last ...

Providers/XBaseFileProvider.cs

@@ -307,8 +307,8 @@ namespace xFileService.Providers
 
             //
             // Retrieve Last Index ...
-            var referencesCount = await CountReferences(providedForId);
+            var maxIndex = (await GetReferencingIndexes(providedForId)).Max();
-            if (forIndex > referencesCount - 1)
+            if (forIndex > maxIndex)
             {
                 XException.NotFound.Throw();
             }
@@ -393,6 +393,7 @@ namespace xFileService.Providers
                 .AsQueryable()
                 .Where(te => te.References.Contains(identifier))
                 .Select(te => te.References)
+                .ToList()
                 .SelectMany(tr => tr.ParseXReferenceList<TKey>())
                 .Where(tr => tr.ProvidedFor == Provider && $"{tr.ReferencedTo}" == $"{providedForId}")
                 .OrderBy(tr => tr.Index)
@@ -631,10 +632,12 @@ namespace xFileService.Providers
         {
             //
             // Validate ...
-            if (model.IsNull() ||
+            var result =
-                providedForId.IsNull() ||
+                !model.Id.IsNull() &&
-                model.Id.IsNull() ||
+                !providedForId.IsNull() &&
-                model.Id.IsDefaultGuid())
+                !model.IsNullOrDefault() &&
+                !model.Id.IsDefaultGuid();
+            if (!result)
             {
                 XException.InvalidArgs.Throw();
             }
@@ -648,30 +651,98 @@ namespace xFileService.Providers
             }
 
             //
-            // Check Model Reference to ID ...
+            // Reading Referencing Indexes ...
-            var isReferenced = model.References
+            var indexes = await GetReferencingIndexes(providedForId);
-                .Any(r => r.ProvidedFor == Provider &&
-                r.ReferencedTo == $"{providedForId}");
 
             //
-            var result = false;
+            // Check Model Reference to ID ...
-            if (isReferenced)
+            var referencesCount = await CountReferences(providedForId);
+            result = referencesCount == 0;
+            if (result)
             {
                 //
-                model.References = model.References
+                // There is not any Reference to Remove ...
-                    .Where(r => r.ProvidedFor != Provider ||
+                return result;
-                        (r.ProvidedFor == Provider &&
+            }
-                        r.ReferencedTo != $"{providedForId}"))
-                    .ToList();
 
+            //
+            // Check Model is Trully Referenced to ProvidedForId or not ...
+            var reference = model.References
+                .FirstOrDefault(r => r.ProvidedFor == Provider &&
+                r.ReferencedTo == $"{providedForId}");
+            result = !model.IsNullOrDefault();
+            if (!result)
+            {
+                XException.ActionFailed.Throw();
+            }
+
+            //
+            // Remove Referenced Item from Model ...
+            model.References = model.References
+                .Where(r => !(r.ProvidedFor == Provider &&
+                r.ReferencedTo == $"{providedForId}"))
+                .ToList();
+
+            //
+            // Update DataBase ...
+            model = await FileProvider.Update(
+                id: model.Id,
+                item: model,
+                userInfo: userInfo,
+                connectionId: connectionId
+            );
+
+            //
+            result = !model.IsNullOrDefault();
+            if (!result)
+            {
+                XException.ActionFailed.Throw();
+            }
+
+            //
+            // Get Max Exists Indexes ...
+            var maxIndex = indexes.Max();
+
+            //
+            // Here We Have to Re Arrange Indexed ...
+            if (reference.Index < maxIndex)
+            {
                 //
-                model = await FileProvider.Update(
+                var startIndex = reference.Index + 1;
-                    item: model,
+                for (int i = startIndex; i <= maxIndex; i++)
-                    id: model.Id,
+                {
-                    userInfo: userInfo,
+                    //
-                    connectionId: connectionId
+                    var dto = await GetReference(
-                );
+                        forIndex: i,
-                result = !model.IsNullOrDefault();
+                        providedForId: providedForId
+                    );
+                    if (!dto.IsNullOrDefault())
+                    {
+                        //
+                        dto.References
+                        .ToList()
+                        .ForEach(iref =>
+                        {
+                            //
+                            if (
+                                iref.Index == i &&
+                                iref.ProvidedFor == Provider &&
+                                iref.ReferencedTo == reference.ReferencedTo
+                            )
+                            {
+                                iref.Index = i - 1;
+                            }
+                        });
+
+                        //
+                        dto = await FileProvider.Update(
+                            item: dto,
+                            id: dto.Id,
+                            userInfo: userInfo,
+                            connectionId: connectionId
+                        );
+                    }
+                }
             }
 
             //