From 626f015a2efa37c25111a629124f4d1850543eea Mon Sep 17 00:00:00 2001
From: Clinton Blackburn <cblackburn@edx.org>
Date: Tue, 13 Jun 2017 17:34:21 -0400
Subject: [PATCH] Added experiments app and API endpoint

---
 lms/djangoapps/experiments/__init__.py        |   6 +
 lms/djangoapps/experiments/admin.py           |  13 ++
 lms/djangoapps/experiments/factories.py       |  14 ++
 lms/djangoapps/experiments/filters.py         |   9 ++
 .../experiments/migrations/0001_initial.py    |  40 ++++++
 .../experiments/migrations/__init__.py        |   0
 lms/djangoapps/experiments/models.py          |  22 +++
 lms/djangoapps/experiments/permissions.py     |  12 ++
 lms/djangoapps/experiments/routers.py         |  46 +++++++
 lms/djangoapps/experiments/serializers.py     |  12 ++
 lms/djangoapps/experiments/tests/__init__.py  |   0
 .../experiments/tests/test_views.py           | 127 ++++++++++++++++++
 lms/djangoapps/experiments/urls.py            |  11 ++
 lms/djangoapps/experiments/views.py           |  43 ++++++
 lms/envs/common.py                            |   2 +
 lms/urls.py                                   |   3 +-
 16 files changed, 358 insertions(+), 2 deletions(-)
 create mode 100644 lms/djangoapps/experiments/__init__.py
 create mode 100644 lms/djangoapps/experiments/admin.py
 create mode 100644 lms/djangoapps/experiments/factories.py
 create mode 100644 lms/djangoapps/experiments/filters.py
 create mode 100644 lms/djangoapps/experiments/migrations/0001_initial.py
 create mode 100644 lms/djangoapps/experiments/migrations/__init__.py
 create mode 100644 lms/djangoapps/experiments/models.py
 create mode 100644 lms/djangoapps/experiments/permissions.py
 create mode 100644 lms/djangoapps/experiments/routers.py
 create mode 100644 lms/djangoapps/experiments/serializers.py
 create mode 100644 lms/djangoapps/experiments/tests/__init__.py
 create mode 100644 lms/djangoapps/experiments/tests/test_views.py
 create mode 100644 lms/djangoapps/experiments/urls.py
 create mode 100644 lms/djangoapps/experiments/views.py

diff --git a/lms/djangoapps/experiments/__init__.py b/lms/djangoapps/experiments/__init__.py
new file mode 100644
index 0000000000..c706668768
--- /dev/null
+++ b/lms/djangoapps/experiments/__init__.py
@@ -0,0 +1,6 @@
+"""
+This app is used by the Rapid Experiments Team to hold data related to experiments.
+
+WARNING: Do NOT use this app for anything long-term (or even short-tem) unless you are a member of the team. This app
+is subject to change at any time without notice to those outside of the Rapid Experiments Team.
