text: /****************************************************************************
   *
   *   Copyright (c) 2015 Roman Bapst. 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
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  /**
   * @file gpssim.cpp
   * Simulated GPS driver
   */
  
  #include <sys/types.h>
  #include <inttypes.h>
  #include <stdio.h>
  #include <stdbool.h>
  #include <stdlib.h>
  #include <semaphore.h>
  #include <string.h>
  #include <fcntl.h>
  #include <poll.h>
  #include <errno.h>
  #include <stdio.h>
  #include <math.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <px4_config.h>
  #include <drivers/drv_hrt.h>
  #include <drivers/device/device.h>
  #include <systemlib/systemlib.h>
  #include <drivers/drv_gps.h>
  #include <uORB/uORB.h>
  #include <uORB/topics/vehicle_gps_position.h>
  #include <uORB/topics/satellite_info.h>
  
  #include <simulator/simulator.h>
  
  #include "DevMgr.hpp"
  #include "VirtDevObj.hpp"
  
  using namespace DriverFramework;
  
  #define GPS_DRIVER_MODE_UBX_SIM
  #define GPSSIM_DEVICE_PATH "/dev/gpssim"
  
  #define TIMEOUT_5HZ 500
  #define RATE_MEASUREMENT_PERIOD 5000000
  
  /* oddly, ERROR is not defined for c++ */
  #ifdef ERROR
  # undef ERROR
  #endif
  static const int ERROR = -1;
  
  /* class for dynamic allocation of satellite info data */
  class GPS_Sat_Info
  {
  public:
  	struct satellite_info_s 	_data;
  };
  
  
  class GPSSIM : public VirtDevObj
  {
  public:
  	GPSSIM(const char *uart_path, bool fake_gps, bool enable_sat_info);
  	virtual ~GPSSIM();
  
  	virtual int			init();
  
  	virtual int			devIOCTL(unsigned long cmd, unsigned long arg);
  
  	/**
  	 * Diagnostics - print some basic information about the driver.
  	 */
  	void				print_info();
  
  protected:
  	virtual void			_measure() {}
  
  private:
  
  	bool				_task_should_exit;				///< flag to make the main worker task exit
  	int				_serial_fd;					///< serial interface to GPS
  	unsigned			_baudrate;					///< current baudrate
  	char				_port[20];					///< device / serial port path
  	volatile int			_task;						///< worker task
  	bool				_healthy;					///< flag to signal if the GPS is ok
  	bool				_baudrate_changed;				///< flag to signal that the baudrate with the GPS has changed
  	bool				_mode_changed;					///< flag that the GPS mode has changed
  	//gps_driver_mode_t		_mode;						///< current mode
  	GPS_Sat_Info			*_Sat_Info;					///< instance of GPS sat info data object
  	struct vehicle_gps_position_s	_report_gps_pos;				///< uORB topic for gps position
  	orb_advert_t			_report_gps_pos_pub;				///< uORB pub for gps position
  	struct satellite_info_s		*_p_report_sat_info;				///< pointer to uORB topic for satellite info
  	orb_advert_t			_report_sat_info_pub;				///< uORB pub for satellite info
  	float				_rate;						///< position update rate
  	bool				_fake_gps;					///< fake gps output
  	SyncObj				_sync;
  
  	/**
  	 * Try to configure the GPS, handle outgoing communication to the GPS
  	 */
  	void			 	config();
  
  	/**
  	 * Trampoline to the worker task
  	 */
  	static void			task_main_trampoline(void *arg);
  
  
  	/**
  	 * Worker task: main GPS thread that configures the GPS and parses incoming data, always running
  	 */
  	void				task_main(void);
  
  	/**
  	 * Set the baudrate of the UART to the GPS
  	 */
  	int				set_baudrate(unsigned baud);
  
  	/**
  	 * Send a reset command to the GPS
  	 */
  	void				cmd_reset();
  
  	int 				receive(int timeout);
  };
  
  
  /*
   * Driver 'main' command.
   */
  extern "C" __EXPORT int gpssim_main(int argc, char *argv[]);
  
  namespace
  {
  
  GPSSIM	*g_dev = nullptr;
  
  }
  
  
  GPSSIM::GPSSIM(const char *uart_path, bool fake_gps, bool enable_sat_info) :
  	VirtDevObj("gps", GPSSIM_DEVICE_PATH, nullptr, 1e6 / 10),
  	_task_should_exit(false),
  	//_healthy(false),
  	//_mode_changed(false),
  	//_mode(GPS_DRIVER_MODE_UBX),
  	//_Helper(nullptr),
  	_Sat_Info(nullptr),
  	_report_gps_pos_pub(nullptr),
  	_p_report_sat_info(nullptr),
  	_report_sat_info_pub(nullptr),
  	_rate(0.0f),
  	_fake_gps(fake_gps)
  {
  	// /* store port name */
  	// strncpy(_port, uart_path, sizeof(_port));
  	// /* enforce null termination */
  	// _port[sizeof(_port) - 1] = '\0';
  
