/*!
 * @file Mw/LowLevel/Wayland.h
 * @brief Wayland Backend
 * @warning This is used internally.
 */
#ifndef __MW_LOWLEVEL_WAYLAND_H__
#define __MW_LOWLEVEL_WAYLAND_H__

#include <Mw/MachDep.h>
#include <Mw/TypeDefs.h>
#include <Mw/LowLevel.h>
#include <Mw/Abstract/Dynamic.h>

#include <Mw/LowLevel/Cairo.h>

#include <xkbcommon/xkbcommon.h>
#include <pthread.h>

#ifdef __cplusplus
extern "C" {
#endif

MWDECL int MwLLWaylandCallInit(void);

#ifdef __cplusplus
}
#endif

#define CSD_BORDER_FRAME_LEFT 5
#define CSD_BORDER_FRAME_RIGHT 5
#define CSD_BORDER_FRAME_TOP 23
#define CSD_BORDER_FRAME_BOTTOM 4

struct _MwLLWayland;

#include <wayland-client-core.h>

#if WAYLAND_LOAD_OPENGL
#include <EGL/egl.h>
#include <wayland-egl-core.h>
#endif

typedef struct wayland_call_table {
	void* lib;
	void* xkb_lib;
#ifdef USE_DBUS
	MwLLDBusFuncTable dbus;
	MwBool		  has_dbus;
#endif

	int (*wl_display_dispatch)(struct wl_display* display);
	int (*wl_display_dispatch_pending)(struct wl_display* display);
	void (*wl_display_disconnect)(struct wl_display* display);
	void (*wl_display_cancel_read)(struct wl_display* display);
	int (*wl_display_prepare_read)(struct wl_display* display);
	int (*wl_display_read_events)(struct wl_display* display);
	int (*wl_display_flush)(struct wl_display* display);
	int (*wl_display_get_fd)(struct wl_display* display);
	int (*wl_display_roundtrip)(struct wl_display* display);
	int (*wl_proxy_add_listener)(struct wl_proxy* proxy, void (**implementation)(void), void* data);
	void (*wl_proxy_destroy)(struct wl_proxy* proxy);
	void (*wl_log_set_handler_client)(wl_log_func_t handler);
	struct wl_proxy* (*wl_proxy_marshal_flags)(struct wl_proxy* proxy, uint32_t opcode,
						   const struct wl_interface* interface,
						   uint32_t		      version,
						   uint32_t		      flags, ...);
	struct wl_display* (*wl_display_connect)(const char* name);
	uint32_t (*wl_proxy_get_version)(struct wl_proxy* proxy);
	struct wl_display* (*wl_display_connect_to_fd)(int fd);
	int (*wl_display_get_error)(struct wl_display* display);

	struct xkb_context* (*xkb_context_new)(enum xkb_context_flags flags);
	void (*xkb_context_unref)(struct xkb_context* context);
	struct xkb_state* (*xkb_state_new)(struct xkb_keymap* keymap);
	void (*xkb_state_unref)(struct xkb_state* state);
	struct xkb_keymap* (*xkb_keymap_new_from_string)(struct xkb_context* context, const char* string, enum xkb_keymap_format format, enum xkb_keymap_compile_flags flags);
	xkb_level_index_t (*xkb_keymap_num_levels_for_key)(struct xkb_keymap* keymap, xkb_keycode_t key, xkb_layout_index_t layout);
	int (*xkb_keymap_key_get_syms_by_level)(struct xkb_keymap* keymap, xkb_keycode_t key, xkb_layout_index_t layout, xkb_level_index_t level, const xkb_keysym_t** syms_out);
	xkb_layout_index_t (*xkb_state_key_get_layout)(struct xkb_state* state, xkb_keycode_t key);
	void (*xkb_keymap_unref)(struct xkb_keymap* keymap);

} wayland_call_table_t;

extern wayland_call_table_t wl_call_tbl;
#ifdef MW_VULKAN
extern MwBool MwWaylandVulkan;
#else
#define MwWaylandVulkan 0
#endif

MWDECL MwBool MwWaylandCairoOnly;

