#! /bin/bash

PKGLIST=""
QUIET="y"
FORCE="n"
PACCONFIG="/etc/pacman.conf"

APPNAME=$(basename "${0}")

# usage: usage <exitvalue>
usage ()
{
    echo "usage ${APPNAME} [options] command <command options>"
    echo " general options:"
    echo "    -f               Force overwrite of working files/squashfs image/bootable image"
    echo "    -p PACKAGE(S)    Additional package(s) to install, can be used multiple times"
    echo "    -C <file>        Config file for pacman. Default $PACCONFIG"
    echo "    -v               Enable verbose output."
    echo "    -h               This message."
    echo " commands:"
    echo "   create <dir>"
    echo "      create a base directory layout to work with"
    echo "      includes all specified packages"
    echo "   iso -p <bootloader> <dir> <image name>"
    echo "      build an iso image from the working dir"
    echo "   usb -p <bootloader> <dir> <image name>"
    echo "      build an iso image from the working dir"
    exit $1
}

while getopts 'i:P:p:a:t:fvh' arg; do
    case "${arg}" in
        p) PKGLIST="${PKGLIST} ${OPTARG}" ;;
        C) PACCONFIG="${OPTARG}" ;;
        f) FORCE="y" ;;
        v) QUIET="n" ;;
        h|?) usage 0 ;;
        *) echo "invalid argument '${arg}'"; usage 1 ;;
    esac
done

#trim spaces
PKGLIST="$(echo $PKGLIST)"

shift $(($OPTIND - 1))

# do UID checking here so someone can at least get usage instructions
if [ "$EUID" != "0" ]; then
    echo "error: This script must be run as root."
    exit 1
fi

if [ ! -f "$PACCONFIG" ]; then
    echo "error: pacman config file '$PACCONFIG' does not exist"
    exit 1
fi

command_name="${1}"
work_dir=""
imgname=""

case "${command_name}" in
    create) work_dir="${2}"; imgname="none" ;;
    iso) work_dir="${2}"; imgname="${3}" ;;
    usb) work_dir="${2}"; imgname="${3}" ;;
    *) echo "invalid command name '${command_name}'"; usage 1 ;;
esac

[ "x${imgname}" = "x" ] && echo "Image name must be specified" && usage 1
[ "x${work_dir}" = "x" ] && echo "Please specify a working directory" && usage 1

echo "${APPNAME} : Configuration Settings"
echo "        working directory:   ${work_dir}"
echo "               image name:   ${imgname}"

# usage: _pacman <packages>...
_pacman ()
{
    local ret
    if [ "${QUIET}" = "y" ]; then
        mkarchroot -C "$PACCONFIG" -f "${work_dir}/root-image" $* 2>&1 >/dev/null
        ret=$?
    else
        mkarchroot -C "$PACCONFIG" -f "${work_dir}/root-image" $*
        ret=$?
    fi

    # Cleanup
    find "${work_dir}" -name *.pacnew -name *.pacsave -name *.pacorig -delete

    if [ $ret -ne 0 ]; then
        exit 1
    fi
}

command_create () {
    echo "====> Creating working directory: ${work_dir}"
    mkdir -p "${work_dir}/iso/"
    mkdir -p "${work_dir}/root-image/"
    echo "# archiso isomounts file
# img - location of image/directory to mount relative to addons directory
# arch - architecture of this image
# mount point - absolute location on the post-initrd root
# type - either 'bind' or 'squashfs' for now

# syntax: <img> <arch> <mount point> <type>

# NOTE: Order matters. If the same file exists in multiple
#  images, the FIRST one mounted, top-down, will take precedence

root-image.sqfs i686 / squashfs
#root-image-x86_64.sqfs x86_64 / squashfs" > "${work_dir}/isomounts"

    echo "README for this archiso created directory

All directories in this dir, except for 'iso' will be squashed
with squashfs and put into the iso dir as iso/<dirname>.sqfs
This should be reflected in the isomounts file

The iso dir is later used to build the actual bootable iso.
Please ensure the proper bootloader is installed or copied
to the iso/ directory.

...TODO: Write more..." > "${work_dir}/README"

    if [ "${PKGLIST}" != "" ]; then
        echo "====> Installing packages to '${work_dir}/root-image/'"
        _pacman "${PKGLIST}"

        echo "Cleaning up what we can"
        if [ -d "${work_dir}/root-image/boot/" ]; then
            # remove the initcpio images that were generated for the host system
            find "${work_dir}/root-image/boot" -name '*.img' -delete
        fi

        #TODO is this needed? do it at the Makefile level?
        if [ -d "${work_dir}/root-image/home/" ]; then
            echo "Creating default home directory"
            install -d -o1000 -g100 -m0755 "${work_dir}/root-image/home/arch"
        fi

        # delete a lot of unnecessary cache/log files
        kill_dirs="var/abs var/cache/man var/cache/pacman var/lib/pacman/sync var/log/* var/mail tmp/* initrd"
        for x in ${kill_dirs}; do
            if [ -e "${work_dir}/root-image/${x}" ]; then
                rm -rf "${work_dir}/root-image/${x}"
            fi
        done
    fi
}

