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/**
 * @file AttitudeControlMath.hpp
 */

#pragma once

#include <matrix/matrix/math.hpp>

namespace AttitudeControlMath
{
/**
 * Rotate a tilt quaternion (without yaw rotation) such that when rotated by a yaw setpoint
 * the resulting tilt is the same as if it was rotated by the current yaw of the vehicle
 * @param q_sp_tilt pure tilt quaternion (yaw = 0) that needs to be corrected
 * @param q_att current attitude of the vehicle
 * @param q_sp_yaw pure yaw quaternion of the desired yaw setpoint
 */
void inline correctTiltSetpointForYawError(matrix::Quatf &q_sp_tilt, const matrix::Quatf &q_att,
		const matrix::Quatf &q_sp_yaw)
{
	const matrix::Vector3f z_unit(0.f, 0.f, 1.f);

	// Extract yaw from the current attitude
	const matrix::Vector3f att_z = q_att.dcm_z();
	const matrix::Quatf q_tilt(z_unit, att_z);
	const matrix::Quatf q_yaw = q_tilt.inversed() * q_att; // This is not euler yaw

	// Find the quaternion that creates a tilt aligned with the body frame
	// when rotated by the yaw setpoint
	// To do so, solve q_yaw * q_tilt_ne = q_sp_yaw * q_sp_rp_compensated
	const matrix::Quatf q_sp_rp_compensated = q_sp_yaw.inversed() * q_yaw * q_sp_tilt;

	// Extract the corrected tilt
	const matrix::Vector3f att_sp_z = q_sp_rp_compensated.dcm_z();
	q_sp_tilt = matrix::Quatf(z_unit, att_sp_z);
}
}