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/**
 * @file BaseSubscriber.hpp
 *
 * Defines basic functionality of UAVCAN v1 subscriber class
 *
 * @author Jacob Crabill <jacob@flyvoly.com>
 */

#pragma once

#include <px4_platform_common/px4_config.h>

#include <lib/parameters/param.h>

#include "../CanardInterface.hpp"

class UavcanBaseSubscriber
{
public:
	static constexpr uint16_t CANARD_PORT_ID_UNSET = 65535U;
	static constexpr uint16_t CANARD_PORT_ID_MAX   = 32767U;

	UavcanBaseSubscriber(CanardInstance &ins, const char *subject_name, uint8_t instance = 0) :
		_canard_instance(ins), _instance(instance)
	{
		_subj_sub._subject_name = subject_name;
		_subj_sub._canard_sub.user_reference = this;
	}

	~UavcanBaseSubscriber()
	{
		unsubscribe();
	}

	bool isValidPortId(int32_t id) const { return id >= 0 && id <= CANARD_PORT_ID_MAX; }

	virtual void subscribe() = 0;
	virtual void unsubscribe()
	{
		SubjectSubscription *curSubj = &_subj_sub;

		while (curSubj != NULL) {
			canardRxUnsubscribe(&_canard_instance, CanardTransferKindMessage, curSubj->_canard_sub.port_id);
			curSubj = curSubj->next;
		}
	};

	virtual void callback(const CanardTransfer &msg) = 0;

	CanardPortID id(uint32_t instance = 0)
	{
		uint32_t i = 0;
		SubjectSubscription *curSubj = &_subj_sub;

		while (curSubj != NULL) {
			if (instance == i) {
				return curSubj->_canard_sub.port_id;
			}

			curSubj = curSubj->next;
			i++;
		}

		return CANARD_PORT_ID_UNSET; // Wrong id return unset
	}

	bool hasPortID(CanardPortID port_id)
	{
		if (!isValidPortId((int32_t)port_id)) {
			return false;
		}

		SubjectSubscription *curSubj = &_subj_sub;

		while (curSubj != NULL) {
			if (port_id == curSubj->_canard_sub.port_id) {
				return true;
			}

			curSubj = curSubj->next;
		}

		return false;
	}

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

		while (curSubj != NULL) {
			if (curSubj->_canard_sub.port_id != CANARD_PORT_ID_UNSET) {
				PX4_INFO("Subscribed %s.%d on port %d", curSubj->_subject_name, _instance, curSubj->_canard_sub.port_id);
			}

			curSubj = curSubj->next;
		}
	}

protected:
	struct SubjectSubscription {
		CanardRxSubscription _canard_sub;
		const char *_subject_name;
		struct SubjectSubscription *next {NULL};
	};

	CanardInstance &_canard_instance;
	SubjectSubscription _subj_sub;
	uint8_t _instance {0};
	/// TODO: 'type' parameter? uavcan.pub.PORT_NAME.type (see 384.Access.1.0.uavcan)
};
