#!/usr/bin/sh

get_service() {
    systemctl --type=service | grep openvpn-client@nordvpn | awk '{print $1}'
}

run_ping() {
    remote=$(grep -E '^remote [0-9.]+ [0-9]+$' $1 | cut -d ' ' -f 2)
    test ! -z "$remote" || exit 1
    bin=$(which ping)
    test $? -eq 0 || echo "ping not found, please install iputils"
    $bin -c 4 -A $remote | tail -n 1 | cut -d / -f 5
}

print_usage() {
    echo "usage: $(basename $0) [options] command [args]"
    echo "Available options:"
    echo "    -v  be verbose, show commands and variables"
    echo "    -h  print this help and exit"
    echo "Available commands:"
    echo "    list [server_name_pattern]"
    echo "        List available servers."
    echo "    ping server_name"
    echo "        Show round trip latency"
    echo "    rank [server_name_pattern]"
    echo "        Ping all servers matching pattern and rank them"
    echo "    status"
    echo "        Show current systemd service status, if any."
    echo "    start|stop|restart server_name"
    echo "        Start, stop or restart systemd service for specified server."
}

while getopts "vh" opt
do
    case $opt in
        v)
            set -x
            shift
            ;;
        *)
            print_usage
            exit $(test $opt == "h")
            ;;
    esac
done

command=$1
shift

case $command in
    list)
        find /etc/openvpn/client/ -type l -name "nordvpn_*${1}*.conf" \
             | xargs -L1 basename \
             | cut -d _ -f 2 \
             | cut -d . -f 1 \
             | sort -g
        ;;
    ping)
        file=/etc/openvpn/client/nordvpn_${1}.conf
        test -f "$file" || exit 1
        run_ping $file
        ;;
    rank)
        tmp=$(mktemp)
        for f in $(find /etc/openvpn/client/ -type l -name "nordvpn_*${1}*.conf")
        do
            echo $(basename $f .conf | cut -d _ -f 2) $(run_ping $f) >> $tmp
        done
        sort -k 2 -n $tmp
        rm -f $tmp
        ;;
    status)
        service=$(get_service)
        test -z "$service" || systemctl status $service
        ;;
    start)
        service=$(get_service)
        test -z "$service" || $0 stop
        if [[ -x /etc/openvpn/vpnfailsafe.sh ]]; then
            ln -fs /etc/openvpn/vpnfailsafe.sh /etc/openvpn/client/nordvpn/updown
        else
            ln -fs /etc/openvpn/update-resolv-conf /etc/openvpn/client/nordvpn/updown
        fi
        if [[ ! -f /etc/openvpn/client/nordvpn_${1}.conf ]]; then
            echo "${1} is not a valid nordvpn server. Exiting."
            exit 1
        fi
        systemctl $command openvpn-client@nordvpn_${1}
        ;;
    stop|restart)
        service=$(get_service)
        test -z "$service" || systemctl $command $service
        ;;
    *)
        print_usage
        exit 1
        ;;
esac