#!/bin/sh

# Originally copied from /mit/broder/bin/renew-and-notify

# Modified to zephyr about expiring tickets, rather than sending mail,
# and to assume that ticket setup has already been done.

# Kill any other copies of this program currently running, since it
# doesn't get cleaned up after screen exits.
#
# Doesn't seem to currently work and the cont-renew-notify process can
# sometimes kill off itself.
#
#command=`basename $0`
#kill `pgrep -u $USER -f "$command" | grep -v $$` > /dev/null 2> /dev/null

# Default to zephyring.
if [ "x$ZEPHYR_SCREEN_NOTIFY" = "x" ]; then
    ZEPHYR_SCREEN_NOTIFY='zwrite -n ${ATHENA_USER:-$USER}'
fi

# Figure out where date is.
date=date
date -d "01/01/2008 12:00:00" > /dev/null 2> /dev/null
if [ $? -ne 0 ]; then
    date="athrun gnu gdate"
fi

# Figure out whether to use echo -e.
echo=echo
echolines=`$echo "1\n2" | wc -l`
if [ $echolines -ne 2 ]; then
    echo="echo -e"
fi

# Sleep 7 seconds to minimize confusion.  In most cases, users will
# only have one zephyr presence.  If they have more than one, though,
# the zephyr notification may succeed before the current session comes
# up.  Some Sun machines will take a while to load barnowl; they'll
# fail at least once before succeeding on a subsequent notification.
sleep 7

while [ 1 ]; do
    kinit -R
    krb524init > /dev/null 2> /dev/null
    sleep 1
    aklog
    zctl load > /dev/null 2> /dev/null
  
    expirestr=`LC_TIME=C klist | grep 'renew until' | sed -e 's/[\t ]*renew until //' | head -n1`

    if [ -z "$expirestr" ]; then
	expire=0
	message="You do not have renewable tickets on `hostname`.\nRun \"kinit -l7d\" to get renewable tickets."
    else
	expire=`$date -d "$expirestr" +%s`
	
	message="Your tickets on `hostname` will expire within the next 24 hours.\nRun \"kinit -l7d\" to get new renewable tickets."
    fi

    # Non-renewable tickets will result in a negative difference.
    now=`$date +%s`
    difference=`expr $expire - $now`
    if [ "$difference" -lt "86400" -a "$notified" != "$expire" ]; then
	notifystatus=-1
	notifytries=0

	# Notify user.  If notification is not successful, retry every
	# 15 seconds up to 7 tries.  This may occur if
	# cont-renew-notify is started before barnowl and barnowl is
	# taking a long time to load.
	while [ "$notifystatus" -ne "0" -a "$notifytries" -lt "7" ]; do
	    $echo "$message" | eval $ZEPHYR_SCREEN_NOTIFY
	    notifystatus=$?
	    if [ "$notifystatus" -ne "0" ]; then
		tries=`expr $tries + 1`
		sleep 15
	    fi
	done
	notified=$expire
    fi
  
    sleep 3600
done