/* PipeWire */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */

#ifndef PIPEWIRE_LINK_H
#define PIPEWIRE_LINK_H

#ifdef __cplusplus
extern "C" {
#endif

#include <spa/utils/defs.h>
#include <spa/utils/hook.h>

#include <pipewire/proxy.h>

/** \defgroup pw_link Link
 *
 * A link is the connection between 2 nodes (\ref pw_node). Nodes are
 * linked together on ports.
 *
 * The link is responsible for negotiating the format and buffers for
 * the nodes.
 *
 */

/**
 * \addtogroup pw_link
 * \{
 */

#define PW_TYPE_INTERFACE_Link	PW_TYPE_INFO_INTERFACE_BASE "Link"

#define PW_LINK_PERM_MASK	PW_PERM_R | PW_PERM_X

#define PW_VERSION_LINK		3
struct pw_link;

#ifndef PW_API_LINK_IMPL
#define PW_API_LINK_IMPL static inline
#endif


/** \enum pw_link_state The different link states */
enum pw_link_state {
	PW_LINK_STATE_ERROR = -2,	/**< the link is in error */
	PW_LINK_STATE_UNLINKED = -1,	/**< the link is unlinked */
	PW_LINK_STATE_INIT = 0,		/**< the link is initialized */
	PW_LINK_STATE_NEGOTIATING = 1,	/**< the link is negotiating formats */
	PW_LINK_STATE_ALLOCATING = 2,	/**< the link is allocating buffers */
	PW_LINK_STATE_PAUSED = 3,	/**< the link is paused */
	PW_LINK_STATE_ACTIVE = 4,	/**< the link is active */
};

/** Convert a \ref pw_link_state to a readable string */
const char * pw_link_state_as_string(enum pw_link_state state);
/** The link information. Extra information can be added in later versions */
struct pw_link_info {
	uint32_t id;			/**< id of the global */
	uint32_t output_node_id;	/**< server side output node id */
	uint32_t output_port_id;	/**< output port id */
	uint32_t input_node_id;		/**< server side input node id */
	uint32_t input_port_id;		/**< input port id */
#define PW_LINK_CHANGE_MASK_STATE	(1 << 0)
#define PW_LINK_CHANGE_MASK_FORMAT	(1 << 1)
#define PW_LINK_CHANGE_MASK_PROPS	(1 << 2)
#define PW_LINK_CHANGE_MASK_ALL		((1 << 3)-1)
	uint64_t change_mask;		/**< bitfield of changed fields since last call */
	enum pw_link_state state;	/**< the current state of the link */
	const char *error;		/**< an error reason if \a state is error */
	struct spa_pod *format;		/**< format over link */
	struct spa_dict *props;		/**< the properties of the link */
};

struct pw_link_info *
pw_link_info_update(struct pw_link_info *info,
		const struct pw_link_info *update);

struct pw_link_info *
pw_link_info_merge(struct pw_link_info *info,
		const struct pw_link_info *update, bool reset);

void
pw_link_info_free(struct pw_link_info *info);


#define PW_LINK_EVENT_INFO	0
#define PW_LINK_EVENT_NUM	1

/** Link events */
struct pw_link_events {
#define PW_VERSION_LINK_EVENTS	0
	uint32_t version;
	/**
	 * Notify link info
	 *
	 * \param info info about the link
	 */
	void (*info) (void *data, const struct pw_link_info *info);
};

#define PW_LINK_METHOD_ADD_LISTENER	0
#define PW_LINK_METHOD_NUM		1

/** Link methods */
struct pw_link_methods {
#define PW_VERSION_LINK_METHODS		0
	uint32_t version;

	int (*add_listener) (void *object,
			struct spa_hook *listener,
			const struct pw_link_events *events,
			void *data);
};

/** \copydoc pw_link_methods.add_listener
 * \sa pw_link_methods.add_listener */
PW_API_LINK_IMPL int pw_link_add_listener(struct pw_link *object,
			struct spa_hook *listener,
			const struct pw_link_events *events,
			void *data)
{
	return spa_api_method_r(int, -ENOTSUP,
			pw_link, (struct spa_interface*)object, add_listener, 0,
			listener, events, data);
}

/**
 * \}
 */

#ifdef __cplusplus
}  /* extern "C" */
#endif

#endif /* PIPEWIRE_LINK_H */
