text: /****************************************************************************
   *
   *   Copyright (c) 2021 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
   * 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.
   *
   ****************************************************************************/
  
  #ifndef BATTERY_STATUS_HPP
  #define BATTERY_STATUS_HPP
  
  #include <uORB/topics/battery_status.h>
  
  class MavlinkStreamBatteryStatus : public MavlinkStream
  {
  public:
  	static MavlinkStream *new_instance(Mavlink *mavlink) { return new MavlinkStreamBatteryStatus(mavlink); }
  
  	static constexpr const char *get_name_static() { return "BATTERY_STATUS"; }
  	static constexpr uint16_t get_id_static() { return MAVLINK_MSG_ID_BATTERY_STATUS; }
  
  	const char *get_name() const override { return get_name_static(); }
  	uint16_t get_id() override { return get_id_static(); }
  
  	unsigned get_size() override
  	{
  		static constexpr unsigned size_per_battery = MAVLINK_MSG_ID_BATTERY_STATUS_LEN + MAVLINK_NUM_NON_PAYLOAD_BYTES;
  		return size_per_battery * _battery_status_subs.advertised_count();
  	}
  
  private:
  	explicit MavlinkStreamBatteryStatus(Mavlink *mavlink) : MavlinkStream(mavlink) {}
  
  	uORB::SubscriptionMultiArray<battery_status_s, battery_status_s::MAX_INSTANCES> _battery_status_subs{ORB_ID::battery_status};
  
  	bool send() override
  	{
  		bool updated = false;
  
  		for (auto &battery_sub : _battery_status_subs) {
  			battery_status_s battery_status;
  
  			if (battery_sub.update(&battery_status)) {
  				/* battery status message with higher resolution */
  				mavlink_battery_status_t bat_msg{};
  				// TODO: Determine how to better map between battery ID within the firmware and in MAVLink
  				bat_msg.id = battery_status.id - 1;
  				bat_msg.battery_function = MAV_BATTERY_FUNCTION_ALL;
  				bat_msg.type = MAV_BATTERY_TYPE_LIPO;
  				bat_msg.current_consumed = (battery_status.connected) ? battery_status.discharged_mah : -1;
  				bat_msg.energy_consumed = -1;
  				bat_msg.current_battery = (battery_status.connected) ? battery_status.current_filtered_a * 100 : -1;
  				bat_msg.battery_remaining = (battery_status.connected) ? ceilf(battery_status.remaining * 100.f) : -1;
  				// MAVLink extension: 0 is unsupported, in uORB it's NAN
  				bat_msg.time_remaining = (battery_status.connected && (PX4_ISFINITE(battery_status.time_remaining_s))) ?
  							 math::max((int)battery_status.time_remaining_s, 1) : 0;
  
  				switch (battery_status.warning) {
  				case (battery_status_s::BATTERY_WARNING_NONE):
  					bat_msg.charge_state = MAV_BATTERY_CHARGE_STATE_OK;
  					break;
  
  				case (battery_status_s::BATTERY_WARNING_LOW):
  					bat_msg.charge_state = MAV_BATTERY_CHARGE_STATE_LOW;
  					break;
  
  				case (battery_status_s::BATTERY_WARNING_CRITICAL):
  					bat_msg.charge_state = MAV_BATTERY_CHARGE_STATE_CRITICAL;
  					break;
  
  				case (battery_status_s::BATTERY_WARNING_EMERGENCY):
  					bat_msg.charge_state = MAV_BATTERY_CHARGE_STATE_EMERGENCY;
  					break;
  
  				case (battery_status_s::BATTERY_WARNING_FAILED):
  					bat_msg.charge_state = MAV_BATTERY_CHARGE_STATE_FAILED;
  					break;
  
  				default:
  					bat_msg.charge_state = MAV_BATTERY_CHARGE_STATE_UNDEFINED;
  					break;
  				}
  
  				// check if temperature valid
  				if (battery_status.connected && PX4_ISFINITE(battery_status.temperature)) {
  					bat_msg.temperature = battery_status.temperature * 100.f;
  
  				} else {
  					bat_msg.temperature = INT16_MAX;
  				}
  
  				static constexpr int mavlink_cells_max = (sizeof(bat_msg.voltages) / sizeof(bat_msg.voltages[0]));
  				static constexpr int uorb_cells_max =
  					(sizeof(battery_status.voltage_cell_v) / sizeof(battery_status.voltage_cell_v[0]));
  
  				for (int cell = 0; cell < mavlink_cells_max; cell++) {
  					if (battery_status.connected && (cell < battery_status.cell_count) && (cell < uorb_cells_max)) {
  						bat_msg.voltages[cell] = battery_status.voltage_cell_v[cell] * 1000.f;
  
  					} else {
  						bat_msg.voltages[cell] = UINT16_MAX;
  					}
  				}
  
  				static constexpr int mavlink_cells_ext_max = (sizeof(bat_msg.voltages_ext) / sizeof(bat_msg.voltages_ext[0]));
  
  				for (int cell = mavlink_cells_max; cell < mavlink_cells_max + mavlink_cells_ext_max; cell++) {
  					if (battery_status.connected && (cell < battery_status.cell_count) && (cell < uorb_cells_max)) {
  						bat_msg.voltages_ext[cell - mavlink_cells_max] = battery_status.voltage_cell_v[cell] * 1000.0f;
  
  					} else {
  						bat_msg.voltages_ext[cell - mavlink_cells_max] = UINT16_MAX;
  					}
  				}
  
  				mavlink_msg_battery_status_send_struct(_mavlink->get_channel(), &bat_msg);
  				updated = true;
  			}
  		}
  
  		return updated;
  	}
  };
  
  #endif // BATTERY_STATUS_HPP
  