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/subsonicscrobblerequest.cpp

@@ -0,0 +1,161 @@
+/*
+ * Strawberry Music Player
+ * Copyright 2019, Jonas Kvinge <jonas@jkvinge.net>
+ * Copyright 2020, Pascal Below <spezifisch@below.fr>
+ *
+ * Strawberry 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry 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 Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "config.h"
+
+#include <QObject>
+#include <QByteArray>
+#include <QString>
+#include <QDateTime>
+#include <QNetworkRequest>
+#include <QNetworkReply>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QJsonValue>
+#include <QtDebug>
+
+#include "core/application.h"
+#include "core/logging.h"
+#include "subsonicservice.h"
+#include "subsonicbaserequest.h"
+#include "subsonicscrobblerequest.h"
+
+const int SubsonicScrobbleRequest::kMaxConcurrentScrobbleRequests = 3;
+
+SubsonicScrobbleRequest::SubsonicScrobbleRequest(SubsonicService *service, SubsonicUrlHandler *url_handler, Application *app, QObject *parent)
+    : SubsonicBaseRequest(service, parent),
+      service_(service),
+      url_handler_(url_handler),
+      app_(app),
+      scrobble_requests_active_(0)
+      {
+
+}
+
+SubsonicScrobbleRequest::~SubsonicScrobbleRequest() {
+
+  while (!replies_.isEmpty()) {
+    QNetworkReply *reply = replies_.takeFirst();
+    disconnect(reply, nullptr, this, nullptr);
+    if (reply->isRunning()) reply->abort();
+    reply->deleteLater();
+  }
+
+}
+
+void SubsonicScrobbleRequest::CreateScrobbleRequest(const QString song_id, const bool submission, const QDateTime start_time) {
+
+  Request request;
+  request.song_id = song_id;
+  request.submission = submission;
+  request.time_ms = start_time.toMSecsSinceEpoch();
+  scrobble_requests_queue_.enqueue(request);
+  if (scrobble_requests_active_ < kMaxConcurrentScrobbleRequests) FlushScrobbleRequests();
+
+}
+
+void SubsonicScrobbleRequest::FlushScrobbleRequests() {
+
+  while (!scrobble_requests_queue_.isEmpty() && scrobble_requests_active_ < kMaxConcurrentScrobbleRequests) {
+
+    Request request = scrobble_requests_queue_.dequeue();
+    ++scrobble_requests_active_;
+
+    ParamList params = ParamList() <<
+      Param("id", request.song_id) <<
+      Param("submission", QVariant(request.submission).toString()) <<
+      Param("time", QVariant(request.time_ms).toString());
+
+    QNetworkReply *reply;
+    reply = CreateGetRequest(QString("scrobble"), params);
+    replies_ << reply;
+    connect(reply, &QNetworkReply::finished, [=] { ScrobbleReplyReceived(reply); });
+
+  }
+
+}
+
+void SubsonicScrobbleRequest::ScrobbleReplyReceived(QNetworkReply *reply) {
+
+  if (!replies_.contains(reply)) return;
+  replies_.removeAll(reply);
+  disconnect(reply, nullptr, this, nullptr);
+  reply->deleteLater();
+
+  --scrobble_requests_active_;
+
+  // "subsonic-response" is empty on success, but some keys like status, version, or type might be present.
+  // Therefore we can only check for errors.
+  QByteArray data = GetReplyData(reply);
+
+  if (data.isEmpty()) {
+    FinishCheck();
+    return;
+  }
+
+  QJsonObject json_obj = ExtractJsonObj(data);
+  if (json_obj.isEmpty()) {
+    FinishCheck();
+    return;
+  }
+
+  if (json_obj.contains("error")) {
+    QJsonValue json_error = json_obj["error"];
+    if (!json_error.isObject()) {
+      Error("Json error is not an object.", json_obj);
+      FinishCheck();
+      return;
+    }
+    json_obj = json_error.toObject();
+    if (!json_obj.isEmpty() && json_obj.contains("code") && json_obj.contains("message")) {
+      int code = json_obj["code"].toInt();
+      QString message = json_obj["message"].toString();
+      Error(QString("%1 (%2)").arg(message).arg(code));
+      FinishCheck();
+    }
+    else {
+      Error("Json error object is missing code or message.", json_obj);
+      FinishCheck();
+      return;
+    }
+    return;
+  }
+
+  FinishCheck();
+
+}
+
+void SubsonicScrobbleRequest::FinishCheck() {
+
+  if (!scrobble_requests_queue_.isEmpty() && scrobble_requests_active_ < kMaxConcurrentScrobbleRequests) FlushScrobbleRequests();
+
+}
+
+void SubsonicScrobbleRequest::Error(const QString &error, const QVariant &debug) {
+
+  if (!error.isEmpty()) {
+    qLog(Error) << "SubsonicScrobbleRequest:" << error;
+    errors_ << error;
+  }
+  if (debug.isValid()) qLog(Debug) << debug;
+
+  FinishCheck();
+
+}

