import re

import sqlalchemy as sa

    nondigits_pattern = re.compile(r'\D')

    def get_phone_search_term(self, term):

        """

        Try to figure out if the given search term represents a whole

        or partial phone number, and if so return just the digits.

        """

        digits = self.nondigits_pattern.sub('', term)

        if digits and len(digits) >= 4:

            return digits

    def customer_autocomplete(self, session, term, **kwargs):

        """

        Override the customer autocomplete, to search by phone number

        as well as customer name.

        """

        model = self.model

        # define the base query

        query = session.query(model.Customer)\

                       .options(orm.joinedload(model.Customer.phones))

        # does search term look like a phone number?

        phone_term = self.get_phone_search_term(term)

        if phone_term:

            # yep, so just search for the phone number

            query = query.join(model.CustomerPhoneNumber,

                               model.CustomerPhoneNumber.parent_uuid == model.Customer.uuid)

            query = query.filter(sa.func.regexp_replace(model.CustomerPhoneNumber.number,

                                                        r'\D', '', 'g')\

                                 .like('%{}%'.format(phone_term)))

        else: # term does not look like a phone number

            # so just search by customer name

            criteria = [model.Customer.name.ilike('%{}%'.format(word))

                        for word in term.split()]

            query = query.filter(sa.and_(*criteria))

        # oh, and sort by something useful

        query = query.order_by(model.Customer.name)

        # generate result list from query

        results = []

        for customer in query:

            phone = customer.first_phone()

            if phone:

                label = "{} {}".format(customer.name, phone.number)

            else:

                label = customer.name

            results.append({'value': customer.uuid,

                            'label': label,

                            'display': customer.name})

        return results