"""Various machine-related utility functions
"""

from __future__ import print_function

import getpass
import socket
import re

# ========================================================================
# Public functions
# ========================================================================


def get_user():
    """Return the current user name (string)"""
    return getpass.getuser()


def get_machine_name():
    """Return the current machine name (string)"""
    # NOTE(wjs, 2021-12-13) The following line needs a "disable=no-member" to workaround a
    # problem on my Mac (probably similar to
    # https://stackoverflow.com/questions/68719442/why-do-i-get-the-pylint-error-module-socket-has-no-gethostname-member-no-m)
    full_hostname = socket.gethostname()  # pylint: disable=no-member
    hostname = full_hostname.split(".")[0]
    return _machine_from_hostname(hostname)


# ========================================================================
# Private functions
# ========================================================================


def _machine_from_hostname(hostname):
    """Given a hostname (string), return the machine name (string)

    This uses some machine-specific rules. The logic here will need to
    be extended if there are other machines with special translation
    rules from hostname to machine name.
    """
    if re.match(r"cheyenne\d+", hostname):
        machine = "cheyenne"
    elif re.match(r"derecho\d+", hostname):
        machine = "derecho"
    else:
        machine = hostname

    return machine