#! /bin/sh

set -e

FILENAME="/etc/kernel/postinst.d/kdump-tools"
DIVERTED_FILENAME="${FILENAME}.distrib"

# Shamelessly stolen from udev's postinst
chrooted() {
    if [ "$(stat -c %d/%i /)" = "$(stat -Lc %d/%i /proc/1/root 2>/dev/null)" ]; then
        # the devicenumber/inode pair of / is the same as that of /sbin/init's
        # root, so we're *not* in a chroot and hence return false.
        return 1
    fi
    echo "A chroot environment has been detected."
    return 0
}

logger "$0 $1"
case "$1" in
    remove)         # when you 'purge', 'remove' is run first' -- only run once
        KVER=$(uname -r)
        if chrooted; then
            # If we are in a chroot then figure out the kernel version
            # in a different way. There could be multiple kernels installed
            # so this is not fool-proof
            KVER=$(dpkg-query -W -f='${binary:Package}\n' linux-image-* | head -n 1 | sed 's/linux-image-//')
        fi

        if [ -e /var/lib/kdump/initramfs-tools/hooks/cleanup ]; then
            echo "Removing /var/lib/kdump/initramfs-tools/hooks/cleanup"
            rm /var/lib/kdump/initramfs-tools/hooks/cleanup
        fi

        if [ -e /var/lib/kdump/initramfs-tools/hooks/makedump ]; then
            echo "Removing /var/lib/kdump/initramfs-tools/hooks/makedump"
            rm /var/lib/kdump/initramfs-tools/hooks/makedump
        fi

        if [ -e /var/lib/kdump/initramfs-tools/scripts/init-bottom/makedump ]; then
            echo "Removing /var/lib/kdump/initramfs-tools/scripts/init-bottom/makedump"
            rm /var/lib/kdump/initramfs-tools/scripts/init-bottom/makedump
        fi

        if [ ! -z ${KVER} ]; then
            if [ -e /var/lib/kdump/initrd.img-${KVER}.distrib ]; then
                echo "Restoring /var/lib/kdump/initrd.img-${KVER}.distrib"
                cp -pr /var/lib/kdump/initrd.img-${KVER}.distrib /var/lib/kdump/initrd.img-${KVER}
            fi
        fi

        if [ -e /etc/kernel/postinst.d/kdump-tools ]; then
            echo "Removing /etc/kernel/postinst.d/kdump-tools  "
            rm  /etc/kernel/postinst.d/kdump-tools
        fi

        # When package is removed, copy the original file back
        if [ -f ${DIVERTED_FILENAME} ]; then
            cp ${DIVERTED_FILENAME} ${FILENAME} ||:
        fi
    ;;

    purge)
        # When package is purged, remove our diversion and copy the original
        # file back.
        dpkg-divert --remove ${FILENAME} ||:

        if [ -f ${DIVERTED_FILENAME} ]; then
            mv ${DIVERTED_FILENAME} ${FILENAME} ||:
        fi
    ;;
esac