File indexing completed on 2025-02-16 04:50:11

 /*
     SPDX-FileCopyrightText: 2015-2020 Krzysztof Nowicki <krissn@op.pl>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #pragma once
 
 #include <QSet>
 #include <QString>
 #include <QTimer>
 
 #include "ewsid.h"
 
 class EwsClient;
 class KJob;
 class EwsEventRequestBase;
 class EwsSettings;
 
 /**
  *  @brief  Mailbox update subscription manager class
  *
  *  This class is responsible for retrieving update notifications from the Exchange server.
  *
  *  The Exchange server has the ability to incrementally inform the client about changes made to
  *  selected folders in the mailbox. Each update informs about creation, modification or removal
  *  of an item or folder. Additionally Exchange has the ability to notify about free/busy status
  *  updates.
  *
  *  Notifications can be delivered in 3 ways:
  *   - pull (i.e. polling) - the client needs to periodically question the server.
  *   - push - the server issues a callback connection to the client with events (not supported)
  *   - streaming - a combination of pull and push, where the client makes the connection, but the
  *                 server keeps it open for a specified period of time and keeps delivering events
  *                 over this connection (supported since Exchange 2010 SP2).
  *
  *  The responsibility of this class is to retrieve and act upon change events from the Exchange
  *  server. The current implementation is simplified:
  *   - when an item update is received the folder containing the update is asked to synchronize
  *     itself.
  *   - when a folder update is received a full collection tree sync is performed.
  *
  *  The above implementation has a major drawback in that operations performed by the resource
  *  itself are also notified back as update events. This means that when for ex. an item is deleted
  *  it is removed from Akonadi database, but subsequently a delete event is received which will try
  *  to delete an item that has already been deleted from Akonadi.
  */
 class EwsSubscriptionManager : public QObject
 {
     Q_OBJECT
 public:
     EwsSubscriptionManager(EwsClient &client, const EwsId &rootId, EwsSettings *settings, QObject *parent);
     ~EwsSubscriptionManager() override;
     void start();
 Q_SIGNALS:
     void foldersModified(EwsId::List folders);
     void folderTreeModified();
     void fullSyncRequested();
     void connectionError();
 
 private:
     void subscribeRequestFinished(KJob *job);
     void verifySubFoldersRequestFinished(KJob *job);
     void getEventsRequestFinished(KJob *job);
     void streamingEventsReceived(KJob *job);
     void getEvents();
     void streamingConnectionTimeout();
 
 private:
     void cancelSubscription();
     void setupSubscription();
     void setupSubscriptionReq(const EwsId::List &ids);
     void reset();
     void resetSubscription();
     void processEvents(EwsEventRequestBase *req, bool finished);
 
     EwsClient &mEwsClient;
     QTimer mPollTimer;
     EwsId mMsgRootId;
 
     QSet<EwsId> mUpdatedFolderIds;
     bool mFolderTreeChanged;
     bool mStreamingEvents;
     QTimer mStreamingTimer;
     EwsEventRequestBase *mEventReq = nullptr;
     EwsSettings *mSettings = nullptr;
 };