1 files changed, 32 insertions, 3 deletions
diff --git a/Services/TagService.cs b/Services/TagService.cs
index 2648bb3..a3c4b29 100644
--- a/Services/TagService.cs
+++ b/Services/TagService.cs
@@ -126,14 +126,29 @@ public class TagService : ITagService {
     public void CreateTagDefinition(string name, string? @namespace = null, string? alias = null) {
         using var db = dbFactory.CreateDbContext();
 
-        TagDefinition tagdef = new() {
+        if(string.IsNullOrEmpty(@namespace))
+            @namespace = null;
+        if(string.IsNullOrEmpty(alias))
+            alias = null;
+
+        TagDefinition tagDef = new() {
             Source    = TagSource.UserTag,
             Namespace = @namespace,
             Name      = name,
             Alias     = alias
         };
-        if(!db.TagDefinitions.Contains(tagdef))
-            db.TagDefinitions.Add(tagdef);
+
+        bool nameExists  = db.TagDefinitions.Any(td => td.Name.ToLower() == name.ToLower());
+        bool aliasExists = false;
+        if(alias is not null)
+            aliasExists = db.TagDefinitions
+                .Where(td => td.Alias != null)
+                .Any(td => td.Alias!.ToLower() == alias.ToLower());
+        if(nameExists || aliasExists)
+            throw new TagDuplicateException(nameExists, aliasExists);
+
+        if(!db.TagDefinitions.Contains(tagDef))
+            db.TagDefinitions.Add(tagDef);
         db.SaveChanges();
     }
 
@@ -162,8 +177,22 @@ public class TagService : ITagService {
 
         if(string.IsNullOrEmpty(@namespace))
             @namespace = null;
+        if(string.IsNullOrEmpty(alias))
+            alias = null;
 
         var tag = db.TagDefinitions.First(td => td.Guid == tagDef);
+
+        TagDefinition? nameExisting = db.TagDefinitions.FirstOrDefault(td => td.Name.ToLower() == name.ToLower());
+        TagDefinition? aliasExisting = null;
+        if(alias is not null)
+            aliasExisting = db.TagDefinitions
+                .Where(td => td.Alias != null)
+                .FirstOrDefault(td => td.Alias!.ToLower() == alias.ToLower());
+        bool nameExists  = nameExisting  is not null && nameExisting  != tag;
+        bool aliasExists = aliasExisting is not null && aliasExisting != tag;
+        if(nameExists || aliasExists)
+            throw new TagDuplicateException(nameExists, aliasExists);
+
         tag.Name      = name;
         tag.Namespace = @namespace;
         tag.Alias     = alias;