {
      // Reached end of paging requests, terminate loop
      return -1;
    }

  if (!request->ctx)
    {
      // First paging request
      if (append_market && spotify_user_country)
	{
	  if (strchr(uri, '?'))
	    next_uri = safe_asprintf("%s&market=%s", uri, spotify_user_country);
	  else
	    next_uri = safe_asprintf("%s?market=%s", uri, spotify_user_country);
	}
      else
	next_uri = strdup(uri);
    }
  else
    {
      // Next paging request
      next_uri = strdup(request->next_uri);
      spotifywebapi_request_end(request);
    }

  ret = request_uri(request, next_uri);
  free(next_uri);

  if (ret < 0)
    return ret;

  request->total = jparse_int_from_obj(request->haystack, "total");
  request->next_uri = jparse_str_from_obj(request->haystack, "next");

  if (jparse_array_from_obj(request->haystack, "items", &request->items) < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "No items in reply from Spotify. See:\n%s\n", request->response_body);
      return -1;
    }

  request->count = json_object_array_length(request->items);

  DPRINTF(E_DBG, L_SPOTIFY, "Got %d items\n", request->count);
  return 0;
}

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

  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");
	}
    }
  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
  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");
    }
  else
    track->is_playable = true;
}

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)
{
  json_object* jsonartists;

  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);

  // 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 int
spotifywebapi_saved_albums_fetch(struct spotify_request *request, json_object **jsontracks, int *track_count, struct spotify_album *album)
{
  json_object *jsonalbum;
  json_object *item;
  json_object *needle;

  memset(album, 0, sizeof(struct spotify_album));
  *track_count = 0;

  if (request->index >= request->count)
    {
      return -1;
    }

  item = json_object_array_get_idx(request->items, request->index);
  if (!(item && json_object_object_get_ex(item, "album", &jsonalbum)))
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Unexpected JSON: Item %d did not have 'album'->'uri'\n", request->index);
      request->index++;
      return -1;
    }

  parse_metadata_album(jsonalbum, album);

  album->added_at = jparse_str_from_obj(item, "added_at");
  album->mtime = jparse_time_from_obj(item, "added_at");

  if (json_object_object_get_ex(jsonalbum, "tracks", &needle))
    {
      if (jparse_array_from_obj(needle, "items", jsontracks) == 0)
	{
	  *track_count = json_object_array_length(*jsontracks);
	}
    }

  request->index++;

  return 0;
}

static int
spotifywebapi_album_track_fetch(json_object *jsontracks, int index, struct spotify_track *track)
{
  json_object *jsontrack;

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

  jsontrack = json_object_array_get_idx(jsontracks, index);

  if (!jsontrack)
    {
      return -1;
    }

  parse_metadata_track(jsontrack, track);

  return 0;
}

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

  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");
    }
}

static int
spotifywebapi_playlists_fetch(struct spotify_request *request, struct spotify_playlist *playlist)
{
  json_object *jsonplaylist;

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

  if (request->index >= request->count)
    {
      DPRINTF(E_DBG, L_SPOTIFY, "All playlists processed\n");
      return -1;
    }

  jsonplaylist = json_object_array_get_idx(request->items, request->index);
  if (!jsonplaylist)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Error fetching playlist at index '%d'\n", request->index);
      return -1;
    }

  parse_metadata_playlist(jsonplaylist, playlist);
  request->index++;

  return 0;
}

/*
 * Extracts the owner and the id from a spotify playlist uri
 *
 * Playlist-uri has the following format: spotify:user:[owner]:playlist:[id]
 * Owner and plid must be freed by the caller.
 */
static int
get_owner_plid_from_uri(const char *uri, char **owner, char **plid)
{
  char *ptr1;
  char *ptr2;
  char *tmp;
  size_t len;

  ptr1 = strchr(uri, ':');
  if (!ptr1)
    return -1;
  ptr1++;
  ptr1 = strchr(ptr1, ':');
  if (!ptr1)
    return -1;
  ptr1++;
  ptr2 = strchr(ptr1, ':');

  len = ptr2 - ptr1;

  tmp = malloc(sizeof(char) * (len + 1));
  strncpy(tmp, ptr1, len);
  tmp[len] = '\0';
  *owner = tmp;

  ptr2++;
  ptr1 = strchr(ptr2, ':');
  if (!ptr1)
    {
      free(tmp);
      return -1;
    }
  ptr1++;
  *plid = strdup(ptr1);

  return 0;
}

static int
spotifywebapi_playlisttracks_fetch(struct spotify_request *request, struct spotify_track *track)
{
  json_object *item;
  json_object *jsontrack;

