#define GUI_API CLAP_WINDOW_API_X11

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xatom.h>

struct GUI {
	Display *display;
	Window window;
	XImage *image;
	uint32_t *bits;
};

static void GUICreate(MyPlugin *plugin) {
	assert(!plugin->gui);
	plugin->gui = (GUI *) calloc(1, sizeof(GUI));

	plugin->gui->display = XOpenDisplay(NULL);
	XSetWindowAttributes attributes = {};
	plugin->gui->window = XCreateWindow(plugin->gui->display, DefaultRootWindow(plugin->gui->display), 0, 0, GUI_WIDTH, GUI_HEIGHT, 0, 0, 
			InputOutput, CopyFromParent, CWOverrideRedirect, &attributes);
	Atom embedInfoAtom = XInternAtom(plugin->gui->display, "_XEMBED_INFO", 0);
	uint32_t embedInfoData[2] = { 0 /* version */, 0 /* not mapped */ };
	XChangeProperty(plugin->gui->display, plugin->gui->window, embedInfoAtom, embedInfoAtom, 32, PropModeReplace, (uint8_t *) embedInfoData, 2);
	XSizeHints sizeHints = {};
	sizeHints.flags = PMinSize | PMaxSize; 
	sizeHints.min_width = sizeHints.max_width = GUI_WIDTH;
	sizeHints.min_height = sizeHints.max_height = GUI_HEIGHT;
	XSetWMNormalHints(plugin->gui->display, plugin->gui->window, &sizeHints);
	XStoreName(plugin->gui->display, plugin->gui->window, pluginDescriptor.name);
	XSelectInput(plugin->gui->display, plugin->gui->window, SubstructureNotifyMask | ExposureMask | PointerMotionMask 
			| ButtonPressMask | ButtonReleaseMask | KeyPressMask | KeyReleaseMask | StructureNotifyMask
			| EnterWindowMask | LeaveWindowMask | ButtonMotionMask | KeymapStateMask | FocusChangeMask | PropertyChangeMask);

	plugin->gui->image = XCreateImage(plugin->gui->display, DefaultVisual(plugin->gui->display, 0), 24, ZPixmap, 0, NULL, 10, 10, 32, 0);
	plugin->gui->bits = (uint32_t *) calloc(1, GUI_WIDTH * GUI_HEIGHT * 4);
	plugin->gui->image->width = GUI_WIDTH;
	plugin->gui->image->height = GUI_HEIGHT;
	plugin->gui->image->bytes_per_line = GUI_WIDTH * 4;
	plugin->gui->image->data = (char *) plugin->gui->bits;

	if (plugin->hostPOSIXFDSupport && plugin->hostPOSIXFDSupport->register_fd) {
		plugin->hostPOSIXFDSupport->register_fd(plugin->host, ConnectionNumber(plugin->gui->display), CLAP_POSIX_FD_READ);
	}
}

static void GUIDestroy(MyPlugin *plugin) {
	assert(plugin->gui);

	if (plugin->hostPOSIXFDSupport && plugin->hostPOSIXFDSupport->unregister_fd) {
		plugin->hostPOSIXFDSupport->unregister_fd(plugin->host, ConnectionNumber(plugin->gui->display));
	}

	free(plugin->gui->bits);
	plugin->gui->image->data = NULL;
	XDestroyImage(plugin->gui->image);
	XDestroyWindow(plugin->gui->display, plugin->gui->window);
	XCloseDisplay(plugin->gui->display);

	free(plugin->gui);
	plugin->gui = nullptr;
}

static void GUISetParent(MyPlugin *plugin, const clap_window_t *window) {
	XReparentWindow(plugin->gui->display, plugin->gui->window, (Window) window->x11, 0, 0);
	XFlush(plugin->gui->display);
}

static void GUISetVisible(MyPlugin *plugin, bool visible) {
	if (visible) XMapRaised(plugin->gui->display, plugin->gui->window);
	else XUnmapWindow(plugin->gui->display, plugin->gui->window);
	XFlush(plugin->gui->display);
}

static void GUIPaint(MyPlugin *plugin, bool internal) {
	if (internal) PluginPaint(plugin, plugin->gui->bits);
	XPutImage(plugin->gui->display, plugin->gui->window, DefaultGC(plugin->gui->display, 0), plugin->gui->image, 0, 0, 0, 0, GUI_WIDTH, GUI_HEIGHT);
}

static void GUIX11ProcessEvent(MyPlugin *plugin, XEvent *event) {
	if (event->type == Expose) {
		if (event->xexpose.window == plugin->gui->window) {
			GUIPaint(plugin, false);
		}
	} else if (event->type == MotionNotify) {
		if (event->xmotion.window == plugin->gui->window) {
			PluginProcessMouseDrag(plugin, event->xmotion.x, event->xmotion.y);
		}
	} else if (event->type == ButtonPress) {
		if (event->xbutton.window == plugin->gui->window && event->xbutton.button == 1) {
			PluginProcessMousePress(plugin, event->xbutton.x, event->xbutton.y);
		}
	} else if (event->type == ButtonRelease) {
		if (event->xbutton.window == plugin->gui->window && event->xbutton.button == 1) {
			PluginProcessMouseRelease(plugin);
		}
	}
}

static void GUIOnPOSIXFD(MyPlugin *plugin) {
	XFlush(plugin->gui->display);

	while (XPending(plugin->gui->display)) {
		XEvent event;
		XNextEvent(plugin->gui->display, &event);

		while (XPending(plugin->gui->display)) {
			XEvent event0;
			XNextEvent(plugin->gui->display, &event0);

			if (event.type == MotionNotify && event0.type == MotionNotify) {
				// Merge adjacent mouse motion events.
			} else {
				GUIX11ProcessEvent(plugin, &event);
				XFlush(plugin->gui->display);
			}

			event = event0;
		}

		GUIX11ProcessEvent(plugin, &event);
		XFlush(plugin->gui->display);
		GUIPaint(plugin, true);
	}
}