/* nautilus-desktop-canvas-view.c - implementation of canvas view for managing the desktop.

   Copyright (C) 2000, 2001 Eazel, Inc.mou

   The Gnome Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The Gnome Library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the Gnome Library; see the file COPYING.LIB.  If not,
   see <http://www.gnu.org/licenses/>.

   Authors: Mike Engber <engber@eazel.com>
   	    Gene Z. Ragan <gzr@eazel.com>
	    Miguel de Icaza <miguel@ximian.com>
*/

#include <config.h>
#include <stdlib.h>

#include "nautilus-desktop-canvas-view.h"

#include "nautilus-desktop-canvas-view-container.h"
#include "nautilus-desktop-icon-file.h"
#include "nautilus-desktop-directory.h"

#include <X11/Xatom.h>
#include <gtk/gtk.h>
#include <eel/eel-glib-extensions.h>
#include <eel/eel-gtk-extensions.h>
#include <eel/eel-vfs-extensions.h>
#include <fcntl.h>
#include <gdk/gdkx.h>
#include <glib/gi18n.h>
#include <src/nautilus-directory-notify.h>
#include <src/nautilus-file-changes-queue.h>
#include <src/nautilus-file-operations.h>
#include <src/nautilus-file-utilities.h>
#include <src/nautilus-ui-utilities.h>
#include <src/nautilus-global-preferences.h>
#include <src/nautilus-link.h>
#include <src/nautilus-metadata.h>
#include <src/nautilus-monitor.h>
#include <src/nautilus-program-choosing.h>
#include <src/nautilus-trash-monitor.h>
#include <src/nautilus-files-view.h>
#include <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

static void     default_zoom_level_changed                        (gpointer                user_data);
static void     real_update_context_menus                         (NautilusFilesView           *view);
static char*    real_get_backing_uri                              (NautilusFilesView           *view);
static void     real_check_empty_states                           (NautilusFilesView           *view);
static void     nautilus_desktop_canvas_view_update_canvas_container_fonts  (NautilusDesktopCanvasView      *view);
static void     font_changed_callback                             (gpointer                callback_data);

G_DEFINE_TYPE (NautilusDesktopCanvasView, nautilus_desktop_canvas_view, NAUTILUS_TYPE_CANVAS_VIEW)

static char *desktop_directory;

#define get_canvas_container(w) nautilus_canvas_view_get_canvas_container(NAUTILUS_CANVAS_VIEW (w))

#define POPUP_PATH_CANVAS_APPEARANCE		"/selection/Canvas Appearance Items"

static void
canvas_container_set_workarea (NautilusCanvasContainer *canvas_container,
			     GdkScreen             *screen,
			     long                  *workareas,
			     int                    n_items)
{
	int left, right, top, bottom;
	int i;
	GdkRectangle geometry;

	left = right = top = bottom = 0;
	gdk_screen_get_monitor_geometry (screen, gdk_screen_get_primary_monitor (screen), &geometry);

	for (i = 0; i < n_items; i += 4) {
		GdkRectangle workarea;

		workarea.x = workareas[i];
		workarea.y = workareas[i + 1];
		workarea.width = workareas[i + 2];
		workarea.height = workareas[i + 3];

		if (!gdk_rectangle_intersect (&geometry, &workarea, &workarea))
			continue;

		left   = MAX (left, workarea.x);
		right  = MAX (right, (workarea.x + workarea.width) - (geometry.x + geometry.width));
		top    = MAX (top, workarea.y);
		bottom = MAX (bottom, (workarea.y + workarea.height) - (geometry.y + geometry.height));
	}

	nautilus_canvas_container_set_margins (canvas_container,
					     0, 0, 0, 0);
}

static void
net_workarea_changed (NautilusDesktopCanvasView *canvas_view,
		      GdkWindow         *window)
{
	long *nworkareas = NULL;
	long *workareas = NULL;
	GdkAtom type_returned;
	int format_returned;
	int length_returned;
	NautilusCanvasContainer *canvas_container;
	GdkScreen *screen;

	g_return_if_fail (NAUTILUS_IS_DESKTOP_CANVAS_VIEW (canvas_view));

	canvas_container = get_canvas_container (canvas_view);

	/* Find the number of desktops so we know how long the
	 * workareas array is going to be (each desktop will have four
	 * elements in the workareas array describing
	 * x,y,width,height) */
	gdk_error_trap_push ();
	if (!gdk_property_get (window,
			       gdk_atom_intern ("_NET_NUMBER_OF_DESKTOPS", FALSE),
			       gdk_x11_xatom_to_atom (XA_CARDINAL),
			       0, 4, FALSE,
			       &type_returned,
			       &format_returned,
			       &length_returned,
			       (guchar **) &nworkareas)) {
		g_warning("Can not calculate _NET_NUMBER_OF_DESKTOPS");
	}
	if (gdk_error_trap_pop()
	    || nworkareas == NULL
	    || type_returned != gdk_x11_xatom_to_atom (XA_CARDINAL)
	    || format_returned != 32)
		g_warning("Can not calculate _NET_NUMBER_OF_DESKTOPS");
	
