import logging

try:
    from config import APP_NAME as ROOT_LOGGER_NAME
except ImportError:
    ROOT_LOGGER_NAME = 'root'


class common_base(dict):
    DEFAULT_VALUES = {}

    def __init__(self):
        super().__init__(self.DEFAULT_VALUES)
        self['__type__'] = self.__class__.__name__
        #
        self.__callback_list__ = []
        self.logger = logging.getLogger(ROOT_LOGGER_NAME).getChild(__name__)

    def add_callback(self, key, data, callback, on_change_only=True):
        """
        key: key or None for all keys
        data: data or None for all data
        """
        cb_tup = (key, data, callback, on_change_only)
        if cb_tup not in self.__callback_list__:
            self.__callback_list__.append(cb_tup)

    def set(self, key, data):
        value_changed = self[key] != data
        self[key] = data
        for cb_key, cb_data, callback, on_change_only in self.__callback_list__:
            if cb_key is None or key == cb_key:                 # key fits to callback definition
                if cb_data is None or cb_data == self[key]:     # data fits to callback definition
                    if value_changed or not on_change_only:     # change status fits to callback definition
                        callback(self, key, self[key])


class mqtt_base(common_base):
    def __init__(self, mqtt_client, topic):
        super().__init__()
        #
        self.mqtt_client = mqtt_client
        self.topic = topic
        for entry in self.topic.split('/'):
            self.logger = self.logger.getChild(entry)