/* defined inline right here so that it doesn't conflict with the other macros */
MwInline int wayland_load_funcs() {
#ifdef __APPLE__
	wl_call_tbl.lib = MwDynamicOpen("libwayland-client.dylib");
#else
	wl_call_tbl.lib = MwDynamicOpen("libwayland-client.so");
#endif
	if(!wl_call_tbl.lib) {
		printf("(libwayland-client not found, falling back to X11)\n");
		return 1;
	}
#ifdef __APPLE__
	wl_call_tbl.xkb_lib = MwDynamicOpen("libxkbcommon.dylib");
#else
	wl_call_tbl.xkb_lib = MwDynamicOpen("libxkbcommon.so");
#endif
	if(!wl_call_tbl.xkb_lib) {
		printf("(libxkbcommon not found, cannot use Wayland backend.)\n");
		return 1;
	}

#define WAYLAND_FUNC(x) \
	wl_call_tbl.x = MwDynamicSymbol(wl_call_tbl.lib, #x); \
	if(!wl_call_tbl.x) { \
		printf("WARNING: Could use Wayland backend if " #x " was found.\n"); \
		return 1; \
	};

	WAYLAND_FUNC(wl_display_dispatch)
	WAYLAND_FUNC(wl_display_dispatch_pending)
	WAYLAND_FUNC(wl_display_disconnect)
	WAYLAND_FUNC(wl_display_cancel_read)
	WAYLAND_FUNC(wl_display_prepare_read)
	WAYLAND_FUNC(wl_display_read_events)
	WAYLAND_FUNC(wl_display_flush)
	WAYLAND_FUNC(wl_display_get_fd)
	WAYLAND_FUNC(wl_display_roundtrip)
	WAYLAND_FUNC(wl_proxy_add_listener)
	WAYLAND_FUNC(wl_proxy_destroy)
	WAYLAND_FUNC(wl_log_set_handler_client)
	WAYLAND_FUNC(wl_proxy_marshal_flags)
	WAYLAND_FUNC(wl_display_connect)
	WAYLAND_FUNC(wl_proxy_get_version)
	WAYLAND_FUNC(wl_display_connect_to_fd)
	WAYLAND_FUNC(wl_display_get_error)

#undef WAYLAND_FUNC

#define XKB_FUNC(x) \
	wl_call_tbl.x = MwDynamicSymbol(wl_call_tbl.xkb_lib, #x); \
	if(!wl_call_tbl.x) { \
		printf("WARNING: Could use Wayland backend if " #x " was found. Do you have libxkbcommon?\n"); \
		return 1; \
	};

	XKB_FUNC(xkb_state_unref)
	XKB_FUNC(xkb_context_new)
	XKB_FUNC(xkb_context_unref)
	XKB_FUNC(xkb_state_new)
	XKB_FUNC(xkb_keymap_new_from_string)
	XKB_FUNC(xkb_keymap_unref)
	XKB_FUNC(xkb_keymap_num_levels_for_key)
	XKB_FUNC(xkb_keymap_key_get_syms_by_level)
	XKB_FUNC(xkb_state_key_get_layout)
#undef XKB_FUNC

	if(cairo_load_funcs() != 0) {
		return 1;
	}

#ifdef USE_DBUS
	wl_call_tbl.has_dbus = MwLLDBusFuncSetup(&wl_call_tbl.dbus);
#endif

	return 0;
}

#define wl_display_dispatch wl_call_tbl.wl_display_dispatch
#define wl_display_dispatch_pending wl_call_tbl.wl_display_dispatch_pending
#define wl_display_disconnect wl_call_tbl.wl_display_disconnect
#define wl_display_cancel_read wl_call_tbl.wl_display_cancel_read
#define wl_display_prepare_read wl_call_tbl.wl_display_prepare_read
#define wl_display_read_events wl_call_tbl.wl_display_read_events
#define wl_display_flush wl_call_tbl.wl_display_flush
#define wl_display_get_fd wl_call_tbl.wl_display_get_fd
#define wl_display_roundtrip wl_call_tbl.wl_display_roundtrip
#define wl_proxy_add_listener wl_call_tbl.wl_proxy_add_listener
#define wl_proxy_destroy wl_call_tbl.wl_proxy_destroy
#define wl_log_set_handler_client wl_call_tbl.wl_log_set_handler_client
#define wl_proxy_marshal_flags wl_call_tbl.wl_proxy_marshal_flags
#define wl_display_connect wl_call_tbl.wl_display_connect
#define wl_proxy_get_version wl_call_tbl.wl_proxy_get_version
#define wl_display_connect_to_fd wl_call_tbl.wl_display_connect_to_fd
#define wl_display_get_error wl_call_tbl.wl_display_get_error

