views.py

import datetime
import feedparser
#import itertools
import json
import logging
import random
import string
import sys
#import time
import urllib
import uuid


from django.conf import settings
from django.contrib.auth import logout, authenticate, login
from django.contrib.auth.forms import PasswordResetForm
from django.contrib.auth.models import User
from django.contrib.auth.decorators import login_required
from django.core.context_processors import csrf
from django.core.mail import send_mail
from django.core.validators import validate_email, validate_slug, ValidationError
from django.db import IntegrityError
from django.http import HttpResponse, HttpResponseForbidden, Http404
from django.shortcuts import redirect
from mitxmako.shortcuts import render_to_response, render_to_string
from bs4 import BeautifulSoup
from django.core.cache import cache

from django_future.csrf import ensure_csrf_cookie, csrf_exempt
from student.models import (Registration, UserProfile, TestCenterUser, TestCenterUserForm,
                            TestCenterRegistration, TestCenterRegistrationForm,
                            PendingNameChange, PendingEmailChange,
                            CourseEnrollment, unique_id_for_user,
                            get_testcenter_registration)

from certificates.models import CertificateStatuses, certificate_status_for_student

from xmodule.course_module import CourseDescriptor
from xmodule.modulestore.exceptions import ItemNotFoundError
from xmodule.modulestore.django import modulestore

#from datetime import date
from collections import namedtuple

from courseware.courses import get_courses, sort_by_announcement
from courseware.access import has_access

from statsd import statsd

log = logging.getLogger("mitx.student")
Article = namedtuple('Article', 'title url author image deck publication publish_date')

def csrf_token(context):
    ''' A csrf token that can be included in a form.
    '''
    csrf_token = context.get('csrf_token', '')
    if csrf_token == 'NOTPROVIDED':
        return ''
    return (u'<div style="display:none"><input type="hidden"'
            ' name="csrfmiddlewaretoken" value="%s" /></div>' % (csrf_token))


# NOTE: This view is not linked to directly--it is called from
# branding/views.py:index(), which is cached for anonymous users.
# This means that it should always return the same thing for anon
# users. (in particular, no switching based on query params allowed)
def index(request, extra_context={}, user=None):
    '''
    Render the edX main page.

    extra_context is used to allow immediate display of certain modal windows, eg signup,
    as used by external_auth.
    '''

    # The course selection work is done in courseware.courses.
    domain = settings.MITX_FEATURES.get('FORCE_UNIVERSITY_DOMAIN')	# normally False
    if domain==False:				# do explicit check, because domain=None is valid
        domain = request.META.get('HTTP_HOST')

    courses = get_courses(None, domain=domain)
    courses = sort_by_announcement(courses)

    # Get the 3 most recent news
    top_news = _get_news(top=3)

    context = {'courses': courses, 'news': top_news}
    context.update(extra_context)
    return render_to_response('index.html', context)


def course_from_id(course_id):
    """Return the CourseDescriptor corresponding to this course_id"""
    course_loc = CourseDescriptor.id_to_location(course_id)
    return modulestore().get_instance(course_id, course_loc)

import re
day_pattern = re.compile('\s\d+,\s')
multimonth_pattern = re.compile('\s?\-\s?\S+\s')

def get_date_for_press(publish_date):
    import datetime
    # strip off extra months, and just use the first:
    date = re.sub(multimonth_pattern, ", ", publish_date)
    if re.search(day_pattern, date):
        date = datetime.datetime.strptime(date, "%B %d, %Y")
    else:
        date = datetime.datetime.strptime(date, "%B, %Y")
    return date

def press(request):
    json_articles = cache.get("student_press_json_articles")
    if json_articles == None:
        if hasattr(settings, 'RSS_URL'):
            content = urllib.urlopen(settings.PRESS_URL).read()
            json_articles = json.loads(content)
        else:
            content = open(settings.PROJECT_ROOT / "templates" / "press.json").read()
            json_articles = json.loads(content)
        cache.set("student_press_json_articles", json_articles)
    articles = [Article(**article) for article in json_articles]
    articles.sort(key=lambda item: get_date_for_press(item.publish_date), reverse=True)
    return render_to_response('static_templates/press.html', {'articles': articles})


def process_survey_link(survey_link, user):
    """
    If {UNIQUE_ID} appears in the link, replace it with a unique id for the user.
    Currently, this is sha1(user.username).  Otherwise, return survey_link.
    """
    return survey_link.format(UNIQUE_ID=unique_id_for_user(user))


def cert_info(user, course):
    """
    Get the certificate info needed to render the dashboard section for the given
    student and course.  Returns a dictionary with keys:

