From df2c9ff93177b830278b9541065dcfb64602033b Mon Sep 17 00:00:00 2001
From: Maxim Rylov <maxim.rylov@sap.com>
Date: Thu, 14 Jan 2021 09:47:56 +0100
Subject: [PATCH] More detailed warnings when HANA driver not found

---
 src/providers/hana/qgshanadriver.cpp        | 28 ++++++++++++---
 src/providers/hana/qgshanadriver.h          |  2 ++
 src/providers/hana/qgshananewconnection.cpp | 39 +++++++++++++++++++--
 3 files changed, 62 insertions(+), 7 deletions(-)

diff --git a/src/providers/hana/qgshanadriver.cpp b/src/providers/hana/qgshanadriver.cpp
index 3b264c02c2a0..21255a4774f2 100644
--- a/src/providers/hana/qgshanadriver.cpp
+++ b/src/providers/hana/qgshanadriver.cpp
@@ -19,6 +19,7 @@
 
 #include <QDir>
 #include <QFileInfo>
+#include <QLibrary>
 
 #include "odbc/Connection.h"
 #include "odbc/Environment.h"
@@ -69,18 +70,37 @@ QgsHanaDriver::~QgsHanaDriver()
   QgsDebugCall;
 }
 
+ConnectionRef QgsHanaDriver::createConnection()
+{
+  return mEnv->createConnection();
+}
+
+const QString &QgsHanaDriver::driver() const
+{
+  return mDriver;
+}
+
 QgsHanaDriver *QgsHanaDriver::instance()
 {
   static QgsHanaDriver instance;
   return &instance;
 }
 
-ConnectionRef QgsHanaDriver::createConnection()
+bool QgsHanaDriver::isInstalled( const QString &name )
 {
-  return mEnv->createConnection();
+  EnvironmentRef env = Environment::create();
+  return env->isDriverInstalled( name.toStdString().c_str() );
 }
 
-const QString &QgsHanaDriver::driver() const
+bool QgsHanaDriver::isValidPath( const QString &path )
 {
-  return mDriver;
+  if ( !QLibrary::isLibrary( path ) )
+    return false;
+
+  QLibrary lib( path );
+  if ( !lib.load() )
+    return false;
+  bool ret = lib.resolve( "SQLConnect" ) != nullptr;
+  lib.unload();
+  return ret;
 }
diff --git a/src/providers/hana/qgshanadriver.h b/src/providers/hana/qgshanadriver.h
index ea216a24d9f3..3047b259027e 100644
--- a/src/providers/hana/qgshanadriver.h
+++ b/src/providers/hana/qgshanadriver.h
@@ -32,6 +32,8 @@ class QgsHanaDriver
     const QString &driver() const;
 
     static QgsHanaDriver *instance();
+    static bool isInstalled( const QString &name );
+    static bool isValidPath( const QString &path );
 
   protected:
     Q_DISABLE_COPY( QgsHanaDriver )
diff --git a/src/providers/hana/qgshananewconnection.cpp b/src/providers/hana/qgshananewconnection.cpp
index 4a5aedf454e3..ac4dc1395e96 100644
--- a/src/providers/hana/qgshananewconnection.cpp
+++ b/src/providers/hana/qgshananewconnection.cpp
@@ -21,6 +21,7 @@
 #include "qgshanasettings.h"
 #include "qgssettings.h"
 
+#include <QFileInfo>
 #include <QInputDialog>
 #include <QMessageBox>
 
@@ -56,6 +57,17 @@ QgsHanaNewConnection::QgsHanaNewConnection(
   connect( buttonBox, &QDialogButtonBox::helpRequested, this, &QgsHanaNewConnection::showHelp );
 
   txtDriver->setText( QgsHanaDriver::instance()->driver() );
+#if defined(Q_OS_WIN)
+  txtDriver->setToolTip( tr( "The name of the HANA ODBC driver.\r\n\r\n"
+                             "The HANA ODBC driver is a part of the SAP HANA Client,\r\n"
+                             "which can be found at https://tools.hana.ondemand.com/#hanatools." ) );
+#else
+  txtDriver->setToolTip( tr( "The name or path to the HANA ODBC driver.\r\n\r\n"
+                             "If the driver is registered in odbcinst.ini, enter the driver's name.\r\n"
+                             "Otherwise, enter the path to the driver (libodbcHDB.so).\r\n\r\n"
+                             "The HANA ODBC driver is a part of the SAP HANA Client,\r\n"
+                             "which can be found at https://tools.hana.ondemand.com/#hanatools." ) );
+#endif
 
   cbxCryptoProvider->addItem( QStringLiteral( "openssl" ), QStringLiteral( "openssl" ) );
   cbxCryptoProvider->addItem( QStringLiteral( "commoncrypto" ), QStringLiteral( "commoncrypto" ) );
@@ -296,9 +308,7 @@ void QgsHanaNewConnection::updateControlsFromSettings( const QgsHanaSettings &se
 void QgsHanaNewConnection::testConnection()
 {
   QString warningMsg;
-  if ( txtDriver->text().isEmpty() )
-    warningMsg = tr( "Driver name has not been specified." );
-  else if ( txtHost->text().isEmpty() )
+  if ( txtHost->text().isEmpty() )
     warningMsg = tr( "Host name has not been specified." );
   else if ( rbtnMultipleContainers->isChecked() && rbtnTenantDatabase->isChecked() &&
             txtTenantDatabaseName->text().isEmpty() )
@@ -309,6 +319,29 @@ void QgsHanaNewConnection::testConnection()
     warningMsg = tr( "Password has not been specified." );
   else if ( txtIdentifier->text().isEmpty() )
     warningMsg = tr( "Identifier has not been specified." );
+  else
+  {
+    QString driver = txtDriver->text();
+    if ( driver.isEmpty() )
+      warningMsg = tr( "Driver name/path has not been specified." );
+    else
+    {
+      if ( !QgsHanaDriver::isInstalled( driver ) )
+      {
+#if defined(Q_OS_WIN)
+        warningMsg = tr( "Driver with name '%1' is not installed." ).arg( driver );
+#else
+        if ( !QgsHanaDriver::isValidPath( driver ) )
+        {
+          if ( QFileInfo::exists( driver ) )
+            warningMsg = tr( "Specified driver '%1' cannot be used to connect to HANA." ).arg( driver );
+          else
+            warningMsg = tr( "Driver with name/path '%1' was not found." ).arg( driver );
+        }
+#endif
+      }
+    }
+  }
 
   if ( !warningMsg.isEmpty() )
   {