#!/bin/sh
#
# vim: set ts=4 sw=4 et:
#
#-
# Copyright (c) 2009-2015 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.
#-
trap "error_out $LINENO $?" INT TERM 0

readonly REQUIRED_PKGS="base-files libgcc dash coreutils sed tar gawk syslinux squashfs-tools"
readonly INITRAMFS_PKGS="binutils xz device-mapper dracut-network dhclient dialog"
readonly PROGNAME=$(basename $0)

info_msg() {
    printf "\033[1m$@\n\033[m"
}
die() {
    info_msg "ERROR: $@"
    error_out 1
}
print_step() {
    CURRENT_STEP=$((CURRENT_STEP+1))
    info_msg "[${CURRENT_STEP}/${STEP_COUNT}] $@"
}
mount_pseudofs() {
    for f in sys dev proc; do
        mkdir -p $ROOTFS/$f
        mount --bind /$f $ROOTFS/$f
    done
}
umount_pseudofs() {
    umount -f $ROOTFS/sys >/dev/null 2>&1
    umount -f $ROOTFS/dev >/dev/null 2>&1
    umount -f $ROOTFS/proc >/dev/null 2>&1
}
error_out() {
    umount_pseudofs
    [ -d "$BUILDDIR" -a -z "$KEEP_BUILDDIR" ] && rm -rf "$BUILDDIR"
    exit ${1:=0}
}

usage() {
    cat <<_EOF
Usage: $PROGNAME [options]

Options:
 -a <xbps-arch>     Set XBPS_ARCH (do not use it unless you know what it is)
 -b <system-pkg>    Set an alternative base-system package (defaults to base-system).
 -r <repo-url>      Use this XBPS repository (may be specified multiple times).
 -c <cachedir>      Use this XBPS cache directory (/var/cache/xbps if unset).
 -k <keymap>        Default keymap to use (us if unset)
 -l <locale>        Default locale to use (en_US.UTF-8 if unset).
 -i <lz4|gzip|bzip2|xz> Compression type for the initramfs image (lz4 if unset).
 -o <file>          Output file name for the netboot tarball (auto if unset).

 -C "cmdline args"  Add additional kernel command line arguments.
 -T "title"         Modify the bootloader title.
 -K                 Do not remove builddir.

The $PROGNAME script generates a network-bootable tarball of Void Linux
This *.tar.gz contains only the autoinstaller.
_EOF
    exit 1
}

copy_void_keys() {
    mkdir -p "$1"/var/db/xbps/keys
    cp keys/*.plist "$1"/var/db/xbps/keys
}

copy_void_conf() {
    install -Dm644 data/void-vpkgs.conf "$1"/usr/share/xbps.d/void-virtualpkgs.conf
}

copy_netmenu_files() {
    mkdir -p $1/usr/lib/dracut/modules.d/05netmenu
    cp dracut/netmenu/* $1/usr/lib/dracut/modules.d/05netmenu/

    # The netmenu can directly launch the manual installer from the initrd
    cp installer.sh $1/usr/lib/dracut/modules.d/05netmenu/
}

copy_autoinstaller_files() {
    mkdir -p $1/usr/lib/dracut/modules.d/01autoinstaller
    cp dracut/autoinstaller/* $1/usr/lib/dracut/modules.d/01autoinstaller/
}

install_prereqs() {
    copy_void_conf $VOIDHOSTDIR
    XBPS_ARCH=$ARCH $XBPS_INSTALL_CMD -r $VOIDHOSTDIR $XBPS_REPOSITORY \
        $XBPS_HOST_CACHEDIR -y ${REQUIRED_PKGS}
    [ $? -ne 0 ] && die "Failed to install required software, exiting..."
}

install_packages() {
    copy_void_conf $ROOTFS

    XBPS_ARCH=$BASE_ARCH ${XBPS_INSTALL_CMD} -r $ROOTFS \
        $XBPS_REPOSITORY $XBPS_CACHEDIR -yn ${PACKAGE_LIST} ${INITRAMFS_PKGS}
    [ $? -ne 0 ] && die "Missing required binary packages, exiting..."

    mount_pseudofs

    LANG=C XBPS_ARCH=$BASE_ARCH ${XBPS_INSTALL_CMD} -U -r $ROOTFS \
        $XBPS_REPOSITORY $XBPS_CACHEDIR -y ${PACKAGE_LIST} ${INITRAMFS_PKGS}
    [ $? -ne 0 ] && die "Failed to install $PACKAGE_LIST"

    xbps-reconfigure -r $ROOTFS -f base-files >/dev/null 2>&1
    chroot $ROOTFS env -i xbps-reconfigure -f base-files

