from .template import template
from .message import message
from .message_builder import message_builder

class builder_template(message_builder):
    def __init__(self, result_type: type) -> None:
        super().__init__()
        self.__required = set()
        self.__result_type = result_type

    def _import_template(self, target: template) -> None:
        default_keys = target.default_keys

        for key in default_keys:
            name = "set_" + key

            setattr(self, name, self._create_setter(key))

        for section in target.sections_names:
            for key in target.get_section_keys(section):
                name = "set_" + key

                if name in default_keys:
                    name = "set_" + key + "_" + section

                setattr(self, name, self._create_setter(key, section))
        
        self.set_key("typename", target.typename)

    def __create_setter_name(self, key: str, section: str | None) -> str:
        if section is None:
            return "kn_" + key
        
        return "ks_" + key + section

    def _set_required_key(
        self,
        key: str, 
        target: str, 
        section: str | None
    ) -> object:
        name = self.__create_setter_name(key, section)

        if not name in self.__required:
            raise RuntimeError("Key " + key + " had been already set.")

        self.__required.remove(name)
        return self.set_key(key, target, section)

    def _create_setter(self, key: str, section: str | None = None) -> object:
        self.__required.add(self.__create_setter_name(key, section)) 

        return lambda target: self._set_required_key(key, target, section)

    def build(self) -> message:

        if len(self.__required) > 0:
            raise RuntimeError("One or more required keys are not set.")

        return super().build(help_type = self.__result_type)