''' helper functions for schemas '''

import colander

from pyramid.csrf import get_csrf_token, check_csrf_token

from ordr.models import User


@colander.deferred
def deferred_csrf_default(node, kw):
    ''' sets the current csrf token '''
    request = kw.get('request')
    return get_csrf_token(request)


@colander.deferred
def deferred_csrf_validator(node, kw):
    ''' validates a submitted csrf token '''
    def validate_csrf(node, value):
        request = kw.get('request')
        if not check_csrf_token(request, raises=False):
            raise colander.Invalid(node, 'Bad CSRF token')
    return validate_csrf


@colander.deferred
def deferred_unique_username_validator(node, kw):
    ''' checks if an username is not registered already '''

    def validate_unique_username(node, value):
        request = kw.get('request')
        user = request.dbsession.query(User).filter_by(username=value).first()
        if user is not None:
            raise colander.Invalid(node, 'User name already registered')
    return validate_unique_username


@colander.deferred
def deferred_unique_email_validator(node, kw):
    ''' checks if an email is not registered already '''
    email_validator = colander.Email()

    def validate_unique_email(node, value):
        email_validator(node, value)  # raises exception on invalid address
        request = kw.get('request')
        user = request.dbsession.query(User).filter_by(email=value).first()
        if user not in (None, request.context.model):
            # allow existing email addresses if
            # it belongs to the user that is currently edited
            raise colander.Invalid(node, 'Email address in use')
    return validate_unique_email


@colander.deferred
def deferred_password_validator(node, kw):
    ''' checks password confirmation for settings '''

    def validate_password_confirmation(node, value):
        request = kw.get('request')
        if request.user is None or not request.user.check_password(value):
            raise colander.Invalid(node, 'Wrong password')
    return validate_password_confirmation