    'status': one of 'generating', 'ready', 'notpassing', 'processing'
    'show_download_url': bool
    'download_url': url, only present if show_download_url is True
    'show_disabled_download_button': bool -- true if state is 'generating'
    'show_survey_button': bool
    'survey_url': url, only if show_survey_button is True
    'grade': if status is not 'processing'
    """
    if not course.has_ended():
        return {}

    return _cert_info(user, course, certificate_status_for_student(user, course.id))

def _cert_info(user, course, cert_status):
    """
    Implements the logic for cert_info -- split out for testing.
    """
    default_status = 'processing'

    default_info = {'status': default_status,
                    'show_disabled_download_button': False,
                    'show_download_url': False,
                    'show_survey_button': False}

    if cert_status is None:
        return default_info

    # simplify the status for the template using this lookup table
    template_state = {
        CertificateStatuses.generating: 'generating',
        CertificateStatuses.regenerating: 'generating',
        CertificateStatuses.downloadable: 'ready',
        CertificateStatuses.notpassing: 'notpassing',
        }

    status = template_state.get(cert_status['status'], default_status)

    d = {'status': status,
         'show_download_url': status == 'ready',
         'show_disabled_download_button': status == 'generating',}

    if (status in ('generating', 'ready', 'notpassing') and
        course.end_of_course_survey_url is not None):
        d.update({
         'show_survey_button': True,
         'survey_url': process_survey_link(course.end_of_course_survey_url, user)})
    else:
        d['show_survey_button'] = False

    if status == 'ready':
        if 'download_url' not in cert_status:
            log.warning("User %s has a downloadable cert for %s, but no download url",
                        user.username, course.id)
            return default_info
        else:
            d['download_url'] = cert_status['download_url']

    if status in ('generating', 'ready', 'notpassing'):
        if 'grade' not in cert_status:
            # Note: as of 11/20/2012, we know there are students in this state-- cs169.1x,
            # who need to be regraded (we weren't tracking 'notpassing' at first).
            # We can add a log.warning here once we think it shouldn't happen.
            return default_info
        else:
            d['grade'] = cert_status['grade']

    return d

@login_required
@ensure_csrf_cookie
def dashboard(request):
    user = request.user
    enrollments = CourseEnrollment.objects.filter(user=user)

    # Build our courses list for the user, but ignore any courses that no longer
    # exist (because the course IDs have changed). Still, we don't delete those
    # enrollments, because it could have been a data push snafu.
    courses = []
    for enrollment in enrollments:
        try:
            courses.append(course_from_id(enrollment.course_id))
        except ItemNotFoundError:
            log.error("User {0} enrolled in non-existent course {1}"
                      .format(user.username, enrollment.course_id))

    message = ""
    if not user.is_active:
        message = render_to_string('registration/activate_account_notice.html', {'email': user.email})


    # Global staff can see what courses errored on their dashboard
    staff_access = False
    errored_courses = {}
    if has_access(user, 'global', 'staff'):
        # Show any courses that errored on load
        staff_access = True
        errored_courses = modulestore().get_errored_courses()

    show_courseware_links_for = frozenset(course.id for course in courses
                                          if has_access(request.user, course, 'load'))

    cert_statuses = { course.id: cert_info(request.user, course) for course in courses}

    exam_registrations = { course.id: exam_registration_info(request.user, course) for course in courses}

    # Get the 3 most recent news
    top_news = _get_news(top=3)

    context = {'courses': courses,
               'message': message,
               'staff_access': staff_access,
               'errored_courses': errored_courses,
               'show_courseware_links_for' : show_courseware_links_for,
               'cert_statuses': cert_statuses,
               'news': top_news,
               'exam_registrations': exam_registrations,
               }

    return render_to_response('dashboard.html', context)


def try_change_enrollment(request):
    """
    This method calls change_enrollment if the necessary POST
    parameters are present, but does not return anything. It
    simply logs the result or exception. This is usually
    called after a registration or login, as secondary action.
    It should not interrupt a successful registration or login.
    """
    if 'enrollment_action' in request.POST:
        try:
            enrollment_output = change_enrollment(request)
            # There isn't really a way to display the results to the user, so we just log it
            # We expect the enrollment to be a success, and will show up on the dashboard anyway
            log.info("Attempted to automatically enroll after login. Results: {0}".format(enrollment_output))
        except Exception, e:
            log.exception("Exception automatically enrolling after login: {0}".format(str(e)))