+"""
diff --git a/lms/djangoapps/experiments/admin.py b/lms/djangoapps/experiments/admin.py
new file mode 100644
index 0000000000..feee039a09
--- /dev/null
+++ b/lms/djangoapps/experiments/admin.py
@@ -0,0 +1,13 @@
+from django.contrib import admin
+
+from .models import ExperimentData
+
+
+@admin.register(ExperimentData)
+class ExperimentDataAdmin(admin.ModelAdmin):
+    list_display = ('user', 'experiment_id', 'key',)
+    list_filter = ('experiment_id',)
+    ordering = ('experiment_id', 'user', 'key',)
+    raw_id_fields = ('user',)
+    readonly_fields = ('created', 'modified',)
+    search_fields = ('experiment_id', 'user', 'key',)
diff --git a/lms/djangoapps/experiments/factories.py b/lms/djangoapps/experiments/factories.py
new file mode 100644
index 0000000000..b718a246e0
--- /dev/null
+++ b/lms/djangoapps/experiments/factories.py
@@ -0,0 +1,14 @@
+import factory
+
+from experiments.models import ExperimentData
+from student.tests.factories import UserFactory
+
+
+class ExperimentDataFactory(factory.DjangoModelFactory):
+    class Meta(object):
+        model = ExperimentData
+
+    user = factory.SubFactory(UserFactory)
+    experiment_id = factory.fuzzy.FuzzyInteger(0)
+    key = factory.Faker('word')
+    value = factory.Faker('word')
diff --git a/lms/djangoapps/experiments/filters.py b/lms/djangoapps/experiments/filters.py
new file mode 100644
index 0000000000..cfbf9be11e
--- /dev/null
+++ b/lms/djangoapps/experiments/filters.py
@@ -0,0 +1,9 @@
+import django_filters
+
+from experiments.models import ExperimentData
+
+
+class ExperimentDataFilter(django_filters.FilterSet):
+    class Meta(object):
+        model = ExperimentData
+        fields = ['experiment_id', 'key', ]
diff --git a/lms/djangoapps/experiments/migrations/0001_initial.py b/lms/djangoapps/experiments/migrations/0001_initial.py
new file mode 100644
index 0000000000..63aa19d55a
--- /dev/null
+++ b/lms/djangoapps/experiments/migrations/0001_initial.py
@@ -0,0 +1,40 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+from django.conf import settings
+import django_extensions.db.fields
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='ExperimentData',
+            fields=[
+                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
+                ('created', django_extensions.db.fields.CreationDateTimeField(auto_now_add=True, verbose_name='created')),
+                ('modified', django_extensions.db.fields.ModificationDateTimeField(auto_now=True, verbose_name='modified')),
+                ('experiment_id', models.PositiveSmallIntegerField(verbose_name=b'Experiment ID', db_index=True)),
+                ('key', models.CharField(max_length=255)),
+                ('value', models.TextField()),
+                ('user', models.ForeignKey(to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'verbose_name': 'Experiment Data',
+                'verbose_name_plural': 'Experiment Data',
+            },
+        ),
+        migrations.AlterUniqueTogether(
+            name='experimentdata',
+            unique_together=set([('user', 'experiment_id', 'key')]),
+        ),
+        migrations.AlterIndexTogether(
+            name='experimentdata',
+            index_together=set([('user', 'experiment_id')]),
+        ),
+    ]
diff --git a/lms/djangoapps/experiments/migrations/__init__.py b/lms/djangoapps/experiments/migrations/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/lms/djangoapps/experiments/models.py b/lms/djangoapps/experiments/models.py
new file mode 100644
index 0000000000..008620ef36
--- /dev/null
+++ b/lms/djangoapps/experiments/models.py
@@ -0,0 +1,22 @@
+from django.conf import settings
+from django.db import models
+from django_extensions.db.models import TimeStampedModel
+
+
+class ExperimentData(TimeStampedModel):
+    user = models.ForeignKey(settings.AUTH_USER_MODEL)
+    experiment_id = models.PositiveSmallIntegerField(
+        null=False, blank=False, db_index=True, verbose_name='Experiment ID'
+    )
+    key = models.CharField(null=False, blank=False, max_length=255)
+    value = models.TextField()
+
+    class Meta(object):
+        index_together = (
+            ('user', 'experiment_id'),
+        )
+        verbose_name = 'Experiment Data'
+        verbose_name_plural = 'Experiment Data'
+        unique_together = (
+            ('user', 'experiment_id', 'key'),
+        )
diff --git a/lms/djangoapps/experiments/permissions.py b/lms/djangoapps/experiments/permissions.py
new file mode 100644
index 0000000000..3e61be1eb5
--- /dev/null
+++ b/lms/djangoapps/experiments/permissions.py
@@ -0,0 +1,12 @@
+from openedx.core.lib.api import permissions
+
+
+class IsStaffOrOwner(permissions.IsStaffOrOwner):
+    """
+    Permission that allows access to admin users or the owner of an object.
