/**
 * @file   OpcUaMonitoredNode.h
 * @brief  QML component for monitoring a single OPC UA node.
 *
 * Inherits QObject + QQmlParserStatus so that initialisation is
 * deferred until all QML bindings are applied (componentComplete).
 */
#ifndef OPCUAMONITOREDNODE_H
#define OPCUAMONITOREDNODE_H

#include <QDateTime>
#include <QObject>
#include <QOpcUaNode>
#include <QQmlEngine>
#include <QQmlParserStatus>
#include <QVariant>

/**
 * @brief Metadata bundle for a monitored OPC UA node.
 *
 * Exposed as a single Q_PROPERTY on OpcUaMonitoredNode so that
 * the QML API stays simple (only `value` is top-level).
 * Advanced users can access fields via dot notation:
 *   node.info.displayName, node.info.status, etc.
 */
struct OpcUaNodeInfo
{
  Q_GADGET
  Q_PROPERTY (QString displayName MEMBER displayName)
  Q_PROPERTY (QString description MEMBER description)
  Q_PROPERTY (QString nodeClass MEMBER nodeClass)
  Q_PROPERTY (QString dataType MEMBER dataType)
  Q_PROPERTY (quint32 accessLevel MEMBER accessLevel)
  Q_PROPERTY (QString status MEMBER status)
  Q_PROPERTY (QDateTime sourceTimestamp MEMBER sourceTimestamp)
  Q_PROPERTY (QDateTime serverTimestamp MEMBER serverTimestamp)

public:
  QString displayName;
  QString description;
  QString nodeClass;
  QString dataType;
  quint32 accessLevel = 0;
  QString status;
  QDateTime sourceTimestamp;
  QDateTime serverTimestamp;
};
Q_DECLARE_METATYPE (OpcUaNodeInfo)

class OpcUaMonitoredNode : public QObject, public QQmlParserStatus
{
  Q_OBJECT
  Q_INTERFACES (QQmlParserStatus)
  QML_ELEMENT

  Q_PROPERTY (QString nodeId READ nodeId WRITE setNodeId NOTIFY nodeIdChanged)
  Q_PROPERTY (
      bool monitored READ monitored WRITE setMonitored NOTIFY monitoredChanged)
  Q_PROPERTY (QVariant value READ value NOTIFY valueChanged)
  Q_PROPERTY (OpcUaNodeInfo info READ info NOTIFY infoChanged)

public:
  explicit OpcUaMonitoredNode (QObject *parent = nullptr);

  QString nodeId () const;
  void setNodeId (const QString &id);

  bool monitored () const;
  void setMonitored (bool monitored);

  QVariant value () const;
  OpcUaNodeInfo info () const;

  void classBegin () override;
  void componentComplete () override;

signals:
  void nodeIdChanged ();
  void monitoredChanged ();
  void valueChanged ();
  void infoChanged ();

private slots:
  void handleAttributeUpdated (QOpcUa::NodeAttribute attr,
                               const QVariant &value);
  void handleValueUpdated (const QVariant &value);
  void handleClientConnectedChanged ();

private:
  void setupNode ();
  void teardownNode ();

  QString m_nodeId;
  bool m_monitored = true;
  bool m_componentComplete = false;

  QOpcUaNode *m_node = nullptr;
  QVariant m_value;
  OpcUaNodeInfo m_info;
};

#endif // OPCUAMONITOREDNODE_H