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/**
 * @file loiter.cpp
 *
 * Helper class to loiter
 *
 * @author Julian Oes <julian@oes.ch>
 * @author Anton Babushkin <anton.babushkin@me.com>
 */

#include "loiter.h"
#include "navigator.h"

Loiter::Loiter(Navigator *navigator) :
	MissionBlock(navigator),
	ModuleParams(navigator)
{
}

void
Loiter::on_inactive()
{
	_loiter_pos_set = false;
}

void
Loiter::on_activation()
{
	if (_navigator->get_reposition_triplet()->current.valid) {
		reposition();

	} else {
		set_loiter_position();
	}
}

void
Loiter::on_active()
{
	if (_navigator->get_reposition_triplet()->current.valid) {
		reposition();
	}

	// reset the loiter position if we get disarmed
	if (_navigator->get_vstatus()->arming_state != vehicle_status_s::ARMING_STATE_ARMED) {
		_loiter_pos_set = false;
	}
}

void
Loiter::set_loiter_position()
{
	if (_navigator->get_vstatus()->arming_state != vehicle_status_s::ARMING_STATE_ARMED &&
	    _navigator->get_land_detected()->landed) {

		// Not setting loiter position if disarmed and landed, instead mark the current
		// setpoint as invalid and idle (both, just to be sure).

		_navigator->set_can_loiter_at_sp(false);
		_navigator->get_position_setpoint_triplet()->current.type = position_setpoint_s::SETPOINT_TYPE_IDLE;
		_navigator->set_position_setpoint_triplet_updated();
		_loiter_pos_set = false;
		return;

	} else if (_loiter_pos_set) {
		// Already set, nothing to do.
		return;
	}

	_loiter_pos_set = true;

	// set current mission item to loiter
	set_loiter_item(&_mission_item, _navigator->get_loiter_min_alt());

	// convert mission item to current setpoint
	struct position_setpoint_triplet_s *pos_sp_triplet = _navigator->get_position_setpoint_triplet();
	pos_sp_triplet->current.velocity_valid = false;
	pos_sp_triplet->previous.valid = false;
	mission_apply_limitation(_mission_item);
	mission_item_to_position_setpoint(_mission_item, &pos_sp_triplet->current);
	pos_sp_triplet->next.valid = false;

	_navigator->set_can_loiter_at_sp(pos_sp_triplet->current.type == position_setpoint_s::SETPOINT_TYPE_LOITER);

	_navigator->set_position_setpoint_triplet_updated();
}

void
Loiter::reposition()
{
	// we can't reposition if we are not armed yet
	if (_navigator->get_vstatus()->arming_state != vehicle_status_s::ARMING_STATE_ARMED) {
		return;
	}

	struct position_setpoint_triplet_s *rep = _navigator->get_reposition_triplet();

	if (rep->current.valid) {
		// set loiter position based on reposition command

		// convert mission item to current setpoint
		struct position_setpoint_triplet_s *pos_sp_triplet = _navigator->get_position_setpoint_triplet();
		pos_sp_triplet->current.velocity_valid = false;
		pos_sp_triplet->previous.yaw = _navigator->get_global_position()->yaw;
		pos_sp_triplet->previous.lat = _navigator->get_global_position()->lat;
		pos_sp_triplet->previous.lon = _navigator->get_global_position()->lon;
		pos_sp_triplet->previous.alt = _navigator->get_global_position()->alt;
		memcpy(&pos_sp_triplet->current, &rep->current, sizeof(rep->current));
		pos_sp_triplet->next.valid = false;

		// set yaw (depends on the value of parameter MIS_YAWMODE):
		// MISSION_YAWMODE_NONE: do not change yaw setpoint
		// MISSION_YAWMODE_FRONT_TO_WAYPOINT: point to next waypoint
		if (_param_yawmode.get() != MISSION_YAWMODE_NONE) {
			float travel_dist = get_distance_to_next_waypoint(_navigator->get_global_position()->lat,
					    _navigator->get_global_position()->lon,
					    pos_sp_triplet->current.lat, pos_sp_triplet->current.lon);

			if (travel_dist > 1.0f) {
				// calculate direction the vehicle should point to.
				pos_sp_triplet->current.yaw = get_bearing_to_next_waypoint(
								      _navigator->get_global_position()->lat,
								      _navigator->get_global_position()->lon,
								      pos_sp_triplet->current.lat,
								      pos_sp_triplet->current.lon);
			}
		}

		_navigator->set_can_loiter_at_sp(pos_sp_triplet->current.type == position_setpoint_s::SETPOINT_TYPE_LOITER);

		_navigator->set_position_setpoint_triplet_updated();

		// mark this as done
		memset(rep, 0, sizeof(*rep));
	}
}