@login_required
def change_enrollment_view(request):
    """Delegate to change_enrollment to actually do the work."""
    return HttpResponse(json.dumps(change_enrollment(request)))



def change_enrollment(request):
    if request.method != "POST":
        raise Http404

    user = request.user
    if not user.is_authenticated():
        raise Http404

    action = request.POST.get("enrollment_action", "")

    course_id = request.POST.get("course_id", None)
    if course_id == None:
        return HttpResponse(json.dumps({'success': False,
                                        'error': 'There was an error receiving the course id.'}))

    if action == "enroll":
        # Make sure the course exists
        # We don't do this check on unenroll, or a bad course id can't be unenrolled from
        try:
            course = course_from_id(course_id)
        except ItemNotFoundError:
            log.warning("User {0} tried to enroll in non-existent course {1}"
                      .format(user.username, enrollment.course_id))
            return {'success': False, 'error': 'The course requested does not exist.'}

        if not has_access(user, course, 'enroll'):
            return {'success': False,
                    'error': 'enrollment in {} not allowed at this time'
                    .format(course.display_name)}

        org, course_num, run=course_id.split("/")
        statsd.increment("common.student.enrollment",
                        tags=["org:{0}".format(org),
                              "course:{0}".format(course_num),
                              "run:{0}".format(run)])

        enrollment, created = CourseEnrollment.objects.get_or_create(user=user, course_id=course.id)
        return {'success': True}

    elif action == "unenroll":
        try:
            enrollment = CourseEnrollment.objects.get(user=user, course_id=course_id)
            enrollment.delete()

            org, course_num, run=course_id.split("/")
            statsd.increment("common.student.unenrollment",
                            tags=["org:{0}".format(org),
                                  "course:{0}".format(course_num),
                                  "run:{0}".format(run)])

            return {'success': True}
        except CourseEnrollment.DoesNotExist:
            return {'success': False, 'error': 'You are not enrolled for this course.'}
    else:
        return {'success': False, 'error': 'Invalid enrollment_action.'}

    return {'success': False, 'error': 'We weren\'t able to unenroll you. Please try again.'}


@ensure_csrf_cookie
def accounts_login(request, error=""):


    return render_to_response('accounts_login.html', { 'error': error })



# Need different levels of logging
@ensure_csrf_cookie
def login_user(request, error=""):
    ''' AJAX request to log in the user. '''
    if 'email' not in request.POST or 'password' not in request.POST:
        return HttpResponse(json.dumps({'success': False,
                                        'value': 'There was an error receiving your login information. Please email us.'}))  # TODO: User error message

    email = request.POST['email']
    password = request.POST['password']
    try:
        user = User.objects.get(email=email)
    except User.DoesNotExist:
        log.warning("Login failed - Unknown user email: {0}".format(email))
        return HttpResponse(json.dumps({'success': False,
                                        'value': 'Email or password is incorrect.'}))  # TODO: User error message

    username = user.username
    user = authenticate(username=username, password=password)
    if user is None:
        log.warning("Login failed - password for {0} is invalid".format(email))
        return HttpResponse(json.dumps({'success': False,
                                        'value': 'Email or password is incorrect.'}))

    if user is not None and user.is_active:
        try:
            login(request, user)
            if request.POST.get('remember') == 'true':
                request.session.set_expiry(None)  # or change to 604800 for 7 days
                log.debug("Setting user session to never expire")
            else:
                request.session.set_expiry(0)
        except Exception as e:
            log.critical("Login failed - Could not create session. Is memcached running?")
            log.exception(e)

        log.info("Login success - {0} ({1})".format(username, email))

        try_change_enrollment(request)

        statsd.increment("common.student.successful_login")

        return HttpResponse(json.dumps({'success': True}))

    log.warning("Login failed - Account not active for user {0}, resending activation".format(username))

    reactivation_email_for_user(user)
    not_activated_msg = "This account has not been activated. We have " + \
                        "sent another activation message. Please check your " + \
                        "e-mail for the activation instructions."
    return HttpResponse(json.dumps({'success': False,
                                    'value': not_activated_msg}))


