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 * modification, are permitted provided that the following conditions
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 *    notice, this list of conditions and the following disclaimer.
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 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
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 /* @file enginefailure.cpp
 * Helper class for a fixedwing engine failure mode
 *
 * @author Thomas Gubler <thomasgubler@gmail.com>
 */
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <fcntl.h>

#include <mavlink/mavlink_log.h>
#include <systemlib/err.h>
#include <geo/geo.h>

#include <uORB/uORB.h>
#include <uORB/topics/mission.h>

#include "navigator.h"
#include "enginefailure.h"

#define DELAY_SIGMA	0.01f

EngineFailure::EngineFailure(Navigator *navigator, const char *name) :
	MissionBlock(navigator, name),
	_ef_state(EF_STATE_NONE)
{
	/* load initial params */
	updateParams();
	/* initial reset */
	on_inactive();
}

EngineFailure::~EngineFailure()
{
}

void
EngineFailure::on_inactive()
{
	_ef_state = EF_STATE_NONE;
}

void
EngineFailure::on_activation()
{
	_ef_state = EF_STATE_NONE;
	advance_ef();
	set_ef_item();
}

void
EngineFailure::on_active()
{
	if (is_mission_item_reached()) {
		advance_ef();
		set_ef_item();
	}
}

void
EngineFailure::set_ef_item()
{
	struct position_setpoint_triplet_s *pos_sp_triplet = _navigator->get_position_setpoint_triplet();

	/* make sure we have the latest params */
	updateParams();

	set_previous_pos_setpoint();
	_navigator->set_can_loiter_at_sp(false);

	switch (_ef_state) {
	case EF_STATE_LOITERDOWN: {
		//XXX create mission item at ground (below?) here

		_mission_item.lat = _navigator->get_global_position()->lat;
		_mission_item.lon = _navigator->get_global_position()->lon;
		_mission_item.altitude_is_relative = false;
		 //XXX setting altitude to a very low value, evaluate other options
		_mission_item.altitude = _navigator->get_home_position()->alt - 1000.0f;
		_mission_item.yaw = NAN;
		_mission_item.loiter_radius = _navigator->get_loiter_radius();
		_mission_item.loiter_direction = 1;
		_mission_item.nav_cmd = NAV_CMD_LOITER_UNLIMITED;
		_mission_item.acceptance_radius = _navigator->get_acceptance_radius();
		_mission_item.pitch_min = 0.0f;
		_mission_item.autocontinue = true;
		_mission_item.origin = ORIGIN_ONBOARD;

		_navigator->set_can_loiter_at_sp(true);
		break;
	}
	default:
		break;
	}

	reset_mission_item_reached();

	/* convert mission item to current position setpoint and make it valid */
	mission_item_to_position_setpoint(&_mission_item, &pos_sp_triplet->current);
	pos_sp_triplet->next.valid = false;

	_navigator->set_position_setpoint_triplet_updated();
}

void
EngineFailure::advance_ef()
{
	switch (_ef_state) {
	case EF_STATE_NONE:
		mavlink_log_emergency(_navigator->get_mavlink_fd(), "Engine failure. Loitering down");
		_ef_state = EF_STATE_LOITERDOWN;
		break;
	default:
		break;
	}
}