#!/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)
readonly PKGBASE="base-system"

trap 'printf "\nInterrupted! exiting...\n"; exit $?' INT TERM HUP

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

die() {
    echo "FATAL: $@"
    [ -d "$rootfs" ] && rm -rf $rootfs
    exit 1
}

usage() {
    echo "Usage: $PROGNAME [-a raspberrypi] [-p 'pkg1 pkg2'] [-V]"
}

run_cmd() {
    info_msg "Running $@ ..."
    if [ -n "${_ARCH}" ]; then
        eval XBPS_TARGET_ARCH=${_ARCH} "$@" >/dev/null 2>&1
    else
        eval "$@" >/dev/null 2>&1
    fi
    [ $? -ne 0 ] && die "Failed to run $@"
}

register_binfmt() {
    if [ "$ARCH" = "${_ARCH}" ]; then
        return 0
    fi
    case "${_ARCH}" in
        armv6l)
            echo ':arm:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/bin/qemu-arm-static:' > /proc/sys/fs/binfmt_misc/register
            cp -f $(which qemu-arm-static) $rootfs/usr/bin || die "failed to copy qemu-arm-static to the rootfs"
            ;;
        *)
            die "Unknown target architecture!"
            ;;
    esac
}

#
# main()
#
while getopts "a:hp:V" opt; do
    case $opt in
        a) TARGET_ARCH="$OPTARG";;
        p) EXTRA_PKGS="$OPTARG";;
        h) usage; exit 0;;
        V) echo "$PROGNAME @@MKLIVE_VERSION@@"; exit 0;;
    esac
done
shift $(($OPTIND - 1))

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

#
# Check for required binaries.
#
for f in systemd-nspawn xbps-install xbps-reconfigure xbps-query; do
    if ! $f --version >/dev/null 2>&1; then
        die "$f binary is missing in your system, exiting."
    fi
done

#
# Sanitize target arch.
#
case "$TARGET_ARCH" in
    raspberrypi) _ARCH=armv6l; QEMU_BIN=qemu-arm-static;;
    *) ;;
esac

#
# Check if package base-system is available.
#
run_cmd "xbps-query -R -ppkgver $PKGBASE"

rootfs=$(mktemp -d || die "FATAL: failed to create tempdir, exiting...")
chmod 755 $rootfs

#
# Install base-system to the rootfs directory.
#
run_cmd "xbps-install -S -r $rootfs -y $PKGBASE $EXTRA_PKGS"

#
# Reconfigure packages for target architecture: must be reconfigured
# thru the qemu user mode binary.
#
if [ -n "$TARGET_ARCH" ]; then
    info_msg "Reconfiguring packages for $TARGET_ARCH ..."
    register_binfmt
    xbps-reconfigure -r $rootfs base-directories
    run_cmd "systemd-nspawn -D $rootfs xbps-reconfigure shadow"
    run_cmd "systemd-nspawn -D $rootfs xbps-reconfigure systemd"
    run_cmd "systemd-nspawn -D $rootfs xbps-reconfigure -a"
    (rm -f $rootfs/lib32; rm -f $rootfs/lib64) >/dev/null 2>&1
else
    run_cmd "systemd-nspawn -D $rootfs xbps-reconfigure -f systemd"
fi

#
# Setup default root password.
#
chroot $rootfs sh -c 'echo "root:voidlinux" | chpasswd -c SHA512'

#
# Cleanup rootfs.
#
rm -rf $rootfs/dev/* $rootfs/run/* $rootfs/tmp/* $rootfs/tmp/.* 2>/dev/null
rm -f $rootfs/etc/.pwd.lock 2>/dev/null
rm -rf $rootfs/var/cache/xbps 2>/dev/null

#
# Generate final tarball.
#
arch=$ARCH
if [ -n "$TARGET_ARCH" ]; then
    rm -f $rootfs/usr/bin/qemu-*-static
    arch=$TARGET_ARCH
fi

tarball=void-${arch}-rootfs-$(date '+%Y%m%d').tar.xz

run_cmd "tar cp -C $rootfs . | xz -9 > $tarball"
rm -rf $rootfs

info_msg "Successfully created $tarball"

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