@ensure_csrf_cookie
def logout_user(request):
    ''' HTTP request to log out the user. Redirects to marketing page'''
    logout(request)
    return redirect('/')


@login_required
@ensure_csrf_cookie
def change_setting(request):
    ''' JSON call to change a profile setting: Right now, location
    '''
    # TODO (vshnayder): location is no longer used
    up = UserProfile.objects.get(user=request.user)  # request.user.profile_cache
    if 'location' in request.POST:
        up.location = request.POST['location']
    up.save()

    return HttpResponse(json.dumps({'success': True,
                                    'location': up.location, }))

def _do_create_account(post_vars):
    """
    Given cleaned post variables, create the User and UserProfile objects, as well as the
    registration for this user.

    Returns a tuple (User, UserProfile, Registration).

    Note: this function is also used for creating test users.
    """
    user = User(username=post_vars['username'],
             email=post_vars['email'],
             is_active=False)
    user.set_password(post_vars['password'])
    registration = Registration()
    # TODO: Rearrange so that if part of the process fails, the whole process fails.
    # Right now, we can have e.g. no registration e-mail sent out and a zombie account
    try:
        user.save()
    except IntegrityError:
        js = {'success': False}
        # Figure out the cause of the integrity error
        if len(User.objects.filter(username=post_vars['username'])) > 0:
            js['value'] = "An account with this username already exists."
            js['field'] = 'username'
            return HttpResponse(json.dumps(js))

        if len(User.objects.filter(email=post_vars['email'])) > 0:
            js['value'] = "An account with this e-mail already exists."
            js['field'] = 'email'
            return HttpResponse(json.dumps(js))

        raise

    registration.register(user)

    profile = UserProfile(user=user)
    profile.name = post_vars['name']
    profile.level_of_education = post_vars.get('level_of_education')
    profile.gender = post_vars.get('gender')
    profile.mailing_address = post_vars.get('mailing_address')
    profile.goals = post_vars.get('goals')

    try:
        profile.year_of_birth = int(post_vars['year_of_birth'])
    except (ValueError, KeyError):
        # If they give us garbage, just ignore it instead
        # of asking them to put an integer.
        profile.year_of_birth = None
    try:
        profile.save()
    except Exception:
        log.exception("UserProfile creation failed for user {0}.".format(user.id))
    return (user, profile, registration)


@ensure_csrf_cookie
def create_account(request, post_override=None):
    '''
    JSON call to create new edX account.
    Used by form in signup_modal.html, which is included into navigation.html
    '''
    js = {'success': False}

    post_vars = post_override if post_override else request.POST

    # if doing signup for an external authorization, then get email, password, name from the eamap
    # don't use the ones from the form, since the user could have hacked those
    DoExternalAuth = 'ExternalAuthMap' in request.session
    if DoExternalAuth:
        eamap = request.session['ExternalAuthMap']
        email = eamap.external_email
        name = eamap.external_name
        password = eamap.internal_password
        post_vars = dict(post_vars.items())
        post_vars.update(dict(email=email, name=name, password=password))
        log.debug('extauth test: post_vars = %s' % post_vars)

    # Confirm we have a properly formed request
    for a in ['username', 'email', 'password', 'name']:
        if a not in post_vars:
            js['value'] = "Error (401 {field}). E-mail us.".format(field=a)
            js['field'] = a
            return HttpResponse(json.dumps(js))

    if post_vars.get('honor_code', 'false') != u'true':
        js['value'] = "To enroll, you must follow the honor code.".format(field=a)
        js['field'] = 'honor_code'
        return HttpResponse(json.dumps(js))

    if post_vars.get('terms_of_service', 'false') != u'true':
        js['value'] = "You must accept the terms of service.".format(field=a)
        js['field'] = 'terms_of_service'
        return HttpResponse(json.dumps(js))

