/****************************************************************************
**
** Copyright (C) 2017 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtOpcUa module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL3$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see http://www.qt.io/terms-conditions. For further
** information use the contact form at http://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPLv3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or later as published by the Free
** Software Foundation and appearing in the file LICENSE.GPL included in
** the packaging of this file. Please review the following information to
** ensure the GNU General Public License version 2.0 requirements will be
** met: http://www.gnu.org/licenses/gpl-2.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qopen62541client.h"
#include "qopen62541subscription.h"
#include <private/qopcuabackend_p.h>

#include <QtCore/qset.h>
#include <QtCore/qstring.h>
#include <QtCore/qtimer.h>

QT_BEGIN_NAMESPACE

class Open62541AsyncBackend : public QOpcUaBackend
{
    Q_OBJECT
public:
    Open62541AsyncBackend(QOpen62541Client *parent);
    ~Open62541AsyncBackend();

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

    // Node functions
    void browse(quint64 handle, UA_NodeId id, const QOpcUaBrowseRequest &request);
    void readAttributes(quint64 handle, UA_NodeId id, QOpcUa::NodeAttributes attr, QString indexRange);

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

    // Subscription
    QOpen62541Subscription *getSubscription(const QOpcUaMonitoringParameters &settings);
    bool removeSubscription(UA_UInt32 subscriptionId);
    void iterateClient();
    void reevaluateClientIterateTimer();
    void handleSubscriptionTimeout(QOpen62541Subscription *sub, QVector<QPair<quint64, QOpcUa::NodeAttribute>> items);
    void cleanupSubscriptions();

public:
    UA_Client *m_uaclient;
    QOpen62541Client *m_clientImpl;
    bool m_useStateCallback;
    double m_minimumIterateInterval;
    const double m_maximumIterateInterval;

private:
    static void clientStateCallback(UA_Client *client, UA_ClientState state);

    QOpen62541Subscription *getSubscriptionForItem(quint64 handle, QOpcUa::NodeAttribute attr);
    QOpcUaApplicationDescription convertApplicationDescription(UA_ApplicationDescription &desc);

    UA_ExtensionObject assembleNodeAttributes(const QOpcUaNodeCreationAttributes &nodeAttributes, QOpcUa::NodeClass nodeClass);
    UA_UInt32 *copyArrayDimensions(const QVector<quint32> &arrayDimensions, size_t *outputSize);

    // Helper
    bool loadFileToByteString(const QString &location, UA_ByteString *target) const;
    bool loadAllFilesInDirectory(const QString &location, UA_ByteString **target, int *size) const;

    QTimer m_clientIterateTimer;

    QHash<quint32, QOpen62541Subscription *> m_subscriptions;

    QHash<quint64, QHash<QOpcUa::NodeAttribute, QOpen62541Subscription *>> m_attributeMapping; // Handle -> Attribute -> Subscription

    double m_minPublishingInterval;
};

QT_END_NAMESPACE