from django.contrib.auth.decorators import login_required

@login_required(login_url='/accounts/login/')
def my_view(request):
  ...

from django.contrib.auth.decorators import user_passes_test

def group_required(*group_names):
  """Requires user membership in at least one of the groups passed in."""

  def in_groups(u):
    if u.is_authenticated():
      if bool(u.groups.filter(name__in=group_names)) | u.is_superuser:
        return True
    return False
  return user_passes_test(in_groups)


# The way to use this decorator is:
@group_required('admins', 'seller')
def my_view(request, pk):
  ...

def anonymous_required(function=None, redirect_url=None):

  if not redirect_url:
    redirect_url = settings.LOGIN_REDIRECT_URL

  actual_decorator = user_passes_test(
    lambda u: u.is_anonymous(),
    login_url=redirect_url
  )

  if function:
    return actual_decorator(function)
  return actual_decorator


# The way to use this decorator is:
@anonymous_required
def my_view(request, pk):
  ...

from django.core.exceptions import PermissionDenied


def superuser_only(function):
  """Limit view to superusers only."""

  def _inner(request, *args, **kwargs):
    if not request.user.is_superuser:
      raise PermissionDenied
    return function(request, *args, **kwargs)

  return _inner


# The way to use this decorator is:
@superuser_only
def my_view(request):
  ...

from django.http import HttpResponseBadRequest


def ajax_required(f):
  """
  AJAX request required decorator
  use it in your views:
 
  @ajax_required
  def my_view(request):
    ....
 
  """

  def wrap(request, *args, **kwargs):
    if not request.is_ajax():
      return HttpResponseBadRequest()
    return f(request, *args, **kwargs)

  wrap.__doc__ = f.__doc__
  wrap.__name__ = f.__name__
  return wrap


# The way to use this decorator is:
@ajax_required
def my_view(request):
  ...

def timeit(method):

  def timed(*args, **kw):
    ts = time.time()
    result = method(*args, **kw)
    te = time.time()
    print('%r (%r, %r) %2.2f sec' % (method.__name__, args, kw, te - ts))
    return result

  return timed


# The way to use this decorator is:
@timeit
def my_view(request):
  ...

from django.http import HttpResponseForbidden

logger = logging.getLogger(__name__)
def user_can_write_a_review(func):
  """View decorator that checks a user is allowed to write a review, in negative case the decorator return Forbidden"""

  @functools.wraps(func)
  def wrapper(request, *args, **kwargs):
    if request.user.is_authenticated() and request.user.points < 10:
      logger.warning('The {} user has tried to write a review, but does not have enough points to do so'.format( request.user.pk))
      return HttpResponseForbidden()

    return func(request, *args, **kwargs)

  return wrapper