# Copyright Spack Project Developers. See COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)
import platform as py_platform
import re
from subprocess import check_output

from spack.version import StandardVersion

from ._operating_system import OperatingSystem


def kernel_version() -> StandardVersion:
    """Return the host's kernel version as a :class:`~spack.version.StandardVersion` object."""
    # Strip '+' characters just in case we're running a
    # version built from git/etc
    return StandardVersion.from_string(re.sub(r"\+", r"", py_platform.release()))


class LinuxDistro(OperatingSystem):
    """This class will represent the autodetected operating system
    for a Linux System. Since there are many different flavors of
    Linux, this class will attempt to encompass them all through
    autodetection using the python module platform and the method
    platform.dist()
    """

    def __init__(self):
        try:
            # This will throw an error if imported on a non-Linux platform.
            from spack.vendor import distro

            distname, version = distro.id(), distro.version()
        except ImportError:
            distname, version = "unknown", ""

        # Grabs major version from tuple on redhat; on other platforms
        # grab the first legal identifier in the version field.  On
        # debian you get things like 'wheezy/sid'; sid means unstable.
        # We just record 'wheezy' and don't get quite so detailed.
        version = re.split(r"[^\w-]", version)

        if "ubuntu" in distname:
            version = ".".join(version[0:2])
        # openSUSE Tumbleweed is a rolling release which can change
        # more than once in a week, so set version to tumbleweed$GLIBVERS
        elif "opensuse-tumbleweed" in distname or "opensusetumbleweed" in distname:
            distname = "opensuse"
            output = check_output(["ldd", "--version"]).decode()
            libcvers = re.findall(r"ldd \(GNU libc\) (.*)", output)
            if len(libcvers) == 1:
                version = "tumbleweed" + libcvers[0]
            else:
                version = "tumbleweed" + version[0]

        else:
            version = version[0]

        super().__init__(distname, version)
