# system
import logging
import os
import subprocess

# local
from .executable import Executable

# parent
from ..._constants import IMAGES_DIRECTORY_NAME, LOCAL_IMAGES_NAME, DEFAULT_IMAGE_NAME


def _prefix_path(prefix, path):
    if isinstance(path, str):
        abs_path = os.path.abspath(path)
        return os.path.realpath(f"{prefix}/{abs_path}")

    elif isinstance(path, list):
        return [_prefix_path(prefix, p) for p in path]


def prefix_path_mnt(path):
    return _prefix_path('/mnt/', path)


def _image_name(image_tag):
    if image_tag is not None:
        return f"{LOCAL_IMAGES_NAME}:{image_tag}"
    else:
        return DEFAULT_IMAGE_NAME


class Rootkit:
    class __Rootkit:
        __image_tag = None

        def __init__(self, image_tag=None):
            self.__image_tag = image_tag

        def __exists(self):
            ps = Executable('docker').run([
                'images',
                '--filter', f"reference={_image_name(self.__image_tag)}",
                '--format', '{{.Repository}}:{{.Tag}}'
            ], stdout=subprocess.PIPE)

            return str(ps.stdout, 'utf-8').strip() == _image_name(self.__image_tag)

        def __build_image(self):
            if self.__exists():
                logging.info(f"Using image {_image_name(self.__image_tag)}")
            else:
                if self.__image_tag is None:
                    logging.info(f"Pulling image {_image_name(self.__image_tag)}")
                    Executable('docker').run([
                        'pull', _image_name(self.__image_tag)
                    ], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)

                else:
                    logging.info(f"Building image {_image_name(self.__image_tag)}")
                    Executable('docker').run([
                        'build',
                        '-t', _image_name(self.__image_tag),
                        '-f', f"{IMAGES_DIRECTORY_NAME}/{self.__image_tag}.Dockerfile",
                        f"{IMAGES_DIRECTORY_NAME}"
                    ], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)

        def run(self, process_args, **kwargs):
            self.__build_image()
            Executable('docker').run([
                'run', '--rm',
                '-v', '/:/mnt',
                '-u', 'root',
                _image_name(self.__image_tag),
                *process_args
            ], **kwargs)

    __image_tag = None
    __instances = {}

    def __init__(self, image_tag=None):
        self.__image_tag = image_tag

        if _image_name(self.__image_tag) not in Rootkit.__instances:
            Rootkit.__instances[_image_name(self.__image_tag)] = Rootkit.__Rootkit(image_tag)

    def __getattr__(self, item):
        return getattr(self.__instances[_image_name(self.__image_tag)], item)