+    The owner is considered the User object represented by obj.user.
+    """
+
+    def has_permission(self, request, view):
+        # The view will handle filtering for the current user
+        return True
diff --git a/lms/djangoapps/experiments/routers.py b/lms/djangoapps/experiments/routers.py
new file mode 100644
index 0000000000..d6161cfdf8
--- /dev/null
+++ b/lms/djangoapps/experiments/routers.py
@@ -0,0 +1,46 @@
+from rest_framework import routers
+from rest_framework.routers import DynamicDetailRoute, DynamicListRoute, Route
+
+
+class DefaultRouter(routers.DefaultRouter):
+    routes = [
+        # List route.
+        Route(
+            url=r'^{prefix}{trailing_slash}$',
+            mapping={
+                'get': 'list',
+                'post': 'create',
+                # Allow PUT as create
+                'put': 'create_or_update',
+            },
+            name='{basename}-list',
+            initkwargs={'suffix': 'List'}
+        ),
+        # Dynamically generated list routes.
+        # Generated using @list_route decorator
+        # on methods of the viewset.
+        DynamicListRoute(
+            url=r'^{prefix}/{methodname}{trailing_slash}$',
+            name='{basename}-{methodnamehyphen}',
+            initkwargs={}
+        ),
+        # Detail route.
+        Route(
+            url=r'^{prefix}/{lookup}{trailing_slash}$',
+            mapping={
+                'get': 'retrieve',
+                'put': 'update',
+                'patch': 'partial_update',
+                'delete': 'destroy'
+            },
+            name='{basename}-detail',
+            initkwargs={'suffix': 'Instance'}
+        ),
+        # Dynamically generated detail routes.
+        # Generated using @detail_route decorator on methods of the viewset.
+        DynamicDetailRoute(
+            url=r'^{prefix}/{lookup}/{methodname}{trailing_slash}$',
+            name='{basename}-{methodnamehyphen}',
+            initkwargs={}
+        ),
+    ]
diff --git a/lms/djangoapps/experiments/serializers.py b/lms/djangoapps/experiments/serializers.py
new file mode 100644
index 0000000000..c50433a692
--- /dev/null
+++ b/lms/djangoapps/experiments/serializers.py
@@ -0,0 +1,12 @@
+from rest_framework import serializers
+
+from .models import ExperimentData
+
+
+class ExperimentDataSerializer(serializers.ModelSerializer):
+    user = serializers.SlugRelatedField(read_only=True, slug_field='username', default=serializers.CurrentUserDefault())
+
+    class Meta(object):
+        model = ExperimentData
+        fields = ('id', 'experiment_id', 'user', 'key', 'value', 'created', 'modified',)
+        read_only_fields = ('user',)
diff --git a/lms/djangoapps/experiments/tests/__init__.py b/lms/djangoapps/experiments/tests/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/lms/djangoapps/experiments/tests/test_views.py b/lms/djangoapps/experiments/tests/test_views.py
new file mode 100644
index 0000000000..817d4a8319
--- /dev/null
+++ b/lms/djangoapps/experiments/tests/test_views.py
@@ -0,0 +1,127 @@
+import urllib
+
+from django.core.urlresolvers import reverse
+from rest_framework.test import APITestCase
+
+from experiments.factories import ExperimentDataFactory
+from experiments.models import ExperimentData
+from experiments.serializers import ExperimentDataSerializer
+from student.tests.factories import UserFactory
+
+
+class ExperimentDataViewSetTests(APITestCase):
+    def assert_data_created_for_user(self, user, method='post', status=201):
+        url = reverse('api_experiments:v0:data-list')
+        data = {
+            'experiment_id': 1,
+            'key': 'foo',
+            'value': 'bar',
+        }
+        self.client.login(username=user.username, password=UserFactory._DEFAULT_PASSWORD)
+        response = getattr(self.client, method)(url, data)
+        self.assertEqual(response.status_code, status)
+
+        # This will raise an exception if no data exists
