Add Avenger Backlog Notifications (#932)

* Create NotificationType Model

- Create Notifications module and NotificationType model
- Start migration for adding notifications
- No functionalities added yet only template code

* Configure Oban and Bamboo for notifications system

* Create NotificationConfig Model

* Create TimeOption Model

* Create NotificationPreference Model

* Create SentNotification Model

* Add Email Field to User Model

* fix: Fix Oban configuration

* chore: Add dependency on bamboo_phoenix for email template rendering

* feat: Implement Oban job for avenger backlog emails

* chore: Prevent browser from opening automatically when a local email is sent

* Add migrations for notification triggers and avenger backlog
notification entry

* Implement notification configuration checks

* Fix formatting errors

* fix: Fix notifications schema typos

Changes:
* Replaced is_enable to is_enabled for Notification Preferences
* Update default is_enabled to true for Notifcation Types

* fix: Fix test configurations not being applied

`import_config` must always appear at the bottom for environment
specific configurations to be applied correctly. All configurations
after this line will overwrite configurations that exists in the
environment specific ones.

* chore: remove unused controllers and views

- remove auto-generated controllers and views that are not used

* chore: Add tests for notifications

* chore: Add test for avenger backlog email

* chore: Resolve style violations

* chore: Resolve style violations

* chore: Resolve style violations

* style: fix formatting

* fix: Fix bad refactoring

* fix: Fix testing environment with Oban and Bamboo

* test: add tests for notification types

* test: add tests for time options

* chore: Update constraints and changesets for notification models

* chore: Update default behaviour for no time_option in user preference

If user preference has no time option, use the time_option from
notification_config instead. This is so that the behaviour of these
users with no preferences would always follow the default chosen by the
course admin

* style: fix formatting

* test: add tests for sent notifications

* Add tests for notifications module

* fix: Fix testing with Oban

Oban introduced changes to testing in v2.12, this commit changes the old
test configurations to the new one recommended by official docs.

* Add more tests for notifications module

* test: add tests for NotificationWorker

* style: fix formatting

* style: fix formatting

* style: fix formatting

* fix: Fix tests under notification types name constraints

* feat: Implement job for assessment submission mail

* fix: Fix assessment submission worker

* chore: Add test for assessment submission

* chore: Add migration to populate existing nus users' emails

Current nus users will have their email attribute populated based on
their username. nus users are identified from the provider attribute.

Future nus users will have their email attribute populated on creation
ideally.

* feat: implement sent_notifications

- move mailing logic to notification worker
- insert into sent_notifications when email is sent out successfully

* fix: fix tests

* style: fix formatting

* fix: fix guard clauses

- move guard clauses to prevent unnecessary querying

* fix: Fix db triggers not running for assessment submission notifications

---------

Co-authored-by: Goh Jun Yi <54541329+Junyi00@users.noreply.github.com>
Co-authored-by: Martin Henz <henz@comp.nus.edu.sg>

Author: 3 people

config/config.exs

@@ -72,10 +72,6 @@ config :sentry,
   root_source_code_path: File.cwd!(),
   context_lines: 5
 
-# Import environment specific config. This must remain at the bottom
-# of this file so it overrides the configuration defined above.
-import_config "#{Mix.env()}.exs"
-
 # Configure Phoenix Swagger
 config :cadet, :phoenix_swagger,
   swagger_files: %{
@@ -93,3 +89,22 @@ config :guardian, Guardian.DB,
   token_types: ["refresh"],
   # default: 60 minute
   sweep_interval: 180
+
+config :cadet, Oban,
+  repo: Cadet.Repo,
+  plugins: [
+    # keep
+    {Oban.Plugins.Pruner, max_age: 60},
+    {Oban.Plugins.Cron,
+     crontab: [
+       {"@daily", Cadet.Workers.NotificationWorker,
+        args: %{"notification_type" => "avenger_backlog"}}
+     ]}
+  ],
+  queues: [default: 10, notifications: 1]
+
+config :cadet, Cadet.Mailer, adapter: Bamboo.LocalAdapter
+
+# Import environment specific config. This must remain at the bottom
+# of this file so it overrides the configuration defined above.
+import_config "#{Mix.env()}.exs"

