#!/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.

"""SiteSettings (Model) query functions.

"""

__authors__ = [

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

  ]

from google.appengine.ext import db

import soc.models.site_settings

import soc.logic.model

def getSiteSettingsFromPath(path):

  """Returns SiteSettings entity for a given path, or None if not found.  

  Args:

    path: a request path of the SiteSettings that uniquely identifies it

  """

  # lookup by Settings:path key name

  key_name = getSiteSettingsKeyNameForPath(path)

  if key_name:

    site_settings = soc.models.site_settings.SiteSettings.get_by_key_name(key_name)

  else:

    site_settings = None

  return site_settings

def getSiteSettingsKeyNameForPath(path):

  """Return a Datastore key_name for a SiteSettings from the path.

  Args:

    path: a request path of the SiteSettings that uniquely identifies it

  """

  if not path:

    return None

  return 'Settings:%s' % path

def updateOrCreateSiteSettingsFromPath(path, **site_settings_properties):

  """Update existing SiteSettings entity, or create new one with supplied properties.

  Args:

    path: a request path of the SiteSettings that uniquely identifies it

    **site_settings_properties: keyword arguments that correspond to Document entity

      properties and their values

  Returns:

    the SiteSettings entity corresponding to the path, with any supplied

    properties changed, or a new SiteSettings entity now associated with the 

    supplied path and properties.

  """

  # attempt to retrieve the existing Site Settings

  site_settings = getSiteSettingsFromPath(path)

  if not site_settings:

    # site settings did not exist, so create one in a transaction

    key_name = getSiteSettingsKeyNameForPath(path)

    site_settings = soc.models.site_settings.SiteSettings.get_or_insert(

      key_name, **site_settings_properties)

  # there is no way to be sure if get_or_insert() returned a new SiteSettings or

  # got an existing one due to a race, so update with site_settings_properties anyway,

  # in a transaction

  return soc.logic.model.updateModelProperties(site_settings, **site_settings_properties)