import logging
import re

logger = logging.getLogger(__name__)

# Form and Model Field Config
COMMON_CHAR_FIELD_LENGTH = 250
NUMBER_MAX_LENGTH = 12
TITLE_MAX_LENGTH = COMMON_CHAR_FIELD_LENGTH
TRAINER_NAME_MAX_LENGTH = COMMON_CHAR_FIELD_LENGTH
PHONE_NUMBER_MAX_LENGTH = COMMON_CHAR_FIELD_LENGTH
LOCATION_MAX_LENGTH = COMMON_CHAR_FIELD_LENGTH
TRANSPORT_OTHER_MAX_LENGTH = COMMON_CHAR_FIELD_LENGTH
DEPARTURE_RIDE_MAX_LENGTH = COMMON_CHAR_FIELD_LENGTH
MEETING_POINT_OTHER_MAX_LENGTH = COMMON_CHAR_FIELD_LENGTH
BASECAMP_MAX_LENGTH = COMMON_CHAR_FIELD_LENGTH
ACCOMMODATION_OTHER_MAX_LENGTH = COMMON_CHAR_FIELD_LENGTH
MEALS_OTHER_MAX_LENGTH = COMMON_CHAR_FIELD_LENGTH
ADDITIONAL_COSTS_MAX_LENGTH = COMMON_CHAR_FIELD_LENGTH


class FieldInitial(object):
    _constraint_re = re.compile(r'^(?P<field>[a-z_]+)(?P<op>[=]+)(?P<value>.*)$')

    def __init__(self, *args):
        self._tuples = []

        if len(args) == 1:
            self._tuples = [(None, args[0])]
        else:
            constraint = None
            for arg in args:
                if constraint is None:
                    constraint = arg
                else:
                    self._tuples.append((constraint, arg))
                    constraint = None

    def get_value(self, session_data):
        parameters = {
            'mode': session_data.get('mode', None),
            'sport': session_data.get('sport', None),
            'level': session_data.get('level', None),
            'overnight': str(bool(session_data.get('last_day', None))),
            'country': session_data.get('country', None),
            'terrain': session_data.get('terrain', None),
            'transport': session_data.get('transport', None),
        }
        for tuple in self._tuples:
            constraint, result = tuple

            if not constraint:
                return result

            match = False
            constraint_parts = constraint.split(',')
            for sub_constraint in constraint_parts:
                c = self._constraint_re.match(sub_constraint)
                if c is not None:
                    c_field = c.group('field')
                    if c_field not in parameters:
                        logger.error('FieldInitial: Invalid field: \'%s\'', sub_constraint)
                        continue
                    c_op = c.group('op')
                    c_value = c.group('value')
                    if c_op == '==':
                        if parameters[c_field] == c_value:
                            match = True
                            continue
                        else:
                            match = False
                            break
                    else:
                        logger.error('FieldInitial: Invalid operator: \'%s\'', sub_constraint)
                        continue
                else:
                    logger.error('FieldInitial: Invalid constraint: \'%s\'', constraint)
                    break

            if match:
                return result

        return None