feat: use MJML to generate HTML emails (HL-999) (#2586)

* feat: add mjml and city of helsinki email templates

* feat: capability to send HTML emails

* feat: new HTML email templates

backend/benefit/applications/management/commands/check_drafts_to_delete.py

@@ -2,12 +2,15 @@
 
 from django.core.management.base import BaseCommand
 from django.utils import timezone
-from django.utils.text import format_lazy
 from django.utils.translation import gettext_lazy as _
 
 from applications.enums import ApplicationStatus
 from applications.models import Application
-from messages.automatic_messages import send_email_to_applicant
+from messages.automatic_messages import (
+    get_email_template_context,
+    render_email_template,
+    send_email_to_applicant,
+)
 
 APPLICATION_ABOUT_TO_BE_DELETED_MESSAGE = _(
     "Your application {id} will be deleted soon. If you want to continue the application process, please do so by "
@@ -62,17 +65,21 @@ def notify_applications(days_to_deletion: int, days_to_keep: int) -> int:
     return applications_to_notify.count()
 
 
+def get_draft_notice_email_notification_subject():
+    return str(_("Your Helsinki benefit draft application will expire"))
+
+
 def _send_notification_mail(application: Application, days_to_deletion: int) -> int:
     """Send a notification mail to the applicant about the upcoming application deletion"""
 
-    subject = _("Your application is about to be deleted")
+    application_deletion_date = (
+        application.modified_at + timedelta(days=days_to_deletion)
+    ).strftime("%d.%m.%Y")
+    context = get_email_template_context(application)
+    context["application_deletion_date"] = application_deletion_date
 
-    message = format_lazy(
-        APPLICATION_ABOUT_TO_BE_DELETED_MESSAGE,
-        id=application.application_number,
-        application_deletion_date=(
-            application.modified_at + timedelta(days=days_to_deletion)
-        ).strftime("%d.%m.%Y"),
-    )
+    subject = get_draft_notice_email_notification_subject()
+    message = render_email_template(context, "draft-notice", "txt")
+    html_message = render_email_template(context, "draft-notice", "html")
 
-    return send_email_to_applicant(application, subject, message)
+    return send_email_to_applicant(application, subject, message, html_message)

backend/benefit/applications/tests/test_applications_api.py

@@ -51,6 +51,9 @@
 from companies.tests.factories import CompanyFactory
 from helsinkibenefit.settings import MAX_UPLOAD_SIZE
 from helsinkibenefit.tests.conftest import *  # noqa
+from messages.automatic_messages import (
+    get_additional_information_email_notification_subject,
+)
 from shared.audit_log import models as audit_models
 from shared.service_bus.enums import YtjOrganizationCode
 from terms.models import TermsOfServiceApproval
@@ -1282,7 +1285,10 @@ def test_application_status_change_as_handler(
                 in application.messages.first().content
             )
             assert len(mailoutbox) == 1
-            assert "You have received a new message" in mailoutbox[0].subject
+            assert (
+                get_additional_information_email_notification_subject()
+                in mailoutbox[0].subject
+            )
 
         if to_status in [
             ApplicationStatus.CANCELLED,

backend/benefit/helsinkibenefit/settings.py

@@ -272,10 +272,15 @@
     "simple_history.middleware.HistoryRequestMiddleware",
 ]
 
+MJML_COMPILED_EMAIL_TEMPLATE_PATHS = [
+    os.path.join(BASE_DIR, "helsinkibenefit/templates/emails/mjml-generated/html"),
+    os.path.join(BASE_DIR, "helsinkibenefit/templates/emails/mjml-generated/txt"),
+]
+
 TEMPLATES = [
     {
         "BACKEND": "django.template.backends.django.DjangoTemplates",
-        "DIRS": [],
+        "DIRS": [] + MJML_COMPILED_EMAIL_TEMPLATE_PATHS,
         "APP_DIRS": True,
         "OPTIONS": {
             "context_processors": [