prefill signature

lib/submitters/maybe_assign_default_browser_signature.rb

@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+
+module Submitters
+  module MaybeAssignDefaultBrowserSignature
+    SIGNED_UUID_PURPPOSE = 'signature'
+
+    module_function
+
+    def call(submitter, params, cookies = nil, attachments = [])
+      if (value = params[:signature_src].presence || params[:signature].presence)
+        find_or_create_signature_from_value(submitter, value, attachments)
+      elsif params[:signed_signature_uuids].present?
+        find_storage_signature(submitter, params[:signed_signature_uuids], attachments)
+      elsif cookies
+        find_session_signature(submitter, cookies, attachments)
+      end
+    end
+
+    def find_or_create_signature_from_value(submitter, value, attachments)
+      _, attachment = Submitters::NormalizeValues.normalize_attachment_value(value,
+                                                                             'signature',
+                                                                             submitter.account,
+                                                                             attachments,
+                                                                             submitter)
+
+      attachment.record ||= submitter
+
+      attachment.save!
+
+      attachment
+    end
+
+    def sign_signature_uuid(uuid)
+      ApplicationRecord.signed_id_verifier.generate(uuid, purpose: SIGNED_UUID_PURPPOSE)
+    end
+
+    def verify_signature_uuid(signed_uuid)
+      ApplicationRecord.signed_id_verifier.verified(signed_uuid, purpose: SIGNED_UUID_PURPPOSE)
+    end
+
+    def find_storage_signature(submitter, signed_uuids, attachments)
+      signed_uuid = signed_uuids[submitter.email]
+
+      return if signed_uuid.blank?
+
+      uuid = verify_signature_uuid(signed_uuid)
+
+      return if uuid.blank?
+
+      find_signature_from_uuid(submitter, uuid, attachments)
+    end
+
+    def find_session_signature(submitter, cookies, attachments)
+      values =
+        begin
+          JSON.parse(cookies.encrypted[:signature_uuids].presence || '{}')
+        rescue JSON::ParserError
+          {}
+        end
+
+      return if values.blank?
+
+      uuid = values[submitter.email]
+
+      return if uuid.blank?
+
+      find_signature_from_uuid(submitter, uuid, attachments)
+    end
+
+    def find_signature_from_uuid(submitter, uuid, attachments)
+      signature_attachment = ActiveStorage::Attachment.find_by(uuid:)
+
+      return unless signature_attachment
+
+      return if signature_attachment.record.email != submitter.email
+
+      existing_attachment = attachments.find do |a|
+        a.blob_id == signature_attachment.blob_id && submitter.id == a.record_id
+      end
+
+      return existing_attachment if existing_attachment
+
+      submitter.attachments_attachments.create_or_find_by!(blob_id: signature_attachment.blob_id)
+    end
+  end
+end