import logging
import os
import subprocess

logger = logging.getLogger()
SUBPROCESS_TIMEOUT = 5


class BaseRenderEngine(object):

    install_paths = []
    supported_extensions = []

    @classmethod
    def name(cls):
        return cls.__name__.lower()

    @classmethod
    def renderer_path(cls):
        path = None
        try:
            path = subprocess.check_output(['which', cls.name()], timeout=SUBPROCESS_TIMEOUT).decode('utf-8').strip()
        except subprocess.CalledProcessError:
            for p in cls.install_paths:
                if os.path.exists(p):
                    path = p
        except Exception as e:
            logger.exception(e)
        return path

    @classmethod
    def version(cls):
        raise NotImplementedError("version not implemented")

    @classmethod
    def get_help(cls):
        path = cls.renderer_path()
        if not path:
            raise FileNotFoundError("renderer path not found")
        help_doc = subprocess.check_output([path, '-h'], stderr=subprocess.STDOUT,
                                           timeout=SUBPROCESS_TIMEOUT).decode('utf-8')
        return help_doc

    @classmethod
    def get_output_formats(cls):
        raise NotImplementedError(f"get_output_formats not implemented for {cls.__name__}")