# -*- coding: utf-8 -*-

from __future__ import annotations

from typing import TYPE_CHECKING, Callable

import tarfile, io
from tarfile import TarFile

from ....lib.log import *

if TYPE_CHECKING:
    from ....lib.ExecContext import ExecContext

def filter(blob: bytes, path_filter: Callable[[str], bool]|None, matched: list[str]|None=None) -> bytes:
    ret = io.BytesIO()
    with tarfile.open(fileobj=ret, mode='w') as tf_out:
        tf_in = TarFile(fileobj=io.BytesIO(blob))
        for info in tf_in.getmembers():
            if path_filter is not None and not path_filter(info.name):
                continue
            log(DEBUG, f'Adding {info.name}')
            if matched is not None:
                matched.append(info.name)
            buf = tf_in.extractfile(info)
            tf_out.addfile(info, buf)
    return ret.getvalue()

def rewrite(blob: bytes, rewrite_filter: Callable[[str], str]) -> bytes:
    ret = io.BytesIO()
    with tarfile.open(fileobj=ret, mode='w') as tf_out:
        tf_in = TarFile(fileobj=io.BytesIO(blob))
        for info in tf_in.getmembers():
            new_name = rewrite_filter(info.name)
            log(DEBUG, f'Rewriting {info.name} -> {new_name}')
            info.name = new_name
            buf = tf_in.extractfile(info)
            tf_out.addfile(info, buf)
    return ret.getvalue()

def merge(blobs: Iterable[bytes], overwrite: bool=False) -> bytes:
    ret = io.BytesIO()
    with tarfile.open(fileobj=ret, mode='w') as tf_out:
        for blob in blobs:
            tf_in = TarFile(fileobj=io.BytesIO(blob))
            existing_names = tf_out.getnames()
            for info in tf_in.getmembers():
                if not overwrite and info.name in existing_names:
                    continue
                buf = tf_in.extractfile(info)
                tf_out.addfile(info, buf)
    return ret.getvalue()

async def extract(dst: ExecContext, blob: bytes, root: str|None=None, verbose: bool=False) -> None:
    cmd = ['tar']
    if root is not None:
        cmd += ['-C', root]
    if verbose:
        cmd += '-v'
    cmd += ['-x', '-f', '-']
    await dst.run(cmd, verbose=verbose, cmd_input=blob)