#pragma once

#include <stdint.h>
#include "error.h"

/* Opaque handle — defined in media_ctrl.c */
struct Media_Ctrl;

struct Media_Device_Info {
	char     driver[16];
	char     model[32];
	char     serial[40];
	char     bus_info[32];
	uint32_t media_version;
	uint32_t hw_revision;
	uint32_t driver_version;
};

struct Media_Entity {
	uint32_t id;
	char     name[32];
	uint32_t type;       /* MEDIA_ENT_F_* value from kernel */
	uint32_t flags;
	uint16_t pad_count;
	uint16_t link_count;
	uint32_t dev_major;  /* associated device node major, 0 if none */
	uint32_t dev_minor;
};

struct Media_Pad {
	uint32_t entity_id;
	uint16_t index;
	uint32_t flags;      /* MEDIA_PAD_FL_SINK / MEDIA_PAD_FL_SOURCE */
};

/* Link flags for Media_Link.flags */
#define MEDIA_LINK_FL_ENABLED    (1u << 0)
#define MEDIA_LINK_FL_IMMUTABLE  (1u << 1)
#define MEDIA_LINK_FL_DYNAMIC    (1u << 2)

/* Pad flags for Media_Pad.flags */
#define MEDIA_PAD_FLAG_SINK    (1u << 0)
#define MEDIA_PAD_FLAG_SOURCE  (1u << 1)

struct Media_Link {
	struct Media_Pad source;
	struct Media_Pad sink;
	uint32_t         flags;
};

/*
 * Enumerate all /dev/media* device nodes present on the system.
 * Calls callback once per device path found.
 */
struct App_Error media_ctrl_find_devices(
	void (*callback)(const char *device_path, void *userdata),
	void *userdata);

struct App_Error media_ctrl_open(const char *device_path, struct Media_Ctrl **out);
void            media_ctrl_close(struct Media_Ctrl *ctrl);

struct App_Error media_ctrl_get_info(
	struct Media_Ctrl *ctrl,
	struct Media_Device_Info *out);

/*
 * Enumerate all entities in the media graph.
 */
struct App_Error media_ctrl_enum_entities(
	struct Media_Ctrl *ctrl,
	void (*callback)(const struct Media_Entity *entity, void *userdata),
	void *userdata);

/*
 * Enumerate pads and links for a specific entity.
 * Pass the entity struct obtained from media_ctrl_enum_entities —
 * the pad and link counts are taken from it.
 * Either callback may be NULL if that information is not needed.
 */
struct App_Error media_ctrl_enum_entity_pads_and_links(
	struct Media_Ctrl *ctrl,
	const struct Media_Entity *entity,
	void (*pad_callback)(const struct Media_Pad *pad, void *userdata),
	void (*link_callback)(const struct Media_Link *link, void *userdata),
	void *userdata);

/*
 * Enable or disable a link between two pads.
 * Immutable links cannot be changed and will return an error.
 */
struct App_Error media_ctrl_set_link(
	struct Media_Ctrl *ctrl,
	uint32_t source_entity_id, uint16_t source_pad_index,
	uint32_t sink_entity_id,   uint16_t sink_pad_index,
	int enabled);

/* Human-readable names for display */
const char *media_entity_type_name(uint32_t type);
const char *media_pad_flag_name(uint32_t flags);