Add Subsonic scrobble support (#545)

* add SubsonicScrobbler, add Scrobble method in SubsonicService

* new class SubsonicScrobbleRequest, use queue again, clean up

* add checkbox to enable server-side scrobbling to Subsonic settings page

* Check serversidescrobbling in SubsonicScrobbler::ReloadSettings instead of SubsonicService

TODO: SubsonicScrobbler::ReloadSettings needs to be called when
SubsonicSettings change.

src/subsonic/subsonicservice.cpp

@@ -27,6 +27,7 @@
 #include <QPair>
 #include <QList>
 #include <QString>
+#include <QVariant>
 #include <QUrl>
 #include <QUrlQuery>
 #include <QNetworkAccessManager>
@@ -53,6 +54,7 @@
 #include "subsonicservice.h"
 #include "subsonicurlhandler.h"
 #include "subsonicrequest.h"
+#include "subsonicscrobblerequest.h"
 #include "settings/settingsdialog.h"
 #include "settings/subsonicsettingspage.h"
 
@@ -379,6 +381,21 @@ void SubsonicService::CheckConfiguration() {
 
 }
 
+void SubsonicService::Scrobble(QString song_id, bool submission, QDateTime time) {
+
+  if (!server_url().isValid() || username().isEmpty() || password().isEmpty()) {
+    return;
+  }
+
+  if (!scrobble_request_.get()) {
+    // we're doing requests every 30-240s the whole time, so keep reusing this instance
+    scrobble_request_.reset(new SubsonicScrobbleRequest(this, url_handler_, app_, this));
+  }
+
+  scrobble_request_->CreateScrobbleRequest(song_id, submission, time);
+
+}
+
 void SubsonicService::ResetSongsRequest() {
 
   if (songs_request_.get()) {