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

  if (request->index >= request->count)
    {
      return -1;
    }

  item = json_object_array_get_idx(request->items, request->index);
  if (!(item && json_object_object_get_ex(item, "track", &jsontrack)))
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Unexpected JSON: Item %d did not have 'track'->'uri'\n", request->index);
      request->index++;
      return -1;
    }

  parse_metadata_track(jsontrack, track);
  track->added_at = jparse_str_from_obj(item, "added_at");
  track->mtime = jparse_time_from_obj(item, "added_at");

  request->index++;

  return 0;
}

static int
spotifywebapi_playlist_start(struct spotify_request *request, const char *path, struct spotify_playlist *playlist)
{
  char uri[1024];
  char *owner;
  char *id;
  int ret;

  ret = get_owner_plid_from_uri(path, &owner, &id);
  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Error extracting owner and id from playlist uri '%s'\n", path);
      return -1;
    }

  ret = snprintf(uri, sizeof(uri), spotify_playlist_uri, owner, id);
  if (ret < 0 || ret >= sizeof(uri))
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Error creating playlist endpoint uri for playlist '%s'\n", path);
      free(owner);
      free(id);
      return -1;
    }

  ret = request_uri(request, uri);
  if (ret < 0)
    {
      free(owner);
      free(id);
      return -1;
    }

  request->haystack = json_tokener_parse(request->response_body);
  parse_metadata_playlist(request->haystack, playlist);

  free(owner);
  free(id);
  return 0;
}

static int
request_user_info()
{
  struct spotify_request request;
  int ret;

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

  ret = request_uri(&request, spotify_me_uri);

  if (ret < 0)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Failed to read user country\n");
    }
  else
    {
      spotify_user = safe_strdup(jparse_str_from_obj(request.haystack, "id"));
      spotify_user_country = safe_strdup(jparse_str_from_obj(request.haystack, "country"));

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

  spotifywebapi_request_end(&request);

  return 0;
}

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", "user-read-private playlist-read-private user-library-read") == 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;
  char *user = NULL;
  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 = spotifywebapi_token_get(code, redirect_uri, &user, &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
tokens_get(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);
    }

  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);

  request_user_info();

  ret = 0;

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

  return ret;
}

static int
spotifywebapi_token_get(const char *code, const char *redirect_uri, char **user, const char **err)
{
  struct keyval kv;
  int ret;

  *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 = tokens_get(&kv, err);

  if (user && ret == 0)
    {
      *user = safe_strdup(spotify_user);
    }
  keyval_clear(&kv);

  return ret;
}

static int
spotifywebapi_token_refresh(char **user)
{
  struct keyval kv;
  char *refresh_token;
  const char *err;
  int ret;

  memset(&kv, 0, sizeof(struct keyval));
  refresh_token = NULL;

  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;
    }

  refresh_token = db_admin_get(DB_ADMIN_SPOTIFY_REFRESH_TOKEN);
  if (!refresh_token)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "No spotify refresh token found\n");

      ret = -1;
      goto out;
    }

  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");
      ret = -1;
    }
  else
    ret = tokens_get(&kv, &err);

  if (user && ret == 0)
    {
      *user = safe_strdup(spotify_user);
    }

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

  CHECK_ERR(L_SPOTIFY, pthread_mutex_unlock(&token_lck));

  return ret;
}


/*
 * 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, 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, 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;
}

static int
spotify_cleanup_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 int
playlist_remove(const char *uri)
{
  struct playlist_info *pli;
  int plid;

  pli = db_pl_fetch_bypath(uri);

  if (!pli)
    {
      DPRINTF(E_LOG, L_SPOTIFY, "Playlist '%s' not found, can't delete\n", uri);
      return -1;
    }

  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);
  spotify_cleanup_files();
  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->artwork     = ARTWORK_SPOTIFY;
  mfi->type        = strdup("spotify");
  mfi->codectype   = strdup("wav");
  mfi->description = strdup("Spotify audio");

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

  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;
      mfi->time_modified = album->mtime;
    }
  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;

      mfi->time_modified = time(NULL);
    }

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

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

  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_add_media(&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);
}


/* Thread: library */
static int
scan_saved_albums()
{
  struct spotify_request request;
  struct spotify_album album;
  struct spotify_track track;
  json_object *jsontracks;
  int track_count;
  int dir_id;
  int i;
  int count;
  int ret;

  count = 0;
  memset(&request, 0, sizeof(struct spotify_request));

  while (0 == spotifywebapi_request_next(&request, spotify_albums_uri, false))
    {
      while (0 == spotifywebapi_saved_albums_fetch(&request, &jsontracks, &track_count, &album))
	{
	  DPRINTF(E_DBG, L_SPOTIFY, "Got saved album: '%s' - '%s' (%s) - track-count: %d\n",
		  album.artist, album.name, album.uri, track_count);

	  db_transaction_begin();

	  dir_id = prepare_directories(album.artist, album.name);
	  ret = 0;
	  for (i = 0; i < track_count && ret == 0; i++)
	    {
	      ret = spotifywebapi_album_track_fetch(jsontracks, i, &track);
	      if (ret < 0 || !track.uri)
		continue;

	      webapi_track_save(&track, &album, NULL, dir_id);
	      if (spotify_saved_plid)
		db_pl_add_item_bypath(spotify_saved_plid, track.uri);
	    }

	  db_transaction_end();