  	/* we need this potentially before it could be set in task_main */
  	g_dev = this;
  	memset(&_report_gps_pos, 0, sizeof(_report_gps_pos));
  
  	/* create satellite info data object if requested */
  	if (enable_sat_info) {
  		_Sat_Info = new(GPS_Sat_Info);
  		_p_report_sat_info = &_Sat_Info->_data;
  		memset(_p_report_sat_info, 0, sizeof(*_p_report_sat_info));
  	}
  }
  
  GPSSIM::~GPSSIM()
  {
  	/* tell the task we want it to go away */
  	_task_should_exit = true;
  
  	/* spin waiting for the task to stop */
  	for (unsigned i = 0; (i < 10) && (_task != -1); i++) {
  		/* give it another 100ms */
  		usleep(100000);
  	}
  
  	/* well, kill it anyway, though this will probably crash */
  	if (_task != -1) {
  		px4_task_delete(_task);
  	}
  
  	g_dev = nullptr;
  }
  
  int
  GPSSIM::init()
  {
  	int ret = ERROR;
  
  	/* do regular cdev init */
  	if (VirtDevObj::init() != OK) {
  		goto out;
  	}
  
  	/* start the GPS driver worker task */
  	_task = px4_task_spawn_cmd("gps", SCHED_DEFAULT,
  				   SCHED_PRIORITY_DEFAULT, 1500, (px4_main_t)&GPSSIM::task_main_trampoline, nullptr);
  
  	if (_task < 0) {
  		PX4_ERR("task start failed: %d", errno);
  		return -errno;
  	}
  
  	ret = OK;
  out:
  	return ret;
  }
  
  int
  GPSSIM::devIOCTL(unsigned long cmd, unsigned long arg)
  {
  	_sync.lock();
  
  	int ret = OK;
  
  	switch (cmd) {
  	case SENSORIOCRESET:
  		cmd_reset();
  		break;
  
  	default:
  		/* give it to parent if no one wants it */
  		ret = VirtDevObj::devIOCTL(cmd, arg);
  		break;
  	}
  
  	_sync.unlock();
  
  	return ret;
  }
  
  void
  GPSSIM::task_main_trampoline(void *arg)
  {
  	g_dev->task_main();
  }
  
  int
  GPSSIM::receive(int timeout)
  {
  	Simulator *sim = Simulator::getInstance();
  	simulator::RawGPSData gps;
  	sim->getGPSSample((uint8_t *)&gps, sizeof(gps));
  
  	_report_gps_pos.timestamp_position = hrt_absolute_time();
  	_report_gps_pos.lat = gps.lat;
  	_report_gps_pos.lon = gps.lon;
  	_report_gps_pos.alt = gps.alt;
  	_report_gps_pos.timestamp_variance = _report_gps_pos.timestamp_position;
  	_report_gps_pos.eph = (float)gps.eph * 1e-2f;
  	_report_gps_pos.epv = (float)gps.epv * 1e-2f;
  	_report_gps_pos.timestamp_velocity = _report_gps_pos.timestamp_position;
  	_report_gps_pos.vel_m_s = (float)(gps.vel) / 100.0f;
  	_report_gps_pos.vel_n_m_s = (float)(gps.vn) / 100.0f;
  	_report_gps_pos.vel_e_m_s = (float)(gps.ve) / 100.0f;
  	_report_gps_pos.vel_d_m_s = (float)(gps.vd) / 100.0f;
  	_report_gps_pos.cog_rad = (float)(gps.cog) * 3.1415f / (100.0f * 180.0f);
  	_report_gps_pos.fix_type = gps.fix_type;
  	_report_gps_pos.satellites_used = gps.satellites_visible;
  
  	usleep(200000);
  	return 1;
  }
  
  void
  GPSSIM::task_main()
  {
  
  	/* loop handling received serial bytes and also configuring in between */
  	while (!_task_should_exit) {
  
  		if (_fake_gps) {
  			_report_gps_pos.timestamp_position = hrt_absolute_time();
  			_report_gps_pos.lat = (int32_t)47.378301e7f;
  			_report_gps_pos.lon = (int32_t)8.538777e7f;
  			_report_gps_pos.alt = (int32_t)1200e3f;
  			_report_gps_pos.timestamp_variance = _report_gps_pos.timestamp_position;
  			_report_gps_pos.s_variance_m_s = 10.0f;
  			_report_gps_pos.c_variance_rad = 0.1f;
  			_report_gps_pos.fix_type = 3;
  			_report_gps_pos.eph = 0.9f;
  			_report_gps_pos.epv = 1.8f;
  			_report_gps_pos.timestamp_velocity = _report_gps_pos.timestamp_position;
  			_report_gps_pos.vel_n_m_s = 0.0f;
  			_report_gps_pos.vel_e_m_s = 0.0f;
  			_report_gps_pos.vel_d_m_s = 0.0f;
  			_report_gps_pos.vel_m_s = sqrtf(_report_gps_pos.vel_n_m_s * _report_gps_pos.vel_n_m_s + _report_gps_pos.vel_e_m_s *
  							_report_gps_pos.vel_e_m_s + _report_gps_pos.vel_d_m_s * _report_gps_pos.vel_d_m_s);
  			_report_gps_pos.cog_rad = 0.0f;
  			_report_gps_pos.vel_ned_valid = true;
  
  			//no time and satellite information simulated
  
  			if (!(m_pub_blocked)) {
  				if (_report_gps_pos_pub != nullptr) {
  					orb_publish(ORB_ID(vehicle_gps_position), _report_gps_pos_pub, &_report_gps_pos);
  
  				} else {
  					_report_gps_pos_pub = orb_advertise(ORB_ID(vehicle_gps_position), &_report_gps_pos);
  				}
  			}
  
  			usleep(2e5);
  
  		} else {
  			//Publish initial report that we have access to a GPS
  			//Make sure to clear any stale data in case driver is reset
  			memset(&_report_gps_pos, 0, sizeof(_report_gps_pos));
  			_report_gps_pos.timestamp_position = hrt_absolute_time();
  			_report_gps_pos.timestamp_variance = hrt_absolute_time();
  			_report_gps_pos.timestamp_velocity = hrt_absolute_time();
  			_report_gps_pos.timestamp_time = hrt_absolute_time();
  
  			if (!(m_pub_blocked)) {
  				if (_report_gps_pos_pub != nullptr) {
  					orb_publish(ORB_ID(vehicle_gps_position), _report_gps_pos_pub, &_report_gps_pos);
  
  				} else {
  					_report_gps_pos_pub = orb_advertise(ORB_ID(vehicle_gps_position), &_report_gps_pos);
  				}
  			}
  
  			// GPS is obviously detected successfully, reset statistics
  			//_Helper->reset_update_rates();
  
  			while ((receive(TIMEOUT_5HZ)) > 0 && !_task_should_exit) {
  				/* opportunistic publishing - else invalid data would end up on the bus */
  
  				if (!(m_pub_blocked)) {
  					orb_publish(ORB_ID(vehicle_gps_position), _report_gps_pos_pub, &_report_gps_pos);
  
  					if (_p_report_sat_info) {
  						if (_report_sat_info_pub != nullptr) {
  							orb_publish(ORB_ID(satellite_info), _report_sat_info_pub, _p_report_sat_info);
  
  						} else {
  							_report_sat_info_pub = orb_advertise(ORB_ID(satellite_info), _p_report_sat_info);
  						}
  					}
  				}
  			}
  
  			// FIXME - if ioctl is called then it will deadlock
  			_sync.lock();
  		}
  	}
  
  	PX4_INFO("exiting");
  
  	/* tell the dtor that we are exiting */
  	_task = -1;
  	return;
  }
  
  
  
  void
  GPSSIM::cmd_reset()
  {
  }
  
  void
  GPSSIM::print_info()
  {
  	//GPS Mode
  	if (_fake_gps) {
  		PX4_INFO("protocol: faked");
  	}
  
  	else {
  		PX4_INFO("protocol: SIM");
  	}
  
  	PX4_INFO("port: %s, baudrate: %d, status: %s", _port, _baudrate, (_healthy) ? "OK" : "NOT OK");
  	PX4_INFO("sat info: %s, noise: %d, jamming detected: %s",
  		 (_p_report_sat_info != nullptr) ? "enabled" : "disabled",
  		 _report_gps_pos.noise_per_ms,
  		 _report_gps_pos.jamming_indicator == 255 ? "YES" : "NO");
  
  	if (_report_gps_pos.timestamp_position != 0) {
  		PX4_INFO("position lock: %dD, satellites: %d, last update: %8.4fms ago", (int)_report_gps_pos.fix_type,
  			 _report_gps_pos.satellites_used, (double)(hrt_absolute_time() - _report_gps_pos.timestamp_position) / 1000.0);
  		PX4_INFO("lat: %d, lon: %d, alt: %d", _report_gps_pos.lat, _report_gps_pos.lon, _report_gps_pos.alt);
  		PX4_INFO("vel: %.2fm/s, %.2fm/s, %.2fm/s", (double)_report_gps_pos.vel_n_m_s,
  			 (double)_report_gps_pos.vel_e_m_s, (double)_report_gps_pos.vel_d_m_s);
  		PX4_INFO("eph: %.2fm, epv: %.2fm", (double)_report_gps_pos.eph, (double)_report_gps_pos.epv);
  		//PX4_INFO("rate position: \t%6.2f Hz", (double)_Helper->get_position_update_rate());
  		//PX4_INFO("rate velocity: \t%6.2f Hz", (double)_Helper->get_velocity_update_rate());
  		PX4_INFO("rate publication:\t%6.2f Hz", (double)_rate);
  
