#
# util.py - Helper utilities for authentication
#
# Copyright (c) 2007-2009  Christian Hammond
# Copyright (c) 2007-2009  David Trowbridge
# Copyright (c) 2007  Micah Dowty
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
"""Basic utility functions for authentication.

This contains some validation functions that may be useful for forms.
"""

from __future__ import unicode_literals

from django import forms
from django.utils.translation import ugettext as _


try:
    # Django renamed forms.util to forms.utils in 1.7.
    from django.forms import utils as form_utils
except ImportError:
    from django.forms import util as form_utils


def validate_test_cookie(form, request):
    """Validate that the test cookie was properly set in a prior request.

    If the test cookie was not set, the given form's ``submit`` field will
    be set with an error saying that cookies must be enabled.

    Args:
        form (Form):
            The form using the validator.

        request (HttpRequest):
            The HTTP request containing the test cookie.
    """
    if not request.session.test_cookie_worked():
        form.errors['submit'] = forms.util.ErrorList(
            [_('Cookies must be enabled.')])


def validate_old_password(form, user, field_name='password'):
    """Validate that the password given on a form was valid.

    This is intended for Password Change forms, and will check that the
    specified password in the form matches the user's current password.

    Args:
        form (Form):
            The form using the validator and containing the field.

        user (User):
            The user whose password is being changed.

        field_name (unicode):
            The name of the password field.
    """
    if (not form.errors.get(field_name) and
        not user.check_password(form.data.get(field_name))):
        form.errors[field_name] = form_utils.ErrorList(
            [_('Incorrect password.')])
