/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/windowmanager/message_bus/wm_message_bus.h
 *  \ingroup wm
 */

#ifndef __WM_MESSAGE_BUS_H__
#define __WM_MESSAGE_BUS_H__

#include <stdio.h>

struct GSet;
struct ID;
struct bContext;
struct wmMsg;

/* opaque (don't expose outside wm_message_bus.c) */
struct wmMsgBus;
struct wmMsgSubscribeKey;
struct wmMsgSubscribeValue;
struct wmMsgSubscribeValueLink;

typedef void (*wmMsgNotifyFn)(
        struct bContext *C, struct wmMsgSubscribeKey *msg_key, struct wmMsgSubscribeValue *msg_val);
typedef void (*wmMsgSubscribeValueFreeDataFn)(
        struct wmMsgSubscribeKey *msg_key, struct wmMsgSubscribeValue *msg_val);

/* Exactly what arguments here is not obvious. */
typedef void (*wmMsgSubscribeValueUpdateIdFn)(
        struct bContext *C,
        struct wmMsgBus *mbus,
        struct ID *id_src, struct ID *id_dst,
        struct wmMsgSubscribeValue *msg_val);
enum {
	WM_MSG_TYPE_RNA = 0,
	WM_MSG_TYPE_STATIC = 1,
};
#define WM_MSG_TYPE_NUM 2

typedef struct wmMsgTypeInfo {
	struct {
		unsigned int (*hash_fn)(const void *msg);
		bool         (*cmp_fn)(const void *a, const void *b);
		void         (*key_free_fn)(void *key);
	} gset;

	void (*update_by_id)(struct wmMsgBus *mbus, struct ID *id_src, struct ID *id_dst);
	void (*remove_by_id)(struct wmMsgBus *mbus, const struct ID *id);
	void (*repr)(FILE *stream, const struct wmMsgSubscribeKey *msg_key);

	/* sizeof(wmMsgSubscribeKey_*) */
	uint msg_key_size;
} wmMsgTypeInfo;

typedef struct wmMsg {
	unsigned int type;
// #ifdef DEBUG
	/* For debugging: '__func__:__LINE__'. */
	const char *id;
// #endif
} wmMsg;

typedef struct wmMsgSubscribeKey {
	/** Linked list for predicable ordering, otherwise we would depend on ghash bucketing. */
	struct wmMsgSubscribeKey *next, *prev;
	ListBase values;
	/* over-alloc, eg: wmMsgSubscribeKey_RNA */
	/* Last member will be 'wmMsg_*' */
} wmMsgSubscribeKey;

/** One of many in #wmMsgSubscribeKey.values */
typedef struct wmMsgSubscribeValue {
	struct wmMsgSubscribe *next, *prev;

	/** Handle, used to iterate and clear. */
	void *owner;
	/** User data, can be whatever we like, free using the 'free_data' callback if it's owned. */
	void *user_data;

	/** Callbacks */
	wmMsgNotifyFn notify;
	wmMsgSubscribeValueUpdateIdFn update_id;
	wmMsgSubscribeValueFreeDataFn free_data;

	/** Keep this subscriber if possible. */
	uint is_persistent : 1;
	/* tag to run when handling events,
	 * we may want option for immediate execution. */
	uint tag : 1;
} wmMsgSubscribeValue;

/** One of many in #wmMsgSubscribeKey.values */
typedef struct wmMsgSubscribeValueLink {
	struct wmMsgSubscribeValueLink *next, *prev;
	wmMsgSubscribeValue params;
} wmMsgSubscribeValueLink;

void WM_msgbus_types_init(void);

struct wmMsgBus *WM_msgbus_create(void);
void             WM_msgbus_destroy(struct wmMsgBus *mbus);

void WM_msgbus_clear_by_owner(struct wmMsgBus *mbus, void *owner);

void WM_msg_dump(struct wmMsgBus *mbus, const char *info);
void WM_msgbus_handle(struct wmMsgBus *mbus, struct bContext *C);

void WM_msg_publish_with_key(struct wmMsgBus *mbus, wmMsgSubscribeKey *msg_key);
wmMsgSubscribeKey *WM_msg_subscribe_with_key(
        struct wmMsgBus *mbus,
        const wmMsgSubscribeKey *msg_key_test,
        const wmMsgSubscribeValue *msg_val_params);

void WM_msg_id_update(
        struct wmMsgBus *mbus,
        struct ID *id_src, struct ID *id_dst);
void WM_msg_id_remove(struct wmMsgBus *mbus, const struct ID *id);

/* -------------------------------------------------------------------------- */
/* wm_message_bus_static.c */

enum {
	/* generic window redraw */
	WM_MSG_STATICTYPE_WINDOW_DRAW = 0,
	WM_MSG_STATICTYPE_SCREEN_EDIT = 1,
	WM_MSG_STATICTYPE_FILE_READ = 2,
};

typedef struct wmMsgParams_Static {
	int event;
} wmMsgParams_Static;

typedef struct wmMsg_Static {
	wmMsg head;  /* keep first */
	wmMsgParams_Static params;
} wmMsg_Static;

typedef struct wmMsgSubscribeKey_Static {
	wmMsgSubscribeKey head;
	wmMsg_Static msg;
} wmMsgSubscribeKey_Static;

void WM_msgtypeinfo_init_static(wmMsgTypeInfo *msg_type);

wmMsgSubscribeKey_Static *WM_msg_lookup_static(
        struct wmMsgBus *mbus, const wmMsgParams_Static *msg_key_params);
void WM_msg_publish_static_params(
        struct wmMsgBus *mbus,
        const wmMsgParams_Static *msg_key_params);
void WM_msg_publish_static(
        struct wmMsgBus *mbus,
        /* wmMsgParams_Static (expanded) */
        int event);
void WM_msg_subscribe_static_params(
        struct wmMsgBus *mbus,
        const wmMsgParams_Static *msg_key_params,
        const wmMsgSubscribeValue *msg_val_params,
        const char *id_repr);
void WM_msg_subscribe_static(
        struct wmMsgBus *mbus,
        int event,
        const wmMsgSubscribeValue *msg_val_params,
        const char *id_repr);

