Refine NTFS group name shortening

LiamNtfs/C4IT_IAM_SET/Helper.cs

@@ -13,6 +13,9 @@ namespace C4IT_IAM_Engine
     {
         public const int MaxAdGroupNameLength = 64;
         public const int MaxAdGroupLoopDigits = 3;
+        private const int MinLeadingRelativePathSegmentLength = 3;
+        private const int MinSingleLeadingRelativePathSegmentLength = 2;
+        private const int MinLastRelativePathSegmentLength = 12;
 
         public sealed class BoundedTemplateContext
         {
@@ -75,13 +78,13 @@ namespace C4IT_IAM_Engine
         {
             var effectiveSegments = (sanitizedSegments ?? Array.Empty<string>()).Where(i => i != null).ToArray();
             var effectiveFolderName = folderName ?? string.Empty;
-            var availableLength = Math.Max(1, maxLength - GetLoopReservationLength(templateValue));
             var originalValue = MaterializeTemplateValue(templateValue, allowRelativePath, defaultRelativePath, effectiveSegments, effectiveFolderName, replacementTags);
+            var measuredValue = MaterializeTemplateValueForLength(templateValue, allowRelativePath, defaultRelativePath, effectiveSegments, effectiveFolderName, replacementTags);
             var usesRelativePath = allowRelativePath && Regex.IsMatch(templateValue ?? string.Empty, @"{{\s*RELATIVEPATH", RegexOptions.IgnoreCase);
             var usesName = Regex.IsMatch(templateValue ?? string.Empty, @"{{\s*NAME\s*}}", RegexOptions.IgnoreCase);
             var strategy = string.Empty;
 
-            while (originalValue.Length > availableLength)
+            while (measuredValue.Length > maxLength)
             {
                 var changed = false;
 
@@ -103,18 +106,17 @@ namespace C4IT_IAM_Engine
                     break;
 
                 originalValue = MaterializeTemplateValue(templateValue, allowRelativePath, defaultRelativePath, effectiveSegments, effectiveFolderName, replacementTags);
+                measuredValue = MaterializeTemplateValueForLength(templateValue, allowRelativePath, defaultRelativePath, effectiveSegments, effectiveFolderName, replacementTags);
             }
 
+            var initialValue = MaterializeTemplateValue(templateValue, allowRelativePath, defaultRelativePath, sanitizedSegments, folderName, replacementTags);
             var result = new BoundedTemplateContext
             {
                 SanitizedSegments = effectiveSegments,
                 FolderName = effectiveSegments.Length > 0 ? effectiveSegments[effectiveSegments.Length - 1] : effectiveFolderName,
-                OriginalValue = MaterializeTemplateValue(templateValue, allowRelativePath, defaultRelativePath, sanitizedSegments, folderName, replacementTags),
+                OriginalValue = initialValue,
                 FinalValue = originalValue,
-                WasShortened = !string.Equals(
+                WasShortened = !string.Equals(initialValue, originalValue, StringComparison.Ordinal),
-                    MaterializeTemplateValue(templateValue, allowRelativePath, defaultRelativePath, sanitizedSegments, folderName, replacementTags),
-                    originalValue,
-                    StringComparison.Ordinal),
                 Strategy = strategy
             };
 
@@ -122,14 +124,14 @@ namespace C4IT_IAM_Engine
             {
                 cLogManager.DefaultLogger.LogEntry(
                     LogLevels.Warning,
-                    $"AD-Gruppenname gekuerzt ({logContext}): '{result.OriginalValue}' ({result.OriginalValue.Length}) -> '{result.FinalValue}' ({result.FinalValue.Length}), Strategie: {result.Strategy}, Limit: {availableLength}.");
+                    $"AD-Gruppenname gekuerzt ({logContext}): '{result.OriginalValue}' ({GetMeasuredTemplateLength(result.OriginalValue)}) -> '{result.FinalValue}' ({GetMeasuredTemplateLength(result.FinalValue)}), Strategie: {result.Strategy}, Limit: {maxLength}.");
             }
 