config/prod.exs

@@ -44,3 +44,5 @@ config :logger, level: :info
 config :ex_aws,
   access_key_id: [:instance_role],
   secret_access_key: [:instance_role]
+
+config :cadet, Cadet.Mailer, adapter: Bamboo.SesAdapter

config/test.exs

@@ -88,3 +88,9 @@ config :arc, storage: Arc.Storage.Local
 
 if "test.secrets.exs" |> Path.expand(__DIR__) |> File.exists?(),
   do: import_config("test.secrets.exs")
+
+config :cadet, Oban,
+  repo: Cadet.Repo,
+  testing: :manual
+
+config :cadet, Cadet.Mailer, adapter: Bamboo.TestAdapter

lib/cadet/accounts/course_registrations.ex

@@ -63,6 +63,13 @@ defmodule Cadet.Accounts.CourseRegistrations do
     |> Repo.all()
   end
 
+  def get_staffs(course_id) do
+    CourseRegistration
+    |> where(course_id: ^course_id)
+    |> where(role: :staff)
+    |> Repo.all()
+  end
+
   def get_users(course_id, group_id) when is_ecto_id(group_id) and is_ecto_id(course_id) do
     CourseRegistration
     |> where([cr], cr.course_id == ^course_id)
@@ -200,4 +207,23 @@ defmodule Cadet.Accounts.CourseRegistrations do
       {:error, changeset} -> {:error, {:bad_request, full_error_messages(changeset)}}
     end
   end
+
+  def get_avenger_of(student_id) when is_ecto_id(student_id) do
+    CourseRegistration
+    |> Repo.get_by(id: student_id)
+    |> Repo.preload(:group)
+    |> Map.get(:group)
+    |> case do
+      nil ->
+        nil
+
+      group ->
+        avenger_id = Map.get(group, :leader_id)
+
+        CourseRegistration
+        |> where([cr], cr.id == ^avenger_id)
+        |> preload(:user)
+        |> Repo.one()
+    end
+  end
 end

lib/cadet/accounts/user.ex

@@ -20,6 +20,7 @@ defmodule Cadet.Accounts.User do
     field(:username, :string)
     field(:provider, :string)
     field(:super_admin, :boolean)
+    field(:email, :string)
 
     belongs_to(:latest_viewed_course, Course)
     has_many(:courses, CourseRegistration)

lib/cadet/application.ex

@@ -20,7 +20,9 @@ defmodule Cadet.Application do
       # Start the GuardianDB sweeper
       worker(Guardian.DB.Token.SweeperServer, []),
       # Start the Quantum scheduler
-      worker(Cadet.Jobs.Scheduler, [])
+      worker(Cadet.Jobs.Scheduler, []),
+      # Start the Oban instance
+      {Oban, Application.fetch_env!(:cadet, Oban)}
     ]
 
     children =

lib/cadet/assessments/assessments.ex

@@ -721,11 +721,24 @@ defmodule Cadet.Assessments do
     |> Repo.one()
   end
 
+  def get_submission_by_id(submission_id) when is_ecto_id(submission_id) do
+    Submission
+    |> where(id: ^submission_id)
+    |> join(:inner, [s], a in assoc(s, :assessment))
+    |> preload([_, a], assessment: a)
+    |> Repo.one()
+  end
+
   def finalise_submission(submission = %Submission{}) do
     with {:status, :attempted} <- {:status, submission.status},
          {:ok, updated_submission} <- update_submission_status_and_xp_bonus(submission) do
       # Couple with update_submission_status_and_xp_bonus to ensure notification is sent
       Notifications.write_notification_when_student_submits(submission)
+      # Send email notification to avenger
+      %{notification_type: "assessment_submission", submission_id: updated_submission.id}
+      |> Cadet.Workers.NotificationWorker.new()
+      |> Oban.insert()
+
       # Begin autograding job
       GradingJob.force_grade_individual_submission(updated_submission)
 
@@ -1151,7 +1164,8 @@ defmodule Cadet.Assessments do
           {:ok, String.t()}
   def all_submissions_by_grader_for_index(
         grader = %CourseRegistration{course_id: course_id},
-        group_only \\ false
+        group_only \\ false,
+        ungraded_only \\ false
       ) do
     show_all = not group_only
 
