fixes bug for showing tree view of categories

Diligent.WebAPI.Business/Services/CategoryService.cs

 
         private async Task<List<Category>> getCategoriesUserCanSee(int userId)
         {
-            var k = await _context.UserCategories.Include(c => c.Category).ToListAsync();
+            var k = await _context.UserCategories.Include(c => c.Category).ThenInclude(p => p.ParentCategory).Where(t => t.UserId == userId).ToListAsync();
             List<Category> t = new();
             foreach (var m in k)
             {
-                if(m.UserId == userId)
+                Category category = m.Category;
+                while (true)
                 {
-                    t.Add(m.Category);
+                    bool s = false;
+                    for (int i = 0; i < k.Count; i++)
+                    {
+                        if(category.Id == k[i].CategoryId)
+                        {
+                            s = true;
+                            break;
+                        }
+                    }
+                    if (s && category.ParentCategory is null)
+                    {
+                        t.Add(m.Category);
+                        break;
+                    }
+                    else if(!s && category.ParentCategory is null)
+                    {
+                        break;
+                    }
+                    else if(s == true)
+                    {
+                        category = category.ParentCategory;
+                        continue;
+                    }
+                    else
+                    {
+                        break;
+                    }
                 }
+ 
             }
+            
             return t;
         }
-
         private List<TreeViewCategoryResponse> GetTreeCategoryItem(List<Category> items, int id)
         {
             List<TreeViewCategoryResponse> response = new();