prefill signature

app/controllers/api/attachments_controller.rb

@@ -1,16 +1,37 @@
 # frozen_string_literal: true
 
 module Api
-  class AttachmentsController < ApiBaseController
-    skip_before_action :authenticate_user!
-    skip_authorization_check
+  class AttachmentsController < ActionController::API
+    include ActionController::Cookies
+    include ActiveStorage::SetCurrent
+
+    COOKIE_STORE_LIMIT = 10
 
     def create
       submitter = Submitter.find_by!(slug: params[:submitter_slug])
 
       attachment = Submitters.create_attachment!(submitter, params)
 
+      if params[:remember_signature] == 'true' && submitter.email.present?
+        cookies.encrypted[:signature_uuids] = build_new_cookie_signatures_json(submitter, attachment)
+      end
+
       render json: attachment.as_json(only: %i[uuid], methods: %i[url filename content_type])
     end
+
+    def build_new_cookie_signatures_json(submitter, attachment)
+      values =
+        begin
+          JSON.parse(cookies.encrypted[:signature_uuids].presence || '{}')
+        rescue JSON::ParserError
+          {}
+        end
+
+      values[submitter.email] = attachment.uuid
+
+      values = values.to_a.last(COOKIE_STORE_LIMIT).to_h if values.size > COOKIE_STORE_LIMIT
+
+      values.to_json
+    end
   end
 end