#!/usr/bin/python2.5

#

# Copyright 2008 the Melange authors.

#

# 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.

"""Helpers used to render response.

"""

__authors__ = [

  '"Todd Larsen" <tlarsen@google.com>',

  '"Pawel Solyga" <pawel.solyga@gmail.com>',

  '"Sverre Rabbelier" <sverre@rabbelier.nl>',

  ]

from google.appengine.api import users

from django import http

from django.template import loader

from soc.logic import accounts

from soc.logic import system

from soc.logic.models import site

from soc.logic.models.user import logic as user_logic

from soc.views import helper

from soc.views.helper import redirects

from soc.views.helper import templates

from soc.views.sitemap import sidebar

def respond(request, template, context=None, response_args=None,

            response_headers=None):

  """Helper to render a response, passing standard stuff to the response.

  Args:

    request: the Django HTTP request object

    template: the template (or search list of templates) to render

    context: the context supplied to the template (implements dict)

    response_args: keyword arguments passed to http.HttpResponse()

      (response_args['content'] is created with

      render_to_string(template, dictionary=context) if it is not present)

    response_headers: optional dict containing HTTP response header names

      and corresponding values to set in the HttpResponse object before it

      is returned; default is None

  Returns:

    django.shortcuts.render_to_response(template, context) results

  Raises:

    Any exceptions that django.template.loader.render_to_string() or

    django.http.HttpResponse() might raise.

  """

  if not context:

    from soc.views.helper import params

    context = getUniversalContext(request)

    useJavaScript(context, params.DEF_JS_USES_LIST)

  if response_args is None:

    response_args = {}

  if 'content' not in response_args:

    content = loader.render_to_string(template, dictionary=context)

    response_args['content'] = content.strip('\n')

  http_response = http.HttpResponse(**response_args)

  if response_headers:

    for key, value in response_headers.iteritems():

      http_response[key] = value

  return http_response

def getUniversalContext(request):

  """Constructs a template context dict will many common variables defined.

  Args:

    request: the Django HTTP request object

  Returns:

    a new context dict containing:

    {

      'request': the Django HTTP request object passed in by the caller

      'account': the logged-in Google Account if there is one

      'user': the User entity corresponding to the Google Account in

        context['account']

      'is_admin': True if users.is_current_user_admin() is True

      'is_debug': True if system.isDebug() is True

      'sign_in': a Google Account login URL

      'sign_out': a Google Account logout URL

      'sidebar_menu_html': an HTML string that renders the sidebar menu

    }

  """

  account = accounts.getCurrentAccount()

  user = None

  is_admin = False

  context = {}

  context['request'] = request

  if account:

    user = user_logic.getForAccount(account)

    is_admin = user_logic.isDeveloper(account=account, user=user)

  context['account'] = account

  context['user'] = user

  context['is_admin'] = is_admin

  context['is_local'] = system.isLocal()

  context['is_debug'] = system.isDebug()

  context['sign_in'] = users.create_login_url(request.path)

  context['sign_out'] = users.create_logout_url(request.path)

  context['sidebar_menu_items'] = sidebar.getSidebar(account, user)

  context['gae_version'] = system.getAppVersion()

  context['soc_release'] = system.getMelangeVersion()

  settings = site.logic.getSingleton()

  context['ga_tracking_num'] = settings.ga_tracking_num

  context['gmaps_api_key'] = settings.gmaps_api_key

  context['site_name'] = settings.site_name

  context['site_notice'] = settings.site_notice

  context['tos_link'] = redirects.getToSRedirect(settings)

  return context

def useJavaScript(context, uses):

  """Updates the context for JavaScript usage.

  """

  for use in uses:

    context['uses_%s' % use] = True

def redirectToChangedSuffix(

    request, old_suffix, new_suffix=None, params=None):

  """Changes suffix of URL path and returns an HTTP redirect response.

  Args:

    request: the Django HTTP request object; redirect path is derived from

      request.path

    old_suffix, new_suffix, params:  see helper.requests.replaceSuffix()

  Returns:

    a Django HTTP redirect response pointing to the altered path.

  """

  path = helper.requests.replaceSuffix(request.path, old_suffix, new_suffix,

                                       params=params)

  return http.HttpResponseRedirect(path)

def errorResponse(error, request, template=None, context=None):

  """Creates an HTTP response from the soc.views.out_of_band.Error exception.

  Args:

    errror: a out_of_band.Error object

    request: a Django HTTP request

    template: the "sibling" template (or a search list of such templates)

      from which to construct the actual template name (or names)

    context: optional context dict supplied to the template, which is

      modified (so supply a copy if such modification is not acceptable)

  """

  if not context:

    context = error.context

  if not context:

    from soc.views.helper import params

    context = getUniversalContext(request)

    useJavaScript(context, params.DEF_JS_USES_LIST)

  if not template:

    template = []

  # make a list of possible "sibling" templates, then append a default

  sibling_templates = templates.makeSiblingTemplatesList(template,

      error.TEMPLATE_NAME, default_template=error.DEF_TEMPLATE)

  context['status'] = error.response_args.get('status')

  if not context.get('message'):

    # supplied context did not explicitly override the message

    context['message'] = error.message_fmt % context

  return respond(request, sibling_templates, context=context,

                 response_args=error.response_args)