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/**
 * @file mavlink_orb_subscription.h
 * uORB subscription definition.
 *
 * @author Anton Babushkin <anton.babushkin@me.com>
 */

#ifndef MAVLINK_ORB_SUBSCRIPTION_H_
#define MAVLINK_ORB_SUBSCRIPTION_H_

#include <systemlib/uthash/utlist.h>
#include <drivers/drv_hrt.h>


class MavlinkOrbSubscription
{
public:
	MavlinkOrbSubscription *next;	/*< pointer to next subscription in list */

	MavlinkOrbSubscription(const orb_id_t topic);
	~MavlinkOrbSubscription();

	bool update(const hrt_abstime t);

	/**
	 * Check if the topic has been published.
	 *
	 * This call will return true if the topic was ever published.
	 * @return true if the topic has been published at least once.
	 */
	bool is_published();
	void *get_data();
	orb_id_t get_topic();

private:
	const orb_id_t _topic;		/*< topic metadata */
	int _fd;					/*< subscription handle */
	bool _published;			/*< topic was ever published */
	void *_data;				/*< pointer to data buffer */
	hrt_abstime _last_check;	/*< time of last check */
	bool _updated;				/*< updated on last check */
};


#endif /* MAVLINK_ORB_SUBSCRIPTION_H_ */