add separator guessing for CSV parsing

GUI/coregui/DataLoaders/QREDataLoader.cpp

@@ -502,8 +502,61 @@ bool QREDataLoader::fillImportDetailsTable(QTableWidget* table, bool fileContent
 
 void QREDataLoader::guessSettings(const QString& filename)
 {
-    // #baimport implement estimateSettings (separator)
-    // search for lines which have start with numbers, then try the separators
+    // search for lines which start with a number, then try the separators
+
+    QFile file(filename);
+    if (!file.open(QFile::ReadOnly | QIODevice::Text))
+        return; // silent fail
+
+    QTextStream in(&file);
+    int lineNr = 0;
+    const int maxLinesToExamine = 100;
+    while (!in.atEnd() && lineNr < maxLinesToExamine) {
+        lineNr++;
+        QString line = in.readLine().trimmed();
+        if (line.isEmpty())
+            continue;
+        if (!line[0].isNumber())
+            continue;
+
+        // line starts with a number => search gap after it
+        int startOfGap = 1;
+        while (startOfGap < line.size() && line[startOfGap].isNumber())
+            startOfGap++;
+
+        if (startOfGap == line.size())
+            continue;
+
+        int endOfGap = startOfGap;
+        while (endOfGap < line.size() && !line[endOfGap].isNumber()) {
+            endOfGap++;
+        }
+
+        QStringRef gapContent(&line, startOfGap, endOfGap - startOfGap + 1);
+        if (gapContent.isEmpty())
+            continue;
+
+        if (gapContent.contains("\t")) {
+            m_importSettings.separator = "\t";
+            return;
+        }
+
+        gapContent = gapContent.trimmed();
+        if (gapContent.isEmpty()) {
+            m_importSettings.separator = " ";
+            return;
+        }
+
+        if (gapContent.contains(";")) {
+            m_importSettings.separator = ";";
+            return;
+        }
+
+        if (gapContent.contains(",")) {
+            m_importSettings.separator = ",";
+            return;
+        }
+    }
 }
 
 void QREDataLoader::parseFile(QString& fileContent) const