@@ -1161,6 +1175,11 @@ defmodule Cadet.Assessments do
         else:
           "where s.student_id in (select cr.id from course_registrations cr inner join groups g on cr.group_id = g.id where g.leader_id = $2) or s.student_id = $2"
 
+    ungraded_where =
+      if ungraded_only,
+        do: "where s.\"gradedCount\" < assts.\"questionCount\"",
+        else: ""
+
     params = if show_all, do: [course_id], else: [course_id, grader.id]
 
     # We bypass Ecto here and use a raw query to generate JSON directly from
@@ -1200,7 +1219,7 @@ defmodule Cadet.Assessments do
                group by s.id) s
              inner join
                (select
-                 a.id, to_json(a) as jsn
+                 a.id, a."questionCount", to_json(a) as jsn
                from
                  (select
                    a.id,
@@ -1240,6 +1259,7 @@ defmodule Cadet.Assessments do
                  from course_registrations cr
                    inner join
                    users u on u.id = cr.user_id) cr) unsubmitters on s.unsubmitted_by_id = unsubmitters.id
+             #{ungraded_where}
            ) q
            """,
            params

lib/cadet/courses/courses.ex

@@ -82,6 +82,12 @@ defmodule Cadet.Courses do
     end
   end
 
+  def get_all_course_ids do
+    Course
+    |> select([c], c.id)
+    |> Repo.all()
+  end
+
   defp retrieve_course(course_id) when is_ecto_id(course_id) do
     Course
     |> where(id: ^course_id)
@@ -233,8 +239,8 @@ defmodule Cadet.Courses do
             )
             |> where(course_id: ^course_id)
             |> Repo.one()} do
-      # It is ok to assume that user course registions already exist, as they would have been created
-      # in the admin_user_controller before calling this function
+      # It is ok to assume that user course registions already exist, as they would
+      # have been created in the admin_user_controller before calling this function
       case role do
         # If student, update his course registration
         :student ->

lib/cadet/email.ex

@@ -0,0 +1,40 @@
+defmodule Cadet.Email do
+  @moduledoc """
+  Contains methods for sending email notifications.
+  """
+  use Bamboo.Phoenix, view: CadetWeb.EmailView
+  import Bamboo.Email
+
+  def avenger_backlog_email(template_file_name, avenger, ungraded_submissions) do
+    if is_nil(avenger.email) do
+      nil
+    else
+      base_email()
+      |> to(avenger.email)
+      |> assign(:avenger_name, avenger.name)
+      |> assign(:submissions, ungraded_submissions)
+      |> subject("Backlog for #{avenger.name}")
+      |> render("#{template_file_name}.html")
+    end
+  end
+
+  def assessment_submission_email(template_file_name, avenger, student, submission) do
+    if is_nil(avenger.email) do
+      nil
+    else
+      base_email()
+      |> to(avenger.email)
+      |> assign(:avenger_name, avenger.name)
+      |> assign(:student_name, student.name)
+      |> assign(:assessment_title, submission.assessment.title)
+      |> subject("New submission for #{submission.assessment.title}")
+      |> render("#{template_file_name}.html")
+    end
+  end
+
+  defp base_email do
+    new_email()
+    |> from("noreply@sourceacademy.org")
+    |> put_html_layout({CadetWeb.LayoutView, "email.html"})
+  end
+end

lib/cadet/jobs/scheduler.ex

@@ -1,5 +1,8 @@
 # credo:disable-for-this-file Credo.Check.Readability.ModuleDoc
 # @moduledoc is actually generated by a macro inside Quantum
 defmodule Cadet.Jobs.Scheduler do
+  @moduledoc """
+  Quantum is used for scheduling jobs with cron jobs.
+  """
   use Quantum, otp_app: :cadet
 end

lib/cadet/mailer.ex

@@ -0,0 +1,6 @@
+defmodule Cadet.Mailer do
+  @moduledoc """
+  Mailer used to sent notification emails.
+  """
+  use Bamboo.Mailer, otp_app: :cadet
+end