Refactor BobinkClient and clean up comments

- Format BobinkAuth.cpp to match GNU style used elsewhere
- Replace brittle error name array with QMetaEnum in BobinkClient
- Move QOpcUaPkiConfiguration include from header to .cpp
- Replace m_discoveryInterval member with file-scope constant
- Add doc comments to SecurityMode and SecurityPolicy enums
- Comment endpoint selection strategy in handleEndpointsReceived
- Add missing QML ids to connectionPage and serverListView

4 files changed, 84 insertions, 63 deletions

diff --git a/demo/Main.qml b/demo/Main.qml
index dae415f..9d3e168 100644
--- a/demo/Main.qml
+++ b/demo/Main.qml
@@ -76,6 +76,7 @@ ApplicationWindow {
             Layout.fillHeight: true
 
             initialItem: Page {
+                id: connectionPage
                 Component.onCompleted: {
                     Bobink.discoveryUrl = discoveryUrlField.text;
                     Bobink.startDiscovery();
@@ -146,6 +147,7 @@ ApplicationWindow {
                     }
 
                     ListView {
+                        id: serverListView
                         Layout.fillWidth: true
                         Layout.preferredHeight: 100
                         clip: true
diff --git a/src/BobinkAuth.cpp b/src/BobinkAuth.cpp
index 03ae2cf..132e4be 100644
--- a/src/BobinkAuth.cpp
+++ b/src/BobinkAuth.cpp
@@ -4,74 +4,98 @@
  */
 #include "BobinkAuth.h"
 
-BobinkAuth::BobinkAuth(QObject *parent)
-    : QObject(parent)
+BobinkAuth::BobinkAuth (QObject *parent) : QObject (parent) {}
+
+BobinkAuth::AuthMode
+BobinkAuth::mode () const
 {
+  return m_mode;
 }
 
-BobinkAuth::AuthMode BobinkAuth::mode() const { return m_mode; }
-
-void BobinkAuth::setMode(AuthMode mode)
+void
+BobinkAuth::setMode (AuthMode mode)
 {
-    if (m_mode == mode)
-        return;
-    m_mode = mode;
-    emit modeChanged();
+  if (m_mode == mode)
+    return;
+  m_mode = mode;
+  emit modeChanged ();
 }
 
-QString BobinkAuth::username() const { return m_username; }
+QString
+BobinkAuth::username () const
+{
+  return m_username;
+}
 
-void BobinkAuth::setUsername(const QString &username)
+void
+BobinkAuth::setUsername (const QString &username)
 {
-    if (m_username == username)
-        return;
-    m_username = username;
-    emit usernameChanged();
+  if (m_username == username)
+    return;
+  m_username = username;
+  emit usernameChanged ();
 }
 
-QString BobinkAuth::password() const { return m_password; }
+QString
+BobinkAuth::password () const
+{
+  return m_password;
+}
 
-void BobinkAuth::setPassword(const QString &password)
+void
+BobinkAuth::setPassword (const QString &password)
 {
-    if (m_password == password)
-        return;
-    m_password = password;
-    emit passwordChanged();
+  if (m_password == password)
+    return;
+  m_password = password;
+  emit passwordChanged ();
 }
 
-QString BobinkAuth::certPath() const { return m_certPath; }
+QString
+BobinkAuth::certPath () const
+{
+  return m_certPath;
+}
 
-void BobinkAuth::setCertPath(const QString &path)
+void
+BobinkAuth::setCertPath (const QString &path)
 {
-    if (m_certPath == path)
-        return;
-    m_certPath = path;
-    emit certPathChanged();
+  if (m_certPath == path)
+    return;
+  m_certPath = path;
+  emit certPathChanged ();
 }
 
-QString BobinkAuth::keyPath() const { return m_keyPath; }
+QString
+BobinkAuth::keyPath () const
+{
+  return m_keyPath;
+}
 
-void BobinkAuth::setKeyPath(const QString &path)
+void
+BobinkAuth::setKeyPath (const QString &path)
 {
-    if (m_keyPath == path)
-        return;
-    m_keyPath = path;
-    emit keyPathChanged();
+  if (m_keyPath == path)
+    return;
+  m_keyPath = path;
+  emit keyPathChanged ();
 }
 
