feat: Report email with LIT authorization path

To act on spam reports the teacher needs to sign in through the
course to authenticate in the study group. The LTI return URL is used
to link back to the course.

Author: arkirchner

app/mailers/report_mailer.rb

@@ -5,6 +5,9 @@ class ReportMailer < ApplicationMailer
 
   def report_content
     @reported_content = params.fetch(:reported_content)
+    study_group = @reported_content.submission.study_group
+    exercise = @reported_content.exercise
+    @course_url = LtiParameter.find_by(study_group:, exercise:)&.lti_parameters&.[]('launch_presentation_return_url')
 
     mail(subject: I18n.t('report_mailer.report_content.subject', content_name: @reported_content.model_name.human))
   end

app/views/report_mailer/report_content.html.slim

@@ -2,3 +2,5 @@ h3 = t('.prolog')
 blockquote style="white-space: pre-wrap;" = @reported_content.question
 p = t('.take_action')
 p = link_to(request_for_comment_url(@reported_content), request_for_comment_url(@reported_content))
+- if @course_url.present?
+  p = link_to(t('.authentication'), @course_url)

app/views/report_mailer/report_content.text.slim

@@ -5,3 +5,8 @@
 == t('.take_action')
 == "\n\n"
 == request_for_comment_url(@reported_content)
+== "\n\n"
+- if @course_url.present?
+  == t('.authentication')
+  == "\n\n"
+  == @course_url

config/locales/de/report.yml

@@ -2,6 +2,7 @@
 de:
   report_mailer:
     report_content:
+      authentication: Übungs-URL für die LTI-Authentifizierung.
       prolog: 'Die folgenden Inhalte wurden als unangemessen gemeldet:'
       subject: 'Spam Report: Ein %{content_name} in CodeOcean wurde als unangemessen markiert.'
       take_action: Bitte ergreifen Sie gegebenenfalls Maßnahmen.

config/locales/en/report.yml

@@ -2,6 +2,7 @@
 en:
   report_mailer:
     report_content:
+      authentication: Exercise URL for LTI authentication.
       prolog: 'The following content has been reported as inappropriate:'
       subject: 'Spam Report: A %{content_name} on CodeOcean has been marked as inappropriate.'
       take_action: Please take action if required.

spec/mailers/report_mailer_spec.rb

@@ -22,6 +22,15 @@
         expect(mail.text_part.body).to include(question)
         expect(mail.html_part.body).to include(question)
       end
+
+      it 'includes the LTI retrun URL for course authentication' do
+        create(:lti_parameter,
+          exercise: reported_content.exercise,
+          study_group: reported_content.submission.study_group)
+
+        expect(mail.text_part.body).to match(%r{https.+/courses/})
+        expect(mail.html_part.body).to match(%r{https.+/courses/})
+      end
     end
   end
 end