import importlib
import shutil


def compress(filename: str):
    supp_compr_algo = {"zip": "zipfile", "gzip": "gzip", "bzip2": "bz2", "lzma": "lzma"}
    extensions = {"zip": ".zip", "gzip": ".gz", "bzip2": ".bz2", "lzma": ".xz"}
    assert set(supp_compr_algo.keys()) == set(extensions.keys())

    compression = "bzip2"

    if compression not in supp_compr_algo:
        raise ValueError(
            f"Unknown compression algorithm '{compression}'; must be one of {list(supp_compr_algo.keys())}")

    try_compression(
        file=filename,
        name=compression,
        module_name=supp_compr_algo[compression],
        extension=extensions[compression],
        function=zip_compression if compression == "zip" else compression_open_context_manager
    )
    print(f"Successfully compressed '{filename}' to '{filename + extensions[compression]}' "
          f"using {compression} as compression algorithm")


def try_compression(file: str, name: str, module_name: str, extension: str, function: callable):
    try:
        compression_module = importlib.import_module(module_name)

        function(file, compression_module, extension)
    except ImportError as ex:
        raise ImportError(f"compression='{name}' failed: required module could not be loaded ({ex})")


def compression_open_context_manager(file: str, module, extension: str):
    with open(file, "rb") as f_in:
        with module.open(file + extension, "wb") as f_out:
            shutil.copyfileobj(f_in, f_out)


def zip_compression(file: str, module, extension: str):
    with module.ZipFile(file + extension, "w", compression=module.ZIP_DEFLATED) as z:
        z.write(file)