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

  spotifywebapi_request_end(&request);

  return 0;
}

/* Thread: library */
static int
scan_playlisttracks(struct spotify_playlist *playlist, int plid)
{
  struct spotify_request request;
  struct spotify_track track;
  int dir_id;

  memset(&request, 0, sizeof(struct spotify_request));

  while (0 == spotifywebapi_request_next(&request, playlist->tracks_href, true))
    {
      db_transaction_begin();

      while (0 == spotifywebapi_playlisttracks_fetch(&request, &track))
	{
	  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);
	      continue;
	    }

	  dir_id = prepare_directories(track.album_artist, track.album);
	  webapi_track_save(&track, NULL, playlist->name, dir_id);
	  db_pl_add_item_bypath(plid, track.uri);
	}

      db_transaction_end();
    }

  spotifywebapi_request_end(&request);

  return 0;
}

/* Thread: library */
static int
scan_playlists()
{
  struct spotify_request request;
  struct spotify_playlist playlist;
  char virtual_path[PATH_MAX];
  int plid;
  int count;
  int trackcount;

  count = 0;
  trackcount = 0;
  memset(&request, 0, sizeof(struct spotify_request));

  while (0 == spotifywebapi_request_next(&request, spotify_playlists_uri, false))
    {
      while (0 == spotifywebapi_playlists_fetch(&request, &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);
	      continue;
	    }

	  if (playlist.owner)
	    {
	      snprintf(virtual_path, PATH_MAX, "/spotify:/%s (%s)", playlist.name, playlist.owner);
	    }
	  else
	    {
	      snprintf(virtual_path, PATH_MAX, "/spotify:/%s", playlist.name);
	    }

	  db_transaction_begin();
	  plid = library_add_playlist_info(playlist.uri, playlist.name, virtual_path, PL_PLAIN, spotify_base_plid, DIR_SPOTIFY);
	  db_transaction_end();

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

	  count++;
	  trackcount += playlist.tracks_count;
	  DPRINTF(E_LOG, L_SPOTIFY, "Scanned %d of %d saved playlists (%d tracks)\n", count, request.total, trackcount);
	}
    }

  spotifywebapi_request_end(&request);

  return 0;
}

/* Thread: library */
static int
scan_playlist(const char *uri)
{
  struct spotify_request request;
  struct spotify_playlist playlist;
  char virtual_path[PATH_MAX];
  int plid;

  memset(&request, 0, sizeof(struct spotify_request));
  memset(&playlist, 0, sizeof(struct spotify_playlist));

  if (0 == spotifywebapi_playlist_start(&request, uri, &playlist))
    {
      if (!playlist.uri)
	{
	  DPRINTF(E_LOG, L_SPOTIFY, "Got playlist with missing uri for path:: '%s'\n", uri);
	}
      else
	{
	  DPRINTF(E_LOG, L_SPOTIFY, "Saving playlist '%s' with %d tracks (%s) \n", playlist.name, playlist.tracks_count, playlist.uri);

	  if (playlist.owner)
	    {
	      snprintf(virtual_path, PATH_MAX, "/spotify:/%s (%s)", playlist.name, playlist.owner);
	    }
	  else
	    {
	      snprintf(virtual_path, PATH_MAX, "/spotify:/%s", playlist.name);
	    }

	  db_transaction_begin();
	  plid = library_add_playlist_info(playlist.uri, playlist.name, virtual_path, PL_PLAIN, spotify_base_plid, DIR_SPOTIFY);
	  db_transaction_end();

	  if (plid > 0)
	    scan_playlisttracks(&playlist, plid);
	  else
	    DPRINTF(E_LOG, L_SPOTIFY, "Error adding playlist: '%s' (%s) \n", playlist.name, playlist.uri);
	}
    }

  spotifywebapi_request_end(&request);

  return 0;
}

static void
create_saved_tracks_playlist()
{
  spotify_saved_plid = library_add_playlist_info("spotify:savedtracks", "Spotify Saved", "/spotify:/Spotify Saved", PL_PLAIN, spotify_base_plid, DIR_SPOTIFY);

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

/*
 * Add or update playlist folder for all spotify playlists (if enabled in config)
 */
static void
create_base_playlist()
{
  cfg_t *spotify_cfg;
  int ret;

  spotify_base_plid = 0;
  spotify_cfg = cfg_getsec(cfg, "spotify");
  if (!cfg_getbool(spotify_cfg, "base_playlist_disable"))
    {
      ret = library_add_playlist_info("spotify:playlistfolder", "Spotify", NULL, PL_FOLDER, 0, 0);
      if (ret < 0)
	DPRINTF(E_LOG, L_SPOTIFY, "Error adding base playlist\n");
      else
	spotify_base_plid = ret;
    }
}

static void
scan()
{
  if (token_valid() && !scanning)
    {
      scanning = true;

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

      scanning = false;
    }
  else
    {
      DPRINTF(E_DBG, L_SPOTIFY, "No valid web api token or scan already in progress, rescan ignored\n");
    }
}

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

  /* Refresh access token for the spotify webapi */
  ret =  spotifywebapi_token_refresh(NULL);
  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 = arg;

  *ret = scan_playlist(uri);
  return COMMAND_END;
}

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

  *ret = playlist_remove(uri);
  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));
}

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)
    {
      memcpy(info->user, spotify_user, (sizeof(info->user) - 1));
    }

  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();
}

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