+        ExperimentData.objects.get(user=user)
+
+        data['user'] = user.username
+        self.assertDictContainsSubset(data, response.data)
+
+    def test_list_permissions(self):
+        """ Users should only be able to list their own data. """
+        url = reverse('api_experiments:v0:data-list')
+        user = UserFactory()
+
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 401)
+
+        ExperimentDataFactory()
+        datum = ExperimentDataFactory(user=user)
+        self.client.login(username=user.username, password=UserFactory._DEFAULT_PASSWORD)
+
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.data['results'], ExperimentDataSerializer([datum], many=True).data)
+
+    def test_list_filtering(self):
+        """ Users should be able to filter by the experiment_id and key fields. """
+        url = reverse('api_experiments:v0:data-list')
+        user = UserFactory()
+        self.client.login(username=user.username, password=UserFactory._DEFAULT_PASSWORD)
+
+        experiment_id = 1
+        ExperimentDataFactory()
+        ExperimentDataFactory(user=user)
+        data = ExperimentDataFactory.create_batch(3, user=user, experiment_id=experiment_id)
+
+        qs = urllib.urlencode({'experiment_id': experiment_id})
+        response = self.client.get('{url}?{qs}'.format(url=url, qs=qs))
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.data['results'], ExperimentDataSerializer(data, many=True).data)
+
+        datum = data[0]
+        qs = urllib.urlencode({'key': datum.key})
+        response = self.client.get('{url}?{qs}'.format(url=url, qs=qs))
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.data['results'], ExperimentDataSerializer([datum], many=True).data)
+
+        qs = urllib.urlencode({'experiment_id': experiment_id, 'key': datum.key})
+        response = self.client.get('{url}?{qs}'.format(url=url, qs=qs))
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.data['results'], ExperimentDataSerializer([datum], many=True).data)
+
+    def test_read_permissions(self):
+        """ Users should only be allowed to read their own data. """
+        user = UserFactory()
+        datum = ExperimentDataFactory(user=user)
+        url = reverse('api_experiments:v0:data-detail', kwargs={'pk': datum.id})
+
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 401)
+
+        self.client.login(username=user.username, password=UserFactory._DEFAULT_PASSWORD)
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 200)
+
+        other_user = UserFactory()
+        self.client.login(username=other_user.username, password=UserFactory._DEFAULT_PASSWORD)
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 404)
+
+    def test_create_permissions(self):
+        """ Users should only be allowed to create data for themselves. """
+        url = reverse('api_experiments:v0:data-list')
+
+        # Authentication is required
+        response = self.client.post(url, {})
+        self.assertEqual(response.status_code, 401)
+
+        self.assert_data_created_for_user(UserFactory())
+        self.assert_data_created_for_user(UserFactory())
+
+    def test_put_as_create(self):
+        """ Users should be able to use PUT to create new data. """
+        user = UserFactory()
+        self.assert_data_created_for_user(user, 'put')
+
+        # Subsequent requests should update the data
+        self.assert_data_created_for_user(user, 'put', 200)
+
+    def test_update_permissions(self):
+        """ Users should only be allowed to update their own data. """
+        user = UserFactory()
+        other_user = UserFactory()
+        datum = ExperimentDataFactory(user=user)
+        url = reverse('api_experiments:v0:data-detail', kwargs={'pk': datum.id})
+        data = {}
+
+        response = self.client.patch(url, data)
+        self.assertEqual(response.status_code, 401)
+
+        self.client.login(username=user.username, password=UserFactory._DEFAULT_PASSWORD)
