from typing import List, Optional, Dict, Tuple
from pathlib import Path


class Config:
    def merge_with(self, other, strict: bool = False):
        """
        Merges the other config into this one
        :param other:
        :param strict: whether conflicting options are allowed or not
        :return: self
        """
        for var in vars(self):
            if not getattr(self, var):
                setattr(self, var, getattr(other, var))
            else:
                if strict and getattr(other, var) is not None and getattr(self, var) != getattr(other, var):
                    raise NotImplementedError
        return self


class FormatterIF:
    """
    A formatter is bound to a specific input file with some
    building configuration.
    """
    def __init__(
            self,
            input_file: Optional[Path] = None,
            config: Optional[Config] = None,
    ):
        self._input_file: Optional[Path] = input_file
        self._config: Optional[Config] = config

    def format(self, build_dir: Path, overwrite: bool = False) -> Optional[List[Tuple[str, Dict]]]:
        """
        :param build_dir: Directory where output files are written to
        :param overwrite: overwrite existing files
        :return: When configuration files are needed for a future
        build of the output files, a list of the file names and their
        needed configurations. Else None.
        """
        raise NotImplementedError

    @property
    def output_files(self) -> List[str]:
        """

        :return: List of files that will be built when the formatter is invoked
        """
        raise NotImplementedError

    @property
    def input_file(self) -> Path:
        if self._input_file is None:
            raise NotImplementedError
        return self._input_file

    @input_file.setter
    def input_file(self, input_file: Path) -> None:
        self._input_file = input_file

    @property
    def config(self) -> Config:
        if self._config is None:
            raise NotImplementedError
        return self._config

    @config.setter
    def config(self, config: Config):
        self._config = config