/* -------------------------------------------------------------------------- */
/* wm_message_bus_rna.c */

typedef struct wmMsgParams_RNA {
	/** when #PointerRNA.data & id.data are NULL. match against all. */
	PointerRNA ptr;
	/** when NULL, match against any property. */
	const PropertyRNA *prop;

	/**
	 * Optional RNA data path for persistent RNA properties, ignore if NULL.
	 * otherwise it's allocated.
	 */
	char *data_path;
} wmMsgParams_RNA;

typedef struct wmMsg_RNA {
	wmMsg head;  /* keep first */
	wmMsgParams_RNA params;
} wmMsg_RNA;

typedef struct wmMsgSubscribeKey_RNA {
	wmMsgSubscribeKey head;
	wmMsg_RNA msg;
} wmMsgSubscribeKey_RNA;

#ifdef __GNUC__
#define _WM_MESSAGE_EXTERN_BEGIN \
	_Pragma("GCC diagnostic push"); \
	_Pragma("GCC diagnostic ignored \"-Wredundant-decls\"");
#define _WM_MESSAGE_EXTERN_END \
	_Pragma("GCC diagnostic pop");
#else
#define _WM_MESSAGE_EXTERN_BEGIN
#define _WM_MESSAGE_EXTERN_END
#endif

void WM_msgtypeinfo_init_rna(wmMsgTypeInfo *msg_type);

wmMsgSubscribeKey_RNA *WM_msg_lookup_rna(
        struct wmMsgBus *mbus, const wmMsgParams_RNA *msg_key_params);
void WM_msg_publish_rna_params(
        struct wmMsgBus *mbus, const wmMsgParams_RNA *msg_key_params);
void WM_msg_publish_rna(
        struct wmMsgBus *mbus,
        /* wmMsgParams_RNA (expanded) */
        PointerRNA *ptr, PropertyRNA *prop);
void WM_msg_subscribe_rna_params(
        struct wmMsgBus *mbus,
        const wmMsgParams_RNA *msg_key_params,
        const wmMsgSubscribeValue *msg_val_params,
        const char *id_repr);
void WM_msg_subscribe_rna(
        struct wmMsgBus *mbus,
        PointerRNA *ptr, const PropertyRNA *prop,
        const wmMsgSubscribeValue *msg_val_params,
        const char *id_repr);

/* ID variants */
void WM_msg_subscribe_ID(
        struct wmMsgBus *mbus, struct ID *id, const wmMsgSubscribeValue *msg_val_params,
        const char *id_repr);
void WM_msg_publish_ID(
        struct wmMsgBus *mbus, struct ID *id);

#define WM_msg_publish_rna_prop(mbus, id_, data_, type_, prop_) { \
	 wmMsgParams_RNA msg_key_params_ = {{{0}}}; \
	_WM_MESSAGE_EXTERN_BEGIN; \
	extern PropertyRNA rna_##type_##_##prop_; \
	_WM_MESSAGE_EXTERN_END; \
	RNA_pointer_create(id_, &RNA_##type_, data_, &msg_key_params_.ptr); \
	msg_key_params_.prop = &rna_##type_##_##prop_; \
	WM_msg_publish_rna_params(mbus, &msg_key_params_); \
} ((void)0)
#define WM_msg_subscribe_rna_prop(mbus, id_, data_, type_, prop_, value) { \
	wmMsgParams_RNA msg_key_params_ = {{{0}}}; \
	_WM_MESSAGE_EXTERN_BEGIN; \
	extern PropertyRNA rna_##type_##_##prop_; \
	_WM_MESSAGE_EXTERN_END; \
	RNA_pointer_create(id_, &RNA_##type_, data_, &msg_key_params_.ptr); \
	msg_key_params_.prop = &rna_##type_##_##prop_; \
	WM_msg_subscribe_rna_params(mbus, &msg_key_params_, value, __func__); \
} ((void)0)

/* Anonymous variants (for convenience) */
#define WM_msg_subscribe_rna_anon_type(mbus, type_, value) { \
	WM_msg_subscribe_rna_params( \
	        mbus, \
	        &(const wmMsgParams_RNA){ \
	            .ptr = (PointerRNA){.type = &RNA_##type_}, \
	            .prop = NULL, \
	        }, \
	        value, __func__); \
} ((void)0)
#define WM_msg_subscribe_rna_anon_prop(mbus, type_, prop_, value) { \
	_WM_MESSAGE_EXTERN_BEGIN; \
	extern PropertyRNA rna_##type_##_##prop_; \
	_WM_MESSAGE_EXTERN_END; \
	WM_msg_subscribe_rna_params( \
	        mbus, \
	        &(const wmMsgParams_RNA){ \
	            .ptr = (PointerRNA){.type = &RNA_##type_}, \
	            .prop = &rna_##type_##_##prop_, \
	        }, \
	        value, __func__); \
} ((void)0)

#endif /* __WM_MESSAGE_BUS_H__ */