#!/bin/bash

set -e

FILE=/etc/cron.d/debsecan

usage () {
    echo "usage: $0 [--upgrade]"
    exit 1
}

if test -e "$FILE" ; then
    if grep '^# AUTOMATICALLY GENERATED$' "$FILE" > /dev/null ; then
	may_overwrite=true
    else
	may_overwrite=false
    fi
else
    may_overwrite=true
fi

case "$1" in
    --upgrade)
	if $may_overwrite ; then
	    :
	else
	    echo "warning: /etc/cron.d/debsecan already exists with unexpected content"
	    echo "warning: You can regenerated it with /usr/sbin/debsecan-create-cron."
	    exit 0
	fi
	;;
    -*)
	echo "error: illegal option '$1'"
	exit 1
	;;
    *)
	if test "$#" -ne 0 ; then
	    echo "error: illegal positional argument"
	    exit 1
	fi
	;;
esac

MIN=$(($RANDOM % 60))

cat > "$FILE" <<EOF
# cron entry for debsecan
MAILTO=root

$MIN * * * * daemon test -x /usr/bin/debsecan && /usr/bin/debsecan --cron
# (Note: debsecan delays actual processing past 2:00 AM, and runs only
# once per day.)
EOF

exit 0