Rename classes to OpcUa* prefix, replace BobinkNode with OpcUaMonitoredNode boilerplate

Rename BobinkAuth → OpcUaAuth, BobinkClient → OpcUaClient (C++ class
names only; QML module URI and singleton name stay as Bobink).
Remove BobinkNode (QQuickItem-based) and add OpcUaMonitoredNode
skeleton using QObject + QQmlParserStatus, following Qt convention
for non-visual QML types.

1 files changed, 193 insertions, 0 deletions

diff --git a/src/OpcUaClient.h b/src/OpcUaClient.h
new file mode 100644
index 0000000..1476911
--- /dev/null
+++ b/src/OpcUaClient.h
@@ -0,0 +1,193 @@
+/**
+ * @file   OpcUaClient.h
+ * @brief  QML singleton managing the OPC UA connection lifecycle.
+ *
+ * Wraps QOpcUaClient into a declarative interface: LDS discovery,
+ * endpoint selection, PKI, and certificate trust flow.
+ * Single connection at a time (app-wide singleton).
+ */
+#ifndef OPCUACLIENT_H
+#define OPCUACLIENT_H
+
+#include <QEventLoop>
+#include <QObject>
+#include <QOpcUaApplicationDescription>
+#include <QOpcUaClient>
+#include <QOpcUaEndpointDescription>
+#include <QOpcUaErrorState>
+#include <QOpcUaProvider>
+#include <QQmlEngine>
+#include <QTimer>
+
+class OpcUaAuth;
+
+class OpcUaClient : public QObject
+{
+  Q_OBJECT
+  QML_SINGLETON
+  QML_NAMED_ELEMENT (Bobink)
+
+  /* -- Connection -- */
+  Q_PROPERTY (bool connected READ connected NOTIFY connectedChanged)
+  Q_PROPERTY (QString serverUrl READ serverUrl WRITE setServerUrl NOTIFY
+                  serverUrlChanged)
+  Q_PROPERTY (OpcUaAuth *auth READ auth WRITE setAuth NOTIFY authChanged)
+
+  /* -- Discovery -- */
+  Q_PROPERTY (QString discoveryUrl READ discoveryUrl WRITE setDiscoveryUrl
+                  NOTIFY discoveryUrlChanged)
+  Q_PROPERTY (bool discovering READ discovering NOTIFY discoveringChanged)
+  Q_PROPERTY (QVariantList servers READ servers NOTIFY serversChanged)
+
+  /* -- PKI -- */
+  Q_PROPERTY (QString pkiDir READ pkiDir WRITE setPkiDir NOTIFY pkiDirChanged)
+  Q_PROPERTY (
+      QString certFile READ certFile WRITE setCertFile NOTIFY certFileChanged)
+  Q_PROPERTY (
+      QString keyFile READ keyFile WRITE setKeyFile NOTIFY keyFileChanged)
+
+public:
+  /// OPC UA message security mode (values match MessageSecurityMode).
+  enum SecurityMode
+  {
+    SignAndEncrypt = 3,
+    Sign = 2,
+    None = 1,
+  };
+  Q_ENUM (SecurityMode)
+
+  /// OPC UA security policy for encryption algorithms.
+  enum SecurityPolicy
+  {
+    Basic256Sha256,
+    Aes128_Sha256_RsaOaep,
+    Aes256_Sha256_RsaPss,
+  };
+  Q_ENUM (SecurityPolicy)
+
+  OpcUaClient (QObject *parent = nullptr);
+
+  /* -- Connection -- */
+
+  bool connected () const;
+
+  QString serverUrl () const;
+  void setServerUrl (const QString &url);
+
+  OpcUaAuth *auth () const;
+  void setAuth (OpcUaAuth *auth);
+
+  /** @brief Discover endpoints, pick the most secure, connect. */
+  Q_INVOKABLE void connectToServer ();
+  /** @brief Connect directly without endpoint discovery. */
+  Q_INVOKABLE void connectDirect (SecurityPolicy policy, SecurityMode mode);
+  Q_INVOKABLE void disconnectFromServer ();
+
