#!/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.

"""User (Model) query functions.

"""

__authors__ = [

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

  ]

from google.appengine.api import users

from google.appengine.ext import db

from soc.logic.helper import notifications

from soc.logic.models import base

from soc.logic.models.site import logic as site_logic

import soc.models.user

class Logic(base.Logic):

  """Logic methods for the User model.

  """

  def __init__(self):

    """Defines the name, key_name and model for this entity.

    """

    super(Logic, self).__init__(soc.models.user.User,

                        skip_properties=['former_accounts'])

  def isFormerAccount(self, account):

    """Returns true if account is a former account of some User.

    """

    # TODO(pawel.solyga): replace 1000 with solution that works for any

    #   number of queries

    users_with_former_accounts = soc.models.user.User.gql(

        'WHERE former_accounts != :1', None).fetch(1000)

    for former_account_user in users_with_former_accounts: 

      if account in former_account_user.former_accounts:

        return True

    return False

  def getForCurrentAccount(self):

    """Retrieves the user entity for the currently logged in account.

    If there is no user logged in, or they have no associated User

    entity, None is returend.

    """

    account = users.get_current_user()

    if not account:

      return None

    user = self.getForFields({'account': account}, unique=True)

    return user

  def agreesToSiteToS(self, entity):

    """Returns indication of User's answer to the site-wide Terms of Service.

    Args:

      entity: User entity to check for agreement to site-wide ToS

    Returns:

      True: no site-wide ToS is currently in effect on the site

      True: site-wide ToS is in effect *and* User agrees to it

        (User explicitly answered "Yes")

      False: site-wide ToS is in effect but User does not agree to it

        (User explicitly answered "No")

      None: site-wide ToS in effect, but User has not answered "Yes" or "No"

        (this answer still evaluates to False, denying access to the site,

         but can be used to detect non-answer to ask the User to provide the

         missing answer)

    """

    if not site_logic.getToS(site_logic.getSingleton()):

      # no site-wide ToS in effect, so let the User slide for now

      return True

    try:

      agrees = entity.agrees_to_tos

    except db.Error:

      # return still-False "third answer" indicating that answer is missing

      return None

    # make sure the stored value is really a Boolean only

    if not agrees:

      return False

    return True

  def getKeyValues(self, entity):

    """See base.Logic.getKeyValues.

    """

    return [entity.link_id]

  def getSuffixValues(self, entity):

    """See base.Logic.getSuffixValues.

    """

    return [entity.link_id]

  def getKeyValuesFromFields(self, fields):

    """See base.Logic.getKeyValuesFromFields.

    """

    return [fields['link_id']]

  def getKeyFieldNames(self):

    """See base.Logic.getKeyFieldNames.

    """

    return ['link_id']

  def _updateField(self, model, name, value):

    """Special case logic for account.

    When the account is changed, the former_accounts field should be appended

    with the old account.

    """

    if (name == 'account') and (model.account != value):

      model.former_accounts.append(model.account)

    return True

  def _onCreate(self, entity):

    """Send out a message to welcome the new user.

    """

    notifications.sendWelcomeMessage(entity)

logic = Logic()