/*************************************************************************/
/*  display_server_javascript.h                                          */
/*************************************************************************/
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/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
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#ifndef DISPLAY_SERVER_JAVASCRIPT_H
#define DISPLAY_SERVER_JAVASCRIPT_H

#include "servers/display_server.h"

#include <emscripten.h>
#include <emscripten/html5.h>

class DisplayServerJavaScript : public DisplayServer {
	//int video_driver_index;

	Vector2 windowed_size;

	ObjectID window_attached_instance_id = {};

	Ref<InputEventKey> deferred_key_event;
	CursorShape cursor_shape = CURSOR_ARROW;
	String cursors[CURSOR_MAX];
	Map<CursorShape, Vector<Variant>> cursors_cache;
	Point2 touches[32];

	Point2i last_click_pos = Point2(-100, -100); // TODO check this again.
	double last_click_ms = 0;
	int last_click_button_index = -1;

	int last_width = 0;
	int last_height = 0;

	bool swap_cancel_ok = false;

	// utilities
	static Point2 compute_position_in_canvas(int p_x, int p_y);
	static void focus_canvas();
	static bool is_canvas_focused();
	template <typename T>
	static void dom2godot_mod(T *emscripten_event_ptr, Ref<InputEventWithModifiers> godot_event);
	static Ref<InputEventKey> setup_key_event(const EmscriptenKeyboardEvent *emscripten_event);
	static const char *godot2dom_cursor(DisplayServer::CursorShape p_shape);
	static void set_css_cursor(const char *p_cursor);
	bool is_css_cursor_hidden() const;

	// events
	static EM_BOOL fullscreen_change_callback(int p_event_type, const EmscriptenFullscreenChangeEvent *p_event, void *p_user_data);

	static EM_BOOL keydown_callback(int p_event_type, const EmscriptenKeyboardEvent *p_event, void *p_user_data);
	static EM_BOOL keypress_callback(int p_event_type, const EmscriptenKeyboardEvent *p_event, void *p_user_data);
	static EM_BOOL keyup_callback(int p_event_type, const EmscriptenKeyboardEvent *p_event, void *p_user_data);

	static EM_BOOL mousemove_callback(int p_event_type, const EmscriptenMouseEvent *p_event, void *p_user_data);
	static EM_BOOL mouse_button_callback(int p_event_type, const EmscriptenMouseEvent *p_event, void *p_user_data);

	static EM_BOOL wheel_callback(int p_event_type, const EmscriptenWheelEvent *p_event, void *p_user_data);

	static EM_BOOL touch_press_callback(int p_event_type, const EmscriptenTouchEvent *p_event, void *p_user_data);
	static EM_BOOL touchmove_callback(int p_event_type, const EmscriptenTouchEvent *p_event, void *p_user_data);

	static EM_BOOL gamepad_change_callback(int p_event_type, const EmscriptenGamepadEvent *p_event, void *p_user_data);
	void process_joypads();

	static Vector<String> get_rendering_drivers_func();
	static DisplayServer *create_func(const String &p_rendering_driver, DisplayServer::WindowMode p_mode, uint32_t p_flags, const Vector2i &p_resolution, Error &r_error);

	static void _dispatch_input_event(const Ref<InputEvent> &p_event);

protected:
	virtual int get_current_video_driver() const;

public:
	// Override return type to make writing static callbacks less tedious.
	static DisplayServerJavaScript *get_singleton();
	static char canvas_id[256];

	WindowMode window_mode = WINDOW_MODE_WINDOWED;

	String clipboard;

	Callable window_event_callback;
	Callable input_event_callback;
	Callable input_text_callback;
	Callable drop_files_callback;

	// utilities
	bool check_size_force_redraw();

	// from DisplayServer
	virtual void alert(const String &p_alert, const String &p_title = "ALERT!");
	virtual bool has_feature(Feature p_feature) const;
	virtual String get_name() const;

	// cursor
	virtual void cursor_set_shape(CursorShape p_shape);
	virtual CursorShape cursor_get_shape() const;
	virtual void cursor_set_custom_image(const RES &p_cursor, CursorShape p_shape = CURSOR_ARROW, const Vector2 &p_hotspot = Vector2());

	// mouse
	virtual void mouse_set_mode(MouseMode p_mode);
	virtual MouseMode mouse_get_mode() const;

	// touch
	virtual bool screen_is_touchscreen(int p_screen = SCREEN_OF_MAIN_WINDOW) const;