    # Confirm appropriate fields are there.
    # TODO: Check e-mail format is correct.
    # TODO: Confirm e-mail is not from a generic domain (mailinator, etc.)? Not sure if
    # this is a good idea
    # TODO: Check password is sane
    for a in ['username', 'email', 'name', 'password', 'terms_of_service', 'honor_code']:
        if len(post_vars[a]) < 2:
            error_str = {'username': 'Username must be minimum of two characters long.',
                         'email': 'A properly formatted e-mail is required.',
                         'name': 'Your legal name must be a minimum of two characters long.',
                         'password': 'A valid password is required.',
                         'terms_of_service': 'Accepting Terms of Service is required.',
                         'honor_code': 'Agreeing to the Honor Code is required.'}
            js['value'] = error_str[a]
            js['field'] = a
            return HttpResponse(json.dumps(js))

    try:
        validate_email(post_vars['email'])
    except ValidationError:
        js['value'] = "Valid e-mail is required.".format(field=a)
        js['field'] = 'email'
        return HttpResponse(json.dumps(js))

    try:
        validate_slug(post_vars['username'])
    except ValidationError:
        js['value'] = "Username should only consist of A-Z and 0-9.".format(field=a)
        js['field'] = 'username'
        return HttpResponse(json.dumps(js))

    # Ok, looks like everything is legit.  Create the account.
    ret = _do_create_account(post_vars)
    if isinstance(ret,HttpResponse):		# if there was an error then return that
        return ret
    (user, profile, registration) = ret

    d = {'name': post_vars['name'],
         'key': registration.activation_key,
         }

    # composes activation email
    subject = render_to_string('emails/activation_email_subject.txt', d)
    # Email subject *must not* contain newlines
    subject = ''.join(subject.splitlines())
    message = render_to_string('emails/activation_email.txt', d)

    try:
        if settings.MITX_FEATURES.get('REROUTE_ACTIVATION_EMAIL'):
            dest_addr = settings.MITX_FEATURES['REROUTE_ACTIVATION_EMAIL']
            message = ("Activation for %s (%s): %s\n" % (user, user.email, profile.name) +
                       '-' * 80 + '\n\n' + message)
            send_mail(subject, message, settings.DEFAULT_FROM_EMAIL, [dest_addr], fail_silently=False)
        elif not settings.GENERATE_RANDOM_USER_CREDENTIALS:
            res = user.email_user(subject, message, settings.DEFAULT_FROM_EMAIL)
    except:
        log.exception(sys.exc_info())
        js['value'] = 'Could not send activation e-mail.'
        return HttpResponse(json.dumps(js))

    # Immediately after a user creates an account, we log them in. They are only
    # logged in until they close the browser. They can't log in again until they click
    # the activation link from the email.
    login_user = authenticate(username=post_vars['username'], password=post_vars['password'])
    login(request, login_user)
    request.session.set_expiry(0)

    try_change_enrollment(request)

    if DoExternalAuth:
        eamap.user = login_user
        eamap.dtsignup = datetime.datetime.now()
        eamap.save()
        log.debug('Updated ExternalAuthMap for %s to be %s' % (post_vars['username'],eamap))

        if settings.MITX_FEATURES.get('BYPASS_ACTIVATION_EMAIL_FOR_EXTAUTH'):
            log.debug('bypassing activation email')
            login_user.is_active = True
            login_user.save()

    statsd.increment("common.student.account_created")

    js = {'success': True}
    return HttpResponse(json.dumps(js), mimetype="application/json")

def exam_registration_info(user, course):
    """ Returns a Registration object if the user is currently registered for a current
    exam of the course.  Returns None if the user is not registered, or if there is no
    current exam for the course.
    """
    exam_info = course.current_test_center_exam
    if exam_info is None:
        return None

    exam_code = exam_info.exam_series_code
    registrations = get_testcenter_registration(user, course.id, exam_code)
    if registrations:
        registration = registrations[0]
    else:
        registration = None
    return registration

@login_required
@ensure_csrf_cookie
def begin_exam_registration(request, course_id):
    """ Handles request to register the user for the current
    test center exam of the specified course.  Called by form
    in dashboard.html.
    """
    user = request.user

    try:
        course = course_from_id(course_id)
    except ItemNotFoundError:
        log.error("User {0} enrolled in non-existent course {1}".format(user.username, course_id))
        raise Http404

    # get the exam to be registered for:
    # (For now, we just assume there is one at most.)
    # if there is no exam now (because someone bookmarked this stupid page),
    # then return a 404:
    exam_info = course.current_test_center_exam
    if exam_info is None:
        raise Http404

