text: /****************************************************************************
   *
   *   Copyright (c) 2020 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
   * "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
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   ****************************************************************************/
  
  #ifndef GPS_STATUS_HPP
  #define GPS_STATUS_HPP
  
  #include <uORB/topics/satellite_info.h>
  
  class MavlinkStreamGPSStatus : public MavlinkStream
  {
  public:
  	static MavlinkStream *new_instance(Mavlink *mavlink) { return new MavlinkStreamGPSStatus(mavlink); }
  
  	static constexpr const char *get_name_static() { return "GPS_STATUS"; }
  	static constexpr uint16_t get_id_static() { return MAVLINK_MSG_ID_GPS_STATUS; }
  
  	const char *get_name() const override { return MavlinkStreamGPSStatus::get_name_static(); }
  	uint16_t get_id() override { return get_id_static(); }
  
  	unsigned get_size() override
  	{
  		return _satellite_info_sub.advertised() ? (MAVLINK_MSG_ID_GPS_STATUS_LEN + MAVLINK_NUM_NON_PAYLOAD_BYTES) : 0;
  	}
  
  private:
  	explicit MavlinkStreamGPSStatus(Mavlink *mavlink) : MavlinkStream(mavlink) {}
  
  	uORB::Subscription _satellite_info_sub{ORB_ID(satellite_info)};
  
  	bool send() override
  	{
  		satellite_info_s sat;
  
  		if (_satellite_info_sub.update(&sat)) {
  			mavlink_gps_status_t msg{};
  
  			msg.satellites_visible = sat.count;
  
  			size_t sat_count = math::min(static_cast<size_t>(sat.count),
  						     sizeof(msg.satellite_used) / sizeof(msg.satellite_used[0]));
  
  			for (size_t i = 0; i < sat_count; i++) {
  				msg.satellite_used[i]      = sat.used[i];
  				msg.satellite_elevation[i] = sat.elevation[i];
  				msg.satellite_azimuth[i]   = sat.azimuth[i];
  				msg.satellite_snr[i]       = sat.snr[i];
  				msg.satellite_prn[i]       = sat.prn[i];
  			}
  
  			mavlink_msg_gps_status_send_struct(_mavlink->get_channel(), &msg);
  
  			return true;
  		}
  
  		return false;
  	}
  };
  
  #endif // GPS_STATUS_HPP
  