#!/bin/sh
#-
# Copyright (c) 2013 Juan Romero Pardines.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#-

readonly PROGNAME=$(basename $0)
readonly ARCH=$(uname -m)

trap 'printf "\nInterrupted! exiting...\n"; cleanup; exit 0' INT TERM HUP

cleanup() {
    umount -f ${ROOTFSDIR}/boot 2>/dev/null
    umount -f ${ROOTFSDIR} 2>/dev/null
    [ -e "$LOOPDEV" ] && losetup -d $LOOPDEV 2>/dev/null
    [ -d "$ROOTFSDIR" ] && rmdir $ROOTFSDIR
}

info_msg() {
    printf "\033[1m$@\n\033[m"
}

die() {
    echo "FATAL: $@"
    exit 1
}

usage() {
    echo "Usage: $PROGNAME [-b fstype] [-o filename] [-r fstype] [-hV] <rootfs-tarball> [size]"
    echo
    echo " The <rootfs-tarball> argument expects a file generated by void-mkrootfs."
    echo " The <size> argument expects a number (GB). If <size> is not set, defaults to 2."
    echo
    echo "OPTIONS"
    echo " -b <fstype>    Set /boot <fstype> (defaults to fat32, 256MB)"
    echo " -o <filename>  Set output <filename>."
    echo " -r <fstype>    Set / <fstype> (defaults to ext4, 256MB - <size>)"
    echo
    echo " Resulting image will have 2 partitions, /boot and / of total <size>." 
    exit 0
}

#
# main()
#
while getopts "b:o:r:hV" opt; do
    case $opt in
        b) BOOT_FSTYPE="$OPTARG";;
        o) FILENAME="$OPTARG";;
        r) ROOT_FSTYPE="$OPTARG";;
        V) echo "$PROGNAME @@MKLIVE_VERSION@@"; exit 0;;
        h) usage;;
    esac
done
shift $(($OPTIND - 1))

ROOTFS_TARBALL="$1"
if [ -z "$ROOTFS_TARBALL" ]; then
    usage
elif [ ! -r "$ROOTFS_TARBALL" ]; then
    die "Cannot read rootfs tarball: $ROOTFS_TARBALL"
fi

if [ "$(id -u)" -ne 0 ]; then
    die "need root perms to continue, exiting."
fi

for f in parted mkfs.${BOOT_FSTYPE} mkfs.${ROOT_FSTYPE}; do
    if ! which ${f} >/dev/null; then
        die "Cannot find ${f}, exiting."
    fi
done

IMGSIZE="$2"
if [ -z "$IMGSIZE" ]; then
    IMGSIZE="2G"
else
    IMGSIZE="${2}G"
fi

if [ -z "$BOOT_FSTYPE" ]; then
    BOOT_FSTYPE="vfat"
fi
if [ -z "$ROOT_FSTYPE" ]; then
    ROOT_FSTYPE="ext4"
fi
if [ -z "$FILENAME" ]; then
    FILENAME="void-image-$(date +%Y%m%d).img"
fi

info_msg "Creating disk image ($IMGSIZE) ..."
dd if=/dev/zero of=$FILENAME bs=$IMGSIZE count=1 conv=sparse >/dev/null 2>&1

info_msg "Creating disk image partitions/filesystems ..."
parted $FILENAME mktable msdos
if [ "$BOOT_FSTYPE" = "vfat" ]; then
    _btype="fat32"
fi
parted $FILENAME mkpart primary ${_btype} 2048s 256M
parted $FILENAME mkpart primary ext2 256M 100%
parted $FILENAME toggle 1 boot
LOOPDEV=$(losetup --show --find -P $FILENAME)
mkfs.${BOOT_FSTYPE} ${LOOPDEV}p1 >/dev/null 2>&1
mkfs.${ROOT_FSTYPE} ${LOOPDEV}p2 >/dev/null 2>&1

info_msg "Unpacking rootfs tarball ..."
ROOTFSDIR=$(mktemp -d)
mount ${LOOPDEV}p2 $ROOTFSDIR
mkdir -p ${ROOTFSDIR}/boot
mount ${LOOPDEV}p1 ${ROOTFSDIR}/boot

tar xfp $ROOTFS_TARBALL -C $ROOTFSDIR

BOOT_UUID=$(blkid -o value -s UUID ${LOOPDEV}p1)
ROOT_UUID=$(blkid -o value -s UUID ${LOOPDEV}p2)
echo "UUID=$BOOT_UUID /boot $BOOT_FSTYPE defaults 0 0" >> ${ROOTFSDIR}/etc/fstab
echo "UUID=$ROOT_UUID / $ROOT_FSTYPE defaults 0 1" >> ${ROOTFSDIR}/etc/fstab
if [ -s ${ROOTFSDIR}/boot/cmdline.txt ]; then
   sed -e "s,rootfstype=ext4,rootfstype=${ROOT_FSTYPE}," -i ${ROOTFSDIR}/boot/cmdline.txt
fi

umount ${ROOTFSDIR}/boot
umount $ROOTFSDIR
losetup -d $LOOPDEV
rmdir $ROOTFSDIR

chmod 644 $FILENAME
info_msg "Successfully created $FILENAME image."

# vim: set ts=4 sw=4 et: