""" this is forms validation classes

http://formencode.org/module-formencode.validators.html

for list off all availible validators

we can create our own validators

The table below outlines the options which can be used in a schema in addition to the validators themselves

pre_validators          []     These validators will be applied before the schema

chained_validators      []     These validators will be applied after the schema

allow_extra_fields      False     If True, then it is not an error when keys that aren't associated with a validator are present

filter_extra_fields     False     If True, then keys that aren't associated with a validator are removed

if_key_missing          NoDefault If this is given, then any keys that aren't available but are expected will be replaced with this value (and then validated). This does not override a present .if_missing attribute on validators. NoDefault is a special FormEncode class to mean that no default values has been specified and therefore missing keys shouldn't take a default value.

ignore_key_missing      False     If True, then missing keys will be missing in the result, if the validator doesn't have .if_missing on it already    

<name> = formencode.validators.<name of validator>

<name> must equal form name

list=[1,2,3,4,5]

for SELECT use formencode.All(OneOf(list), Int())

"""

from formencode.validators import UnicodeString, OneOf, Int, Number, Regex

from pylons import session

from pylons.i18n.translation import _

from pylons_app.lib.auth import get_crypt_password

from pylons_app.model import meta

from pylons_app.model.db import Users

from sqlalchemy.exc import OperationalError

from sqlalchemy.orm.exc import NoResultFound, MultipleResultsFound

from webhelpers.pylonslib.secure_form import authentication_token

import formencode

import logging

log = logging.getLogger(__name__)

#this is needed to translate the messages using _() in validators

class State_obj(object):

    _ = staticmethod(_)

#===============================================================================

# VALIDATORS

#===============================================================================

class ValidAuthToken(formencode.validators.FancyValidator):

    messages = {'invalid_token':_('Token mismatch')}

    def validate_python(self, value, state):

        if value != authentication_token():

            raise formencode.Invalid(self.message('invalid_token', state,

                                            search_number=value), value, state)

class ValidAuth(formencode.validators.FancyValidator):

    messages = {

            'invalid_password':_('invalid password'),

            'invalid_login':_('invalid user name'),

            'disabled_account':_('Your acccount is disabled')

            }

    #error mapping

    e_dict = {'username':messages['invalid_login'],

              'password':messages['invalid_password']}

    def validate_python(self, value, state):

        sa = meta.Session

        crypted_passwd = get_crypt_password(value['password'])

        username = value['username']

        try:

            user = sa.query(Users).filter(Users.username == username).one()

        except (NoResultFound, MultipleResultsFound, OperationalError) as e:

            log.error(e)

            user = None

        if user:

            if user.active:

                if user.username == username and user.password == crypted_passwd:

                    from pylons_app.lib.auth import AuthUser

                    auth_user = AuthUser()

                    auth_user.username = username

                    auth_user.is_authenticated = True

                    auth_user.is_admin = user.admin

                    session['hg_app_user'] = auth_user

                    session.save()

                    return value

                else:

                    log.warning('user %s not authenticated', username)

                    raise formencode.Invalid(self.message('invalid_password',

                                             state=State_obj), value, state,

                                             error_dict=self.e_dict)

            else:

                log.warning('user %s is disabled', username)

                raise formencode.Invalid(self.message('disabled_account',

                                         state=State_obj),

                                         value, state, error_dict=self.e_dict)

#===============================================================================

# FORMS        

#===============================================================================

class LoginForm(formencode.Schema):

    allow_extra_fields = True

    filter_extra_fields = True

    username = UnicodeString(

                             strip=True,

                             min=3,

                             not_empty=True,

                             messages={

                                       'empty':_('Please enter a login'),

                                       'tooShort':_('Enter a value %(min)i characters long or more')}

                            )

    password = UnicodeString(

                            strip=True,

                            min=3,

                            not_empty=True,

                            messages={

                                      'empty':_('Please enter a password'),

                                      'tooShort':_('Enter a value %(min)i characters long or more')}

                                )

    #chained validators have access to all data

    chained_validators = [ValidAuth]