#399

backend/app/services/post_create_plan.rb

@@ -12,6 +12,7 @@ class PostCreatePlan
     direct_tag_specs, tag_sections = parse_direct_tag_specs
     default_tag_specs = build_default_tag_specs(direct_tag_specs)
     snapshot_tag_specs = merge_tag_specs(direct_tag_specs + default_tag_specs)
+    preload_existing_tags_by_name!(snapshot_tag_specs.map { _1[:name] })
     validate_new_tag_specs!(snapshot_tag_specs)
     post_tag_specs = expand_parent_tag_specs(snapshot_tag_specs)
     video_ms = normalise_video_ms(snapshot_tag_specs)
@@ -161,6 +162,17 @@ class PostCreatePlan
     end
   end
 
+  def preload_existing_tags_by_name! names
+    wanted_names = Array(names).map { _1.to_s }.reject(&:blank?).uniq
+    missing_names = wanted_names - existing_tags_by_name.keys
+    return if missing_names.empty?
+
+    existing_tags_by_name.merge!(
+        Tag.joins(:tag_name)
+           .where(tag_names: { name: missing_names })
+           .index_by(&:name))
+  end
+
   def canonical_tag_name_without_sections raw_name
     name, = parse_raw_tag_name(raw_name)
     name