#!/bin/bash

# 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

#declare array for values and fields found in control file
declare -a AllValues AllFields

collect_values() {
      local i line

      i=0
      while read line
      do
        AllFields[$i]=${line%%:*}
        AllValues[$i]=`echo ${line#*:}` # echo to remove spaces
        let i=i+1
      done < ${pkg_dir}/${CONTROL}/control
}

required_field() {
        local field i
        field=$1

        i=0
        for af in "${AllFields[@]}"
        do
          if [ "$field" = "$af" ]
          then
            # return value
            echo "${AllValues[$i]}"
            return 0;
          fi
          let i=i+1
        done
        # not found
	echo "*** Error: $CONTROL/control is missing field $field" >&2
	return 1
}

#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

	tilde_files=`find . -name '*~'`
	if [ -n "$tilde_files" ]; then
		echo "*** Warning: The following files have names ending in '~'.
You probably want to remove them: " >&2
		ls -ld $tilde_files
		echo >&2
	fi

	large_uid_files=`find . -uid +99`

	if [ "$ogargs" = "" ]  && [ -n "$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/Version://; s/^.://g;'`
	[ "$?" -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 | grep '[^a-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"
###
ogargs=""
outer=ar
usage="Usage: $0 [-c] [-o owner] [-g group] <pkg_directory> [<destination_directory>]"
while getopts "cg:o:" opt; do
    case $opt in
	o ) owner=$OPTARG
	    ogargs="--owner=$owner"
	    ;;
	g ) group=$OPTARG
	    ogargs="$ogargs --group=$group"
	    ;;
        c ) outer=tar
            ;;
	\? ) 	echo $usage  >&2
	esac
done

# maks sure that tar produces headers compatible with busybox format
# debian needs this
ogargs="$ogargs --format=oldgnu"

shift $(($OPTIND - 1))

# continue on to process additional arguments

case $# in
1)
	dest_dir=.
	;;
2)
	dest_dir=$2
	;;
*)
	echo echo $usage >&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

# load values 
collect_values 

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=$dest_dir/IPKG_BUILD.$$
mkdir $tmp_dir

tar $ogargs -C $pkg_dir -czf $tmp_dir/data.tar.gz . --exclude=$CONTROL
tar $ogargs -C $pkg_dir/$CONTROL -czf $tmp_dir/control.tar.gz .

echo "2.0" > $tmp_dir/debian-binary

pkg_file=$dest_dir/${pkg}_${version}_${arch}.ipk
here_dir=$PWD
## tar -C $tmp_dir -czf $pkg_file ./debian-binary ./data.tar.gz ./control.tar.gz
rm -f $pkg_file
if [ "$outer" = "ar" ] ; then
  cd $tmp_dir ; ar crf $here_dir/$pkg_file ./debian-binary ./data.tar.gz ./control.tar.gz
else
  cd $tmp_dir ; tar -zcf $here_dir/$pkg_file ./debian-binary ./data.tar.gz ./control.tar.gz
fi
cd $here_dir
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"