-QOpcUaAuthenticationInformation BobinkAuth::toAuthenticationInformation() const
+QOpcUaAuthenticationInformation
+BobinkAuth::toAuthenticationInformation () const
 {
-    QOpcUaAuthenticationInformation info;
-    switch (m_mode) {
+  QOpcUaAuthenticationInformation info;
+  switch (m_mode)
+    {
     case Anonymous:
-        info.setAnonymousAuthentication();
-        break;
+      info.setAnonymousAuthentication ();
+      break;
     case UserPass:
-        info.setUsernameAuthentication(m_username, m_password);
-        break;
+      info.setUsernameAuthentication (m_username, m_password);
+      break;
     case Certificate:
-        info.setCertificateAuthentication(m_certPath, m_keyPath);
-        break;
+      info.setCertificateAuthentication (m_certPath, m_keyPath);
+      break;
     }
-    return info;
+  return info;
 }
diff --git a/src/BobinkClient.cpp b/src/BobinkClient.cpp
index 6d1c608..7355a0c 100644
--- a/src/BobinkClient.cpp
+++ b/src/BobinkClient.cpp
@@ -6,11 +6,15 @@
 #include "BobinkAuth.h"
 
 #include <QDir>
+#include <QMetaEnum>
+#include <QOpcUaPkiConfiguration>
 #include <QOpcUaUserTokenPolicy>
 #include <QStandardPaths>
 
 using namespace Qt::Literals::StringLiterals;
 
+static constexpr qint32 DISCOVERY_INTERVAL = 30000; // ms
+
 static QString
 defaultPkiDir ()
 {
@@ -87,23 +91,13 @@ BobinkClient::setupClient ()
   connect (m_client, &QOpcUaClient::errorChanged, this,
            [this] (QOpcUaClient::ClientError error)
              {
-               static const QLatin1StringView names[] = {
-                 "NoError"_L1,
-                 "InvalidUrl"_L1,
-                 "AccessDenied"_L1,
-                 "ConnectionError"_L1,
-                 "UnknownError"_L1,
-                 "UnsupportedAuthenticationInformation"_L1,
-                 "InvalidAuthenticationInformation"_L1,
-                 "InvalidEndpointDescription"_L1,
-                 "NoMatchingUserIdentityTokenFound"_L1,
-                 "UnsupportedSecurityPolicy"_L1,
-                 "InvalidPki"_L1,
-               };
-               qint32 idx = static_cast<qint32> (error);
-               if (idx > 0 && idx <= 10)
-                 emit connectionError (
-                     QStringLiteral ("Client error: %1").arg (names[idx]));
+               if (error == QOpcUaClient::NoError)
+                 return;
+               auto me = QMetaEnum::fromType<QOpcUaClient::ClientError> ();
+               const char *key = me.valueToKey (static_cast<int> (error));
+               emit connectionError (
+                   QStringLiteral ("Client error: %1")
+                       .arg (key ? QLatin1StringView (key) : "Unknown"_L1));
              });
 }
 
@@ -290,6 +284,7 @@ BobinkClient::handleEndpointsReceived (
       return;
     }
 
+  // Pick the endpoint with the highest securityLevel (server-assigned score).
   QOpcUaEndpointDescription best = endpoints.first ();
   for (const auto &ep : endpoints)
     {
@@ -381,7 +376,7 @@ BobinkClient::startDiscovery ()
     return;
 
   doDiscovery ();
-  m_discoveryTimer.start (m_discoveryInterval);
+  m_discoveryTimer.start (DISCOVERY_INTERVAL);
 
   if (!m_discovering)
     {
diff --git a/src/BobinkClient.h b/src/BobinkClient.h
index 2b41e05..c566a67 100644
--- a/src/BobinkClient.h
+++ b/src/BobinkClient.h
@@ -15,7 +15,6 @@
 #include <QOpcUaClient>
 #include <QOpcUaEndpointDescription>
 #include <QOpcUaErrorState>
-#include <QOpcUaPkiConfiguration>
 #include <QOpcUaProvider>
 #include <QQmlEngine>
 #include <QTimer>
@@ -48,6 +47,7 @@ class BobinkClient : public QObject
       QString keyFile READ keyFile WRITE setKeyFile NOTIFY keyFileChanged)
 
 public:
+  /// OPC UA message security mode (values match MessageSecurityMode).
   enum SecurityMode
   {
     SignAndEncrypt = 3,
@@ -56,6 +56,7 @@ public:
   };
   Q_ENUM (SecurityMode)
 
+  /// OPC UA security policy for encryption algorithms.
   enum SecurityPolicy
   {
     Basic256Sha256,
@@ -175,7 +176,6 @@ private:
 
   /* -- Discovery -- */
   QString m_discoveryUrl;
-  qint32 m_discoveryInterval = 30000; // ms
   QTimer m_discoveryTimer;
   bool m_discovering = false;
   QList<QOpcUaApplicationDescription> m_discoveredServers;