+  /** @brief Accept the pending server certificate. */
+  Q_INVOKABLE void acceptCertificate ();
+  /** @brief Reject the pending server certificate. */
+  Q_INVOKABLE void rejectCertificate ();
+
+  /* -- Discovery -- */
+
+  QString discoveryUrl () const;
+  void setDiscoveryUrl (const QString &url);
+
+  bool discovering () const;
+
+  const QList<QOpcUaApplicationDescription> &discoveredServers () const;
+  QVariantList servers () const;
+
+  Q_INVOKABLE void startDiscovery ();
+  Q_INVOKABLE void stopDiscovery ();
+
+  /* -- PKI -- */
+
+  QString pkiDir () const;
+  void setPkiDir (const QString &path);
+
+  QString certFile () const;
+  void setCertFile (const QString &path);
+
+  QString keyFile () const;
+  void setKeyFile (const QString &path);
+
+  /** @brief Auto-detect cert/key from the PKI directory and apply. */
+  Q_INVOKABLE void autoDetectPki ();
+  /** @brief Apply PKI dirs and cert/key. Call before connecting. */
+  Q_INVOKABLE void applyPki ();
+
+  /* -- C++ only -- */
+
+  static OpcUaClient *instance ();
+  QOpcUaClient *opcuaClient () const;
+
+signals:
+  /* -- Connection -- */
+  void connectedChanged ();
+  void serverUrlChanged ();
+  void authChanged ();
+  /**
+   * @brief Emitted when the server presents an untrusted cert.
+   *
+   * The connection blocks until acceptCertificate() or
+   * rejectCertificate() is called (30 s timeout, auto-rejects).
+   */
+  void certificateTrustRequested (const QString &certInfo);
+  void connectionError (const QString &message);
+  void statusMessage (const QString &message);
+
+  /* -- Discovery -- */
+  void discoveryUrlChanged ();
+  void discoveringChanged ();
+  void serversChanged ();
+
+  /* -- PKI -- */
+  void pkiDirChanged ();
+  void certFileChanged ();
+  void keyFileChanged ();
+
+private slots:
+  /* -- Connection -- */
+  void handleStateChanged (QOpcUaClient::ClientState state);
+  void
+  handleEndpointsReceived (const QList<QOpcUaEndpointDescription> &endpoints,
+                           QOpcUa::UaStatusCode statusCode,
+                           const QUrl &requestUrl);
+  void handleConnectError (QOpcUaErrorState *errorState);
+  void handleClientError (QOpcUaClient::ClientError error);
+
+  /* -- Discovery -- */
+  void handleFindServersFinished (
+      const QList<QOpcUaApplicationDescription> &servers,
+      QOpcUa::UaStatusCode statusCode, const QUrl &requestUrl);
+  void doDiscovery ();
+
+private:
+  void setupClient ();
+
+  /* -- Connection -- */
+  QOpcUaProvider *m_provider = nullptr;
+  QOpcUaClient *m_client = nullptr;
+  OpcUaAuth *m_auth = nullptr;
+  QString m_serverUrl;
+  bool m_connected = false;
+  QEventLoop *m_certLoop = nullptr;
+  bool m_certAccepted = false;
+
+  /* -- Discovery -- */
+  QString m_discoveryUrl;
+  QTimer m_discoveryTimer;
+  bool m_discovering = false;
+  QList<QOpcUaApplicationDescription> m_discoveredServers;
+  QVariantList m_serversCache;
+
+  /* -- PKI -- */
+  QString m_pkiDir;
+  QString m_certFile;
+  QString m_keyFile;
+
+  static inline OpcUaClient *s_instance = nullptr;
+};
+
+#endif // OPCUACLIENT_H