#!/bin/sh
#
#  Copyright (c) 2014 Canonical
#
#  Author: Oliver Grawert <ogra@canonical.com>
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License as
#  published by the Free Software Foundation; either version 2 of the
#  License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
#  USA
#

set -e

TARPATH=$1
CUST_TARPATH=$2
SYSIMG=$3

prepare_ubports_systemfs()
{
	rm -f $WORKDIR/system.img
	dd if=/dev/zero of=$WORKDIR/system.img seek=500K bs=4096 count=0
	mkfs.ext2 -F $WORKDIR/system.img
	mkdir -p $WORKDIR/system
	mount -o loop $WORKDIR/system.img $WORKDIR/system/
}

cleanup()
{
	echo
	echo "cleaning up"
	mount | grep -q $WORKDIR/system 2>/dev/null && umount $WORKDIR/system
	cleanup_device
	#rm -rf $WORKDIR
	echo
}

cleanup_device()
{
	[ -e $WORKDIR/device-clean ] && return
	umount $WORKDIR/system/ && rm -rf $WORKDIR/system
	[ -e $WORKDIR ] && touch $WORKDIR/device-clean 2>/dev/null || true
}

trap cleanup 0 1 2 3 9 15

SUDOARGS="$@"

if [ -z "$TARPATH" ]; then
    echo "need valid rootfs tarball path"
    usage
fi

TARTYPE=$(file --mime-type $TARPATH|sed 's/^.* //')
case ${TARTYPE#application\/} in
    gzip|x-gzip)
	;;
    *)
	echo "Need valid rootfs tarball gzip type"
	usage
	;;
esac


if [ -z "$CUST_$TARPATH" ]; then
    echo "need valid custom tarball path"
    usage
fi

TARTYPE=$(file --mime-type $CUST_TARPATH|sed 's/^.* //')
case ${TARTYPE#application\/} in
    gzip|x-gzip)
	;;
    *)
	echo "Need valid custom tarball gzip type"
	usage
	;;
esac

if [ -z "$SYSIMG" ]; then
    echo "need valid systemfs tarball path"
    usage
fi

if [ "$(file --mime-type $SYSIMG|sed 's/^.* //')" != "application/x-xz" ]; then
	echo "system tarball needs to be valid path and type .tar.xz"
	usage
fi

[ $(id -u) -ne 0 ] && exec sudo $0 $SUDOARGS


WORKDIR=$(mktemp -d /tmp/halium-install.XXXXX)
TMPMOUNT="$WORKDIR/tmpmount"

prepare_ubports_systemfs

OUTDIR=$(pwd)
TARBALL=$(readlink -f $TARPATH)
echo -n "unpacking rootfs tarball to system-image ... "
cd $WORKDIR/system && zcat $TARBALL | tar xf - --numeric-owner
cd $OUTDIR
echo "[done]"

echo "Testing for SWAP.swap"
[ -e $WORKDIR/system/SWAP.swap ] && rm $WORKDIR/system/SWAP.swap

TARBALL=$(readlink -f $CUST_TARPATH)
echo -n "adding custom tarball ... "
# --strip-components=1 since the tarball dir is system/
cd $WORKDIR/system && zcat $TARBALL | tar xf - --strip-components=1 --numeric-owner
cd $OUTDIR
echo "[done]"

TARBALL=$(readlink -f $SYSIMG)
echo -n "unpacking systemfs tarball to system-image ... "
# --strip-components=1 since the tarball dir is system/
cd $WORKDIR/system && xzcat $TARBALL | tar xf - --exclude=partitions --strip-components=1 --numeric-owner
cd $OUTDIR
echo "[done]"

echo -n "prepare other stuff in system-image ... "
cd $WORKDIR/system
mkdir -p android/firmware
mkdir -p android/persist
mkdir -p userdata
for link in cache data factory firmware persist system; do
  ln -s /android/$link $link
done
cd lib && ln -s /system/lib/modules modules && cd ..
ln -s /android/system/vendor vendor
[ -e etc/mtab ] && rm etc/mtab
cd etc && ln -s /proc/mounts mtab && cd ..

cd $OUTDIR
echo "[done]"

echo "umount .../system"
umount $WORKDIR/system
echo "save prepared systemfs"
mv $WORKDIR/system.img $OUTDIR/prepared-system.img

echo -n "cleaning up on device ... "
cleanup_device
echo "[done]"