    # Enable choosen UTF-8 locale and generate it into the target rootfs.
    if [ -f $ROOTFS/etc/default/libc-locales ]; then
        sed -e "s/\#\(${LOCALE}.*\)/\1/g" -i $ROOTFS/etc/default/libc-locales
    fi
    chroot $ROOTFS env -i xbps-reconfigure -a

    if [ -x installer.sh ]; then
        install -Dm755 installer.sh $ROOTFS/usr/sbin/void-installer
    else
        install -Dm755 /usr/sbin/void-installer $ROOTFS/usr/sbin/void-installer
    fi
    # Cleanup and remove useless stuff.
    rm -rf $ROOTFS/var/cache/* $ROOTFS/run/* $ROOTFS/var/run/*
}

copy_include_directory() {
    find $INCLUDE_DIRECTORY -mindepth 1 -maxdepth 1 -exec cp -rfpPv {} $ROOTFS/ \;
}

generate_initramfs() {
    local _args

    copy_netmenu_files $ROOTFS
    copy_autoinstaller_files $ROOTFS
    if [ "$BASE_SYSTEM_PKG" = "base-system-systemd" ]; then
        _args="--add systemd"
    else
        _args="--omit systemd"
    fi
    chroot $ROOTFS env -i /usr/bin/dracut -N --${INITRAMFS_COMPRESSION} \
        --add-drivers "ahci" --force-add "autoinstaller netmenu" ${_args} "/boot/initrd" $KERNELVERSION
    [ $? -ne 0 ] && die "Failed to generate the initramfs"

    mv $ROOTFS/boot/initrd $BOOT_DIR
    cp $ROOTFS/boot/vmlinuz-$KERNELVERSION $BOOT_DIR/vmlinuz
    chmod 0644 $BOOT_DIR/initrd
}

generate_pxelinux_boot() {
    cp -f $SYSLINUX_DATADIR/pxelinux.0 "$BOOT_DIR"
    cp -f $SYSLINUX_DATADIR/ldlinux.c32 "$BOOT_DIR"
    cp -f $SYSLINUX_DATADIR/libcom32.c32 "$BOOT_DIR"
    cp -f $SYSLINUX_DATADIR/vesamenu.c32 "$BOOT_DIR"
    cp -f $SYSLINUX_DATADIR/libutil.c32 "$BOOT_DIR"
    cp -f $SYSLINUX_DATADIR/chain.c32 "$BOOT_DIR"
    cp -f pxelinux.cfg/pxelinux.cfg.in "$PXELINUX_DIR"/default
    cp -f ${SPLASH_IMAGE} "$BOOT_DIR"

    sed -i  -e "s|@@SPLASHIMAGE@@|$(basename ${SPLASH_IMAGE})|" \
        -e "s|@@KERNVER@@|${KERNELVERSION}|" \
        -e "s|@@KEYMAP@@|${KEYMAP}|" \
        -e "s|@@ARCH@@|$BASE_ARCH|" \
        -e "s|@@LOCALE@@|${LOCALE}|" \
        -e "s|@@BOOT_TITLE@@|${BOOT_TITLE}|" \
        -e "s|@@BOOT_CMDLINE@@|${BOOT_CMDLINE}|" \
        $PXELINUX_DIR/default
}

generate_netboot_tarball() {
    cd $IMAGEDIR/tftp
    tar -zcvf $CURDIR/$OUTPUT_FILE.tar.gz .
    cd $CURDIR
}

#
# main()
#
while getopts "a:b:r:c:C:T:Kk:l:i:o:p:h" opt; do
    case $opt in
        a) BASE_ARCH="$OPTARG";;
        b) BASE_SYSTEM_PKG="$OPTARG";;
        r) XBPS_REPOSITORY="--repository=$OPTARG $XBPS_REPOSITORY";;
        c) XBPS_CACHEDIR="--cachedir=$OPTARG";;
        K) readonly KEEP_BUILDDIR=1;;
        k) KEYMAP="$OPTARG";;
        l) LOCALE="$OPTARG";;
        i) INITRAMFS_COMPRESSION="$OPTARG";;
        o) OUTPUT_FILE="$OPTARG";;
        p) PACKAGE_LIST="$OPTARG";;
        C) BOOT_CMDLINE="$OPTARG";;
        T) BOOT_TITLE="$OPTARG";;
        h) usage;;
    esac
done
shift $((OPTIND - 1))

