#!/bin/bash
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

FORCE="n"
RUN=""

working_dir=""

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

# usage: usage <exitvalue>
usage ()
{
    echo "usage ${APPNAME} [options] working-dir [package-list | app]"
    echo " options:"
    echo "    -r <app>      Run 'app' within the context of the chroot"
    echo "    -u            Update the chroot via pacman"
    echo "    -f            Force overwrite of files in the working-dir"
    echo "    -C <file>     location of a pacman config file"
    echo "    -M <file>     location of a makepkg config file"
    echo "    -h            This message"
    exit $1
}

while getopts 'r:ufhC:M:' arg; do
    case "${arg}" in
        r) RUN="$OPTARG" ;;
        u) RUN="pacman -Syu" ;;
        f) FORCE="y" ;;
        C) pac_conf="$OPTARG" ;;
        M) makepkg_conf="$OPTARG" ;;
        h|?) usage 0 ;;
        *) echo "invalid argument '${arg}'"; usage 1 ;;
    esac
done

if [ "$EUID" != "0" ]; then
    echo "error: this script must be run as root."
    exit 1
fi

shift $(($OPTIND - 1))

if [ "$RUN" = "" -a $# -lt 2 ]; then
    echo "you must specify a directory and one or more packages"
    usage 1
elif [ $# -lt 1 ]; then
    echo "you must specify a directory"
    usage 1
fi

working_dir="$(readlink -f ${1})"
shift 1

[ "${working_dir}" = "" ] && echo "error: please specify a working directory" && usage 1

# {{{ functions 

chroot_mount ()
{
    echo "mounting sysfs : /sys"
    [ -e "${working_dir}/sys" ] || mkdir "${working_dir}/sys"
    mount -t sysfs sysfs "${working_dir}/sys"

    echo "mounting procfs : /proc"
    [ -e "${working_dir}/proc" ] || mkdir "${working_dir}/proc"
    mount -t proc proc "${working_dir}/proc"

    echo "binding device nodes : /dev"
    [ -e "${working_dir}/dev" ] || mkdir "${working_dir}/dev"
    mount -o bind /dev "${working_dir}/dev"

    echo "binding pacman cache : /var/cache/pacman"
    [ -e "${working_dir}/var/cache/pacman" ] || mkdir -p "${working_dir}/var/cache/pacman"
    mount -o bind /var/cache/pacman "${working_dir}/var/cache/pacman"

    echo "copying mtab : /etc/mtab"
    cp /etc/mtab "${working_dir}/etc/mtab"

    echo "copying resolv.conf : /etc/resolv.conf"
    cp /etc/resolv.conf "${working_dir}/etc/resolv.conf"

    trap 'chroot_umount' 0 1 2 15
}

chroot_umount ()
{
    echo "cleaning up mounts"
    umount "${working_dir}/proc"
    umount "${working_dir}/sys"
    umount "${working_dir}/dev"
    umount "${working_dir}/var/cache/pacman"
}
# }}}

if [ "$RUN" != "" ]; then
    # run chroot {{{
    #Sanity check
    if [ ! -f "${working_dir}/.arch-chroot" ]; then
        echo "error: '${working_dir}' does not appear to be a Arch chroot"
        echo "  please build the image using mkarchroot"
        exit 1
    fi

    chroot_mount

    echo "starting chroot ($RUN)"
    chroot "${working_dir}" ${RUN}

    # }}}
else
    # {{{ build chroot
    if [ -e "${working_dir}" -a "${FORCE}" = "n" ]; then
        echo "error: working dir '${working_dir}' already exists - try using -f"
        exit 1
    fi

    mkdir -p "${working_dir}/var/lib/pacman/"
    mkdir -p "${working_dir}/etc/"

    chroot_mount

    pacargs="--noconfirm -v " #--noprogressbar -v
    pacargs="$pacargs --root=${working_dir}"
    # pacman takes these as relative to the given root
    pacargs="$pacargs --dbpath=/var/lib/pacman"
    pacargs="$pacargs --cachedir=/var/cache/pacman/pkg"
    if [ "$pac_conf" != "" ]; then
        pacargs="$pacargs --config=${pac_conf}"
    fi

    if [ $# -eq 0 ]; then
        echo "no packages to install"
    else
        echo "installing packages:"
        for i in $@; do echo -e "\t$i"; done

        op="-Sy"
        if [ "$FORCE" = "y" ]; then
            op="${op}f"
        fi
        if ! pacman ${op} ${pacargs} $@; then
            echo "error: failed to install all packages"
            exit 1
        fi
    fi

    if [ -d "${working_dir}/lib/modules" ]; then
        echo "running ldconfig"
        ldconfig -r "${working_dir}"
    fi

    if [ "$pac_conf" != "" ]; then
        echo "installing custom pacman.conf"
        cp ${pac_conf} ${working_dir}/etc/pacman.conf
    fi

    if [ "$makepkg_conf" != "" ]; then
        echo "installing custom makepkg.conf"
        cp ${makepkg_conf} ${working_dir}/etc/makepkg.conf
    fi

    echo "generating default locales"
    cp /etc/locale.gen "${working_dir}/etc/locale.gen"
    chroot "${working_dir}" locale-gen

    if [ ! -e "${working_dir}/.arch-chroot" ]; then
        date +%s > "${working_dir}/.arch-chroot"
    fi
    # }}}
fi

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