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/**
 * @file FlightTaskOrbit.h
 *
 * Flight task for orbiting in a circle around a target position
 *
 * @author Matthias Grob <maetugr@gmail.com>
 */

#pragma once

#include "FlightTask.hpp"

class FlightTaskOrbit : public FlightTask
{
public:
	FlightTaskOrbit() {};
	virtual ~FlightTaskOrbit() {};

	/**
	 * Call once on the event where you switch to the task
	 * @return 0 on success, >0 on error otherwise
	 */
	virtual int activate()
	{
		FlightTask::activate();
		return 0;
	};

	/**
	 * Call once on the event of switching away from the task
	 * 	@return 0 on success, >0 on error otherwise
	 */
	virtual int disable() { return 0; };

	/**
	 * Call regularly in the control loop cycle to execute the task
	 * @return 0 on success, >0 on error otherwise
	 */
	virtual int update()
	{
		FlightTask::update();

		r += _sticks(1) * _deltatime;
		r = math::constrain(r, 0.5f, 4.f);
		v -= _sticks(0) * _deltatime;
		v = math::constrain(v, -7.f, 7.f);
		altitude += _sticks(3) * _deltatime;
		altitude = math::constrain(altitude, 2.f, 5.f);

		matrix::Vector2<float> target_to_position = matrix::Vector2f(_position.data()) - matrix::Vector2f();
		// TODO: add local frame target position here

		/* xy velocity to go around in a circle */
		matrix::Vector2<float> velocity_xy = matrix::Vector2f(target_to_position(1), -target_to_position(0));
		velocity_xy.normalize();
		velocity_xy *= v;

		/* xy velocity adjustment to stay on the radius distance */
		velocity_xy += (r - target_to_position.norm()) * target_to_position.normalized();

		//printf("%f %f %f\n", (double)altitude, (double)r, (double)v);

		_set_position_setpoint(matrix::Vector3f(NAN, NAN, -altitude));
		_set_velocity_setpoint(matrix::Vector3f(velocity_xy(0), velocity_xy(1), 0.f));
		return 0;
	};

private:

	float r = 1.f; /* radius with which to orbit the target */
	float v =  0.1f; /* linear velocity for orbiting in m/s */
	float altitude = 2.f; /* altitude in meters */

};