  	}
  
  	usleep(100000);
  }
  
  /**
   * Local functions in support of the shell command.
   */
  namespace gpssim
  {
  
  GPSSIM	*g_dev = nullptr;
  
  void	start(const char *uart_path, bool fake_gps, bool enable_sat_info);
  void	stop();
  void	test();
  void	reset();
  void	info();
  
  /**
   * Start the driver.
   */
  void
  start(const char *uart_path, bool fake_gps, bool enable_sat_info)
  {
  	DevHandle h;
  
  	/* create the driver */
  	g_dev = new GPSSIM(uart_path, fake_gps, enable_sat_info);
  
  	if (g_dev == nullptr) {
  		goto fail;
  	}
  
  	if (OK != g_dev->init()) {
  		goto fail;
  	}
  
  	/* set the poll rate to default, starts automatic data collection */
  	DevMgr::getHandle(GPSSIM_DEVICE_PATH, h);
  
  	if (!h.isValid()) {
  		PX4_ERR("getHandle failed: %s", GPS0_DEVICE_PATH);
  		goto fail;
  	}
  
  	return;
  
  fail:
  
  	if (g_dev != nullptr) {
  		delete g_dev;
  		g_dev = nullptr;
  	}
  
  	PX4_ERR("start failed");
  }
  
  /**
   * Stop the driver.
   */
  void
  stop()
  {
  	delete g_dev;
  	g_dev = nullptr;
  }
  
  /**
   * Perform some basic functional tests on the driver;
   * make sure we can collect data from the sensor in polled
   * and automatic modes.
   */
  void
  test()
  {
  	PX4_INFO("PASS");
  }
  
  /**
   * Reset the driver.
   */
  void
  reset()
  {
  	DevHandle h;
  	DevMgr::getHandle(GPSSIM_DEVICE_PATH, h);
  
  	if (!h.isValid()) {
  		PX4_ERR("failed ");
  	}
  
  	if (h.ioctl(SENSORIOCRESET, 0) < 0) {
  		PX4_ERR("reset failed");
  	}
  }
  
  /**
   * Print the status of the driver.
   */
  void
  info()
  {
  	if (g_dev == nullptr) {
  		PX4_ERR("gpssim not running");
  	}
  
  	g_dev->print_info();
  }
  
  } // namespace
  
  
  int
  gpssim_main(int argc, char *argv[])
  {
  
  	/* set to default */
  	const char *device_name = GPS_DEFAULT_UART_PORT;
  	bool fake_gps = false;
  	bool enable_sat_info = false;
  
  	/*
  	 * Start/load the driver.
  	 */
  	if (!strcmp(argv[1], "start")) {
  		if (g_dev != nullptr) {
  			PX4_WARN("gpssim already started");
  			return 0;
  		}
  
  		/* work around getopt unreliability */
  		if (argc > 3) {
  			if (!strcmp(argv[2], "-d")) {
  				device_name = argv[3];
  
  			} else {
  				goto out;
  			}
  		}
  
  		/* Detect fake gps option */
  		for (int i = 2; i < argc; i++) {
  			if (!strcmp(argv[i], "-f")) {
  				fake_gps = true;
  			}
  		}
  
  		/* Detect sat info option */
  		for (int i = 2; i < argc; i++) {
  			if (!strcmp(argv[i], "-s")) {
  				enable_sat_info = true;
  			}
  		}
  
  		gpssim::start(device_name, fake_gps, enable_sat_info);
  	}
  
  	if (!strcmp(argv[1], "stop")) {
  		gpssim::stop();
  	}
  
  	/*
  	 * Test the driver/device.
  	 */
  	if (!strcmp(argv[1], "test")) {
  		gpssim::test();
  	}
  
  	/*
  	 * Reset the driver.
  	 */
  	if (!strcmp(argv[1], "reset")) {
  		gpssim::reset();
  	}
  
  	/*
  	 * Print driver status.
  	 */
  	if (!strcmp(argv[1], "status")) {
  		gpssim::info();
  	}
  
  	return 0;
  
  out:
  	PX4_INFO("unrecognized command, try 'start', 'stop', 'test', 'reset' or 'status'\n [-d /dev/ttyS0-n][-f (for enabling fake)][-s (to enable sat info)]");
  	return 1;
  }
  