#! /bin/bash

PKGLIST=""
QUIET="y"
FORCE="n"
PACCONFIG="/etc/pacman.conf"
export LABEL="ARCH_$(date +%Y%m)"
PUBLISHER="Arch Linux <http://www.archlinux.org>"
APPLICATION="Arch Linux Live/Rescue CD"
CREATE_DEFAULT="n"

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 "    -L <label>       Set a label for the disk"
    echo "    -P <publisher>   Set a publisher for the disk"
    echo "    -A <application> Set an application name for the disk"
    echo "    -d               Create default user directory /home/arch"
    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 <dir> <image name>"
    echo "      build an iso image from the working dir"
    exit $1
}

while getopts 'p:C:L:P:A:dfvh' arg; do
    case "${arg}" in
        p) PKGLIST="${PKGLIST} ${OPTARG}" ;;
        C) PACCONFIG="${OPTARG}" ;;
    	L) LABEL="${OPTARG}" ;;
    	P) PUBLISHER="${OPTARG}" ;;
    	A) APPLICATION="${OPTARG}" ;;
        d) CREATE_DEFAULT="y" ;;
        f) FORCE="y" ;;
        v) QUIET="n" ;;
        h|?) usage 0 ;;
        *) echo "invalid argument '${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}" ;;
    *) 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

        if [ ${CREATE_DEFAULT} == "y" ]; then
            if [ -d "${work_dir}/root-image/home/" ]; then
                echo "Creating default home directory"
                install -d -o1000 -g100 -m0755 "${work_dir}/root-image/home/arch"
            fi
        fi

        # Delete pacman database sync cache files (*.tar.gz)
        find "${work_dir}/root-image/var/lib/pacman" -maxdepth 1 -type f -delete
        # Delete pacman database sync cache
        find "${work_dir}/root-image/var/lib/pacman/sync" -delete
        # Delete pacman package cache
        find "${work_dir}/root-image/var/cache/pacman/pkg" -type f -delete
        # Delete all log files, keeps empty dirs.
        find "${work_dir}/root-image/var/log" -type f -delete
        # Delete all temporary files and dirs
        find "${work_dir}/root-image/var/tmp" -mindepth 1 -delete
        # Delete all temporary files and dirs
        find "${work_dir}/root-image/tmp" -mindepth 1 -delete
    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 "${sqimg}" ]; then
        dirhaschanged=$(find ${1} -newer ${sqimg})
        if [ "${dirhaschanged}" != "" ]; then
            echo "SquashFS image '${sqimg}' is not up to date, rebuilding..."
            rm "${sqimg}"
        else
            echo "SquashFS image '${sqimg}' is up to date, skipping."
            return
        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/"

    if ! sed "s|archisolabel=[^ ]*|archisolabel=${LABEL}|" -i ${work_dir}/iso/boot/isolinux/isolinux.cfg; then
        echo "Error: ${work_dir}/iso/boot/isolinux/isolinux.cfg, doesn't exist, aborting."
        exit 1
    fi
}

command_iso () {
    _imgcommon

    echo "Creating ISO image..."
    qflag=""
    [ "${QUIET}" = "y" ] && qflag="-quiet"
    mkisofs ${qflag} -r -l \
        -b boot/isolinux/isolinux.bin -c boot/isolinux/boot.cat \
        -uid 0 -gid 0 \
        -udf -allow-limited-size -iso-level 3 \
        -input-charset utf-8 -p "prepared by mkarchiso" \
        -no-emul-boot -boot-load-size 4 -boot-info-table \
        -publisher "${PUBLISHER}" \
        -A "${APPLICATION}" \
        -V "${LABEL}" \
        -o "${imgname}" "${work_dir}/iso/"
    isohybrid "${imgname}"
}

# 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

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