#!/bin/sh
#===============================================================================
#
#  Copyright (C) 2024 by Digi International Inc.
#  All rights reserved.
#
#  This program is free software; you can redistribute it and/or modify it
#  under the terms of the GNU General Public License version 2 as published by
#  the Free Software Foundation.
#
#
#  !Description: Initialize LVGL demo
#
#===============================================================================

readonly DEMO_NAME="lvgl_demo"
readonly DEMO_PATH="/usr/bin/${DEMO_NAME}"
readonly DEMO_TITLE="LVGL Demo Application"
readonly DEMO_DISPLAY="##LVGL_DEMO_DISPLAY##"
readonly DEMO_ENV="##LVGL_DEMO_ENV##"
readonly PID_FILE="/run/${DEMO_NAME}.pid"

log() {
	if type "systemd-cat" >/dev/null 2>/dev/null; then
		systemd-cat -p "${1}" -t "${DEMO_NAME}" printf "%s" "${2}"
	fi
	logger -p "${1}" -t "${DEMO_NAME}" "${2}"
}

get_demo_pid() {
	local pid="$(pgrep -f ${DEMO_PATH})"

	[ -n "${pid}" ] && { echo "${pid}"; return 0; }

	return 1
}

check_is_running() {
	local pid

	if [ -s "${PID_FILE}" ]; then
		pid="$(cat ${PID_FILE})"
	else
		pid="$(get_demo_pid)"
		echo "${pid}" > ${PID_FILE}
	fi

	if [ "${pid}" ]; then
		kill -0 "${pid}" >/dev/null 2>&1 && return 0
	fi

	rm -f "${PID_FILE}"

	return 1
}

wait_for_wayland() {
	local count=20
	local wayland_socket="/run/user/0/${DEMO_DISPLAY}"

	while [ ! -S "${wayland_socket}" ]; do
		sleep 1
		count=$((count-1))
		if [ "${count}" = 0 ]; then
			return 1
		fi
	done
	sleep 1
	return 0
}

stop() {
	check_is_running || return

	local pid="$(cat ${PID_FILE})"
	kill -TERM "${pid}" >/dev/null 2>&1

	local STOP_TIMEOUT="5"
	for i in $(seq ${STOP_TIMEOUT}); do
		check_is_running || { log info "stopped"; break; }
		if [ "${i}" -eq ${STOP_TIMEOUT} ]; then
			log warning "stop: ${DEMO_NAME} did not stop gracefully"
			kill -KILL "${pid}" >/dev/null 2>&1
		fi
		sleep 1
	done
}

start() {
	check_is_running && { log warning "start: ${DEMO_NAME} ALREADY running"; exit 0; }

	if [ -d "/usr/share/wayland" ]; then
		wait_for_wayland
	else
		# Disable the cursor when displaying at full screen on fbdev
		echo "0" > /sys/class/graphics/fbcon/cursor_blink
	fi

	# Launch demo
	env ${DEMO_ENV} ${DEMO_PATH} >/dev/null 2>&1 &

	if [ $? -eq 0 ]; then
		echo $! > ${PID_FILE}
		log info "$(cat ${PID_FILE})"
		log info "started"
	fi
}

case "$1" in
	start)
		echo -n "Starting ${DEMO_TITLE}: "
		start
		echo "done."
		;;
	stop)
		stop
		echo -n "Stopping ${DEMO_TITLE}: "
		if [ -n "`/bin/pidof ${DEMO_PATH}`" ] ; then
			echo "FAIL"
		else
			echo "OK"
		fi
		;;
	restart)
		stop
		sleep 1
		start
		;;
	*)
		echo "Usage: $0 {start|stop|restart}"
		exit 1
		;;
esac