import logging
import sys
from pathlib import Path
from typing_extensions import TypeVar

H = TypeVar('H', bound=logging.Handler)


class RunLogger(logging.Logger):
    def __init__(self, name, level=logging.INFO, stream=sys.stdout):
        super().__init__(name, level)

        self.handlers.clear()

        self.handlers.append(
            self._configure_handler(logging.StreamHandler(stream), level)
        )


    def set_output_file(self, outfile: Path, level=logging.INFO):
        for handler in list(self.handlers):
            if not isinstance(handler, logging.FileHandler):
                continue
            self.handlers.remove(handler)

        self.handlers.append(
            self._create_file_handler(outfile, level)
        )



    @staticmethod
    def _create_file_handler(file: str|Path, level) -> logging.FileHandler:
        file = Path(file)

        if file.exists():
            file.rename(file.with_suffix('.log.backup'))

        handler = logging.FileHandler(file)
        return RunLogger._configure_handler(handler, level)


    @staticmethod
    def _configure_handler(handler: H, level) -> H:
        handler.setLevel(level)
        formatter = logging.Formatter('%(message)s')
        handler.setFormatter(formatter)
        return handler