feat: #164 certificate of course completion

.github/workflows/pr-check.yml

@@ -39,11 +39,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.11, 3.12, 3.13, 3.14]
+        python-version: [3.12, 3.13, 3.14]
         django-versions: [5.0, 6.0]
-        exclude:
-          - python-version: '3.11'
-            django-versions: 6.0
     steps:
       - name: Checkout code
         uses: actions/checkout@v6

django_email_learning/migrations/0008_alter_apikey_salt_alter_imapconnection_salt_and_more.py

@@ -0,0 +1,59 @@
+# Generated by Django 6.0.2 on 2026-02-13 07:33
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        (
+            "django_email_learning",
+            "0007_alter_apikey_salt_alter_imapconnection_salt_and_more",
+        ),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="apikey",
+            name="salt",
+            field=models.CharField(
+                default="24cbbf453c064d1c99017f78d01115a1",
+                editable=False,
+                max_length=32,
+            ),
+        ),
+        migrations.AlterField(
+            model_name="imapconnection",
+            name="salt",
+            field=models.CharField(
+                default="24cbbf453c064d1c99017f78d01115a1",
+                editable=False,
+                max_length=32,
+            ),
+        ),
+        migrations.CreateModel(
+            name="Certificate",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("issued_at", models.DateTimeField(auto_now_add=True)),
+                ("name_on_certificate", models.CharField(max_length=200)),
+                ("random_suffix", models.IntegerField()),
+                (
+                    "enrollment",
+                    models.OneToOneField(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="certificate",
+                        to="django_email_learning.enrollment",
+                    ),
+                ),
+            ],
+        ),
+    ]

django_email_learning/migrations/0009_deliveryschedule_delivered_at_alter_apikey_salt_and_more.py

@@ -0,0 +1,38 @@
+# Generated by Django 6.0.2 on 2026-02-13 08:07
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        (
+            "django_email_learning",
+            "0008_alter_apikey_salt_alter_imapconnection_salt_and_more",
+        ),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="deliveryschedule",
+            name="delivered_at",
+            field=models.DateTimeField(blank=True, null=True),
+        ),
+        migrations.AlterField(
+            model_name="apikey",
+            name="salt",
+            field=models.CharField(
+                default="ff58446e143a4d69b7773604efeb581c",
+                editable=False,
+                max_length=32,
+            ),
+        ),
+        migrations.AlterField(
+            model_name="imapconnection",
+            name="salt",
+            field=models.CharField(
+                default="ff58446e143a4d69b7773604efeb581c",
+                editable=False,
+                max_length=32,
+            ),
+        ),
+    ]

django_email_learning/models.py

@@ -15,17 +15,23 @@
     MinValueValidator,
     MinLengthValidator,
 )
+from django_email_learning.services.email_sender_service import EmailSenderService
+from django.core.mail import EmailMultiAlternatives
+from django.template.loader import render_to_string
 from django.core.exceptions import ImproperlyConfigured
 from cryptography.fernet import Fernet, InvalidToken
 from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
 from cryptography.hazmat.primitives import hashes
 from django.forms import ValidationError
 from django.contrib.auth.models import User
 from django.utils import timezone
+from django.utils.translation import gettext as _
 from datetime import timedelta
 from django_email_learning.services import jwt_service
+
 from PIL import Image
 from typing import Optional
+from datetime import datetime
 
 
 logger = logging.getLogger(__name__)
@@ -522,16 +528,58 @@ class Meta:
         ]
 
     def graduate(self) -> None:
-        if self.status != EnrollmentStatus.ACTIVE:
-            raise ValidationError("Only active enrollments can be marked as completed.")
-        self.status = EnrollmentStatus.COMPLETED
-        self.final_state_at = timezone.now()
-        logger.info(
-            f"Learner ID {self.learner.id} has completed the course {self.course.title}."
+        with transaction.atomic():
+            if self.status != EnrollmentStatus.ACTIVE:
+                raise ValidationError(
+                    "Only active enrollments can be marked as completed."
+                )
+            self.status = EnrollmentStatus.COMPLETED
+            self.final_state_at = timezone.now()
+            logger.info(
+                f"Learner ID {self.learner.id} has completed the course {self.course.title}."
+            )
+            self.save()
+            self.send_certificate_form()
+
+    def send_certificate_form(self) -> None:
+        if self.status != EnrollmentStatus.COMPLETED:
+            raise ValidationError(
+                "Certificate form can only be sent for completed enrollments."
+            )
+        token_payload = {
+            "enrollment_id": self.id,
+        }
+        logging.info(
+            f"Executing SendCertificateFormCommand for enrollment ID {self.id}"
         )
+        token = jwt_service.generate_jwt(token_payload, exp=datetime.max)
+        certificate_path = reverse(
+            "django_email_learning:personalised:certificate_form"
+        )
+        link = f"{settings.DJANGO_EMAIL_LEARNING['SITE_BASE_URL']}{certificate_path}?token={token}"
 
-        # TODO: send certificate email here
-        self.save()
+        subject = _("Finalize your Certificate")
+
+        context = {
+            "course_title": self.course.title,
+            "organization_name": self.course.organization.name,
+            "link": link,
+        }
+        payload = render_to_string("emails/certificate_form.txt", context)
+
+        email_service = EmailSenderService()
+        email_message = EmailMultiAlternatives(
+            subject=subject,
+            body=payload,
+            from_email=email_service.from_email,
+            to=[self.learner.email],
+        )
+        email_message.attach_alternative(
+            render_to_string("emails/certificate_form.html", context), "text/html"
+        )
+
+        email_service.send(email_message)
+        logging.info(f"Certificate form email sent for enrollment ID {self.id}")
 
     def fail(self) -> None:
         if self.status != EnrollmentStatus.ACTIVE:
@@ -565,6 +613,31 @@ def schedule_first_content_delivery(self) -> None:
             raise ValidationError("No published content available to schedule.")
 