	// clipboard
	virtual void clipboard_set(const String &p_text);
	virtual String clipboard_get() const;

	// screen
	virtual int get_screen_count() const;
	virtual Point2i screen_get_position(int p_screen = SCREEN_OF_MAIN_WINDOW) const;
	virtual Size2i screen_get_size(int p_screen = SCREEN_OF_MAIN_WINDOW) const;
	virtual Rect2i screen_get_usable_rect(int p_screen = SCREEN_OF_MAIN_WINDOW) const;
	virtual int screen_get_dpi(int p_screen = SCREEN_OF_MAIN_WINDOW) const;

	// windows
	virtual Vector<DisplayServer::WindowID> get_window_list() const;
	virtual WindowID get_window_at_screen_position(const Point2i &p_position) const;

	virtual void window_attach_instance_id(ObjectID p_instance, WindowID p_window = MAIN_WINDOW_ID);
	virtual ObjectID window_get_attached_instance_id(WindowID p_window = MAIN_WINDOW_ID) const;

	virtual void window_set_rect_changed_callback(const Callable &p_callable, WindowID p_window = MAIN_WINDOW_ID);

	virtual void window_set_window_event_callback(const Callable &p_callable, WindowID p_window = MAIN_WINDOW_ID);
	virtual void window_set_input_event_callback(const Callable &p_callable, WindowID p_window = MAIN_WINDOW_ID);
	virtual void window_set_input_text_callback(const Callable &p_callable, WindowID p_window = MAIN_WINDOW_ID);

	virtual void window_set_drop_files_callback(const Callable &p_callable, WindowID p_window = MAIN_WINDOW_ID);

	virtual void window_set_title(const String &p_title, WindowID p_window = MAIN_WINDOW_ID);

	virtual int window_get_current_screen(WindowID p_window = MAIN_WINDOW_ID) const;
	virtual void window_set_current_screen(int p_screen, WindowID p_window = MAIN_WINDOW_ID);

	virtual Point2i window_get_position(WindowID p_window = MAIN_WINDOW_ID) const;
	virtual void window_set_position(const Point2i &p_position, WindowID p_window = MAIN_WINDOW_ID);

	virtual void window_set_transient(WindowID p_window, WindowID p_parent);

	virtual void window_set_max_size(const Size2i p_size, WindowID p_window = MAIN_WINDOW_ID);
	virtual Size2i window_get_max_size(WindowID p_window = MAIN_WINDOW_ID) const;

	virtual void window_set_min_size(const Size2i p_size, WindowID p_window = MAIN_WINDOW_ID);
	virtual Size2i window_get_min_size(WindowID p_window = MAIN_WINDOW_ID) const;

	virtual void window_set_size(const Size2i p_size, WindowID p_window = MAIN_WINDOW_ID);
	virtual Size2i window_get_size(WindowID p_window = MAIN_WINDOW_ID) const;
	virtual Size2i window_get_real_size(WindowID p_window = MAIN_WINDOW_ID) const; // FIXME: Find clearer name for this.

	virtual void window_set_mode(WindowMode p_mode, WindowID p_window = MAIN_WINDOW_ID);
	virtual WindowMode window_get_mode(WindowID p_window = MAIN_WINDOW_ID) const;

	virtual bool window_is_maximize_allowed(WindowID p_window = MAIN_WINDOW_ID) const;

	virtual void window_set_flag(WindowFlags p_flag, bool p_enabled, WindowID p_window = MAIN_WINDOW_ID);
	virtual bool window_get_flag(WindowFlags p_flag, WindowID p_window = MAIN_WINDOW_ID) const;

	virtual void window_request_attention(WindowID p_window = MAIN_WINDOW_ID);
	virtual void window_move_to_foreground(WindowID p_window = MAIN_WINDOW_ID);

	virtual bool window_can_draw(WindowID p_window = MAIN_WINDOW_ID) const;

	virtual bool can_any_window_draw() const;

	// events
	virtual void process_events();

	// icon
	virtual void set_icon(const Ref<Image> &p_icon);

	// others
	virtual bool get_swap_cancel_ok();
	virtual void swap_buffers();

	static void register_javascript_driver();
	DisplayServerJavaScript(const String &p_rendering_driver, WindowMode p_mode, uint32_t p_flags, const Vector2i &p_resolution, Error &r_error);
	~DisplayServerJavaScript();
};

#endif // DISPLAY_SERVER_JAVASCRIPT_H