#!/bin/sh
#
# Roman Bogorodskiy <novel@FreeBSD.org>

version=0.1
config_file="/usr/local/etc/fetch_delta.conf"

#test -f ${config_file} && source ${config_file}

SYS_FETCH=${SYS_FETCH:=/usr/bin/fetch}
FETCH=${FETCH:=/usr/local/bin/wget}
DELTUP=${DELTUP:=/usr/local/bin/deltup}
#MPDIR=${TMPDIR:=/tmp}
#xport TMPDIR=${TMPDIR}

try_to_fetch_delta() {
	prefix=`echo $1|sed -e 's/[[:digit:]][[:print:]]*$//'`
	suffix=".`echo $1|sed -e 's/.*[.]//g'`"
	
	# if there are more than 1 file we get last 'cause 
	# it's most likely it'll be the newest version you have
	old_file=`ls ${prefix}*${suffix} 2>/dev/null|tail -1`
	new_file=$1

	if test \"${old_file}\" = \"${new_file}\"; then
		echo "I see (probably) a corrupted file ${old_file}!"
		return 1;
	fi
	
	if test -z ${old_file}; then
		echo "---> It seems there are no previous versions of ${new_file} here, fetching tarball";
		return 1
	else 
		URL="http://linux01.gwdg.de/~nlissne/deltup.php?have=${old_file}&want=${new_file}&version=0.7"
		echo "---> Delta URL: ${URL}"
		echo "---> Fetching delta"
		rm -f ${old_file}-${new_file}.dtu* 2>&1 > /dev/null
		${FETCH} ${URL}

		# check return status
		if test $? -ne 0 && test -f ${old_file}-${new_file}.dtu; then
			echo "---> Failed to download delta"
			return 1;
		else
			echo "---> Succeed, patching"
			${DELTUP} -p ${old_file}-${new_file}.dtu

			if test ! -f ${new_file}; then
				echo "Patching failed (probalby the delta you want has not been generated by server yet)"
				return 1;
			fi
	       	fi
		return 0;
	fi
		
}

# command executed by `make fetch' should look like that: 
#	${FETCH_CMD} -S size_of_distfile url
#f test $# -eq 3; then
#	try_to_fetch_delta `basename $2`;
#elif test $# -eq 1; then
	# looks like `make makesum` or something like that -> we're going to download original tarball
	# because we don't want to break distinfo
#	echo "---> Falling back to downloading orignal tarball"
#	${SYS_FETCH} $*;
#else
#	echo "Something goes wrong. Dance around me!"
#	exit 1;
#fi

if test $2; then
	try_to_fetch_delta `basename $2`;
else
	${SYS_FETCH} $*;
fi
	
if test $? -eq 1; then
	echo "---> Falling back to downloading orignal tarball"
	${SYS_FETCH} $*;
fi