# _mksquash dirname
_mksquash () {
    if [ ! -d "$1" ]; then
        echo "Error: '$1' is not a directory"
        return 1
    fi

    sqimg="${work_dir}/iso/$(basename ${1}).sqfs"
    echo "====> Generating SquashFS image for '${1}'"
    if [ -e "${sqimg}" ]; then
        if [ "${FORCE}" = "y" ]; then
            echo -n "Removing old SquashFS image..."
            rm "${sqimg}"
            echo "done."
        else
            echo "error: SquashFS image '${sqimg}' already exists, aborting."
            exit 1
        fi
    fi

    echo "Creating SquashFS image. This may take some time..."
    start=$(date +%s)
    if [ "${QUIET}" = "y" ]; then
        mksquashfs "${1}" "${sqimg}" -noappend >/dev/null
    else
        mksquashfs "${1}" "${sqimg}" -noappend
    fi
    minutes=$(echo $start $(date +%s) | awk '{ printf "%0.2f",($2-$1)/60 }')
    echo "Image creation done in $minutes minutes."
}

_imgcommon () {
    for d in $(find "${work_dir}" -maxdepth 1 -type d -name '[^.]*'); do
        if [ "$d" != "${work_dir}/iso" -a \
             "$(basename "$d")" != "iso" -a \
             "$d" != "${work_dir}" ]; then
            _mksquash "$d"
        fi
    done

    echo "====> Making bootable image"

    # Sanity checks
    if [ ! -d "${work_dir}/iso" ]; then
        echo "Error: '${work_dir}/iso' doesn't exist. What did you do?!"
        exit 1
    fi

    if [ ! -f "${work_dir}/isomounts" ]; then
        echo "Error: the isomounts file doesn't exist. This image won't do anything"
        echo "  Protecting you from yourself and erroring out here..."
        exit 1
    fi

    if [ -e "${imgname}" ]; then
        if [ "${FORCE}" = "y" ]; then
            echo "Removing existing bootable image..."
            rm -rf "${imgname}"
        else
            echo "error: Image '${imgname}' already exists, aborting."
            exit 1
        fi
    fi

    cp "${work_dir}/isomounts" "${work_dir}/iso/"
}

command_iso () {
    _imgcommon

    bootflags=""
    if [ "$PKGLIST" = "grub" -o "$PKGLIST" = "grub-gfx" ]; then
        if [ ! -e "${work_dir}/iso/boot/grub/stage2_eltorito" ]; then
            echo "error: grub stage files not found in '${work_dir}/iso/boot/grub'"
            exit 1
        fi

        bootflags="-b boot/grub/stage2_eltorito"
    elif [ "$PKGLIST" = "syslinux" ]; then
        if [ ! -e "${work_dir}/iso/boot/isolinux/isolinux.bin" ]; then
            echo "error: isolinux bin file not found in '${work_dir}/iso/boot/isolinux'"
            exit 1
        fi

        bootflags="-b boot/isolinux/isolinux.bin -c boot/isolinux/boot.cat"
    else
        echo "No bootloader specified. Use the -p flag to specify"
        echo "  Supported Bootloaders:"
        echo "     grub"
        echo "     grub-gfx"
        echo "     syslinux"
        exit 1
    fi

    echo "Creating ISO image..."
    qflag=""
    [ "${QUIET}" = "y" ] && qflag="-q"
    mkisofs ${qflag} -r -l $bootflags -uid 0 -gid 0 \
        -input-charset utf-8 -p "prepared by mkarchiso" \
        -no-emul-boot -boot-load-size 4 -boot-info-table \
        -publisher "Arch Linux <http://www.archlinux.org>" \
        -A "Arch Linux Live/Rescue CD" \
        -o "${imgname}" "${work_dir}/iso/"
}

command_usb () {
    _imgcommon
    
    fsimg="${imgname}.part1"

    # ext2 overhead's upper bound is 6%, empirically tested up to 1GB
    rootsize=$(du -bs "${work_dir}/iso" | cut -f1)
    imgsz=$(( (${rootsize}*106)/100/512 + 1)) # image size in sectors

    # create the filesystem image file
    dd if=/dev/zero of="$fsimg" bs=512 count="$imgsz"

    # create a filesystem on the image
    mke2fs -m 0 -F "$fsimg"

    # mount the filesystem and copy data
    modprobe loop
    TMPDIR=$(mktemp -d archiso-usbXXXXXX)
    mount -o loop "$fsimg" "$TMPDIR"
    cp -a "${work_dir}"/iso/* "$TMPDIR"
    umount "$TMPDIR"
    rm -rf "$TMPDIR"

    # add sectors 0-62, then glue together
    dd if=/dev/zero of="${imgname}" bs=512 count=63
    cat "$fsimg" >> "${imgname}"
    rm "$fsimg"

    # create a partition table
    # if this looks like voodoo, it's because it is
    sfdisk -uS -f "${imgname}" << EOF
63,$imgsz,83,*
0,0,00
0,0,00
0,0,00
EOF

    # install grub on the image
    grub --no-floppy --batch << EOF
device (hd0) ${imgname}
root (hd0,0)
setup (hd0)
EOF

}

# Go through the main commands in order. If 'all' was specified, then we want
# to do everything. Start with 'install'.
if [ "${command_name}" = "create"  ]; then
    command_create
fi
if [ "${command_name}" = "iso" ]; then
    command_iso
fi
if [ "${command_name}" = "usb" ]; then
    command_usb
fi

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