/*
 * Copyright (C) 2014 Collabora Ltd.
 *
 * 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 St, Fifth Floor,
 * Boston, MA  02110-1301  USA
 *
 * Author: Jonny Lamb <jonny.lamb@collabora.co.uk>
 */

#include <stdio.h>
#include <assert.h>

#include <weston/compositor.h>

#include "shell-helper-server-protocol.h"

struct shell_helper {
	struct weston_compositor *compositor;

	struct wl_listener destroy_listener;

	struct weston_layer *panel_layer;
};

static void
shell_helper_move_surface(struct wl_client *client,
			  struct wl_resource *resource,
			  struct wl_resource *surface_resource,
			  int32_t x,
			  int32_t y)
{
	struct shell_helper *helper = wl_resource_get_user_data(resource);
	struct weston_surface *surface =
		wl_resource_get_user_data(surface_resource);
	struct weston_view *view;

	view = container_of(surface->views.next, struct weston_view, surface_link);

	if (!view)
		return;

	weston_view_set_position(view, x, y);
	weston_view_update_transform(view);
}

static void
configure_surface(struct weston_surface *es, int32_t sx, int32_t sy)
{
	struct weston_view *existing_view = es->configure_private;
	struct weston_view *new_view;

	new_view = container_of(es->views.next, struct weston_view, surface_link);

	if (wl_list_empty(&new_view->layer_link)) {
		/* be sure to append to the list, not insert */
		wl_list_insert(&existing_view->layer_link, &new_view->layer_link);
		weston_compositor_schedule_repaint(es->compositor);
	}
}

static void
shell_helper_add_surface_to_layer(struct wl_client *client,
				  struct wl_resource *resource,
				  struct wl_resource *new_surface_resource,
				  struct wl_resource *existing_surface_resource)
{
	struct shell_helper *helper = wl_resource_get_user_data(resource);
	struct weston_surface *new_surface =
		wl_resource_get_user_data(new_surface_resource);
	struct weston_surface *existing_surface =
		wl_resource_get_user_data(existing_surface_resource);
	struct weston_view *new_view, *existing_view, *next;
	struct wl_layer *layer;

	if (new_surface->configure) {
		wl_resource_post_error(new_surface_resource,
				       WL_DISPLAY_ERROR_INVALID_OBJECT,
				       "surface role already assigned");
		return;
	}

	existing_view = container_of(existing_surface->views.next,
				     struct weston_view,
				     surface_link);

	wl_list_for_each_safe(new_view, next, &new_surface->views, surface_link)
		weston_view_destroy(new_view);
	new_view = weston_view_create(new_surface);

	new_surface->configure = configure_surface;
	new_surface->configure_private = existing_view;
	new_surface->output = existing_view->output;
}

static void
configure_panel(struct weston_surface *es, int32_t sx, int32_t sy)
{
	struct shell_helper *helper = es->configure_private;
	struct weston_view *view;

	view = container_of(es->views.next, struct weston_view, surface_link);

	if (wl_list_empty(&view->layer_link)) {
		wl_list_insert(&helper->panel_layer->view_list, &view->layer_link);
		weston_compositor_schedule_repaint(es->compositor);
	}
}

static void
shell_helper_set_panel(struct wl_client *client,
		       struct wl_resource *resource,
		       struct wl_resource *surface_resource)
{
	struct shell_helper *helper = wl_resource_get_user_data(resource);
	struct weston_surface *surface =
		wl_resource_get_user_data(surface_resource);
	struct weston_view *view = container_of(surface->views.next,
						struct weston_view,
						surface_link);

	/* we need to save the panel's layer so we can use it later on, but
	 * it hasn't yet been defined because the original surface configure
	 * function hasn't yet been calld. if we call it here we will have
	 * access to the layer. */
	surface->configure(surface, 0, 0);

	helper->panel_layer = container_of(&view->layer_link,
					   struct weston_layer,
					   view_list);

	/* set new configure functions that only ensure the surface is in the
	 * correct layer. */
	surface->configure = configure_panel;
	surface->configure_private = helper;
}

enum SlideState {
	SLIDE_STATE_NONE,
	SLIDE_STATE_SLIDING_OUT,
	SLIDE_STATE_OUT,
	SLIDE_STATE_SLIDING_BACK,
	SLIDE_STATE_BACK
};

enum SlideRequest {
	SLIDE_REQUEST_NONE,
	SLIDE_REQUEST_OUT,
	SLIDE_REQUEST_BACK
};

static const struct shell_helper_interface helper_implementation = {
	shell_helper_move_surface,
	shell_helper_add_surface_to_layer,
	shell_helper_set_panel,
};

static void
bind_helper(struct wl_client *client, void *data, uint32_t version, uint32_t id)
{
	struct shell_helper *helper = data;
	struct wl_resource *resource;

	resource = wl_resource_create(client, &shell_helper_interface, 1, id);
	if (resource)
		wl_resource_set_implementation(resource, &helper_implementation,
					       helper, NULL);
}

static void
helper_destroy(struct wl_listener *listener, void *data)
{
	struct shell_helper *helper =
		container_of(listener, struct shell_helper, destroy_listener);

	free(helper);
}

WL_EXPORT int
module_init(struct weston_compositor *ec,
	    int *argc, char *argv[])
{
	struct shell_helper *helper;

	helper = zalloc(sizeof *helper);
	if (helper == NULL)
		return -1;

	helper->compositor = ec;
	helper->panel_layer = NULL;

	helper->destroy_listener.notify = helper_destroy;
	wl_signal_add(&ec->destroy_signal, &helper->destroy_listener);

	if (wl_global_create(ec->wl_display, &shell_helper_interface, 1,
			     helper, bind_helper) == NULL)
		return -1;

	return 0;
}