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/**
 * @file DynamicPortSubscriber.hpp
 *
 * Defines basic functionality of UAVCAN v1 subscriber class with Non-fixed unregulated port identifier
 *
 * @author Jacob Crabill <jacob@flyvoly.com>
 */

#pragma once

#include <px4_platform_common/px4_config.h>

#include <lib/parameters/param.h>

#include <uavcan/_register/Access_1_0.h>

#include "../CanardInterface.hpp"
#include "../ParamManager.hpp"
#include "BaseSubscriber.hpp"

class UavcanDynamicPortSubscriber : public UavcanBaseSubscriber
{
public:
	UavcanDynamicPortSubscriber(CanardInstance &ins, UavcanParamManager &pmgr, const char *subject_name,
				    uint8_t instance = 0) :
		UavcanBaseSubscriber(ins, subject_name, instance), _param_manager(pmgr) { };

	void updateParam()
	{
		SubjectSubscription *curSubj = &_subj_sub;

		while (curSubj != NULL) {
			char uavcan_param[90];
			snprintf(uavcan_param, sizeof(uavcan_param), "uavcan.sub.%s.%d.id", curSubj->_subject_name, _instance);

			// Set _port_id from _uavcan_param
			uavcan_register_Value_1_0 value;

			if (_param_manager.GetParamByName(uavcan_param, value)) {
				int32_t new_id = value.integer32.value.elements[0];

				// Allow, for example, a default PX4 param value of '-1' to disable subscription
				if (!isValidPortId(new_id)) {
					// but always use the standard 'unset' value for comparison
					new_id = CANARD_PORT_ID_UNSET;
				}

				/* FIXME how about partial subscribing */
				if (curSubj->_canard_sub.port_id != new_id) {
					if (new_id == CANARD_PORT_ID_UNSET) {
						// Cancel subscription
						unsubscribe();

					} else {
						if (curSubj->_canard_sub.port_id != CANARD_PORT_ID_UNSET) {
							// Already active; unsubscribe first
							unsubscribe();
						}

						// Subscribe on the new port ID
						curSubj->_canard_sub.port_id = (CanardPortID)new_id;
						PX4_INFO("Subscribing %s.%d on port %d", curSubj->_subject_name, _instance, curSubj->_canard_sub.port_id);
						subscribe();
					}
				}
			}

			curSubj = curSubj->next;
		}
	};

	UavcanDynamicPortSubscriber *next()
	{
		return _next_sub;
	}

	void setNext(UavcanDynamicPortSubscriber *next)
	{
		_next_sub = next;
	}

protected:
	UavcanParamManager &_param_manager;
	UavcanDynamicPortSubscriber *_next_sub {NULL};
};
