[fix:] csv-import now recognizes quotation marks

Tasks/DataImport.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Reflection;
+using System.Text;
 
 namespace Logof_Client;
 
@@ -41,7 +42,7 @@ public class DataImport
             if (string.IsNullOrWhiteSpace(line))
                 continue;
 
-            var parts = line.Split(separator).Select(p => p.Trim()).ToArray();
+            var parts = ParseCsvLine(line, separator);
 
             if (parts.Length < 24)
             {
@@ -107,7 +108,7 @@ public class DataImport
             return (false, null);
         }
 
-        var headers = headerLine.Split(separator).Select(h => h.Trim()).ToArray();
+        var headers = ParseCsvLine(headerLine, separator);
 
         var imported =
             new KasAddressList(KasAddressList.GenerateName(Path.GetFileNameWithoutExtension(pathToCsv.LocalPath)));
@@ -126,7 +127,7 @@ public class DataImport
             if (string.IsNullOrWhiteSpace(line))
                 continue;
 
-            var parts = line.Split(separator).Select(p => p.Trim()).ToArray();
+            var parts = ParseCsvLine(line, separator);
 
             var fieldValues = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
 
@@ -241,4 +242,41 @@ public class DataImport
     {
         return int.TryParse(input, out var result) ? result : 0;
     }
-}
+
+    private static string[] ParseCsvLine(string line, char separator)
+    {
+        var fields = new List<string>();
+        var current = new StringBuilder();
+        var inQuotes = false;
+
+        for (var i = 0; i < line.Length; i++)
+        {
+            var c = line[i];
+
+            if (c == '"')
+            {
+                if (inQuotes && i + 1 < line.Length && line[i + 1] == '"')
+                {
+                    current.Append('"');
+                    i++;
+                    continue;
+                }
+
+                inQuotes = !inQuotes;
+                continue;
+            }
+
+            if (c == separator && !inQuotes)
+            {
+                fields.Add(current.ToString().Trim());
+                current.Clear();
+                continue;
+            }
+
+            current.Append(c);
+        }
+
+        fields.Add(current.ToString().Trim());
+        return fields.ToArray();
+    }
+}