Certificates: Add regeneration command

* Adds regenerate_user command, which lets you run certificates for one
  particular user in one particular class, regardless of whether they
  have a pre-existing certificate.

lms/djangoapps/certificates/management/commands/regenerate_user.py

+"""Django management command to force certificate regeneration for one user"""
+
+from optparse import make_option
+
+from django.contrib.auth.models import User
+from django.core.management.base import BaseCommand, CommandError
+
+from certificates.queue import XQueueCertInterface
+from xmodule.course_module import CourseDescriptor
+from xmodule.modulestore.django import modulestore
+
+
+class Command(BaseCommand):
+    help = """Put a request on the queue to recreate the certificate for a particular user in a particular course."""
+
+    option_list = BaseCommand.option_list + (
+        make_option('-n', '--noop',
+                    action='store_true',
+                    dest='noop',
+                    default=False,
+                    help="Don't grade or add certificate requests to the queue"),
+        make_option('-c', '--course',
+                    metavar='COURSE_ID',
+                    dest='course',
+                    default=False,
+                    help='The course id (e.g., mit/6-002x/circuits-and-electronics) for which the student named in'
+                         '<username> should be graded'),
+        make_option('-u', '--user',
+                    metavar='USERNAME',
+                    dest='username',
+                    default=False,
+                    help='The username or email address for whom grading and certification should be requested'),
+    )
+
+    def handle(self, *args, **options):
+
+        user = options['username']
+        course_id = options['course']
+        if not (course_id and user):
+            raise CommandError('both course id and student username are required')
+
+        student = None
+        print "Fetching enrollment for student {0} in {1}".format(user, course_id)
+        if '@' in user:
+            student = User.objects.get(email=user, courseenrollment__course_id=course_id)
+        else:
+            student = User.objects.get(username=user, courseenrollment__course_id=course_id)
+
+        print "Fetching course data for {0}".format(course_id)
+        course = modulestore().get_instance(course_id, CourseDescriptor.id_to_location(course_id), depth=2)
+
+        if not options['noop']:
+            # Add the certificate request to the queue
+            xq = XQueueCertInterface()
+            ret = xq.regen_cert(student, course_id, course=course)
+            print '{0} - {1}'.format(student, ret)
+        else:
+            print "noop option given, skipping work queueing..."

lms/djangoapps/certificates/management/commands/ungenerated_certs.py

@@ -14,12 +14,13 @@ from pytz import UTC
 class Command(BaseCommand):
 
     help = """
-    Find all students that need certificates
-    for courses that have finished and
-    put their cert requests on the queue
+    Find all students that need certificates for courses that have finished and
+    put their cert requests on the queue.
 
-    Use the --noop option to test without actually
-    putting certificates on the queue to be generated.
+    If --user is given, only grade and certify the requested username.
+
+    Use the --noop option to test without actually putting certificates on the
+    queue to be generated.
     """
 
     option_list = BaseCommand.option_list + (
@@ -80,6 +81,7 @@ class Command(BaseCommand):
             enrolled_students = User.objects.filter(
                 courseenrollment__course_id=course_id).prefetch_related(
                     "groups").order_by('username')
+
             xq = XQueueCertInterface()
             total = enrolled_students.count()
             count = 0

lms/djangoapps/certificates/models.py

@@ -52,15 +52,15 @@ Eligibility:
 
 
 class CertificateStatuses(object):
-    unavailable = 'unavailable'
-    generating = 'generating'
-    regenerating = 'regenerating'
-    deleting = 'deleting'
-    deleted = 'deleted'
+    deleted      = 'deleted'
+    deleting     = 'deleting'
     downloadable = 'downloadable'
-    notpassing = 'notpassing'
-    restricted = 'restricted'
-    error = 'error'
+    error        = 'error'
+    generating   = 'generating'
+    notpassing   = 'notpassing'
+    regenerating = 'regenerating'
+    restricted   = 'restricted'
+    unavailable  = 'unavailable'
 
 
 class CertificateWhitelist(models.Model):

lms/djangoapps/certificates/queue.py

@@ -75,28 +75,34 @@ class XQueueCertInterface(object):
         self.whitelist = CertificateWhitelist.objects.all()
         self.restricted = UserProfile.objects.filter(allow_certificate=False)
 
-    def regen_cert(self, student, course_id):
-        """
+    def regen_cert(self, student, course_id, course=None):
+        """(Re-)Make certificate for a particular student in a particular course
+
         Arguments:
-          student - User.object
+          student   - User.object
           course_id - courseenrollment.course_id (string)
 
-        Removes certificate for a student, will change
-        the certificate status to 'regenerating'.
-
-        Certificate must be in the 'error' or 'downloadable' state
-
-        If the student has a passing grade a certificate
-        request will be put on the queue
-
-        If the student is not passing his state will change
-        to status.notpassing
+        WARNING: this command will leave the old certificate, if one exists,
+                 laying around in AWS taking up space. If this is a problem, 
+                 take pains to clean up storage before running this command.
 
-        otherwise it will return the current state
+        Change the certificate status to unavailable (if it exists) and request
+        grading. Passing grades will put a certificate request on the queue.
 
+        Return the status object.
         """
-
-        raise NotImplementedError
+        # TODO: when del_cert is implemented and plumbed through certificates 
+        #       repo also, do a deletion followed by a creation r/t a simple
+        #       recreation. XXX: this leaves orphan cert files laying around in
+        #       AWS. See note in the docstring too.
+        try:
+            certificate = GeneratedCertificate.objects.get(user=student, course_id=course_id)
+            certificate.status = status.unavailable
+            certificate.save()
+        except GeneratedCertificate.DoesNotExist:
+            pass
+
+        return self.add_cert(student, course_id, course)
 
     def del_cert(self, student, course_id):
 
@@ -134,7 +140,6 @@ class XQueueCertInterface(object):
         If a student has allow_certificate set to False in the
         userprofile table the status will change to 'restricted'
 
-
         If a student does not have a passing grade the status
         will change to status.notpassing
 
@@ -143,11 +148,12 @@ class XQueueCertInterface(object):
         """
 
         VALID_STATUSES = [status.generating,
-                status.unavailable, status.deleted, status.error,
-                status.notpassing]
+                          status.unavailable, 
+                          status.deleted, 
+                          status.error,
+                          status.notpassing]
 
-        cert_status = certificate_status_for_student(
-                              student, course_id)['status']
+        cert_status = certificate_status_for_student(student, course_id)['status']
 
         if cert_status in VALID_STATUSES:
             # grade the student