#!/bin/bash

#
#/
#/ Usage:
#/ check-systemctl-service.sh --help <unit-file>
#/ 
#/ Options:
#/  -u, --user      Check for running within current user
#/  -h, --help      Display this help message
#/ 
#/ Checks if a systemd unit is active
#/ 
#/ Exit Codes:
#/  0 Everything OK
#/  2 Unit is not running
#/  3 Unknown status
#/


Usage() {
    grep '^#/' "${script_dir}/${script_name}" | sed 's/^#\/\w*//'
}

GetOptions() {
    # https://stackoverflow.com/a/29754866
    OPTIONS=uh
    LONGOPTS=user,help

    # -use ! and PIPESTATUS to get exit code with errexit set
    # -temporarily store output to be able to check for errors
    # -activate quoting/enhanced mode (e.g. by writing out “--options”)
    # -pass arguments only via   -- "$@"   to separate them correctly
    ! PARSED=$(getopt --options=$OPTIONS --longoptions=$LONGOPTS --name "$0" -- "$@")
    if [[ ${PIPESTATUS[0]} -ne 0 ]]; then
        # e.g. return value is 1
        #  then getopt has complained about wrong arguments to stdout
        Usage
        exit 2
    fi

    # read getopt's output this way to handle the quoting right:
    eval set -- "$PARSED"

    # now enjoy the options in order and nicely split until we see --
    while true; do
        case "$1" in
            -u|--user)
                user='--user'
                shift 1
                ;;
            -h|--help)
                Usage
                exit 0
                ;;
            --)
                shift
                break
                ;;
            *)
                echo "SERVICE UNKNOWN - ${1} is not a valid parameter"
                exit 3
                ;;
        esac
    done

    if [ -z ${1+x} ]; then 
        echo "SERVICE UNKNOWN - Unitfile not given"
        exit 3
    else 
        service=${1}
    fi
}
user=''
service=''
LC_NUMERIC="C"
script_name=$(basename "${0}")
script_dir=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
GetOptions "$@"

if [[ $(systemctl ${user} list-units "${service}*" | wc -l) -gt 3 ]]; then
    result=$(systemctl ${user} is-active ${service})
else
    result='inexistent'
fi


if [[ $result == 'active' ]]; then
    rval=0
    rmsg="OK"
elif [[ $result == 'inexistent' ]]; then
    rval=1
    rmsg="WARNING"
else
    rval=2
    rmsg="CRITICAL"
fi

echo "SERIVCE ${rmsg} - Service $service $result"
exit $rval