Merge pull request #955 from chme/jsonapi-track-playlists

Add JSON API endpoint to fetch playlists for a track

README_JSON_API.md

@@ -758,6 +758,7 @@ curl -X PUT "http://localhost:3689/api/queue/items/2"
 | GET       | [/api/library/albums/{id}](#get-an-album)                   | Get an album                         |
 | GET       | [/api/library/albums/{id}/tracks](#list-album-tracks)       | Get list of tracks for an album      |
 | GET       | [/api/library/tracks/{id}](#get-a-track)                    | Get a track                          |
+| GET       | [/api/library/tracks/{id}/playlists](#list-playlists-for-a-track) | Get list of playlists for a track |
 | PUT       | [/api/library/tracks/{id}](#update-track-properties)        | Update a tracks properties (rating, play_count) |
 | GET       | [/api/library/genres](#list-genres)                         | Get list of genres                   |
 | GET       | [/api/library/count](#get-count-of-tracks-artists-and-albums) | Get count of tracks, artists and albums |
@@ -1508,6 +1509,63 @@ curl -X GET "http://localhost:3689/api/library/track/1"
 ```
 
 
+### List playlists for a track
+
+Get the list of playlists that contain a track (does not return smart playlists)
+
+**Endpoint**
+
+```http
+GET /api/library/tracks/{id}/playlists
+```
+
+**Path parameters**
+
+| Parameter       | Value                |
+| --------------- | -------------------- |
+| id              | Track id             |
+
+**Query parameters**
+
+| Parameter       | Value                                                       |
+| --------------- | ----------------------------------------------------------- |
+| offset          | *(Optional)* Offset of the first playlist to return         |
+| limit           | *(Optional)* Maximum number of playlist to return           |
+
+**Response**
+
+| Key             | Type     | Value                                     |
+| --------------- | -------- | ----------------------------------------- |
+| items           | array    | Array of [`playlist`](#playlist-object) objects              |
+| total           | integer  | Total number of playlists                 |
+| offset          | integer  | Requested offset of the first playlist    |
+| limit           | integer  | Requested maximum number of playlists     |
+
+**Example**
+
+```shell
+curl -X GET "http://localhost:3689/api/library/tracks/27/playlists"
+```
+
+```json
+{
+  "items": [
+    {
+      "id": 1,
+      "name": "playlist",
+      "path": "/music/srv/playlist.m3u",
+      "smart_playlist": false,
+      "uri": "library:playlist:1"
+    },
+    ...
+  ],
+  "total": 2,
+  "offset": 0,
+  "limit": -1
+}
+```
+
+
 ### Update track properties
 
 Change properties of a specific track (supported properties are "rating" and "play_count")

src/httpd_jsonapi.c

@@ -3176,6 +3176,71 @@ jsonapi_reply_library_tracks_put_byid(struct httpd_request *hreq)
   return HTTP_OK;
 }
 
+static int
+jsonapi_reply_library_track_playlists(struct httpd_request *hreq)
+{
+  struct query_params query_params;
+  json_object *reply;
+  json_object *items;
+  char *path;
+  const char *track_id;
+  int id;
+  int total;
+  int ret = 0;
+
+  if (!is_modified(hreq->req, DB_ADMIN_DB_MODIFIED))
+    return HTTP_NOTMODIFIED;
+
+  track_id = hreq->uri_parsed->path_parts[3];
+  if (safe_atoi32(track_id, &id) < 0)
+    {
+      DPRINTF(E_LOG, L_WEB, "Error converting track id '%s' to int.\n", track_id);
+      return HTTP_INTERNAL;
+    }
+
+  path = db_file_path_byid(id);
+  if (!path)
+    {
+      DPRINTF(E_WARN, L_WEB, "No file path found for track with id '%s' not found.\n", track_id);
+      return HTTP_BADREQUEST;
+    }
+
+  reply = json_object_new_object();
+  items = json_object_new_array();
+  json_object_object_add(reply, "items", items);
+
+  memset(&query_params, 0, sizeof(struct query_params));
+
+  ret = query_params_limit_set(&query_params, hreq);
+  if (ret < 0)
+    goto error;
+
+  query_params.type = Q_FIND_PL;
+  query_params.filter = db_mprintf("filepath = '%q'", path);
+
+  ret = fetch_playlists(&query_params, items, &total);
+  if (ret < 0)
+    goto error;
+
+  json_object_object_add(reply, "total", json_object_new_int(total));
+  json_object_object_add(reply, "offset", json_object_new_int(query_params.offset));
+  json_object_object_add(reply, "limit", json_object_new_int(query_params.limit));
+
+  ret = evbuffer_add_printf(hreq->reply, "%s", json_object_to_json_string(reply));
+  if (ret < 0)
+    DPRINTF(E_LOG, L_WEB, "track playlists: Couldn't add playlists to response buffer.\n");
+
+ error:
+  free_query_params(&query_params, 1);
+  jparse_free(reply);
+  free(path);
+
+  if (ret < 0)
+    return HTTP_INTERNAL;
+
+  return HTTP_OK;
+}
+
 static int
 jsonapi_reply_library_playlists(struct httpd_request *hreq)
 {
@@ -4159,6 +4224,7 @@ static struct httpd_uri_map adm_handlers[] =
     { EVHTTP_REQ_PUT,    "^/api/library/albums/[[:digit:]]+/tracks$",    jsonapi_reply_library_album_tracks_put_byid },
     { EVHTTP_REQ_GET,    "^/api/library/tracks/[[:digit:]]+$",           jsonapi_reply_library_tracks_get_byid },
     { EVHTTP_REQ_PUT,    "^/api/library/tracks/[[:digit:]]+$",           jsonapi_reply_library_tracks_put_byid },
+    { EVHTTP_REQ_GET,    "^/api/library/tracks/[[:digit:]]+/playlists$", jsonapi_reply_library_track_playlists },
     { EVHTTP_REQ_GET,    "^/api/library/genres$",                        jsonapi_reply_library_genres},
     { EVHTTP_REQ_GET,    "^/api/library/count$",                         jsonapi_reply_library_count },
     { EVHTTP_REQ_GET,    "^/api/library/files$",                         jsonapi_reply_library_files },