From e9ec63e4b6488ad278edfa98f4566d861da796a2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carlos=20Andr=C3=A9s=20Rocha?= <rocha@edx.org>
Date: Mon, 15 Oct 2012 18:45:36 -0400
Subject: [PATCH] Add ajax endpoint to retrieve and assign course software
 licenses

---
 lms/djangoapps/licenses/models.py |  2 +-
 lms/djangoapps/licenses/views.py  | 53 ++++++++++++++++++++++++++++++-
 lms/urls.py                       |  8 +++++
 3 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/lms/djangoapps/licenses/models.py b/lms/djangoapps/licenses/models.py
index 929fba10ec..d259892f5d 100644
--- a/lms/djangoapps/licenses/models.py
+++ b/lms/djangoapps/licenses/models.py
@@ -65,7 +65,7 @@ def _create_license(user, software):
         # table/rows with select_for_update to prevent race conditions
         with transaction.commit_on_success():
             selected = UserLicense.objects.select_for_update()
-            license = selected.filter(user__isnull=True)[0]
+            license = selected.filter(user__isnull=True, software=software)[0]
             license.user = user
             license.save()
     except IndexError:
diff --git a/lms/djangoapps/licenses/views.py b/lms/djangoapps/licenses/views.py
index 7cf8e6591e..9b32478e0e 100644
--- a/lms/djangoapps/licenses/views.py
+++ b/lms/djangoapps/licenses/views.py
@@ -1,9 +1,18 @@
 import logging
+import json
+import re
+from urlparse import urlparse
 from collections import namedtuple, defaultdict
 
+
 from mitxmako.shortcuts import render_to_string
 
-from models import get_courses_licenses, get_or_create_license
+from django.contrib.auth.models import User
+from django.http import HttpResponse, Http404
+from django.views.decorators.csrf import requires_csrf_token, csrf_protect
+
+from models import CourseSoftware
+from models import get_courses_licenses, get_or_create_license, get_license
 
 
 log = logging.getLogger("mitx.licenses")
@@ -33,3 +42,45 @@ def get_licenses_by_course(user, courses):
         data_by_course[course_id] = render_to_string(template, context)
 
     return data_by_course
+
+
+@requires_csrf_token
+def user_software_license(request):
+    if request.method != 'POST' or not request.is_ajax():
+        raise Http404
+
+    # get the course id from the referer
+    url_path = urlparse(request.META.get('HTTP_REFERER', '')).path
+    pattern = re.compile('^/courses/(?P<id>[^/]+/[^/]+/[^/]+)/.*/?$')
+    match = re.match(pattern, url_path)
+
+    if not match:
+        raise Http404
+    course_id = match.groupdict().get('id', '')
+
+    user_id = request.session.get('_auth_user_id')
+    software_name = request.POST.get('software')
+    generate = request.POST.get('generate', False) == 'true'
+
+    print user_id, software_name, generate
+
+    try:
+        software = CourseSoftware.objects.get(name=software_name,
+                                              course_id=course_id)
+        print software
+    except CourseSoftware.DoesNotExist:
+        raise Http404
+
+    user = User.objects.get(id=user_id)
+
+    if generate:
+        license = get_or_create_license(user, software)
+    else:
+        license = get_license(user, software)
+
+    if license:
+        response = {'serial': license.serial}
+    else:
+        response = {'error': 'No serial number found'}
+
+    return HttpResponse(json.dumps(response), mimetype='application/json')
diff --git a/lms/urls.py b/lms/urls.py
index 89a541ab06..e025478387 100644
--- a/lms/urls.py
+++ b/lms/urls.py
@@ -154,6 +154,14 @@ if settings.COURSEWARE_ENABLED:
         url(r'^preview/chemcalc', 'courseware.module_render.preview_chemcalc',
             name='preview_chemcalc'),
 
+        # Software Licenses
+
+        # TODO: for now, this is the endpoint of an ajax replay
+        # service that retrieve and assigns license numbers for
+        # software assigned to a course. The numbers have to be loaded
+        # into the database.
+        url(r'^software-licenses$', 'licenses.views.user_software_license', name="user_software_license"),
+
         url(r'^courses/(?P<course_id>[^/]+/[^/]+/[^/]+)/xqueue/(?P<userid>[^/]*)/(?P<id>.*?)/(?P<dispatch>[^/]*)$',
             'courseware.module_render.xqueue_callback',
             name='xqueue_callback'),