Improve BlockedUserAlert emails

- a new mailer + new template
- a new method in BlockUserAlert to mail to a set of concerned people
  which replace the current one in blocked_user_monitor.rb
- the corresponding spec
- new line in preview mailer

app/mailers/blocked_user_alert_mailer.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+class BlockedUserAlertMailer < ApplicationMailer
+  def self.send_mails_to_concerned(alert)
+    return unless Features.email?
+    email(alert).deliver_now
+  end
+
+  def email(alert)
+    @alert = alert
+    set_recipients
+    return if @recipients.empty?
+    params = { to: @recipients,
+             subject: @alert.main_subject }
+    params[:reply_to] = @alert.reply_to unless @alert.reply_to.nil?
+    mail(params)
+  end
+
+  private
+
+  def set_recipients
+    @course = @alert.course
+    @user = @alert.user
+    @recipients = (@course.instructors.pluck(:email) +
+                   @course.nonstudents.where(greeter: true).pluck(:email)) <<
+                  @user.email
+  end
+end

app/models/alert_types/blocked_user_alert.rb

@@ -29,4 +29,10 @@ def main_subject
   def url
     "https://en.wikipedia.org/wiki/Special:Log?type=block&user=&page=User%3A#{user.url_encoded_username}&wpdate=&tagfilter=&subtype="
   end
+
+  def send_mails_to_concerned
+    BlockedUserAlertMailer.send_mails_to_concerned(self)
+    return if emails_disabled?
+    update(email_sent_at: Time.zone.now)
+  end
 end

app/views/blocked_user_alert_mailer/email.html.haml

@@ -0,0 +1,35 @@
+%link{rel: 'stylesheet', href:'/mailer.css'}
+%p.paragraph
+  Please investigate:
+  %a.link{ href: @alert.url }= @alert.main_subject
+
+- if @alert.user_contributions_url
+  %p.paragraph
+    %a.link{href: @alert.user_contributions_url}= "#{@alert.user.username} contributions"
+
+- if @alert.message
+  %p.paragraph.preserve-whitespace
+    = "Message regarding #{@alert.user.username}:"
+    = @alert.message
+
+  %p.paragraph
+    User email:
+    = @alert.user.email
+
+  %p.paragraph
+    User real name:
+    = @alert.user.real_name
+
+- if @alert.article
+  %p.paragraph
+    Article:
+    %a.link{href: @alert.article.url}= @alert.article.title
+
+- if @alert.revision
+  %p.paragraph
+    %a.link{href: @alert.revision.url} diff
+
+- if @alert.details
+  %p.paragraph.preserve-whitespace
+    Alert details:
+    = @alert.details

lib/alerts/blocked_user_monitor.rb

@@ -68,8 +68,7 @@ def alert_exists?(block, user)
   end
 
   def create_alert_and_send_email(block, user)
-    BlockedUserAlert
-      .create(user:, details: block, course: user.courses.last)
-      .email_content_expert
+    alert = BlockedUserAlert.create(user:, details: block, course: user.courses.last)
+    alert.send_mails_to_concerned
   end
 end

spec/lib/alerts/blocked_user_monitor_spec.rb

@@ -5,25 +5,48 @@
 
 describe BlockedUserMonitor do
   describe '.create_alerts_for_recently_blocked_users' do
-    let(:user) { create(:user, username: 'Verdantpowerinc') }
-    let(:course) { create(:course) }
+    let(:user) { create(:user, username: 'Verdantpowerinc', email: '[email protected]') }
+    let(:instructor_1) { create(:user, username: 'Instructor1', email: '[email protected]') }
+    let(:instructor_2) { create(:user, username: 'Instructor2', email: '[email protected]') }
+    let(:staff) { create(:user, username: 'staff', email: '[email protected]', greeter: true) }
+    let(:course) do
+      now = Time.zone.now
+      create(:course, start: now.days_ago(7), end: now.days_since(7))
+    end
 
     before do
       create(:courses_user, user:, course:)
+      create(:courses_user, course:, user: instructor_1,
+             role: CoursesUsers::Roles::INSTRUCTOR_ROLE)
+      create(:courses_user, course:, user: instructor_2,
+             role: CoursesUsers::Roles::INSTRUCTOR_ROLE)
+      create(:courses_user, course:, user: staff,
+            role: CoursesUsers::Roles::WIKI_ED_STAFF_ROLE)
       stub_block_log_query
     end
 
     it 'creates an Alert record for a blocked user' do
-      expect(Alert.count).to eq(0)
-      described_class.create_alerts_for_recently_blocked_users
-      expect(Alert.count).to eq(1)
+      expect { described_class.create_alerts_for_recently_blocked_users }
+        .to change(BlockedUserAlert, :count).by(1)
     end
 
     it 'does not create multiple alerts for the same block' do
-      expect(Alert.count).to eq(0)
-      described_class.create_alerts_for_recently_blocked_users
+      expect do
+        2.times { described_class.create_alerts_for_recently_blocked_users }
+      end.to change(BlockedUserAlert, :count).by(1)
+    end
+
+    it 'uses the proper mailer' do
+      expect(BlockedUserAlertMailer).to receive(:send_mails_to_concerned)
       described_class.create_alerts_for_recently_blocked_users
-      expect(Alert.count).to eq(1)
+    end
+
+    it 'sends a mail to staff, instructors & student' do
+      expect do
+        described_class.create_alerts_for_recently_blocked_users
+      end.to change { BlockedUserAlertMailer.deliveries.count }.by(1)
+      msg = BlockedUserAlertMailer.deliveries.first
+      expect(msg.to).to match_array([instructor_1, instructor_2, user, staff].map(&:email))
     end
   end
 end

spec/mailers/previews/alert_mailer_preview.rb

@@ -12,6 +12,10 @@ def blocked_edits_alert
     AlertMailer.alert(example_blocked_edits_alert, example_user)
   end
 
+  def blocked_student_alert
+    BlockedUserAlertMailer.email(example_user_blocked_alert)
+  end
+
   def check_timeline_alert
     AlertMailer.alert(example_alert(type: 'CheckTimelineAlert'), example_user)
   end
@@ -136,4 +140,17 @@ def example_blocked_edits_alert
               user: example_user,
               details:)
   end
+
+  def example_user_blocked_alert
+    user = example_user
+    message = "Student #{user.username} have been blocked on Wikipedia.
+This mail to inform staff, student as well as instructors."
+    alert = Alert.new(type: 'BlockedUserAlert', user:,
+                      course: example_course, message:)
+    alert.tap do |alrt|
+      alrt.define_singleton_method(:main_subject) do
+        "User #{user.username} have been blocked on Wikipedia"
+      end
+    end
+  end
 end