src/subsonic/subsonicscrobblerequest.h

@@ -0,0 +1,90 @@
+/*
+ * Strawberry Music Player
+ * Copyright 2019, Jonas Kvinge <jonas@jkvinge.net>
+ * Copyright 2020, Pascal Below <spezifisch@below.fr>
+ *
+ * Strawberry 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry 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 Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef SUBSONICSCROBBLEREQUEST_H
+#define SUBSONICSCROBBLEREQUEST_H
+
+#include "config.h"
+
+#include <memory>
+
+#include <QtGlobal>
+#include <QObject>
+#include <QDateTime>
+#include <QPair>
+#include <QQueue>
+#include <QVariant>
+#include <QString>
+#include <QStringList>
+
+#include "subsonicbaserequest.h"
+
+class QNetworkReply;
+class Application;
+class SubsonicService;
+class SubsonicUrlHandler;
+
+class SubsonicScrobbleRequest : public SubsonicBaseRequest {
+  Q_OBJECT
+
+ public:
+  explicit SubsonicScrobbleRequest(SubsonicService *service, SubsonicUrlHandler *url_handler, Application *app, QObject *parent);
+  ~SubsonicScrobbleRequest() override;
+
+  void CreateScrobbleRequest(const QString song_id, const bool submission, const QDateTime start_time);
+
+ private slots:
+  void ScrobbleReplyReceived(QNetworkReply *reply);
+
+ private:
+  typedef QPair<QString, QString> Param;
+  typedef QList<Param> ParamList;
+
+  struct Request {
+    explicit Request() : submission(false) {}
+    // subsonic song id
+    QString song_id;
+    // submission: true=Submission, false=NowPlaying
+    bool submission;
+    // song start time
+    qint64 time_ms;
+  };
+
+  void FlushScrobbleRequests();
+  void FinishCheck();
+
+  void Error(const QString &error, const QVariant &debug = QVariant()) override;
+
+  static const int kMaxConcurrentScrobbleRequests;
+
+  SubsonicService *service_;
+  SubsonicUrlHandler *url_handler_;
+  Application *app_;
+
+  QQueue<Request> scrobble_requests_queue_;
+
+  int scrobble_requests_active_;
+
+  QStringList errors_;
+  QList<QNetworkReply*> replies_;
+
+};
+
+#endif  // SUBSONICSCROBBLEREQUEST_H

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()) {

src/subsonic/subsonicservice.h

@@ -35,6 +35,7 @@
 #include <QUrl>
 #include <QNetworkAccessManager>
 #include <QSslError>
+#include <QDateTime>
 
 #include "core/song.h"
 #include "internet/internetservice.h"
@@ -45,6 +46,7 @@ class QNetworkReply;
 class Application;
 class SubsonicUrlHandler;
 class SubsonicRequest;
+class SubsonicScrobbleRequest;
 class CollectionBackend;
 class CollectionModel;
 
@@ -79,6 +81,7 @@ class SubsonicService : public InternetService {
   QSortFilterProxyModel *songs_collection_sort_model() override { return collection_sort_model_; }
 
   void CheckConfiguration();
+  void Scrobble(QString song_id, bool submission, QDateTime time);
 
  public slots:
   void ShowConfig() override;
@@ -116,6 +119,7 @@ class SubsonicService : public InternetService {
   QSortFilterProxyModel *collection_sort_model_;
 
   std::shared_ptr<SubsonicRequest> songs_request_;
+  std::shared_ptr<SubsonicScrobbleRequest> scrobble_request_;
 
   QUrl server_url_;
   QString username_;