1 files changed, 56 insertions, 0 deletions
diff --git a/app/services/draft_notes/create_service.rb b/app/services/draft_notes/create_service.rb
new file mode 100644
index 00000000000..501778b7d5f
--- /dev/null
+++ b/app/services/draft_notes/create_service.rb
@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+module DraftNotes
+  class CreateService < DraftNotes::BaseService
+    attr_accessor :in_draft_mode, :in_reply_to_discussion_id
+
+    def initialize(merge_request, current_user, params = nil)
+      @in_reply_to_discussion_id = params.delete(:in_reply_to_discussion_id)
+      super
+    end
+
+    def execute
+      if in_reply_to_discussion_id.present?
+        unless discussion
+          return base_error(_('Thread to reply to cannot be found'))
+        end
+
+        params[:discussion_id] = discussion.reply_id
+      end
+
+      if params[:resolve_discussion] && !can_resolve_discussion?
+        return base_error(_('User is not allowed to resolve thread'))
+      end
+
+      draft_note = DraftNote.new(params)
+      draft_note.merge_request = merge_request
+      draft_note.author = current_user
+      draft_note.save
+
+      if in_reply_to_discussion_id.blank? && draft_note.diff_file&.unfolded?
+        merge_request.diffs.clear_cache
+      end
+
+      draft_note
+    end
+
+    private
+
+    def base_error(text)
+      DraftNote.new.tap do |draft|
+        draft.errors.add(:base, text)
+      end
+    end
+
+    def discussion
+      @discussion ||= merge_request.notes.find_discussion(in_reply_to_discussion_id)
+    end
+
+    def can_resolve_discussion?
+      note = discussion&.notes&.first
+      return false unless note
+
+      current_user && Ability.allowed?(current_user, :resolve_note, note)
+    end
+  end
+end