#!/bin/sh

set -e

now=`date +%Y%m%dT%H%M`
logdir=/var/lib/insserv
logfile="$logdir/run-$now.log"

# Make sure insserv is in path
PATH=/usr/lib/insserv:/sbin:$PATH

# Based on code from dash postinst
check_divert() {
    package=insserv
    div=$(dpkg-divert --list $2)
    distrib=${4:-$2.distrib}
    case "$1" in
    false)
        if [ -n "$div" ] && [ -z "${div%%*by $package}" ]; then
	    mv $distrib $2
	    dpkg-divert --package $package --remove $2
	fi
	;;
    status) # Return true if the divert is in effect
        if [ -n "$div" ] && [ -z "${div%%*by $package}" ]; then
            :
	else
	    false
	fi
    esac
}

convert_rc_s_to_k() {
  runlevel=$1
  for link in $(cd $target/etc/rc$runlevel.d; ls S* || true); do
      set `echo $link|sed "s%S\(..\)\(.*\)%\1 \2%"`
      seq=$1
      service=$2
      mv $target/etc/rc$runlevel.d/$link $target/etc/rc$runlevel.d/K$seq$service
  done
}

legacy_bootordering() {
    for f in /etc/rc0.d/S* ; do
	if [ -f $f ] ; then
	    return 0
	fi
    done

    return 1
}

activate_insserv() {
    echo "info: Reordering boot system, log to $logfile" 1>&2
    (
	echo "info: Converting rc0.d/S* and rc6.d/S* to K*." 1>&2
	convert_rc_s_to_k 0
	convert_rc_s_to_k 6
	echo "info: running insserv" 1>&2
	insserv -v
    ) > $logfile 2>&1 || return 1

    return 0
}

case "$1" in
    configure)
	if check_divert status /usr/sbin/update-rc.d \
	    /usr/sbin/update-rc.d-insserv ; then
		check_divert false /usr/sbin/update-rc.d \
			/usr/sbin/update-rc.d-insserv
	fi

	if dpkg --compare-versions "$2" lt "2.88dsf-41ubuntu13"; then
	    rm -f /etc/init.d/.legacy-bootordering
	fi

	if legacy_bootordering ; then
	    # Still using legacy ordering, try to convert
	    if activate_insserv ; then
		echo "success: Enabled dependency based boot system." 1>&2
	    else
		echo "error: Something failed while migrating." 1>&2
		cat 1>&2 <<EOF

error: Unable to migrate to dependency based boot sequencing.

See http://wiki.debian.org/LSBInitScripts/DependencyBasedBoot for
more information about dependency based boot sequencing. To
reattempt the migration process run 'dpkg --configure sysv-rc'.

EOF
		exit 1;
	    fi
	fi
	;;
    *)
	;;
esac