    # determine if the user is registered for this course:
    registration = exam_registration_info(user, course)

    # we want to populate the registration page with the relevant information,
    # if it already exists.  Create an empty object otherwise.
    try:
        testcenteruser = TestCenterUser.objects.get(user=user)
    except TestCenterUser.DoesNotExist:
        testcenteruser = TestCenterUser()
        testcenteruser.user = user

    context = {'course': course,
               'user': user,
               'testcenteruser': testcenteruser,
               'registration': registration,
               'exam_info': exam_info,
               }

    return render_to_response('test_center_register.html', context)

@ensure_csrf_cookie
def create_exam_registration(request, post_override=None):
    '''
    JSON call to create a test center exam registration.
    Called by form in test_center_register.html
    '''
    post_vars = post_override if post_override else request.POST

    # first determine if we need to create a new TestCenterUser, or if we are making any update
    # to an existing TestCenterUser.
    username = post_vars['username']
    user = User.objects.get(username=username)
    course_id = post_vars['course_id']
    course = course_from_id(course_id)  # assume it will be found....

    # make sure that any demographic data values received from the page have been stripped.
    # Whitespace is not an acceptable response for any of these values
    demographic_data = {}
    for fieldname in TestCenterUser.user_provided_fields():
        if fieldname in post_vars:
            demographic_data[fieldname] = (post_vars[fieldname]).strip()

    try:
        testcenter_user = TestCenterUser.objects.get(user=user)
        needs_updating = testcenter_user.needs_update(demographic_data)
        log.info("User {0} enrolled in course {1} {2}updating demographic info for exam registration".format(user.username, course_id, "" if needs_updating else "not "))
    except TestCenterUser.DoesNotExist:
        # do additional initialization here:
        testcenter_user = TestCenterUser.create(user)
        needs_updating = True
        log.info("User {0} enrolled in course {1} creating demographic info for exam registration".format(user.username, course_id))

    # perform validation:
    if needs_updating:
        # first perform validation on the user information
        # using a Django Form.
        form = TestCenterUserForm(instance=testcenter_user, data=demographic_data)
        if form.is_valid():
            form.update_and_save()
        else:
            response_data = {'success': False}
            # return a list of errors...
            response_data['field_errors'] = form.errors
            response_data['non_field_errors'] = form.non_field_errors()
            return HttpResponse(json.dumps(response_data), mimetype="application/json")

    # create and save the registration:
    needs_saving = False
    exam = course.current_test_center_exam
    exam_code = exam.exam_series_code
    registrations = get_testcenter_registration(user, course_id, exam_code)
    if registrations:
        registration = registrations[0]
        # NOTE: we do not bother to check here to see if the registration has changed,
        # because at the moment there is no way for a user to change anything about their
        # registration.  They only provide an optional accommodation request once, and
        # cannot make changes to it thereafter.
        # It is possible that the exam_info content has been changed, such as the
        # scheduled exam dates, but those kinds of changes should not be handled through
        # this registration screen.

    else:
        accommodation_request = post_vars.get('accommodation_request','')
        registration = TestCenterRegistration.create(testcenter_user, exam, accommodation_request)
        needs_saving = True
        log.info("User {0} enrolled in course {1} creating new exam registration".format(user.username, course_id))

    if needs_saving:
        # do validation of registration.  (Mainly whether an accommodation request is too long.)
        form = TestCenterRegistrationForm(instance=registration, data=post_vars)
        if form.is_valid():
            form.update_and_save()
        else:
            response_data = {'success': False}
            # return a list of errors...
            response_data['field_errors'] = form.errors
            response_data['non_field_errors'] = form.non_field_errors()
            return HttpResponse(json.dumps(response_data), mimetype="application/json")


