/*
 * Copyright 2021 Vincent Sanders <vince@netsurf-browser.org>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf 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; version 2 of the License.
 *
 * NetSurf 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, see <http://www.gnu.org/licenses/>.
 */

/**
 * \file
 * Implementation of netsurf window (widget) for fltk.
 */

#include <stddef.h>
#include <FL/Fl.H>
#include <FL/Fl_Double_Window.H>
#include <FL/fl_draw.H>

extern "C" {

#include "utils/errors.h"
#include "netsurf/types.h"
#include "netsurf/mouse.h"
#include "netsurf/window.h"
#include "netsurf/plotters.h"
#include "netsurf/content.h"
#include "netsurf/browser_window.h"
#include "netsurf/mouse.h"

}

#include "fltk/window.h"
#include "fltk/plotters.h"

extern bool nsfltk_done;

class NS_Widget : public Fl_Widget
{
private:
	struct browser_window *mbw;

protected:
	void draw();
	int handle(int event);

public:
	NS_Widget(int X,int Y,int W,int H, struct browser_window *bw)
		: Fl_Widget(X,Y,W,H), mbw(bw) {}
};


class NS_Window : public Fl_Double_Window
{
private:
	struct browser_window *mbw;
	NS_Widget *mnswidget;

	void close_callback(Fl_Widget *w);
	static void static_close_callback(Fl_Widget *w, void *f) { ((NS_Window *)f)->close_callback(w); }

public:
	NS_Window(int W, int H, struct browser_window *bw)
		: Fl_Double_Window(W,H), mbw(bw) {
		this->callback(static_close_callback, (void *)this);
		mnswidget = new NS_Widget(0, 0, W, H, bw);
		this->end();
	}
	~NS_Window() { nsfltk_done=true; }

	NS_Widget *get_nswidget() { return mnswidget; }
};

struct gui_window {
	struct browser_window *bw;
	NS_Window *window;
};

/**
 * method to handle events on the netsurf browsing widget
 */
int NS_Widget::handle(int event)
{
	int state = BROWSER_MOUSE_HOVER;
	int button;

	switch (event) {
	case FL_PUSH:
		button = Fl::event_button();
		if (button == FL_LEFT_MOUSE) {
			state |= BROWSER_MOUSE_PRESS_1;
		}
		browser_window_mouse_click(mbw,
					   (browser_mouse_state)state,
					   Fl::event_x() - x(),
					   Fl::event_y() - y());
		return 1;

	case FL_RELEASE:
		button = Fl::event_button();
		if (button == FL_LEFT_MOUSE) {
			state |= BROWSER_MOUSE_CLICK_1;

		}
		browser_window_mouse_click(mbw,
					   (browser_mouse_state)state,
					   Fl::event_x() - x(),
					   Fl::event_y() - y());

		return 1;
	default:
		return Fl_Widget::handle(event);
	}
}


/**
 * method to redraw the netsurf browsing widget
 */
void NS_Widget::draw()
{
	struct rect clip;
	fl_clip_box(x(), y(), w(), h(), clip.x0, clip.y0, clip.x1, clip.y1);
	/* clip box generates width/height so convert to absolute */
	clip.x1 += clip.x0;
	clip.y1 += clip.y0;
	struct redraw_context ctx = {
		.interactive = true,
		.background_images = true,
		.plot = &nsfltk_plotters,
		.priv = NULL,
	};

	browser_window_redraw(mbw, x(), y(), &clip, &ctx);

}

/**
 * callback when fltk window is closed
 */
void NS_Window::close_callback(Fl_Widget *w)
{
	browser_window_destroy(mbw);
}

/**
 * Create and open a gui window for a browsing context.
 *
 * The implementing front end must create a context suitable
 *  for it to display a window referred to as the "gui window".
 *
 * The frontend will be expected to request the core redraw
 *  areas of the gui window which have become invalidated
 *  either from toolkit expose events or as a result of a
 *  invalidate() call.
 *
 * Most core operations used by the frontend concerning browser
 *  windows require passing the browser window context therefor
 *  the gui window must include a reference to the browser
 *  window passed here.
 *
 * If GW_CREATE_CLONE flag is set existing is non-NULL.
 *
 * \param bw The core browsing context associated with the gui window
 * \param existing An existing gui_window, may be NULL.
 * \param flags flags to control the gui window creation.
 * \return gui window, or NULL on error.
 */
static struct gui_window *
nsfltk_window_create(struct browser_window *bw,
		     struct gui_window *existing,
		     gui_window_create_flags flags)
{
	struct gui_window *gw;
	gw = (struct gui_window *)calloc(1, sizeof(struct gui_window));

	gw->window = new NS_Window(800,600, bw);

	gw->window->show();

	return gw;
}

/**
 * Destroy previously created gui window
 *
 * \param gw The gui window to destroy.
 */
static void nsfltk_window_destroy(struct gui_window *gw)
{
	Fl::delete_widget(gw->window);
	free(gw);
}


