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#include "AutoMode.hpp"

using namespace time_literals;

AutoMode::AutoMode(ModuleParams *parent) : ModuleParams(parent)
{
	updateParams();
	_rover_position_setpoint_pub.advertise();
}

void AutoMode::updateParams()
{
	ModuleParams::updateParams();
	_max_yaw_rate = _param_ro_yaw_rate_limit.get() * M_DEG_TO_RAD_F;

	if (_param_ra_wheel_base.get() > FLT_EPSILON && _max_yaw_rate > FLT_EPSILON
	    && _param_ra_max_str_ang.get() > FLT_EPSILON) {
		_min_speed = _param_ra_wheel_base.get() * _max_yaw_rate / tanf(_param_ra_max_str_ang.get());
	}
}

void AutoMode::autoControl()
{
	if (_vehicle_attitude_sub.updated()) {
		vehicle_attitude_s vehicle_attitude{};
		_vehicle_attitude_sub.copy(&vehicle_attitude);
		_vehicle_attitude_quaternion = matrix::Quatf(vehicle_attitude.q);
		_vehicle_yaw = matrix::Eulerf(_vehicle_attitude_quaternion).psi();
	}

	if (_vehicle_local_position_sub.updated()) {
		vehicle_local_position_s vehicle_local_position{};
		_vehicle_local_position_sub.copy(&vehicle_local_position);

		if (!_global_ned_proj_ref.isInitialized()
		    || (_global_ned_proj_ref.getProjectionReferenceTimestamp() != vehicle_local_position.ref_timestamp)) {
			_global_ned_proj_ref.initReference(vehicle_local_position.ref_lat, vehicle_local_position.ref_lon,
							   vehicle_local_position.ref_timestamp);
		}

		_curr_pos_ned = Vector2f(vehicle_local_position.x, vehicle_local_position.y);
	}

	if (_position_setpoint_triplet_sub.updated()) {
		updateWaypointsAndAcceptanceRadius();
	}

	// Distances to waypoints
	const float distance_to_prev_wp = sqrt(powf(_curr_pos_ned(0) - _prev_wp_ned(0),
					       2) + powf(_curr_pos_ned(1) - _prev_wp_ned(1), 2));
	const float distance_to_curr_wp = sqrt(powf(_curr_pos_ned(0) - _curr_wp_ned(0),
					       2) + powf(_curr_pos_ned(1) - _curr_wp_ned(1), 2));

	rover_position_setpoint_s rover_position_setpoint{};
	rover_position_setpoint.timestamp = hrt_absolute_time();
	rover_position_setpoint.position_ned[0] = _curr_wp_ned(0);
	rover_position_setpoint.position_ned[1] = _curr_wp_ned(1);
	rover_position_setpoint.start_ned[0] = _prev_wp_ned(0);
	rover_position_setpoint.start_ned[1] = _prev_wp_ned(1);
	rover_position_setpoint.arrival_speed = arrivalSpeed(_cruising_speed, _min_speed, _acceptance_radius, _curr_wp_type,
						_waypoint_transition_angle, _max_yaw_rate);
	rover_position_setpoint.cruising_speed = cruisingSpeed(_cruising_speed, _min_speed, distance_to_prev_wp,
			distance_to_curr_wp, _acceptance_radius, _prev_acceptance_radius, _waypoint_transition_angle,
			_prev_waypoint_transition_angle, _max_yaw_rate);
	rover_position_setpoint.yaw = NAN;
	_rover_position_setpoint_pub.publish(rover_position_setpoint);
}

void AutoMode::updateWaypointsAndAcceptanceRadius()
{
	position_setpoint_triplet_s position_setpoint_triplet{};
	_position_setpoint_triplet_sub.copy(&position_setpoint_triplet);
	_curr_wp_type = position_setpoint_triplet.current.type;

	RoverControl::globalToLocalSetpointTriplet(_curr_wp_ned, _prev_wp_ned, _next_wp_ned, position_setpoint_triplet,
			_curr_pos_ned, _global_ned_proj_ref);

	_prev_waypoint_transition_angle = _waypoint_transition_angle;
	_waypoint_transition_angle = RoverControl::calcWaypointTransitionAngle(_prev_wp_ned, _curr_wp_ned, _next_wp_ned);

