import logging
import os
import subprocess

logger = logging.getLogger()
SUBPROCESS_TIMEOUT = 5


class BaseRenderEngine(object):

    install_paths = []
    supported_extensions = []

    def __init__(self, custom_path=None):
        self.custom_renderer_path = custom_path
        if not self.renderer_path():
            raise FileNotFoundError(f"Cannot find path to renderer for {self.name()} instance")

    def renderer_path(self):
        return self.custom_renderer_path or self.default_renderer_path()

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

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

    def version(self):
        raise NotImplementedError("version not implemented")

    @staticmethod
    def downloader():  # override when subclassing if using a downloader class
        return None

    @staticmethod
    def worker_class():  # override when subclassing to link worker class
        raise NotImplementedError("Worker class not implemented")

    def ui_options(self):  # override to return options for ui
        return {}

    def get_help(self):  # override if renderer uses different help flag
        path = self.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

    def get_project_info(self, project_path, timeout=10):
        raise NotImplementedError(f"get_project_info not implemented for {self.__name__}")

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

    @classmethod
    def get_arguments(cls):
        pass

    def perform_presubmission_tasks(self, project_path):
        return project_path