/****************************************************************************
 *
 *   Copyright (c) 2012-2016 PX4 Development Team. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name PX4 nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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/**
 * @file top.c
 * Tool similar to UNIX top command
 * @see http://en.wikipedia.org/wiki/Top_unix
 *
 * @author Lorenz Meier <lorenz@px4.io>
 */

#include <px4_platform_common/px4_config.h>
#include <stdio.h>
#include <fcntl.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>
#include <poll.h>

#include <px4_platform/cpuload.h>
#include <px4_platform_common/printload.h>
#include <drivers/drv_hrt.h>
#include <px4_platform_common/module.h>

static void print_usage()
{
	PRINT_MODULE_DESCRIPTION("Monitor running processes and their CPU, stack usage, priority and state");

	PRINT_MODULE_USAGE_NAME_SIMPLE("top", "command");
	PRINT_MODULE_USAGE_COMMAND_DESCR("once", "print load only once");
}

extern "C" __EXPORT int top_main(int argc, char *argv[])
{
	print_load_s load{};
	init_print_load(&load);
	px4_usleep(200000);

	/* clear screen */
	dprintf(1, "\033[2J\n");

	if (argc > 1) {
		if (!strcmp(argv[1], "once")) {
			px4_sleep(1);
			print_load(STDOUT_FILENO, &load);

		} else {
			print_usage();
		}

		cpuload_monitor_stop();
		return 0;
	}

	for (;;) {
		print_load(STDOUT_FILENO, &load);

		/* Sleep 200 ms waiting for user input five times ~ 1s */
		for (int k = 0; k < 5; k++) {
			char c;

			struct pollfd fds;
			int ret;
			fds.fd = 0; /* stdin */
			fds.events = POLLIN;
			ret = poll(&fds, 1, 0);

			if (ret > 0) {

				ret = read(0, &c, 1);

				if (ret) {
					cpuload_monitor_stop();
					return 1;
				}

				switch (c) {
				case 0x03: // ctrl-c
				case 0x1b: // esc
				case 'c':
				case 'q':
					cpuload_monitor_stop();
					return 0;
					/* not reached */
				}
			}

			px4_usleep(200000);
		}
	}

	cpuload_monitor_stop();
	return 0;
}