#! /bin/sh

set -e

# source debconf library
. /usr/share/debconf/confmodule

# debconf is not a registry, so we only fiddle with the default file if it
# does not exist
DEFAULT_DISPLAY_MANAGER_FILE=/etc/X11/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 "$DEFAULT_DISPLAY_MANAGER" ]; then
    DAEMON_NAME=
    if db_get "$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
      # FIXME - redo this part uses shell-lib.sh from xfree86
      #observe "committing change of default X display manager"
      echo "$DAEMON_NAME" > "$DEFAULT_DISPLAY_MANAGER_FILE"
    fi
  fi
fi

# remove the displaced old default display manager file if it exists
if [ -e "$DEFAULT_DISPLAY_MANAGER_FILE.dpkg-tmp" ]; then
  rm "$DEFAULT_DISPLAY_MANAGER_FILE.dpkg-tmp"
fi

# set default-display-manager systemd service link according to our config
DEFAULT_SERVICE=/etc/systemd/system/display-manager.service
if [ "$1" = configure ] && [ -d /etc/systemd/system/ ]; then
  if [ -e "$DEFAULT_DISPLAY_MANAGER_FILE" ]; then
    SERVICE=/lib/systemd/system/$(basename $(cat "$DEFAULT_DISPLAY_MANAGER_FILE")).service
    SERVICE=`echo "$SERVICE" | sed "s/tdm\./tdm-trinity./"`
    if [ -h "$DEFAULT_SERVICE" ] && [ $(readlink "$DEFAULT_SERVICE") = /dev/null ]; then
      echo "Display manager service is masked" >&2
    elif [ -e "$SERVICE" ]; then
      ln -sf "$SERVICE" "$DEFAULT_SERVICE"
    else
      echo "WARNING: $SERVICE is the selected default display manager but does not exist" >&2
      rm -f "$DEFAULT_SERVICE"
    fi
  else
    rm -f "$DEFAULT_SERVICE"
  fi
fi

# restarting the daemon may cause output to stdout
db_stop

# don't start tdm if we are upgrading without stopping it
NOSTART=
if [ -e /var/run/tdm-trinity.upgrade ]; then
  NOSTART=yes
fi
# or if we're currently in X on the display it attempts to manage by default
for HOST in "" \
            "localhost" \
            "$(hostname 2> /dev/null)" \
            "$(hostname -f 2> /dev/null)"; do
  if echo "$DISPLAY" | grep -q "^$HOST:0.*"; then
    NOSTART=yes
    break
  fi
done
# or if it's already running
if start-stop-daemon --stop --quiet --signal 0 --pid /var/run/tdm.pid --exec /opt/trinity/bin/tdm; then
  NOSTART=yes
fi
# or if the options file says not to
if ! grep -qs ^restart-on-upgrade /etc/trinity/tdm/tdm.options; then
  NOSTART=yes
fi


# md5sum of the stock Xservers shipped with KDE 3.3.2, which shipped with Sarge
SARGEXSERVERS=d3ab063f564492e0e31830f56ccd350e

CONFIGLEVEL=`grep -s ^ConfigVersion= /etc/trinity/tdm/tdmrc | sed s/^ConfigVersion=//`

if [ -e /etc/trinity/tdm/tdmrc ]; then
  if dpkg --compare-versions "$CONFIGLEVEL" ge "2.3"; then
    TDMRCUPDATED=yes
  fi
fi

if [ -e /etc/trinity/tdm/Xservers ]; then
  if [ `md5sum /etc/trinity/tdm/Xservers | sed s/\ .*$//` = $SARGEXSERVERS ]; then
    XSERVERSUNCHANGED=yes
  fi
fi

# From KDE 3.4, /etc/trinity/tdm/Xservers is no longer required, so we remove it, if
# the user has updated their tdmrc (if they haven't, tdm notices and keeps using
# Xservers), and if it wasn't touched, i.e. there are no local changes the user
# will want to merge into tdmrc.

case "$1" in

  configure)

    if [ ! -z $TDMRCUPDATED ] && [ ! -z $XSERVERSUNCHANGED ]; then
      echo "Removing obsolete /etc/trinity/tdm/Xservers (detected no user changes)."
      rm -f /etc/trinity/tdm/Xservers
    elif [ ! -z $TDMRCUPDATED ] && [ -e /etc/trinity/tdm/Xservers ]; then
      echo "Note that /etc/trinity/tdm/Xservers is no longer used by TDM."
      echo "You must merge your changes (if any) into /etc/trinity/tdm/tdmrc manually."
      echo "Otherwise, /etc/trinity/tdm/Xservers is safe to remove."
    fi

    rm -f /etc/init.d/tdm-trinity
    ln -s /lib/init/upstart-job /etc/init.d/tdm-trinity

  ;;

  abort-upgrade|abort-remove|abort-deconfigure)
  ;;

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

esac

# Upstart is not active?
UPSTART_ACTIVE=`dbus-send --system --print-reply --dest=com.ubuntu.Upstart /com/ubuntu/Upstart org.freedesktop.DBus.Properties.Get string:com.ubuntu.Upstart0_6 string:version 2>/dev/null || true`
if [ -z "$UPSTART_ACTIVE" ]; then
  echo "Upstart is not active - masking initctl" >&2
  dpkg-divert --local --rename --add /sbin/initctl
  ln -s /bin/true /sbin/initctl
fi

#DEBHELPER#

# Upstart is not active?
if [ -z "$UPSTART_ACTIVE" ]; then
  rm /sbin/initctl
  dpkg-divert --local --rename --remove /sbin/initctl
fi

exit 0