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#include "output.h"

#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/vehicle_global_position.h>
#include <uORB/topics/mount_orientation.h>
#include <px4_platform_common/defines.h>
#include <lib/geo/geo.h>
#include <math.h>
#include <mathlib/mathlib.h>
#include <matrix/math.hpp>

using namespace time_literals;

namespace gimbal
{

OutputBase::OutputBase(const Parameters &parameters)
	: _parameters(parameters)
{
	_last_update = hrt_absolute_time();
}

void OutputBase::publish()
{
	mount_orientation_s mount_orientation{};

	for (unsigned i = 0; i < 3; ++i) {
		mount_orientation.attitude_euler_angle[i] = _angle_outputs[i];
	}

	mount_orientation.timestamp = hrt_absolute_time();
	_mount_orientation_pub.publish(mount_orientation);
}

float OutputBase::_calculate_pitch(double lon, double lat, float altitude,
				   const vehicle_global_position_s &global_position)
{
	if (!_projection_reference.isInitialized()) {
		_projection_reference.initReference(global_position.lat, global_position.lon, hrt_absolute_time());
	}

	float x1, y1, x2, y2;
	_projection_reference.project(lat, lon, x1, y1);
	_projection_reference.project(global_position.lat, global_position.lon, x2, y2);
	float dx = x1 - x2, dy = y1 - y2;
	float target_distance = sqrtf(dx * dx + dy * dy);
	float z = altitude - global_position.alt;

	return atan2f(z, target_distance);
}

bool OutputBase::check_and_handle_setpoint_timeout(ControlData &control_data, const hrt_abstime &now)
{
	bool ret = false;
	const bool timeout = (control_data.timestamp_last_update + 2_s < now);
	const bool type_angle = (control_data.type == ControlData::Type::Angle);

	if (timeout && type_angle) {
		// Avoid gimbal keeps on spinning if the last setpoint was angular_velocity but it times out
		for (int i = 0; i < 3; ++i) {
			float &vel = control_data.type_data.angle.angular_velocity[i];

			if (PX4_ISFINITE(vel) && (fabsf(vel) > FLT_EPSILON)) {
				vel = 0.f;
				ret = true;
			}
		}
	}

	return ret;
}

void OutputBase::_set_angle_setpoints(const ControlData &control_data)
{
	switch (control_data.type) {
	case ControlData::Type::Angle:

		{
			for (int i = 0; i < 3; ++i) {
				switch (control_data.type_data.angle.frames[i]) {
				case ControlData::TypeData::TypeAngle::Frame::AngularRate:
					break;

				case ControlData::TypeData::TypeAngle::Frame::AngleBodyFrame:
					_absolute_angle[i] = false;
					break;

				case ControlData::TypeData::TypeAngle::Frame::AngleAbsoluteFrame:
					_absolute_angle[i] = true;
					break;
				}

				_angle_velocity[i] = control_data.type_data.angle.angular_velocity[i];
			}

			for (int i = 0; i < 4; ++i) {
				_q_setpoint[i] = control_data.type_data.angle.q[i];
			}
		}

		break;

	case ControlData::Type::LonLat:
		_handle_position_update(control_data, true);
		break;

	case ControlData::Type::Neutral:
		_q_setpoint[0] = 1.f;
		_q_setpoint[1] = 0.f;
		_q_setpoint[2] = 0.f;
		_q_setpoint[3] = 0.f;
		_angle_velocity[0] = NAN;
		_angle_velocity[1] = NAN;
		_angle_velocity[2] = NAN;
		break;
	}
}

void OutputBase::_handle_position_update(const ControlData &control_data, bool force_update)
{
	if (control_data.type != ControlData::Type::LonLat) {
		return;
	}

	vehicle_global_position_s vehicle_global_position{};

	if (force_update) {
		_vehicle_global_position_sub.copy(&vehicle_global_position);

	} else {
		if (!_vehicle_global_position_sub.update(&vehicle_global_position)) {
			return;
		}
	}

	const double &vlat = vehicle_global_position.lat;
	const double &vlon = vehicle_global_position.lon;

	const double &lat = control_data.type_data.lonlat.lat;
	const double &lon = control_data.type_data.lonlat.lon;
	const float &alt = control_data.type_data.lonlat.altitude;

	float roll = PX4_ISFINITE(control_data.type_data.lonlat.roll_offset)
		     ? control_data.type_data.lonlat.roll_offset
		     : 0.0f;

