/******************************************************************************
**
** Copyright (C) 2019 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtOpcUa module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL$
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** accordance with the commercial license agreement provided with the
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) any later version
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** the Free Software Foundation and appearing in the file LICENSE.GPL3
** included in the packaging of this file. Please review the following
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******************************************************************************/

#ifndef QUACPPASYNCBACKEND_H
#define QUACPPASYNCBACKEND_H

#include <private/qopcuabackend_p.h>

#include <QtCore/QMutex>
#include <QtCore/QSet>
#include <QtCore/QString>
#include <QtCore/QTimer>

#include <QtOpcUa/qopcuaerrorstate.h>
#include <QtOpcUa/qopcuatype.h>
#include <uabase.h>
#include <uaclientsdk.h>

QT_BEGIN_NAMESPACE

class QUACppClient;
class QUACppNode;
class QUACppSubscription;

class UACppAsyncBackend : public QOpcUaBackend,
        public UaClientSdk::UaSessionCallback
{
    Q_OBJECT
public:
    UACppAsyncBackend(QUACppClient *parent);
    ~UACppAsyncBackend();

    void connectionStatusChanged(OpcUa_UInt32 clientConnectionId, UaClientSdk::UaClient::ServerStatus serverStatus) override;
    bool connectError(OpcUa_UInt32 clientConnectionId, UaClientSdk::UaClient::ConnectServiceType serviceType, const UaStatus &error, bool clientSideError) override;

public Q_SLOTS:
    void connectToEndpoint(const QOpcUaEndpointDescription &endpoint);
    void disconnectFromEndpoint();

    void browse(quint64 handle, const UaNodeId &id, const QOpcUaBrowseRequest &request);
    void readAttributes(quint64 handle, const UaNodeId &id, QOpcUa::NodeAttributes attr, QString indexRange);
    void writeAttribute(quint64 handle, const UaNodeId &id, QOpcUa::NodeAttribute attrId, QVariant value, QOpcUa::Types type, QString indexRange);
    void writeAttributes(quint64 handle, const UaNodeId &id, QOpcUaNode::AttributeMap toWrite, QOpcUa::Types valueAttributeType);
    void enableMonitoring(quint64 handle, const UaNodeId &id, QOpcUa::NodeAttributes attr, const QOpcUaMonitoringParameters &settings);
    void modifyMonitoring(quint64 handle, QOpcUa::NodeAttribute attr, QOpcUaMonitoringParameters::Parameter item, QVariant value);
    void disableMonitoring(quint64 handle, QOpcUa::NodeAttributes attr);
    void callMethod(quint64 handle, const UaNodeId &objectId, const UaNodeId &methodId, QVector<QOpcUa::TypedVariant> args);
    void resolveBrowsePath(quint64 handle, const UaNodeId &startNode, const QVector<QOpcUaRelativePathElement> &path);
    void requestEndpoints(const QUrl &url);

    bool removeSubscription(quint32 subscriptionId);

    void findServers(const QUrl &url, const QStringList &localeIds, const QStringList &serverUris);

    void readNodeAttributes(const QVector<QOpcUaReadItem> &nodesToRead);
    void writeNodeAttributes(const QVector<QOpcUaWriteItem> &nodesToWrite);

    // Node management
    void addNode(const QOpcUaAddNodeItem &nodeToAdd);
    void deleteNode(const QString &nodeId, bool deleteTargetReferences);
    void addReference(const QOpcUaAddReferenceItem &referenceToAdd);
    void deleteReference(const QOpcUaDeleteReferenceItem &referenceToDelete);

    // Helper
    QOpcUaErrorState::ConnectionStep connectionStepFromUaServiceType(UaClientSdk::UaClient::ConnectServiceType type) const;

public:
    QUACppSubscription *getSubscription(const QOpcUaMonitoringParameters &settings);
    QUACppSubscription *getSubscriptionForItem(quint64 handle, QOpcUa::NodeAttribute attr);
    void cleanupSubscriptions();
    Q_DISABLE_COPY(UACppAsyncBackend);
    UaClientSdk::UaSession *m_nativeSession;
    QUACppClient *m_clientImpl;
    QHash<quint32, QUACppSubscription *> m_subscriptions;
    QHash<quint64, QHash<QOpcUa::NodeAttribute, QUACppSubscription *>> m_attributeMapping; // Handle -> Attribute -> Subscription
    static quint32 m_numClients;
    static bool m_platformLayerInitialized;
    QMutex m_lifecycleMutex;
    double m_minPublishingInterval;
    bool m_disableEncryptedPasswordCheck{false};

private:
    bool assembleNodeAttributes(OpcUa_ExtensionObject *uaExtensionObject, const QOpcUaNodeCreationAttributes &nodeAttributes, QOpcUa::NodeClass nodeClass);
};

QT_END_NAMESPACE

#endif // QUACPPASYNCBACKEND_H