 
+class Certificate(models.Model):
+    enrollment = models.OneToOneField(
+        Enrollment, on_delete=models.CASCADE, related_name="certificate"
+    )
+    issued_at = models.DateTimeField(auto_now_add=True)
+    name_on_certificate = models.CharField(max_length=200)
+    random_suffix = models.IntegerField()
+
+    @property
+    def certificate_number(self) -> str:
+        return f"{self.enrollment.course.id}-{self.enrollment.id}-{self.id}-{self.random_suffix}"
+
+    def save(  # type: ignore[no-untyped-def]
+        self, *, force_insert=False, force_update=False, using=None, update_fields=None
+    ):
+        if not self.random_suffix:
+            self.random_suffix = random.randint(100000, 999999)
+        return super().save(
+            force_insert=force_insert,
+            force_update=force_update,
+            using=using,
+            update_fields=update_fields,
+        )
+
+
 class ContentDelivery(models.Model):
     enrollment = models.ForeignKey(
         Enrollment, on_delete=models.CASCADE, related_name="content_deliveries"
@@ -664,6 +737,7 @@ class DeliverySchedule(models.Model):
         db_index=True,
     )
     failed_attempts = models.IntegerField(default=0)
+    delivered_at = models.DateTimeField(null=True, blank=True)
 
     def generate_link(self) -> str:
         payload = {
@@ -695,6 +769,11 @@ def generate_link(self) -> str:
     def __str__(self) -> str:
         return f"Delivery for {self.delivery.course_content.title} to {self.delivery.enrollment.learner.email} at {self.time} - Status: {self.status}"
 
+    def save(self, *args, **kwargs) -> None:  # type: ignore[no-untyped-def]
+        if self.status == DeliveryStatus.DELIVERED and not self.delivered_at:
+            self.delivered_at = timezone.now()
+        super().save(*args, **kwargs)
+
 
 class QuizSubmission(models.Model):
     delivery = models.ForeignKey(

django_email_learning/personalised/api/urls.py

@@ -1,8 +1,16 @@
 from django.urls import path
-from django_email_learning.personalised.api.views import QuizSubmissionView
+from django_email_learning.personalised.api.views import (
+    QuizSubmissionView,
+    SubmitCertificateFormView,
+)
 
 app_name = "django_email_learning"
 
 urlpatterns = [
     path("quiz/", QuizSubmissionView.as_view(), name="quiz_submission"),
+    path(
+        "certificate-form/",
+        SubmitCertificateFormView.as_view(),
+        name="submit_certificate_form",
+    ),
 ]

django_email_learning/personalised/api/views.py

@@ -8,6 +8,8 @@
 from django.utils.translation import gettext as _
 from django_email_learning.models import (
     ContentDelivery,
+    Enrollment,
+    Certificate,
     QuizSubmission,
     Quiz,
     EnrollmentStatus,
@@ -175,3 +177,45 @@ def calculate_score_and_passed(
         score = max(0, score)
         passed = score >= quiz.required_score
         return score, passed
+
+
+class SubmitCertificateFormView(View):
+    def post(self, request, *args, **kwargs):  # type: ignore[no-untyped-def]
+        payload = json.loads(request.body)
+        token = payload.get("token")
+        name = payload.get("name")
+
+        if not name:
+            return JsonResponse({"error": _("Name is required")}, status=400)
+
+        try:
+            decoded = jwt_service.decode_jwt(token=token)
+        except jwt_service.InvalidTokenException as jde:
+            return JsonResponse({"error": str(jde)}, status=400)
+        except jwt_service.ExpiredTokenException as ete:
+            return JsonResponse({"error": str(ete)}, status=410)
+
+        enrollment_id = decoded["enrollment_id"]
+
+        try:
+            enrollment = Enrollment.objects.get(id=enrollment_id)
+        except Enrollment.DoesNotExist:
+            return JsonResponse(
+                {"error": "The enrollment associated with this token does not exist."},
+                status=500,
+            )
+
+        if enrollment.status != EnrollmentStatus.COMPLETED:
+            return JsonResponse(
+                {
+                    "error": "The enrollment is not completed. Certificate cannot be issued."
+                },
+                status=400,
+            )
+        Certificate.objects.update_or_create(
+            enrollment=enrollment, defaults={"name_on_certificate": name}
+        )
+
+        return JsonResponse(
+            {"message": _("Certificate name submitted successfully.")}, status=200
+        )

django_email_learning/personalised/urls.py

@@ -2,6 +2,8 @@
 from django_email_learning.personalised.views import (
     QuizPublicView,
     VerifyEnrollmentView,
+    CertificateFormView,
+    CertificateView,
     UnsubscribeView,
 )
 
@@ -12,5 +14,11 @@
     path(
         "verify-enrollment/", VerifyEnrollmentView.as_view(), name="verify_enrollment"
     ),
+    path("certificate-form/", CertificateFormView.as_view(), name="certificate_form"),
+    path(
+        "certificate/<str:certificate_number>/",
+        CertificateView.as_view(),
+        name="certificate",
+    ),
     path("unsubscribe/", UnsubscribeView.as_view(), name="unsubscribe"),
 ]