#!/bin/bash

#    IngRRD (https://forge.riquer.fr/p/ingrrd/)
#    Copyright (C) 2014-2015  Vincent Riquer
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Affero General Public License as
#    published by the Free Software Foundation, either version 3 of the
#    License, or (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU Affero General Public License for more details.
#
#    You should have received a copy of the GNU Affero General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

send_headers() {
	local timestamp do_exit header thisdate expiredate
	read timestamp < <(stat -c %Y $0 settings "$rrdfile" lib/* .importing 2>/dev/null|sort -r)
	thisdate=$(LC_ALL=C TZ=GMT date +'%a, %d %b %Y %X %Z' -d @$timestamp)
	expiredate=$(LC_ALL=C TZ=GMT date +'%a, %d %b %Y %X %Z' -d "+${1:-60} second")
	if [[ $thisdate == $HTTP_IF_MODIFIED_SINCE ]]
	then
		echo "Status: 304 Not Modified"
		do_exit=1
	fi
	echo "Last-Modified: $thisdate"
	echo "Expires: $expiredate"
	echo "Cache-Control: must-revalidate, max-age=${1:-60}"
	while read header
	do
		echo "$header"
	done
	echo
	(( do_exit )) && exit
}