XBPS_REPOSITORY="$XBPS_REPOSITORY --repository=http://repo.voidlinux.eu/current --repository=http://repo.voidlinux.eu/current/musl"

ARCH=$(xbps-uhelper arch)

# Set defaults
: ${BASE_ARCH:=$(uname -m)}
: ${XBPS_CACHEDIR:=-c $(pwd -P)/xbps-cachedir-${BASE_ARCH}}
: ${XBPS_HOST_CACHEDIR:=-c $(pwd -P)/xbps-cachedir-${ARCH}}
: ${KEYMAP:=us}
: ${LOCALE:=en_US.UTF-8}
: ${INITRAMFS_COMPRESSION:=xz}
: ${SQUASHFS_COMPRESSION:=xz}
: ${BASE_SYSTEM_PKG:=base-system}
: ${BOOT_TITLE:="Void Linux"}

# Required packages in the image for a working system.
PACKAGE_LIST="$BASE_SYSTEM_PKG $PACKAGE_LIST"

# Check for root permissions.
if [ "$(id -u)" -ne 0 ]; then
    die "Must be run as root, exiting..."
fi

readonly CURDIR="$PWD"

ISO_VOLUME="VOID_LIVE"
if [ -n "$ROOTDIR" ]; then
    BUILDDIR=$(mktemp --tmpdir="$ROOTDIR" -d)
else
    BUILDDIR=$(mktemp --tmpdir="$(pwd -P)" -d)
fi
BUILDDIR=$(readlink -f $BUILDDIR)
IMAGEDIR="$BUILDDIR/image"
ROOTFS="$IMAGEDIR/rootfs"
VOIDHOSTDIR="$BUILDDIR/void-host"
BOOT_DIR="$IMAGEDIR/tftp"
PXELINUX_DIR="$BOOT_DIR/pxelinux.cfg"
PXELINUX_CFG="$PXELINUX_DIR/default"
CURRENT_STEP=0
STEP_COUNT=6
[ -n "${INCLUDE_DIRECTORY}" ] && ((STEP_COUNT=STEP_COUNT+1))

: ${SYSLINUX_DATADIR:=$VOIDHOSTDIR/usr/share/syslinux}
: ${SPLASH_IMAGE:=data/splash.png}
: ${XBPS_INSTALL_CMD:=xbps-install}
: ${XBPS_REMOVE_CMD:=xbps-remove}
: ${XBPS_QUERY_CMD:=xbps-query}
: ${XBPS_RINDEX_CMD:=xbps-rindex}
: ${XBPS_UHELPER_CMD:=xbps-uhelper}
: ${XBPS_RECONFIGURE_CMD:=xbps-reconfigure}

mkdir -p $ROOTFS $VOIDHOSTDIR $PXELINUX_DIR

print_step "Synchronizing XBPS repository data..."
copy_void_keys $ROOTFS
copy_void_keys $VOIDHOSTDIR
XBPS_ARCH=$BASE_ARCH $XBPS_INSTALL_CMD -r $ROOTFS ${XBPS_REPOSITORY} -S
XBPS_ARCH=$ARCH $XBPS_INSTALL_CMD -r $VOIDHOSTDIR $XBPS_REPOSITORY -S

_linux_series=$(XBPS_ARCH=$BASE_ARCH $XBPS_QUERY_CMD -r $ROOTFS ${XBPS_REPOSITORY:=-R} -x linux|head -1)
_kver=$(XBPS_ARCH=$BASE_ARCH $XBPS_QUERY_CMD -r $ROOTFS ${XBPS_REPOSITORY:=-R} -p pkgver ${_linux_series})
KERNELVERSION=$($XBPS_UHELPER_CMD getpkgversion ${_kver})

: ${OUTPUT_FILE="void-netboot-${BASE_ARCH}-${KERNELVERSION}-$(date +%Y%m%d)"}

print_step "Installing software to generate the image: ${REQUIRED_PKGS} ..."
install_prereqs

mkdir -p "$ROOTFS"/etc
[ -s data/motd ] && cp data/motd $ROOTFS/etc
[ -s data/issue ] && cp data/issue $ROOTFS/etc

print_step "Installing void pkgs into the rootfs: ${PACKAGE_LIST} ..."
install_packages

print_step "Generating initramfs image ($INITRAMFS_COMPRESSION)..."
generate_initramfs

print_step "Generating pxelinux support..."
generate_pxelinux_boot

print_step "Generating netboot tarball..."
generate_netboot_tarball

info_msg "Created $(readlink -f $CURDIR/$OUTPUT_FILE) ($hsize) successfully."