    # only do the following if there is accommodation text to send,
    # and a destination to which to send it.
    # TODO: still need to create the accommodation email templates
#    if 'accommodation_request' in post_vars and 'TESTCENTER_ACCOMMODATION_REQUEST_EMAIL' in settings:
#        d = {'accommodation_request': post_vars['accommodation_request'] }
#
#        # composes accommodation email
#        subject = render_to_string('emails/accommodation_email_subject.txt', d)
#        # Email subject *must not* contain newlines
#        subject = ''.join(subject.splitlines())
#        message = render_to_string('emails/accommodation_email.txt', d)
#
#        try:
#            dest_addr = settings['TESTCENTER_ACCOMMODATION_REQUEST_EMAIL']
#            from_addr = user.email
#            send_mail(subject, message, from_addr, [dest_addr], fail_silently=False)
#        except:
#            log.exception(sys.exc_info())
#            response_data = {'success': False}
#            response_data['non_field_errors'] =  [ 'Could not send accommodation e-mail.', ]
#            return HttpResponse(json.dumps(response_data), mimetype="application/json")


    js = {'success': True}
    return HttpResponse(json.dumps(js), mimetype="application/json")


def get_random_post_override():
    """
    Return a dictionary suitable for passing to post_vars of _do_create_account or post_override
    of create_account, with random user info.
    """
    def id_generator(size=6, chars=string.ascii_uppercase + string.ascii_lowercase + string.digits):
        return ''.join(random.choice(chars) for x in range(size))

    return {'username': "random_" + id_generator(),
            'email': id_generator(size=10, chars=string.ascii_lowercase) + "_dummy_test@mitx.mit.edu",
            'password': id_generator(),
            'name': (id_generator(size=5, chars=string.ascii_lowercase) + " " +
                     id_generator(size=7, chars=string.ascii_lowercase)),
                     'honor_code': u'true',
                     'terms_of_service': u'true', }


def create_random_account(create_account_function):
    def inner_create_random_account(request):
        return create_account_function(request, post_override=get_random_post_override())

    return inner_create_random_account

# TODO (vshnayder): do we need GENERATE_RANDOM_USER_CREDENTIALS for anything?
if settings.GENERATE_RANDOM_USER_CREDENTIALS:
    create_account = create_random_account(create_account)


@ensure_csrf_cookie
def activate_account(request, key):
    ''' When link in activation e-mail is clicked
    '''
    r = Registration.objects.filter(activation_key=key)
    if len(r) == 1:
        user_logged_in = request.user.is_authenticated()
        already_active = True
        if not r[0].user.is_active:
            r[0].activate()
            already_active = False
        resp = render_to_response("registration/activation_complete.html", {'user_logged_in': user_logged_in, 'already_active': already_active})
        return resp
    if len(r) == 0:
        return render_to_response("registration/activation_invalid.html", {'csrf': csrf(request)['csrf_token']})
    return HttpResponse("Unknown error. Please e-mail us to let us know how it happened.")


@ensure_csrf_cookie
def password_reset(request):
    ''' Attempts to send a password reset e-mail. '''
    if request.method != "POST":
        raise Http404

    # By default, Django doesn't allow Users with is_active = False to reset their passwords,
    # but this bites people who signed up a long time ago, never activated, and forgot their
    # password. So for their sake, we'll auto-activate a user for whom password_reset is called.
    try:
        user = User.objects.get(email=request.POST['email'])
        user.is_active = True
        user.save()
    except:
        log.exception("Tried to auto-activate user to enable password reset, but failed.")

    form = PasswordResetForm(request.POST)
    if form.is_valid():
        form.save(use_https = request.is_secure(),
                  from_email = settings.DEFAULT_FROM_EMAIL,
                  request = request,
                  domain_override = request.get_host())
        return HttpResponse(json.dumps({'success':True,
                                        'value': render_to_string('registration/password_reset_done.html', {})}))
    else:
        return HttpResponse(json.dumps({'success': False,
                                        'error': 'Invalid e-mail'}))

@ensure_csrf_cookie
def reactivation_email(request):
    ''' Send an e-mail to reactivate a deactivated account, or to
    resend an activation e-mail. Untested. '''
    email = request.POST['email']
    try:
        user = User.objects.get(email='email')
    except User.DoesNotExist:
        return HttpResponse(json.dumps({'success': False,
                                        'error': 'No inactive user with this e-mail exists'}))
    return reactivation_email_for_user(user)

def reactivation_email_for_user(user):
    reg = Registration.objects.get(user=user)

    d = {'name': user.profile.name,
         'key': reg.activation_key}

    subject = render_to_string('emails/activation_email_subject.txt', d)
    subject = ''.join(subject.splitlines())
    message = render_to_string('emails/activation_email.txt', d)

    res = user.email_user(subject, message, settings.DEFAULT_FROM_EMAIL)

    return HttpResponse(json.dumps({'success': True}))


