#!/bin/sh
# This script reads filenames from STDIN and outputs any relevant requires
# information that needs to be included in the package.
#
# Based on rpm-4.4.2/scripts/find-req.pl
# Authors: Elan Ruusamäe <glen@pld-linux.org>

export PATH="/sbin:/usr/sbin:/bin:/usr/bin"

# save $- state, to enable in functions
debug=$-

# enable debug: FIND_JAVAREQ_DEBUG=true
FIND_JAVAREQ_DEBUG=${FIND_JAVAREQ_DEBUG:-false}

javaclassversion() {
	set -$debug
	[ $# -gt 0 ] || return 1
	$FIND_JAVAREQ_DEBUG && echo >&2 ">> class: $*"

	local classver=$(echo "$@" | xargs -r file | grep -o 'compiled Java class data, version [0-9.]*' | awk '{print $NF}' | sort -u)
	if [ -z "$classver" ]; then
		return 1
	fi

	local v
	for v in $classver; do
		echo "java(ClassDataVersion) >= $v"
	done
	return 0
}

javajarversion() {
	set -$debug
	local jar="$1"
	local tmp ret=0
	$FIND_JAVAREQ_DEBUG && echo >&2 ">> jar: $jar"

	# check only files, symlinks could point outside buildroot
	[ -f "$jar" -a ! -L "$jar" ] || return $ret

	tmp=$(mktemp -d)
	unzip -q -d $tmp $jar >&2
	# workaround for .jar files with stupid permissions
	chmod -R u+rwX $tmp

	# find .jar and .class files
	find_requires $(find $tmp -type f -regex '^.+\.(class|jar)$') || ret=1
	rm -rf $tmp
	return $ret
}

find_requires() {
	set -$debug
	local ret=0

	$FIND_JAVAREQ_DEBUG && echo >&2 ">> find_requires: $*"
	for file in $@; do
		case $file in
		*.jar)
			javajarversion "$file" || ret=1
		;;
		*.class)
			javaclassversion "$file" || {
				echo >&2 "ERROR: Class version could not be extracted from $file"
				ret=1
			}
		;;
		*)
			$FIND_JAVAREQ_DEBUG && echo >&2 ">> find_requires: no handle: $file"
		;;
		esac
	done
	return $ret
}

t=$(mktemp)
ret=0
find_requires $(cat -) > $t || ret=1
sort -u $t
rm -f $t
exit $ret