-            if (result.FinalValue.Length > availableLength)
+            if (measuredValue.Length > maxLength)
             {
                 cLogManager.DefaultLogger.LogEntry(
                     LogLevels.Warning,
-                    $"AD-Gruppenname ueberschreitet weiterhin das sichere Limit ({logContext}): '{result.FinalValue}' ({result.FinalValue.Length}), Limit: {availableLength}.");
+                    $"AD-Gruppenname ueberschreitet weiterhin das sichere Limit ({logContext}): '{result.FinalValue}' ({measuredValue.Length}), Limit: {maxLength}.");
             }
 
             return result;
@@ -176,6 +178,35 @@ namespace C4IT_IAM_Engine
                 .ToUpper();
         }
 
+        private static string MaterializeTemplateValueForLength(
+            string templateValue,
+            bool allowRelativePath,
+            string defaultRelativePath,
+            string[] sanitizedSegments,
+            string folderName,
+            IDictionary<string, string> replacementTags)
+        {
+            return NormalizeLoopPlaceholderLength(
+                MaterializeTemplateValue(templateValue, allowRelativePath, defaultRelativePath, sanitizedSegments, folderName, replacementTags));
+        }
+
+        private static string NormalizeLoopPlaceholderLength(string templateValue)
+        {
+            if (string.IsNullOrWhiteSpace(templateValue))
+                return templateValue ?? string.Empty;
+
+            return Regex.Replace(
+                templateValue,
+                @"{{(?<prefix>[^}]*)(?<loop>LOOP)(?<postfix>[^{]*)}}",
+                match => match.Groups["prefix"].Value + new string('9', MaxAdGroupLoopDigits) + match.Groups["postfix"].Value,
+                RegexOptions.IgnoreCase);
+        }
+
+        private static int GetMeasuredTemplateLength(string templateValue)
+        {
+            return NormalizeLoopPlaceholderLength(templateValue).Length;
+        }
+
         private static int GetLoopReservationLength(string templateValue)
         {
             if (string.IsNullOrWhiteSpace(templateValue))
@@ -196,8 +227,10 @@ namespace C4IT_IAM_Engine
                 return false;
 
             var lastIndex = segments.Length - 1;
+            if (segments.Length > 2)
+            {
                 var candidateIndex = -1;
-            var candidateLength = 1;
+                var candidateLength = MinLeadingRelativePathSegmentLength;
 
                 for (var i = 0; i < lastIndex; i++)
                 {
@@ -214,12 +247,39 @@ namespace C4IT_IAM_Engine
                     return true;
                 }
 
-            if (segments.Length > 1)
-            {
                 segments = segments.Skip(1).ToArray();
                 return true;
             }
 
+            if (segments.Length == 2)
+            {
+                if (segments[0].Length > MinSingleLeadingRelativePathSegmentLength)
+                {
+                    segments[0] = segments[0].Substring(0, segments[0].Length - 1);
+                    return true;
+                }
+
+                if (segments[lastIndex].Length > MinLastRelativePathSegmentLength)
+                {
+                    segments[lastIndex] = segments[lastIndex].Substring(0, segments[lastIndex].Length - 1);
+                    return true;
+                }
+
+                if (segments[0].Length > 1)
+                {
+                    segments[0] = segments[0].Substring(0, segments[0].Length - 1);
+                    return true;
+                }
+
+                if (segments[lastIndex].Length > 1)
+                {
+                    segments[lastIndex] = segments[lastIndex].Substring(0, segments[lastIndex].Length - 1);
+                    return true;
+                }
+
+                return false;
+            }
+
             if (segments[lastIndex].Length > 1)
             {
                 segments[lastIndex] = segments[lastIndex].Substring(0, segments[lastIndex].Length - 1);