@ensure_csrf_cookie
def change_email_request(request):
    ''' AJAX call from the profile page. User wants a new e-mail.
    '''
    ## Make sure it checks for existing e-mail conflicts
    if not request.user.is_authenticated:
        raise Http404

    user = request.user

    if not user.check_password(request.POST['password']):
        return HttpResponse(json.dumps({'success': False,
                                        'error': 'Invalid password'}))

    new_email = request.POST['new_email']
    try:
        validate_email(new_email)
    except ValidationError:
        return HttpResponse(json.dumps({'success': False,
                                        'error': 'Valid e-mail address required.'}))

    if len(User.objects.filter(email=new_email)) != 0:
        ## CRITICAL TODO: Handle case sensitivity for e-mails
        return HttpResponse(json.dumps({'success': False,
                                        'error': 'An account with this e-mail already exists.'}))

    pec_list = PendingEmailChange.objects.filter(user=request.user)
    if len(pec_list) == 0:
        pec = PendingEmailChange()
        pec.user = user
    else:
        pec = pec_list[0]

    pec.new_email = request.POST['new_email']
    pec.activation_key = uuid.uuid4().hex
    pec.save()

    if pec.new_email == user.email:
        pec.delete()
        return HttpResponse(json.dumps({'success': False,
                                        'error': 'Old email is the same as the new email.'}))

    d = {'key': pec.activation_key,
         'old_email': user.email,
         'new_email': pec.new_email}

    subject = render_to_string('emails/email_change_subject.txt', d)
    subject = ''.join(subject.splitlines())
    message = render_to_string('emails/email_change.txt', d)

    res = send_mail(subject, message, settings.DEFAULT_FROM_EMAIL, [pec.new_email])

    return HttpResponse(json.dumps({'success': True}))


@ensure_csrf_cookie
def confirm_email_change(request, key):
    ''' User requested a new e-mail. This is called when the activation
    link is clicked. We confirm with the old e-mail, and update
    '''
    try:
        pec = PendingEmailChange.objects.get(activation_key=key)
    except PendingEmailChange.DoesNotExist:
        return render_to_response("invalid_email_key.html", {})

    user = pec.user
    d = {'old_email': user.email,
         'new_email': pec.new_email}

    if len(User.objects.filter(email=pec.new_email)) != 0:
        return render_to_response("email_exists.html", d)

    subject = render_to_string('emails/email_change_subject.txt', d)
    subject = ''.join(subject.splitlines())
    message = render_to_string('emails/confirm_email_change.txt', d)
    up = UserProfile.objects.get(user=user)
    meta = up.get_meta()
    if 'old_emails' not in meta:
        meta['old_emails'] = []
    meta['old_emails'].append([user.email, datetime.datetime.now().isoformat()])
    up.set_meta(meta)
    up.save()
    # Send it to the old email...
    user.email_user(subject, message, settings.DEFAULT_FROM_EMAIL)
    user.email = pec.new_email
    user.save()
    pec.delete()
    # And send it to the new email...
    user.email_user(subject, message, settings.DEFAULT_FROM_EMAIL)

    return render_to_response("email_change_successful.html", d)


@ensure_csrf_cookie
def change_name_request(request):
    ''' Log a request for a new name. '''
    if not request.user.is_authenticated:
        raise Http404

    try:
        pnc = PendingNameChange.objects.get(user=request.user)
    except PendingNameChange.DoesNotExist:
        pnc = PendingNameChange()
    pnc.user = request.user
    pnc.new_name = request.POST['new_name']
    pnc.rationale = request.POST['rationale']
    if len(pnc.new_name) < 2:
        return HttpResponse(json.dumps({'success': False, 'error': 'Name required'}))
    pnc.save()

    # The following automatically accepts name change requests. Remove this to
    # go back to the old system where it gets queued up for admin approval.
    accept_name_change_by_id(pnc.id)

    return HttpResponse(json.dumps({'success': True}))


@ensure_csrf_cookie
def pending_name_changes(request):
    ''' Web page which allows staff to approve or reject name changes. '''
    if not request.user.is_staff:
        raise Http404

    changes = list(PendingNameChange.objects.all())
    js = {'students': [{'new_name': c.new_name,
                        'rationale':c.rationale,
                        'old_name':UserProfile.objects.get(user=c.user).name,
                        'email':c.user.email,