# Copyright 2008 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
Template tags for the auth module. These are inserted into Django as "built-in"
tags so you do not need to use the load statement in your template to get
access to them.
"""

from django.template import Library
from django.template import Node

from google.appengine.api import users


class AuthLoginUrlsNode(Node):
  """Template node that creates an App Engine login or logout URL.

  If create_login_url is True the App Engine's login URL is rendered into
  the template, otherwise the logout URL.
  """
  def __init__(self, create_login_url, redirect):
    self.redirect = redirect
    self.create_login_url = create_login_url

  def render(self, context):
    if self.create_login_url:
      return users.create_login_url(self.redirect)
    else:
      return users.create_logout_url(self.redirect)


def auth_login_urls(parser, token):
  """Template tag registered as 'auth_login_url' and 'auth_logout_url'
  when the module is imported.

  Both tags take an optional argument that specifies the redirect URL and
  defaults to '/'.
  """
  bits = list(token.split_contents())
  if len(bits) == 2:
    redirect = bits[1]
  else:
    redirect = "/"
  login = bits[0] == "auth_login_url"
  return AuthLoginUrlsNode(login, redirect)


register = Library()
register.tag("auth_login_url", auth_login_urls)
register.tag("auth_logout_url", auth_login_urls)