from ScEpTIC.exceptions import ConfigurationException

class ScEpTICBaseConfig:
    """
    ScEpTIC sub-functions base configuration class
    """

    # Each configuration parameter must specify:
    # 'class' -> the class type of the parameter's value
    # 'mode' -> the allowed configuration method (set / add)
    # Optionals:
    # 'values' -> list of allowed values for the parameter ( 'class' must be set to 'specific')
    # 'value_check_function' -> function that checks if the provided value is correct
    _config_domain = {}

    def __init__(self, main_config):
        """
        :param main_config: main configuration container
        """
        self._main_config = main_config


    def _check(self, config_name, config_value, mode):
        """
        Checks the values of a configuration parameter
        :param config_name: the configuration name
        :param config_value: the configuration value
        :param mode: the configuration method
        """
        domain = self._config_domain[config_name]

        if domain['mode'] != mode:
            raise ConfigurationException(f"[{self.__class__.__name__}] Wrong configuration mode '{mode}_config()' for {config_name}. Only '{domain['mode']}_config()' is allowed")

        if domain['class'] == 'specific':
            if config_value not in domain['values']:
                raise ConfigurationException(f"[{self.__class__.__name__}] Wrong value for {config_name}: {config_value} not allowed.")

        elif not isinstance(config_value, domain['class']):
            raise ConfigurationException(f"[{self.__class__.__name__}] Wrong value for {config_name}. {domain['class']} required, but {config_value.__class__.__name__} was given.")

        if 'value_check_function' in domain:
            if not domain['value_check_function'](config_value):
                raise ConfigurationException(f"[{self.__class__.__name__}] Wrong value for {config_name}: {config_value} not allowed.")


    def set_config(self, config_name, config_value):
        """
        Sets a configuration parameter
        :param config_name: the configuration name
        :param config_value: the configuration value
        """
        self._check(config_name, config_value, 'set')
        setattr(self, config_name, config_value)
        self._check_callback(config_name, config_value)


    def add_config(self, config_name, config_value):
        """
        Adds a configuration parameter
        :param config_name: the configuration name
        :param config_value: the configuration value
        """
        self._check(config_name, config_value, 'add')
        getattr(self, config_name).append(config_value)
        self._check_callback(config_name, config_value)


    def _register_config_callback(self, config_name, callback):
        """
        Registers a configuration callback that executes whenever config_name is changed
        :param config_name: the configuration name
        :param callback: the callback function
        """
        if config_name == '*':
            for name in self._config_domain.keys():
                self._config_domain[name]['callback'] = callback

        else:
            self._config_domain[config_name]['callback'] = callback


    def _check_callback(self, config_name, config_value):
        """
        Check if config_name has a configuration callback function and executes it
        :param config_name: the configuration name
        :param config_value: the configuration value
        """
        if 'callback' in self._config_domain[config_name]:
            self._config_domain[config_name]['callback'](config_name, config_value)