#define xkb_state_unref wl_call_tbl.xkb_state_unref
#define xkb_context_new wl_call_tbl.xkb_context_new
#define xkb_context_unref wl_call_tbl.xkb_context_unref
#define xkb_state_new wl_call_tbl.xkb_state_new
#define xkb_keymap_new_from_string wl_call_tbl.xkb_keymap_new_from_string
#define xkb_keymap_unref wl_call_tbl.xkb_keymap_unref
#define xkb_keymap_num_levels_for_key wl_call_tbl.xkb_keymap_num_levels_for_key
#define xkb_keymap_key_get_syms_by_level wl_call_tbl.xkb_keymap_key_get_syms_by_level
#define xkb_state_key_get_layout wl_call_tbl.xkb_state_key_get_layout

#ifndef WL_PROTOCOLS_DEFINED
#define WL_PROTOCOLS_DEFINED
#include "Wayland/wayland-core-protocol.h"
#include "Wayland/xdg-shell-client-protocol.h"
#include "Wayland/viewporter-client-protocol.h"
#include "Wayland/xdg-decoration-client-protocol.h"
#include "Wayland/cursor-shape-client-protocol.h"
#include "Wayland/primary-selection-client-protocol.h"
#include "Wayland/pointer-constraints-client-protocol.h"
#include "Wayland/relative-pointer-client-protocol.h"
#include "Wayland/xdg-toplevel-icon-client-protocol.h"
#include "Wayland/wlr-layer-shell-client-protocol.h"
#endif

typedef struct wayland_protocol {
	void* listener;
	void* context;
} wayland_protocol_t;

typedef wayland_protocol_t*(wl_setup_func)(MwU32, struct _MwLLWayland*, MwU32 version);
typedef void(wl_destroy_func)(struct _MwLLWayland* wayland, wayland_protocol_t* data);

typedef struct wayland_protocol_callback_table {
	wl_setup_func*	 setup;
	wl_destroy_func* destroy;
} wayland_protocol_callback_table_t;

struct _MwLLWaylandTopLevel {
	struct xdg_surface*	     xdg_surface;
	struct xdg_toplevel*	     xdg_top_level;
	struct xdg_toplevel_listener xdg_toplevel_listener;
	struct xdg_surface_listener  xdg_surface_listener;
	MwBool			     maxim_state;

	MwBool compositor_created;
	MwBool xdg_wm_base_created;
	MwBool xdg_surface_created;

	struct wl_subsurface*	 ssurface;
	struct wl_subcompositor* scompositor;
};

struct _MwLLWaylandSublevel {
	struct wl_subsurface*	 subsurface;
	struct wl_subcompositor* subcompositor;

	MwLL parent;

	struct xdg_surface* xdg_surface;
};

struct _MwLLWaylandPopup {
	struct xdg_surface*	    xdg_surface;
	struct xdg_popup*	    xdg_popup;
	struct xdg_positioner*	    xdg_positioner;
	struct xdg_surface_listener xdg_surface_listener;
	struct xdg_wm_base*	    xdg_wm_base;
	MwLL			    topmost_parent;
};

struct _MwLLWaylandLayerSurface {
	struct zwlr_layer_surface_v1* surface;
};

/* Shared set of anything needed for a shm buffer.  */
struct _MwLLWaylandShmBuffer {
	struct wl_shm*	    shm;
	struct wl_shm_pool* shm_pool;
	struct wl_buffer*   shm_buffer;
	struct wl_shm_pool* shm_pool_back;
	struct wl_buffer*   shm_buffer_back;
	struct wl_surface*  surface;
	struct wl_output*   output;