	// interface: use fixed pitch value > -pi otherwise consider ROI altitude
	float pitch = (control_data.type_data.lonlat.pitch_fixed_angle >= -M_PI_F) ?
		      control_data.type_data.lonlat.pitch_fixed_angle :
		      _calculate_pitch(lon, lat, alt, vehicle_global_position);

	float yaw = get_bearing_to_next_waypoint(vlat, vlon, lat, lon);
	// We set the yaw angle in the absolute frame in this case.
	_absolute_angle[2] = true;

	// add offsets from VEHICLE_CMD_DO_SET_ROI_WPNEXT_OFFSET
	if (PX4_ISFINITE(control_data.type_data.lonlat.pitch_offset)) {
		pitch += control_data.type_data.lonlat.pitch_offset;
	}

	if (PX4_ISFINITE(control_data.type_data.lonlat.yaw_offset)) {
		yaw += control_data.type_data.lonlat.yaw_offset;
	}

	matrix::Quatf(matrix::Eulerf(roll, pitch, yaw)).copyTo(_q_setpoint);

	_angle_velocity[0] = NAN;
	_angle_velocity[1] = NAN;
	_angle_velocity[2] = NAN;
}

void OutputBase::_calculate_angle_output(const hrt_abstime &t)
{
	if (_vehicle_land_detected_sub.updated()) {
		vehicle_land_detected_s vehicle_land_detected;

		if (_vehicle_land_detected_sub.copy(&vehicle_land_detected)) {
			_landed = vehicle_land_detected.landed || vehicle_land_detected.maybe_landed;
		}
	}

	// We only need to apply additional compensation if the required angle is
	// absolute (world frame) as well as the gimbal is not capable of doing that
	// calculation. (Most gimbals stabilize at least roll and pitch
	// and only need compensation for yaw, if at all.)
	bool compensate[3];

	for (int i = 0; i < 3; ++i) {
		compensate[i] = _stabilize[i] && _absolute_angle[i];
	}

	// get the output angles and stabilize if necessary
	matrix::Eulerf euler_vehicle{};

	if (compensate[0] || compensate[1] || compensate[2]) {
		vehicle_attitude_s vehicle_attitude;

		if (_vehicle_attitude_sub.copy(&vehicle_attitude)) {
			euler_vehicle = matrix::Quatf(vehicle_attitude.q);
		}
	}

	float dt = math::constrain((t - _last_update) * 1.e-6f, 0.001f, 1.f);

	const matrix::Quatf q_setpoint(_q_setpoint);
	const bool q_setpoint_valid = q_setpoint.isAllFinite();
	matrix::Eulerf euler_gimbal{};

	if (q_setpoint_valid) {
		euler_gimbal = q_setpoint;
	}

	for (int i = 0; i < 3; ++i) {

		if (q_setpoint_valid && PX4_ISFINITE(euler_gimbal(i))) {
			_angle_outputs[i] = euler_gimbal(i);
		}

		if (PX4_ISFINITE(_angle_velocity[i])) {
			_angle_outputs[i] += dt * _angle_velocity[i];
		}

		if (compensate[i] && PX4_ISFINITE(euler_vehicle(i))) {
			_angle_outputs[i] -= euler_vehicle(i);
		}

		if (PX4_ISFINITE(_angle_outputs[i]) && _parameters.mnt_rc_in_mode == 0) {
			// if we are in angle input mode, we bring angles into proper range [-pi, pi]
			_angle_outputs[i] = matrix::wrap_pi(_angle_outputs[i]);
		}
	}

	// constrain angle outputs to [-range/2, range/2]
	_angle_outputs[0] = math::constrain(_angle_outputs[0], math::radians(-_parameters.mnt_range_roll / 2),
					    math::radians(_parameters.mnt_range_roll / 2));
	_angle_outputs[1] = math::constrain(_angle_outputs[1], math::radians(-_parameters.mnt_range_pitch / 2),
					    math::radians(_parameters.mnt_range_pitch / 2));
	_angle_outputs[2] = math::constrain(_angle_outputs[2], math::radians(-_parameters.mnt_range_yaw / 2),
					    math::radians(_parameters.mnt_range_yaw / 2));

	// constrain pitch to [MNT_LND_P_MIN, MNT_LND_P_MAX] if landed
	if (_landed) {
		if (PX4_ISFINITE(_angle_outputs[1])) {
			_angle_outputs[1] = math::constrain(_angle_outputs[1],
							    math::radians(_parameters.mnt_lnd_p_min),
							    math::radians(_parameters.mnt_lnd_p_max));
		}
	}
}

void OutputBase::set_stabilize(bool roll_stabilize, bool pitch_stabilize, bool yaw_stabilize)
{
	_stabilize[0] = roll_stabilize;
	_stabilize[1] = pitch_stabilize;
	_stabilize[2] = yaw_stabilize;
}

} /* namespace gimbal */