From 22f8b6522803793ca28d3ce0abf5db17117fd600 Mon Sep 17 00:00:00 2001
From: Troy Sankey <tsankey@edx.org>
Date: Tue, 10 Dec 2019 13:08:52 -0500
Subject: [PATCH] Add history to GeneratedCertificate

DE-1881
---
 .../0016_historicalgeneratedcertificate.py    | 51 +++++++++++++++++++
 lms/djangoapps/certificates/models.py         |  8 +++
 .../tests/test_tasks_helper.py                |  2 +-
 3 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 lms/djangoapps/certificates/migrations/0016_historicalgeneratedcertificate.py

diff --git a/lms/djangoapps/certificates/migrations/0016_historicalgeneratedcertificate.py b/lms/djangoapps/certificates/migrations/0016_historicalgeneratedcertificate.py
new file mode 100644
index 0000000000..80261cb07a
--- /dev/null
+++ b/lms/djangoapps/certificates/migrations/0016_historicalgeneratedcertificate.py
@@ -0,0 +1,51 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.26 on 2019-12-10 18:05
+from __future__ import unicode_literals
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+import opaque_keys.edx.django.models
+import simple_history.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('certificates', '0015_add_masters_choice'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='HistoricalGeneratedCertificate',
+            fields=[
+                ('id', models.IntegerField(auto_created=True, blank=True, db_index=True, verbose_name='ID')),
+                ('course_id', opaque_keys.edx.django.models.CourseKeyField(blank=True, default=None, max_length=255)),
+                ('verify_uuid', models.CharField(blank=True, db_index=True, default='', max_length=32)),
+                ('download_uuid', models.CharField(blank=True, default='', max_length=32)),
+                ('download_url', models.CharField(blank=True, default='', max_length=128)),
+                ('grade', models.CharField(blank=True, default='', max_length=5)),
+                ('key', models.CharField(blank=True, default='', max_length=32)),
+                ('distinction', models.BooleanField(default=False)),
+                ('status', models.CharField(default='unavailable', max_length=32)),
+                ('mode', models.CharField(choices=[('verified', 'verified'), ('honor', 'honor'), ('audit', 'audit'), ('professional', 'professional'), ('no-id-professional', 'no-id-professional'), ('masters', 'masters')], default='honor', max_length=32)),
+                ('name', models.CharField(blank=True, max_length=255)),
+                ('created_date', models.DateTimeField(blank=True, editable=False)),
+                ('modified_date', models.DateTimeField(blank=True, editable=False)),
+                ('error_reason', models.CharField(blank=True, default='', max_length=512)),
+                ('history_id', models.AutoField(primary_key=True, serialize=False)),
+                ('history_date', models.DateTimeField()),
+                ('history_change_reason', models.CharField(max_length=100, null=True)),
+                ('history_type', models.CharField(choices=[('+', 'Created'), ('~', 'Changed'), ('-', 'Deleted')], max_length=1)),
+                ('history_user', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='+', to=settings.AUTH_USER_MODEL)),
+                ('user', models.ForeignKey(blank=True, db_constraint=False, null=True, on_delete=django.db.models.deletion.DO_NOTHING, related_name='+', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'ordering': ('-history_date', '-history_id'),
+                'verbose_name': 'historical generated certificate',
+                'get_latest_by': 'history_date',
+            },
+            bases=(simple_history.models.HistoricalChanges, models.Model),
+        ),
+    ]
diff --git a/lms/djangoapps/certificates/models.py b/lms/djangoapps/certificates/models.py
index e7ee233246..d337e6e863 100644
--- a/lms/djangoapps/certificates/models.py
+++ b/lms/djangoapps/certificates/models.py
@@ -54,6 +54,7 @@ import uuid
 
 import six
 from config_models.models import ConfigurationModel
+from django.apps import apps
 from django.conf import settings
 from django.contrib.auth.models import User
 from django.core.exceptions import ValidationError
@@ -66,6 +67,7 @@ from model_utils import Choices
 from model_utils.fields import AutoCreatedField
 from model_utils.models import TimeStampedModel
 from opaque_keys.edx.django.models import CourseKeyField
+from simple_history.models import HistoricalRecords
 
 from badges.events.course_complete import course_badge_check
 from badges.events.course_meta import completion_check, course_group_check
@@ -280,6 +282,12 @@ class GeneratedCertificate(models.Model):
     modified_date = models.DateTimeField(auto_now=True)
     error_reason = models.CharField(max_length=512, blank=True, default='')
 
+    # This is necessary because CMS does not install the certificates app, but it
+    # imports this models code. Simple History will attempt to connect to the installed
+    # model in the certificates app, which will fail.
+    if 'certificates' in apps.app_configs:
+        history = HistoricalRecords()
+
     class Meta(object):
         unique_together = (('user', 'course_id'),)
         app_label = "certificates"
diff --git a/lms/djangoapps/instructor_task/tests/test_tasks_helper.py b/lms/djangoapps/instructor_task/tests/test_tasks_helper.py
index 4778b6be2b..60f804af6a 100644
--- a/lms/djangoapps/instructor_task/tests/test_tasks_helper.py
+++ b/lms/djangoapps/instructor_task/tests/test_tasks_helper.py
@@ -2268,7 +2268,7 @@ class TestCertificateGeneration(InstructorTaskModuleTestCase):
             'failed': 3,
             'skipped': 2
         }
-        with self.assertNumQueries(130):
+        with self.assertNumQueries(146):
             self.assertCertificatesGenerated(task_input, expected_results)
 
         expected_results = {