#! /bin/sh
# prerm script for kdm-trinity
#
# see: dh_installdeb(1)

set -e

# summary of how this script can be called:
#        * <prerm> `remove'
#        * <old-prerm> `upgrade' <new-version>
#        * <new-prerm> `failed-upgrade' <old-version>
#        * <conflictor's-prerm> `remove' `in-favour' <package> <new-version>
#        * <deconfigured's-prerm> `deconfigure' `in-favour'
#          <package-being-installed> <version> `removing'
#          <conflicting-package> <version>
# for details, see http://www.debian.org/doc/debian-policy/ or
# the debian-policy package

# debconf may not be available if some massive purging is going on
HAVE_DEBCONF=
if [ -e /usr/share/debconf/confmodule ]; then
  . /usr/share/debconf/confmodule
  HAVE_DEBCONF=yes
fi

case "$1" in
    # we NEVER want to unconditionally stop kdm; see below
    upgrade|failed-upgrade)
        REMOVING=
    ;;

    remove|deconfigure)
        REMOVING=yes
	rm -f /etc/init.d/kdm-trinity
    ;;

    *)
        echo "prerm called with unknown argument \`$1'" >&2
        exit 1
    ;;
esac

STOP=
# are we supposed to restart on upgrade?  if REMOVING kdm, we don't care what
# the user says, we have to stop the daemon
if grep -qs ^restart-on-upgrade /etc/trinity/kdm/kdm.options ||
   [ -n "$REMOVING" ]; then
  # is there an kdm process running?
  if start-stop-daemon --stop --quiet --signal 0 --name kdm-trinity; then
    # any children?
    PARENTS=$(pidof /usr/bin/kdm-trinity || true)
    CHILDREN=
    if [ -n "$PARENTS" ]; then    
      for PROCESS in $PARENTS; do
        # make sure we got numbers back
        [ $PROCESS -eq $PROCESS ] 2> /dev/null ||
        exit
        # FIXME - redo this part uses shell-lib.sh from xfree86
        #  die "pidof returned non-numeric value"
        # we could use grep -q here if ps would ignore SIGPIPE :-P
        if (ps axj | grep "^ *$PROCESS" > /dev/null 2>&1); then
          CHILDREN=yes
        fi
      done
      if [ -n "$CHILDREN" ]; then
        if [ -n "$HAVE_DEBCONF" ]; then
          # ask the question
          db_input high kdm/stop_running_server_with_children || true
          db_go
          # what did the user say?
          ANSWER=
          if db_get kdm/stop_running_server_with_children; then
            ANSWER="$RET"
          fi
          if [ "$ANSWER" = "true" ]; then
            STOP=yes
          fi
          # forget that we have seen the question; this is the sort of
          # non-configuration question that should be asked every time
          db_fset kdm/stop_running_server_with_children seen false
        fi
      else
        STOP=yes
      fi
    fi
  fi
fi

if [ -n "$STOP" ]; then
  if [ -x "`which invoke-rc.d 2>/dev/null`" ]; then
    invoke-rc.d kdm-trinity stop || true
  else
    /etc/init.d/kdm-trinity stop || true
  fi
else
  if [ "$1" = "upgrade" -o "$1" = "failed-upgrade" ]; then
    touch /var/run/kdm-trinity.upgrade
  fi
fi

DEFAULT_DISPLAY_MANAGER_FILE=/etc/X11/default-display-manager

if [ "$1" = "remove" -o "$1" = "deconfigure" ]; then
  if [ -n "$HAVE_DEBCONF" ]; then
    # disown this question
    db_unregister shared/default-x-display-manager || true
    # does the question still exist?
    if db_get shared/default-x-display-manager; then
      if db_metaget shared/default-x-display-manager owners; then
        # FIXME - redo this part uses shell-lib.sh from xfree86
        #observe "X display managers now available are \"$OWNERS\""
        db_subst shared/default-x-display-manager choices "$RET"
      fi
      DEFAULT_DISPLAY_MANAGER=
      if db_get shared/default-x-display-manager; then
        DEFAULT_DISPLAY_MANAGER="$RET"
      fi
      # are we removing the currently selected display manager?
      if [ -n "$DEFAULT_DISPLAY_MANAGER" ]; then
        if [ "kdm-trinity" = "$DEFAULT_DISPLAY_MANAGER" ]; then
          if [ -e "$DEFAULT_DISPLAY_MANAGER_FILE" ]; then
            if db_get "$DEFAULT_DISPLAY_MANAGER/daemon_name"; then
              # does the display manager file reference the current default?  if
              # so, remove it because it will now be wrong
              if [ -n "$RET" ]; then
                if [ "$(cat "$DEFAULT_DISPLAY_MANAGER_FILE")" = "$RET" ]; then
                  rm "$DEFAULT_DISPLAY_MANAGER_FILE"
                fi
              fi
            fi
          fi
          # ask the user to choose a new default
          db_fset shared/default-x-display-manager seen false
          db_input critical shared/default-x-display-manager || true
          db_go
          # if the default display manager file doesn't exist, write it with
          # the path to the new default display manager
          if [ ! -e "$DEFAULT_DISPLAY_MANAGER_FILE" ]; then
            DEFAULT_DISPLAY_MANAGER=
            if db_get shared/default-x-display-manager; then
              DEFAULT_DISPLAY_MANAGER="$RET"
            fi
            if [ -n "$DEFAULT_DISPLAY_MANAGER" ]; then
              # FIXME - redo this part uses shell-lib.sh from xfree86
              #warn "new default display manager has been selected; please be" \
              #     "sure to run \"dpkg-reconfigure $RET\" to ensure that it" \
              #     "is configured"
              DAEMON_NAME=
              if db_get "$DEFAULT_DISPLAY_MANAGER"/daemon_name; then
                DAEMON_NAME="$RET"
              fi
              if [ ! -n "$DAEMON_NAME" ]; then
                # if we were unable to determine the name of the selected daemon (for
                # instance, if the selected default display manager doesn't provide a
                # daemon_name question), guess
                DAEMON_NAME=$(which "$DEFAULT_DISPLAY_MANAGER" 2>/dev/null)
                if [ ! -n "$DAEMON_NAME" ]; then
                  echo .
                  # FIXME - redo this part uses shell-lib.sh from xfree86
                  #warn "unable to determine path to default X display manager" \
                  #     "$DEFAULT_DISPLAY_MANAGER; not updating" \
                  #     "$DEFAULT_DISPLAY_MANAGER_FILE"
                fi
              fi
              if [ -n "$DAEMON_NAME" ]; then
                echo "$DAEMON_NAME" > "$DEFAULT_DISPLAY_MANAGER_FILE"
              fi
            fi
          fi
        fi
      fi
    fi
  fi
fi

exit 0
