"""System related functions."""

import shutil
import subprocess
import sys

from autonomic import logger

log = logger.get_logger(__name__)


def ensure_installed(package):
    """Ensure a system dependency is installed"""
    if shutil.which(package) is None:
        msg = "{} is not installed?".format(package)
        exit_with_msg(msg)


def run_command(command):
    """Run a command."""
    try:
        log.info("Running '{}'".format(" ".join(command)))
        subprocess.check_output(command)
    except subprocess.CalledProcessError as exception:
        msg = "{} failed! Saw {}".format(" ".join(command), str(exception))
        exit_with_msg(msg)


def exit(code=1):
    sys.exit(code)


def exit_with_msg(msg, code=1):
    log.critical(msg)
    exit(code)