Improve the handling of notifications

The aim is to put some additional filtering in place to better stop floods of old notifications. This is achieved with a couple of new filters and better tracking of old notifications.

- Make sure to paginate through all notification on initialization to ensure they are all added to old notifications. While we were not previously putting a limit on the number of returned notifications the server can and will do this when there are a very large amount.
- Find the newest timestamp for each connection on initialization and don't post any notifications with an earlier timestamp.
- Track old notifications on a per-connection basis.

Closes network/neochat#358 and network/neochat#423

src/notificationsmanager.h

@@ -4,11 +4,18 @@
 #pragma once
 
 #include <QImage>
+#include <QJsonObject>
 #include <QMap>
 #include <QObject>
 #include <QPointer>
 #include <QString>
-#include <QJsonObject>
+#include <csapi/notifications.h>
+#include <jobs/basejob.h>
+
+namespace Quotient
+{
+class Connection;
+}
 
 class KNotification;
 class NeoChatRoom;
@@ -181,9 +188,23 @@ public:
      */
     QVector<QVariant> getKeywordNotificationActions();
 
+#ifdef QUOTIENT_07
+    /**
+     * @brief Handle the notifications for the given connection.
+     */
+    void handleNotifications(QPointer<Quotient::Connection> connection);
+#endif
+
 private:
     NotificationsManager(QObject *parent = nullptr);
 
+    QHash<QString, qint64> m_initialTimestamp;
+    QHash<QString, QStringList> m_oldNotifications;
+
+    QStringList m_connActiveJob;
+
+    bool shouldPostNotification(QPointer<Quotient::Connection> connection, const QJsonValue &notification);
+
     QHash<QString, KNotification *> m_notifications;
     QHash<QString, QPointer<KNotification>> m_invitations;
 
@@ -218,6 +239,8 @@ private:
     QVector<QVariant> toActions(PushNotificationAction::Action action, const QString &sound = "default");
 
 private Q_SLOTS:
+    void processNotificationJob(QPointer<Quotient::Connection> connection, Quotient::GetNotificationsJob *job, bool initialization);
+
     void updateNotificationRules(const QString &type);
 
 Q_SIGNALS: