xpak2gpkg

#!/usr/bin/env bash

if [[ ${#} -lt 1 || ${#} -gt 2 ]]; then
	echo "Usage: ${0} <source.xpak> [<dest.gpkg.tar>]" >&2
	exit 1
fi

die() {
	echo "${*}"
	exit 1
}

input=${1}
output=${2:-${input%.xpak}.gpkg.tar}

type -P qtbz2 &>/dev/null || die "qtbz2 (from portage-utils) required"
type -P qxpak &>/dev/null || die "qxpak (from portage-utils) required"

tmpdir=$(mktemp -d)
trap 'cd; rm -r "${tmpdir}"' EXIT

echo "Splitting the binary package ..." >&2
qtbz2 -d "${tmpdir}" -s "${input}" || die "qtbz2 splitting failed"

cd "${tmpdir}" || die "cd to tmpdir failed"
filename=${input##*/}
data=${filename}.tar.bz2
xpak=${filename}.xpak

comp_mime=$(file -b --mime-type "${data}")
case ${comp_mime} in
	application/x-bzip2)
		comp_suffix=.bz2
		comp=(bzip2 -9)
		;;
	application/x-gzip)
		comp_suffix=.gz
		comp=(gzip -9)
		;;
	application/x-lzip)
		comp_suffix=.lz
		comp=(lzip -9)
		;;
	application/x-xz)
		comp_suffix=.xz
		comp=(xz -e9)
	*)
		die "Unknown compression format: ${comp_mime}"
		;;
esac

basename=${filename%.xpak}
mkdir "${basename}" || die "mkdir failed"
mv "${data}" "${basename}/contents.tar${comp_suffix}" || die "mv contents failed"

echo "Repacking metadata ..." >&2
mkdir "${basename}/metadata" || die "mkdir (2) failed"
qxpak -d "${basename}/metadata" -x "${xpak}" || die "qxpak failed to unpack"
rm "${xpak}" || die "rm xpak failed"
envfile=${basename}/metadata/environment.bz2
if [[ -f ${envfile} ]]; then
	bzip2 -d "${envfile}" || die "unpacking environment.bz2 failed"
fi
tar -C "${basename}" -c -f "${basename}/metadata.tar" metadata || die "tar metadata failed"
rm -r "${basename}/metadata" || die "rm metadata failed"
"${comp[@]}" "${basename}/metadata.tar" || die "${comp[*]} metadata.tar failed"

echo "Signing tarballs ..." >&2
gpg --detach-sign "${basename}/metadata.tar${comp_suffix}" || die "signing metadata failed"
gpg --detach-sign "${basename}/contents.tar${comp_suffix}" || die "signing contents failed"

echo "Packing the final tarball ..." >&2
cd - >/dev/null || die "cd back failed"
tar -c -C "${tmpdir}" -f "${output}" \
	-V "gpkg: ${basename}" \
	"${basename}/metadata.tar${comp_suffix}.sig" \
	"${basename}/metadata.tar${comp_suffix}" \
	"${basename}/contents.tar${comp_suffix}.sig" \
	"${basename}/contents.tar${comp_suffix}"

echo "Output written to: ${output}" >&2