#!/bin/sh
#
# /etc/rc.d/rc.ak820-lcd: show CPU/GPU temperature and time on the
# Ajazz AK820 Pro TFT screen.
#
# To start at boot, make this script executable and add to /etc/rc.d/rc.local:
#   [ -x /etc/rc.d/rc.ak820-lcd ] && /etc/rc.d/rc.ak820-lcd start
# and to /etc/rc.d/rc.local_shutdown:
#   [ -x /etc/rc.d/rc.ak820-lcd ] && /etc/rc.d/rc.ak820-lcd stop

PIDFILE=/var/run/ak820-lcd.pid
# Extra options for "ak820-ctl lcd", e.g. "--interval 5 --max-interval 60".
LCD_OPTS=""

running() {
  [ -r $PIDFILE ] && kill -0 $(cat $PIDFILE) 2>/dev/null
}

start() {
  if running ; then
    echo "ak820-lcd is already running."
    return
  fi
  echo "Starting ak820-lcd."
  # ak820-ctl exits when the keyboard is unplugged or the upload fails, so
  # restart it in a loop. setsid makes the loop a process group leader,
  # which lets stop() kill the loop and ak820-ctl together. Progress
  # output goes to /dev/null, errors to syslog.
  setsid /bin/sh -c "while : ; do
    /usr/bin/ak820-ctl lcd $LCD_OPTS 2>&1 >/dev/null | /usr/bin/logger -t ak820-lcd
    sleep 30
  done" </dev/null >/dev/null 2>&1 &
  echo $! > $PIDFILE
}

stop() {
  if running ; then
    echo "Stopping ak820-lcd."
    kill -- -$(cat $PIDFILE)
  fi
  rm -f $PIDFILE
}

case "$1" in
  start) start ;;
  stop) stop ;;
  restart) stop ; sleep 1 ; start ;;
  status)
    if running ; then
      echo "ak820-lcd is running."
    else
      echo "ak820-lcd is stopped."
      exit 1
    fi
    ;;
  *) echo "usage: $0 start|stop|restart|status" ; exit 1 ;;
esac