	MwU8*  buf;
	MwU8*  buf_back;
	MwU64  buf_size;
	int    fd;
	int    fd_back;
	MwBool setup;
};

enum _MwLLWaylandType {
	MwLL_WAYLAND_UNKNOWN = 0,
	MwLL_WAYLAND_TOPLEVEL,
	MwLL_WAYLAND_SUBLEVEL,
	MwLL_WAYLAND_POPUP,
	MwLL_WAYLAND_LAYER_SURFACE,
};

typedef struct wl_clipboard_device_context {
	struct {
		struct wl_data_device*			wl;
		struct zwp_primary_selection_device_v1* zwp;
	} device;
	struct {
		struct wl_data_offer*		       wl;
		struct zwp_primary_selection_offer_v1* zwp;
	} offer;

	MwLL ll;
	// struct wl_seat* seat;
} wl_clipboard_device_context_t;

struct _MwLLWayland {
	struct _MwLLCommon common;
	struct _MwLLCairo  cairo;

	union {
		/* Pointer for data that's only loaded if the widget is a toplevel */
		struct _MwLLWaylandTopLevel* toplevel;
		/* Pointer for data that's only loaded if the widget is a sublevel */
		struct _MwLLWaylandSublevel* sublevel;
		/* Pointer for data that's only loaded if the widget is a popup */
		struct _MwLLWaylandPopup* popup;
		/* Pointer for data that's only loaded if the widget is a layer surface */
		struct _MwLLWaylandLayerSurface* layer_surface;
	};

	enum _MwLLWaylandType type;
	enum _MwLLWaylandType type_to_be;

	MwRect clipping_rect;
	MwBool no;

	MwBool	changing;
	MwBool	detatching;
	MwPoint detach_point;

	MwBool did_initial_resize;

	MwBool is_toplevel;

	MwBool is_clipping;
	MwRect clip;

	/* Map of Wayland interfaces to their relevant setup functions. */
	struct {
		char*				   key;
		wayland_protocol_callback_table_t* value;
	}* wl_protocol_setup_map;

	/* Map of Wayland interfaces to any information we keep about them once we've registered them. */
	struct {
		char*		    key;
		wayland_protocol_t* value;
	}* wl_protocol_map;

	MwBool do_csd;
	MwBool has_decorations;
	char   title[256];

	struct xkb_context* xkb_context;
	struct xkb_keymap*  xkb_keymap;
	struct xkb_state*   xkb_state;

	struct wl_display*	    display;
	struct wl_registry*	    registry;
	struct wl_compositor*	    compositor;
	struct wl_registry_listener registry_listener;
	struct wl_region*	    o_region;
	struct wl_region*	    region;
	struct wl_output*	    output;

	struct wp_viewport* vp;

	MwBool					do_lock_pointer;
	struct zwp_pointer_constraints_v1*	pointer_constraints;
	struct zwp_relative_pointer_manager_v1* relative_pointer_manager;
	struct zwp_relative_pointer_v1*		relative_pointer;
	struct zwp_locked_pointer_v1*		locked_pointer;
	MwBool					pointer_constrained;
	MwBool					valid;

#ifdef USE_DBUS
	MwLLDBusContext dbus;
#endif

	MwBool dark_theme_detection;
	MwU32  dark_theme;

	/* clipboard related stuff.
	 * Note that unlike most interfaces, we don't keep zwp_primary_selection stuff in a wayland_protocol_t because we use wl_data_device as a fallback and want to have it share memory space.*/

	struct {
		struct wl_data_device_manager*			wl;
		struct zwp_primary_selection_device_manager_v1* zwp;
	} clipboard_manager;
	union {
		struct wl_data_source*			wl;
		struct zwp_primary_selection_source_v1* zwp;
	} clipboard_source;
	char*  clipboard_buffer;
	MwBool supports_zwp;
	MwBool zwp_setup;

	uint32_t			clipboard_serial;
	wl_clipboard_device_context_t** clipboard_devices_wl;
	wl_clipboard_device_context_t** clipboard_devices_zwp;

	struct wl_pointer* pointer;
	MwU32		   pointer_serial;
	struct wl_seat*	   pointer_seat;

	struct wl_keyboard* keyboard;
	MwU32		    keyboard_serial;

