#!/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.

"""This module contains the User Model."""

__authors__ = [

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

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

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

]

from google.appengine.ext import db

from django.utils.translation import ugettext_lazy

class User(db.Model):

  """A user and associated login credentials, the fundamental identity entity.

  User is a separate Model class from Person because the same login 

  ID may be used to, for example, serve as Contributor in one Program 

  and a Reviewer in another.

  Also, this allows a Person to, in the future, re-associate that 

  Person entity with a different Google Account if necessary.

  A User entity participates in the following relationships implemented 

  as a db.ReferenceProperty elsewhere in another db.Model:

   persons)  a 1:many relationship of Person entities identified by the

     User.  This relation is implemented as the 'persons' back-reference

     Query of the Person model 'user' reference.

  """

  #: A Google Account, which also provides a "private" email address.

  #: This email address is only used in an automated fashion by 

  #: Melange web applications and is not made visible to other users 

  #: of any Melange application.

  id = db.UserProperty(required=True)

  #: Required field storing a nickname; displayed publicly.

  #: Nicknames can be any valid UTF-8 text.

  nick_name = db.StringProperty(required=True,

      verbose_name=ugettext_lazy('Nick name'))

  #: Required field storing linkname used in URLs to identify user.

  #: Lower ASCII characters only.

  link_name = db.StringProperty(required=True,

      verbose_name=ugettext_lazy('Link name'))

  link_name.help_text = ugettext_lazy(

      'Field used in URLs to identify user. '

      'Lower ASCII characters only.')

  @staticmethod

  def doesUserExist(id=None):

    """Returns if user already exists in the Datastore.

    Args:

      user: a Google Account object,

    """

    #: let's do a gql query and check if user exists in datastore

    data = self.getUserForId(id)

    if data:

      return True

    else:

      return False

  @staticmethod

  def getUserForId(id=None):

    """Returns User entity from datastore, or None if not found.  

    Args:

      user: a Google Account object,

    """

    return User.gql('WHERE id = :1', id).get()

  @staticmethod

  def getUserForLinkname(link_name=None):

    """Returns User entity for linkname or None if not found.

    Args:

      link_name: linkname used in URLs to identify user,

    """

    return User.gql('WHERE link_name = :1', link_name).get()