#!/bin/sh

# ipkg-build -- construct a .ipk from a directory
# Carl Worth <cworth@east.isi.edu>
# based on a script by Steve Redler IV, steve@sr-tech.com 5-21-2001
set -e

ipkg_extract_value() {
	sed -e "s/^[^:]*:[[:space:]]*//"
}

required_field() {
	field=$1

	value=`grep "^$field:" < $CONTROL/control | ipkg_extract_value`
	if [ -z "$value" ]; then
		echo "*** Error: $CONTROL/control is missing field $field" >&2
		return 1
	fi
	echo $value
	return 0
}

pkg_appears_sane() {
	local pkg_dir=$1

	local owd=`pwd`
	cd $pkg_dir

	PKG_ERROR=0

#	large_uid_files=`find . -uid +99`
#	if [ -n "$large_uid_files" ]; then
#		echo "*** Warning: The following files have a UID greater than 99.
#You probably want to chown these to a system user: " >&2
#		ls -ld $large_uid_files
#		echo >&2
#	fi
	    

	if [ ! -f "$CONTROL/control" ]; then
		echo "*** Error: Control file $pkg_dir/$CONTROL/control not found." >&2
		cd $owd
		return 1
	fi

	pkg=`required_field Package`
	[ "$?" -ne 0 ] && PKG_ERROR=1

	version=`required_field Version | sed 's/.*://;'`
	[ "$?" -ne 0 ] && PKG_ERROR=1

	arch=`required_field Architecture`
	[ "$?" -ne 0 ] && PKG_ERROR=1

	required_field Maintainer >/dev/null
	[ "$?" -ne 0 ] && PKG_ERROR=1

	required_field Description >/dev/null
	[ "$?" -ne 0 ] && PKG_ERROR=1

	section=`required_field Section`
	[ "$?" -ne 0 ] && PKG_ERROR=1
	if [ -z "$section" ]; then
	    echo "The Section field should have one of the following values:" >&2
	    echo "admin, base, comm, editors, extras, games, graphics, kernel, libs, misc, net, text, web, x11" >&2
	fi

	priority=`required_field Priority`
	[ "$?" -ne 0 ] && PKG_ERROR=1
	if [ -z "$priority" ]; then
	    echo "The Priority field should have one of the following values:" >&2
	    echo "required, important, standard, optional, extra." >&2
	    echo "If you don't know which priority value you should be using, then use \`optional'" >&2
	fi

	if echo $pkg | egrep '[^a-zA-Z0-9.+-]'; then
		echo "*** Error: Package name $name contains illegal characters, (other than [a-z0-9.+-])" >&2
		PKG_ERROR=1;
	fi

	local bad_fields=`sed -ne 's/^\([^[:space:]][^:[:space:]]\+[[:space:]]\+\)[^:].*/\1/p' < $CONTROL/control | sed -e 's/\\n//'`
	if [ -n "$bad_fields" ]; then
		bad_fields=`echo $bad_fields`
		echo "*** Error: The following fields in $CONTROL/control are missing a ':'" >&2
		echo "	$bad_fields" >&2
		echo "ipkg-build: This may be due to a missing initial space for a multi-line field value" >&2
		PKG_ERROR=1
	fi

	for script in $CONTROL/preinst $CONTROL/postinst $CONTROL/prerm $CONTROL/postrm; do
		if [ -f $script -a ! -x $script ]; then
			echo "*** Error: package script $script is not executable" >&2
			PKG_ERROR=1
		fi
	done

	if [ -f $CONTROL/conffiles ]; then
		for cf in `cat $CONTROL/conffiles`; do
			if [ ! -f ./$cf ]; then
				echo "*** Error: $CONTROL/conffiles mentions conffile $cf which does not exist" >&2
				PKG_ERROR=1
			fi
		done
	fi

	cd $owd
	return $PKG_ERROR
}

###
# ipkg-build "main"
###

case $# in
1)
	dest_dir=.
	;;
2)
	dest_dir=$2
	;;
*)
	echo "Usage: ipkg-build <pkg_directory> [<destination_directory>]" >&2
	exit 1 
	;;
esac

pkg_dir=$1

if [ ! -d $pkg_dir ]; then
	echo "*** Error: Directory $pkg_dir does not exist" >&2
	exit 1
fi

# CONTROL is second so that it takes precedence
CONTROL=
[ -d $pkg_dir/DEBIAN ] && CONTROL=DEBIAN
[ -d $pkg_dir/CONTROL ] && CONTROL=CONTROL
if [ -z "$CONTROL" ]; then
	echo "*** Error: Directory $pkg_dir has no CONTROL subdirectory." >&2
	exit 1
fi

if ! pkg_appears_sane $pkg_dir; then
	echo >&2
	echo "ipkg-build: Please fix the above errors and try again." >&2
	exit 1
fi

tmp_dir=/tmp/IPKG_BUILD.$$
mkdir $tmp_dir

tar -C $pkg_dir -cpf $tmp_dir/data.tar . --exclude=$CONTROL
gzip -9  $tmp_dir/data.tar
tar -C $pkg_dir/$CONTROL -cf $tmp_dir/control.tar .
gzip -9  $tmp_dir/control.tar

echo "2.0" > $tmp_dir/debian-binary

pkg_file=${pkg}_${version}_${arch}.ipk
tar -C $tmp_dir -cf $tmp_dir/$pkg_file ./debian-binary ./data.tar.gz ./control.tar.gz
gzip -9 $tmp_dir/$pkg_file
mv $tmp_dir/$pkg_file.gz $dest_dir/$pkg_file

rm $tmp_dir/debian-binary $tmp_dir/data.tar.gz $tmp_dir/control.tar.gz
rmdir $tmp_dir

echo "Packaged contents of $pkg_dir into $pkg_file"