	MwU64 events_pending;

	MwU32 mod_state;

	MwBool configured; /* Whether or not xdg_toplevel_configure has run once */

	MwBool held_down;

	MwI32	x, y;
	MwI32	ox, oy;
	MwU32	ww, wh;	       /* Window position */
	MwPoint cur_mouse_pos; /* Currently known mouse position */
	MwLL	currentlyHeldWidget;
	MwLL	focusedWidget;

	int resizing;
	int setting_wh;

	MwU32 mw, mh; /* Monitor width and height as advertised by wl_output.mode */

	MwLL parent;

	MwBool force_render;
	MwBool did_event_loop_early;

	MwBool dispatching_resize;

	MwBool is_toplevel_menu;

	struct _MwLLWaylandShmBuffer  framebuffer;
	struct _MwLLWaylandShmBuffer  backbuffer;
	struct _MwLLWaylandShmBuffer  cursor;
	struct _MwLLWaylandShmBuffer* icon;

	MwLLPixmap icon_pixmap;

	pthread_mutex_t eventsMutex;

	int cancelEvent;
	int numCallbacksRunning;

	uint32_t last_time;

	MwBool moving;

	MwI64  keyboard_rate;
	MwI32  keyboard_delay;
	int    last_pressed_key;
	MwBool holding_key;
	MwU64  next_elapsed;
	long   start_time;
	long   end_time;
};

struct _MwLLWaylandColor {
	struct _MwLLCommonColor common;
};

#define _MwLLWaylandPixmap _MwLLCairoPixmap

/* Setup the framebuffer with the saved width/height */
void MwLLWaylandFramebufferSetup(struct _MwLLWayland* wayland);
/* Destroy the framebuffer */
void MwLLWaylandFramebufferDestroy(struct _MwLLWayland* handle);

/* Setup the framebuffer with the saved width/height */
void MwLLWaylandBackbufferSetup(struct _MwLLWayland* wayland);
/* Destroy the backbuffer */
void MwLLWaylandBackbufferDestroy(struct _MwLLWayland* handle);

void MwLLWaylandBufferSetup(struct _MwLLWaylandShmBuffer* buffer, MwU32 width, MwU32 height);
void MwLLWaylandBufferUpdate(MwLL self, struct _MwLLWaylandShmBuffer* buffer);
void MwLLWaylandBufferDestroy(struct _MwLLWaylandShmBuffer* buffer);

void MwLLWaylandRegionSetup(MwLL handle);
void MwLLWaylandRegionInvalidate(MwLL handle);

void MwLLWaylandHangUntilConfigured(MwLL handle);

MwBool MwLLWaylandWidgetIsDestroyed(MwLL self);
void   MwLLWaylandWidgetUndestroy(MwLL self);

/* Function for setting up the callbacks/structs that will be registered upon the relevant interfaces being found. */
void MwLLWaylandSetupCallbacks(struct _MwLLWayland* wayland);

void MwLLWaylandClipboardRead(wl_clipboard_device_context_t* ctx, int clipboard_type);

/* Flush Wayland events */
void MwLLWaylandFlush(MwLL handle);

/* Standard procedure before event callbacks in Wayland  */
#define WAYLAND_EVENT_OP_START(self) \
	if(MwLLWaylandWidgetIsDestroyed(self)) { \
		return; \
	}

/* Footer for WAYLAND_EVENT_OP_START */
#define WAYLAND_EVENT_OP_END(self)

#define WIDGET_CHECK(handle) \
	if(!handle->wayland.valid) { \
		return; \
	}

/* the two decoration manager constructs */
typedef struct zxdg_decoration_manager_v1_context {
	struct zxdg_decoration_manager_v1*  manager;
	struct zxdg_toplevel_decoration_v1* decoration;
} zxdg_decoration_manager_v1_context_t;

extern struct zwp_relative_pointer_v1_listener MwLLWaylandRelativePointerListener;

#endif