+        response = self.client.patch(url, data)
+        self.assertEqual(response.status_code, 200)
+
+        self.client.login(username=other_user.username, password=UserFactory._DEFAULT_PASSWORD)
+        response = self.client.patch(url, data)
+        self.assertEqual(response.status_code, 404)
diff --git a/lms/djangoapps/experiments/urls.py b/lms/djangoapps/experiments/urls.py
new file mode 100644
index 0000000000..635ea7b7e7
--- /dev/null
+++ b/lms/djangoapps/experiments/urls.py
@@ -0,0 +1,11 @@
+from django.conf.urls import include, url
+
+from experiments import routers
+from experiments.views import ExperimentDataViewSet
+
+router = routers.DefaultRouter()
+router.register(r'data', ExperimentDataViewSet, base_name='data')
+
+urlpatterns = [
+    url(r'^v0/', include(router.urls, namespace='v0')),
+]
diff --git a/lms/djangoapps/experiments/views.py b/lms/djangoapps/experiments/views.py
new file mode 100644
index 0000000000..4f6bf93d3e
--- /dev/null
+++ b/lms/djangoapps/experiments/views.py
@@ -0,0 +1,43 @@
+from edx_rest_framework_extensions.authentication import JwtAuthentication
+from rest_framework import permissions, viewsets
+from rest_framework.filters import DjangoFilterBackend
+
+from experiments import filters
+from experiments.models import ExperimentData
+from experiments.permissions import IsStaffOrOwner
+from experiments.serializers import ExperimentDataSerializer
+from openedx.core.lib.api.authentication import SessionAuthenticationAllowInactiveUser
+
+
+class ExperimentDataViewSet(viewsets.ModelViewSet):
+    authentication_classes = (JwtAuthentication, SessionAuthenticationAllowInactiveUser,)
+    filter_backends = (DjangoFilterBackend,)
+    filter_class = filters.ExperimentDataFilter
+    permission_classes = (permissions.IsAuthenticated, IsStaffOrOwner,)
+    queryset = ExperimentData.objects.all()
+    serializer_class = ExperimentDataSerializer
+
+    def filter_queryset(self, queryset):
+        queryset = queryset.filter(user=self.request.user)
+        return super(ExperimentDataViewSet, self).filter_queryset(queryset)
+
+    def create_or_update(self, request, *args, **kwargs):
+        # If we have a primary key, treat this as a regular update request
+        if self.kwargs.get('pk'):
+            return self.update(request, *args, **kwargs)
+
+        # If we only have data, check to see if an instance exists in the database. If so, update it.
+        # Otherwise, create a new instance.
+        experiment_id = request.data.get('experiment_id')
+        key = request.data.get('key')
+
+        if experiment_id and key:
+            try:
+                obj = self.get_queryset().get(user=self.request.user, experiment_id=experiment_id, key=key)
+                self.kwargs['pk'] = obj.pk
+                self.request.data['id'] = obj.pk
+                return self.update(request, *args, **kwargs)
+            except ExperimentData.DoesNotExist:
+                pass
+
+        return self.create(request, *args, **kwargs)
diff --git a/lms/envs/common.py b/lms/envs/common.py
index 72e0b9939f..84b675ffb9 100644
--- a/lms/envs/common.py
+++ b/lms/envs/common.py
@@ -2232,6 +2232,8 @@ INSTALLED_APPS = (
     'openedx.features.course_experience',
     'openedx.features.course_search',
     'openedx.features.enterprise_support',
+
+    'experiments',
 )
 
 ######################### CSRF #########################################
diff --git a/lms/urls.py b/lms/urls.py
index 6f12d30e13..ba5e524b53 100644
--- a/lms/urls.py
+++ b/lms/urls.py
@@ -108,10 +108,9 @@ urlpatterns = (
 
     # URLs for API access management
     url(r'^api-admin/', include('openedx.core.djangoapps.api_admin.urls', namespace='api_admin')),
-)
 
-urlpatterns += (
     url(r'^dashboard/', include('learner_dashboard.urls')),
+    url(r'^api/experiments/', include('experiments.urls', namespace='api_experiments')),
 )
 
 # TODO: This needs to move to a separate urls.py once the student_account and