/**
 * Invalidate an area of a window.
 *
 * The specified area of the window should now be considered
 *  out of date. If the area is NULL the entire window must be
 *  invalidated. It is expected that the windowing system will
 *  then subsequently cause redraw/expose operations as
 *  necessary.
 *
 * \note the frontend should not attempt to actually start the
 *  redraw operations as a result of this callback because the
 *  core redraw functions may already be threaded.
 *
 * \param gw The gui window to invalidate.
 * \param rect area to redraw or NULL for the entire window area
 * \return NSERROR_OK on success or appropriate error code
 */
static nserror
nsfltk_window_invalidate(struct gui_window *gw, const struct rect *rect)
{
	NS_Widget *nswidget;
	nswidget = gw->window->get_nswidget();

	if (rect == NULL) {
		nswidget->damage(FL_DAMAGE_ALL);
	} else {
		nswidget->damage(FL_DAMAGE_ALL,
				 rect->x0,
				 rect->y0,
				 rect->x1 - rect->x0,
				 rect->y1 - rect->y0);
	}
	return NSERROR_OK;
}


/**
 * Get the scroll position of a browser window.
 *
 * \param gw The gui window to obtain the scroll position from.
 * \param sx receives x ordinate of point at top-left of window
 * \param sy receives y ordinate of point at top-left of window
 * \return true iff successful
 */
static bool nsfltk_window_get_scroll(struct gui_window *gw, int *sx, int *sy)
{
	return false;
}


/**
 * Set the scroll position of a browser window.
 *
 * scrolls the viewport to ensure the specified rectangle of
 *   the content is shown.
 * If the rectangle is of zero size i.e. x0 == x1 and y0 == y1
 *   the contents will be scrolled so the specified point in the
 *   content is at the top of the viewport.
 * If the size of the rectangle is non zero the frontend may
 *   add padding or centre the defined area or it may simply
 *   align as in the zero size rectangle
 *
 * \param gw The gui window to scroll.
 * \param rect The rectangle to ensure is shown.
 * \return NSERROR_OK on success or appropriate error code.
 */
static nserror
nsfltk_window_set_scroll(struct gui_window *gw, const struct rect *rect)
{
	return NSERROR_OK;
}


/**
 * Find the current dimensions of a browser window's content area.
 *
 * This is used to determine the actual available drawing size
 * in pixels. This allows contents that can be dynamically
 * reformatted, such as HTML, to better use the available
 * space.
 *
 * \param gw The gui window to measure content area of.
 * \param width receives width of window
 * \param height receives height of window
 * \return NSERROR_OK on success and width and height updated
 *          else error code.
 */
static nserror
nsfltk_window_get_dimensions(struct gui_window *gw, int *width, int *height)
{
	NS_Widget *nswidget;
	nswidget = gw->window->get_nswidget();

	*width = nswidget->w();
	*height = nswidget->h();

	return NSERROR_OK;
}


/**
 * Miscellaneous event occurred for a window
 *
 * This is used to inform the frontend of window events which
 *   require no additional parameters.
 *
 * \param gw The gui window the event occurred for
 * \param event Which event has occurred.
 * \return NSERROR_OK if the event was processed else error code.
 */
static nserror
nsfltk_window_event(struct gui_window *gw, enum gui_window_event event)
{
	return NSERROR_OK;
}

static struct gui_window_table window_table = {
	.create = nsfltk_window_create,
	.destroy = nsfltk_window_destroy,
	.invalidate = nsfltk_window_invalidate,
	.get_scroll = nsfltk_window_get_scroll,
	.set_scroll = nsfltk_window_set_scroll,
	.get_dimensions = nsfltk_window_get_dimensions,
	.event = nsfltk_window_event,
	.set_title = NULL,
	.set_url = NULL,
	.set_icon = NULL,
	.set_status = NULL,
	.set_pointer = NULL,
	.place_caret = NULL,
	.drag_start = NULL,
	.save_link = NULL,
	.create_form_select_menu = NULL,
	.file_gadget_open = NULL,
	.drag_save_object = NULL,
	.drag_save_selection = NULL,
	.console_log = NULL,
};

struct gui_window_table *nsfltk_window_table = &window_table;