#!/bin/sh

USER="$1"

INSTANCE="$2"

die() {

	echo "FATAL: ${@:-}" >&2

	exit 2

}

cleanup() {

	[ -n "$VNCPID" ] || return

	if kill -0 $VNCPID 2>/dev/null; then

		kill $VNCPID

	fi

}

trap cleanup TERM INT HUP

[ -n "$USER" -a -n "$INSTANCE" ] || die "Invalid usage!"

/usr/sbin/runuser -l "$USER" -c "/usr/bin/vncserver ${INSTANCE}"

[ $? -eq 0 ] || die "'runuser -l $USER' failed!"

# Wait up to 5 seconds for vncserver to be up

for tries in $(seq 1 50); do

	[ -e "~$USER/.vnc/$(hostname)${INSTANCE}.pid" ] && break

	sleep 0.1

done

eval HOME=~$USER

VNCPID=$(cat "$HOME/.vnc/$(hostname)${INSTANCE}.pid" 2>/dev/null || true)

[ -n "$VNCPID" ] || die "'vncserver ${INSTANCE}' failed to start after 5 seconds!"

echo "'vncserver ${INSTANCE}' has PID $VNCPID, waiting until it exits ..."

while kill -0 $VNCPID 2>/dev/null; do

	sleep 5

done

echo "PID $VNCPID exited, exiting ..."