From c905cc7416b87bb17ec4d9ec920188a9fba8e407 Mon Sep 17 00:00:00 2001
From: ichuang <ichuang@mit.edu>
Date: Tue, 2 Apr 2013 16:45:06 -0400
Subject: [PATCH] add masquerade.py

---
 lms/djangoapps/courseware/masquerade.py | 103 ++++++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 lms/djangoapps/courseware/masquerade.py

diff --git a/lms/djangoapps/courseware/masquerade.py b/lms/djangoapps/courseware/masquerade.py
new file mode 100644
index 0000000000..24d0c9f355
--- /dev/null
+++ b/lms/djangoapps/courseware/masquerade.py
@@ -0,0 +1,103 @@
+#---------------------------------------- Masequerade ----------------------------------------
+#
+# Allow course staff to see a student or staff view of courseware.
+# Which kind of view has been selected is stored in the session state.
+
+import json
+import logging
+import urllib
+
+from functools import partial
+
+from django.conf import settings
+from django.core.context_processors import csrf
+from django.core.urlresolvers import reverse
+from django.contrib.auth.models import User
+from django.contrib.auth.decorators import login_required
+from django.http import Http404
+from django.shortcuts import redirect
+from mitxmako.shortcuts import render_to_response, render_to_string
+#from django.views.decorators.csrf import ensure_csrf_cookie
+from django_future.csrf import ensure_csrf_cookie
+from django.views.decorators.cache import cache_control
+from django.http import HttpResponse
+
+from courseware import grades
+from courseware.access import has_access
+from courseware.courses import (get_courses, get_course_with_access,
+                                get_courses_by_university, sort_by_announcement)
+import courseware.tabs as tabs
+from courseware.models import StudentModuleCache
+from module_render import toc_for_course, get_module, get_instance_module, get_module_for_descriptor
+
+from django_comment_client.utils import get_discussion_title
+
+from student.models import UserTestGroup, CourseEnrollment
+from util.cache import cache, cache_if_anonymous
+from xmodule.modulestore import Location
+from xmodule.modulestore.django import modulestore
+from xmodule.modulestore.exceptions import InvalidLocationError, ItemNotFoundError, NoPathToItem
+from xmodule.modulestore.search import path_to_location
+
+log = logging.getLogger(__name__)
+
+def handle_ajax(request, marg):
+    log.debug('masquerade handle_ajax marg=%s' % marg)
+    return HttpResponse(json.dumps({}))
+
+
+MASQ_VAR = 'masquerade_identity'
+
+class Masquerade(object):
+    '''
+    Manage masquerade identity (allows staff to view courseware as either staff or student)
+
+    State variables:
+
+    actual_user = User instance of the real, un-masqueraded user
+    user = User instance (what actual user is masquerading as)
+    usertype = "staff" or "student" or "nonstaff"
+    
+    '''
+
+    def __init__(self, request, staff_access=False):
+        '''
+        request = Django http request object
+        '''
+        self.request = request
+        self.actual_user = request.user
+        self.user = request.user
+        self.usertype = "nonstaff"
+        if request.user is not None and staff_access:
+            self.usertype = request.session.get(MASQ_VAR,'staff')
+            if self.usertype=='student':
+                self.user = self.get_student_user()
+                    
+    def get_student_user(self):
+        '''
+        Each staff user can have a corresponding student identity, with
+        the same username + "__student".  Return that User.
+        Create the student user if doesn't already exist.
+        '''
+        suffix = '__student'
+        if self.user.username.endswith(suffix):
+            return self.user
+        user = User.get_or_create(username=self.user+suffix, email=self.user.email)
+        profile = UserProfile.get_or_create(user=user, name=self.user.profile.name+suffix)
+        return user
+
+    def toggle_status(self):
+        """
+        Toggle status from staff from student
+        """
+        if self.usertype=='student':
+            self.user = self.actual_user
+        elif self.usertype=='staff':
+            self.user = self.get_student_user()
+
+    def view_status(self):
+        '''
+        Return string version of status of view
+        '''
+        STAT = {'staff': '<font color="red">Staff view</font>', 'student': '<font color="orange">Student view</font>'}
+        return STAT.get(self.usertype,'')