	// Update acceptance radius
	_prev_acceptance_radius = _acceptance_radius;

	if (_param_ra_acc_rad_max.get() >= _param_nav_acc_rad.get()) {
		_acceptance_radius = updateAcceptanceRadius(_waypoint_transition_angle, _param_nav_acc_rad.get(),
				     _param_ra_acc_rad_gain.get(), _param_ra_acc_rad_max.get(), _param_ra_wheel_base.get(), _param_ra_max_str_ang.get());

	} else {
		_acceptance_radius = _param_nav_acc_rad.get();
	}

	// Waypoint cruising speed
	_cruising_speed = position_setpoint_triplet.current.cruising_speed > 0.f ? math::constrain(
				  position_setpoint_triplet.current.cruising_speed, 0.f, _param_ro_speed_limit.get()) : _param_ro_speed_limit.get();
}

float AutoMode::updateAcceptanceRadius(const float waypoint_transition_angle,
				       const float default_acceptance_radius, const float acceptance_radius_gain,
				       const float acceptance_radius_max, const float wheel_base, const float max_steer_angle)
{
	// Calculate acceptance radius s.t. the rover cuts the corner tangential to the current and next line segment
	float acceptance_radius = default_acceptance_radius;

	if (PX4_ISFINITE(_waypoint_transition_angle)) {
		const float theta = waypoint_transition_angle / 2.f;
		const float min_turning_radius = wheel_base / sinf(max_steer_angle);
		const float acceptance_radius_temp = min_turning_radius / tanf(theta);
		const float acceptance_radius_temp_scaled = acceptance_radius_gain *
				acceptance_radius_temp; // Scale geometric ideal acceptance radius to account for kinematic and dynamic effects
		acceptance_radius = math::constrain<float>(acceptance_radius_temp_scaled, default_acceptance_radius,
				    acceptance_radius_max);
	}

	// Publish updated acceptance radius
	position_controller_status_s pos_ctrl_status{};
	pos_ctrl_status.acceptance_radius = acceptance_radius;
	pos_ctrl_status.timestamp = hrt_absolute_time();
	_position_controller_status_pub.publish(pos_ctrl_status);
	return acceptance_radius;
}

float AutoMode::arrivalSpeed(const float cruising_speed, const float miss_speed_min, const float acc_rad,
			     const int curr_wp_type, const float waypoint_transition_angle, const float max_yaw_rate)
{
	if (!PX4_ISFINITE(waypoint_transition_angle)
	    || curr_wp_type == position_setpoint_s::SETPOINT_TYPE_LAND
	    || curr_wp_type == position_setpoint_s::SETPOINT_TYPE_IDLE) {
		return 0.f; // Stop at the waypoint

	} else {
		const float turning_circle = acc_rad * tanf(waypoint_transition_angle / 2.f);
		const float cornering_speed = max_yaw_rate * turning_circle;
		return math::constrain(cornering_speed, miss_speed_min, cruising_speed); // Slow down for cornering
	}
}

float AutoMode::cruisingSpeed(const float cruising_speed, const float miss_speed_min,
			      const float distance_to_prev_wp, const float distance_to_curr_wp, const float acc_rad, const float prev_acc_rad,
			      const float waypoint_transition_angle, const float prev_waypoint_transition_angle, const float max_yaw_rate)
{
	// Catch improper values
	if (miss_speed_min < -FLT_EPSILON  || miss_speed_min > cruising_speed) {
		return cruising_speed;
	}

	// Cornering slow down effect
	if (distance_to_prev_wp <= prev_acc_rad && prev_acc_rad > FLT_EPSILON && PX4_ISFINITE(prev_waypoint_transition_angle)) {
		const float turning_circle = prev_acc_rad * tanf(prev_waypoint_transition_angle / 2.f);
		const float cornering_speed = max_yaw_rate * turning_circle;
		return math::constrain(cornering_speed, miss_speed_min, cruising_speed);

	}

	if (distance_to_curr_wp <= acc_rad && acc_rad > FLT_EPSILON && PX4_ISFINITE(waypoint_transition_angle)) {
		const float turning_circle = acc_rad * tanf(waypoint_transition_angle / 2.f);
		const float cornering_speed = max_yaw_rate * turning_circle;
		return math::constrain(cornering_speed, miss_speed_min, cruising_speed);

	}

	return cruising_speed; // Fallthrough

}