	/* Note : gdk_property_get() is broken (API documents admit
	 * this).  As a length argument, it expects the number of
	 * _bytes_ of data you require.  Internally, gdk_property_get
	 * converts that value to a count of 32 bit (4 byte) elements.
	 * However, the length returned is in bytes, but is calculated
	 * via the count of returned elements * sizeof(long).  This
	 * means on a 64 bit system, the number of bytes you have to
	 * request does not correspond to the number of bytes you get
	 * back, and is the reason for the workaround below.
	 */ 
	gdk_error_trap_push ();
	if (nworkareas == NULL || (*nworkareas < 1) 
	    || !gdk_property_get (window,
				  gdk_atom_intern ("_NET_WORKAREA", FALSE),
				  gdk_x11_xatom_to_atom (XA_CARDINAL),
				  0, ((*nworkareas) * 4 * 4), FALSE,
				  &type_returned,
				  &format_returned,
				  &length_returned,
				  (guchar **) &workareas)) {
		g_warning("Can not get _NET_WORKAREA");
		workareas = NULL;
	}

	if (gdk_error_trap_pop ()
	    || workareas == NULL
	    || type_returned != gdk_x11_xatom_to_atom (XA_CARDINAL)
	    || ((*nworkareas) * 4 * sizeof(long)) != length_returned
	    || format_returned != 32) {
		g_warning("Can not determine workarea, guessing at layout");
		nautilus_canvas_container_set_margins (canvas_container,
						     0, 0, 0, 0);
	} else {
		screen = gdk_window_get_screen (window);

		canvas_container_set_workarea
			(canvas_container, screen, workareas, length_returned / sizeof (long));
	}

	if (nworkareas != NULL)
		g_free (nworkareas);

	if (workareas != NULL)
		g_free (workareas);
}

static guint
real_get_id (NautilusFilesView *view)
{
	return NAUTILUS_VIEW_DESKTOP_ID;
}

static void
nautilus_desktop_canvas_view_dispose (GObject *object)
{
	NautilusDesktopCanvasView *canvas_view;

	canvas_view = NAUTILUS_DESKTOP_CANVAS_VIEW (object);

	g_signal_handlers_disconnect_by_func (nautilus_icon_view_preferences,
					      default_zoom_level_changed,
					      canvas_view);
	g_signal_handlers_disconnect_by_func (nautilus_preferences,
					      font_changed_callback,
					      canvas_view);
	g_signal_handlers_disconnect_by_func (gnome_lockdown_preferences,
					      nautilus_files_view_update_context_menus,
					      canvas_view);

	G_OBJECT_CLASS (nautilus_desktop_canvas_view_parent_class)->dispose (object);
}

static void
nautilus_desktop_canvas_view_end_loading (NautilusFilesView *view,
                                          gboolean all_files_seen)
{
	gboolean needs_reorganization;
	gchar *stored_size_icon;
	guint current_zoom;
	guint current_icon_size;
	gchar *current_icon_size_string;
	NautilusFile *file;

  	NAUTILUS_FILES_VIEW_CLASS (nautilus_desktop_canvas_view_parent_class)->end_loading (view, all_files_seen);

        if (!all_files_seen)
          return;

  	file = nautilus_files_view_get_directory_as_file (view);
  	g_return_if_fail (file != NULL);

	stored_size_icon = nautilus_file_get_metadata (file, NAUTILUS_METADATA_KEY_DESKTOP_ICON_SIZE, NULL);
	current_zoom = nautilus_canvas_container_get_zoom_level (get_canvas_container (view));
	current_icon_size = nautilus_canvas_container_get_icon_size_for_zoom_level (current_zoom);
	needs_reorganization = stored_size_icon == NULL || atoi (stored_size_icon) != current_icon_size;

	if (needs_reorganization) {
		current_icon_size_string = g_strdup_printf ("%d", current_icon_size);
		nautilus_canvas_view_clean_up_by_name (NAUTILUS_CANVAS_VIEW (view));
	  	nautilus_file_set_metadata (file, NAUTILUS_METADATA_KEY_DESKTOP_ICON_SIZE,
                                            NULL, current_icon_size_string);

	  	g_free (current_icon_size_string);
	}

	g_free (stored_size_icon);
}

static NautilusCanvasContainer *
real_create_canvas_container (NautilusCanvasView *canvas_view)
{
        return NAUTILUS_CANVAS_CONTAINER (nautilus_desktop_canvas_view_container_new ());
}

static void
nautilus_desktop_canvas_view_class_init (NautilusDesktopCanvasViewClass *class)
{
	NautilusFilesViewClass *vclass;
        NautilusCanvasViewClass *canvas_class;

	vclass = NAUTILUS_FILES_VIEW_CLASS (class);
	canvas_class = NAUTILUS_CANVAS_VIEW_CLASS (class);


	G_OBJECT_CLASS (class)->dispose = nautilus_desktop_canvas_view_dispose;

        canvas_class->create_canvas_container = real_create_canvas_container;

	vclass->update_context_menus = real_update_context_menus;
	vclass->get_view_id = real_get_id;
	vclass->end_loading = nautilus_desktop_canvas_view_end_loading;
	vclass->get_backing_uri = real_get_backing_uri;
	vclass->check_empty_states = real_check_empty_states;
}

static void
desktop_canvas_container_realize (GtkWidget *widget,
				  NautilusDesktopCanvasView *desktop_canvas_view)
{
	GdkWindow *bin_window;
	GdkRGBA transparent = { 0, 0, 0, 0 };

	bin_window = gtk_layout_get_bin_window (GTK_LAYOUT (widget));
	gdk_window_set_background_rgba (bin_window, &transparent);
}

static NautilusCanvasZoomLevel
get_default_zoom_level (void)
{
	NautilusCanvasZoomLevel default_zoom_level;

	default_zoom_level = g_settings_get_enum (nautilus_icon_view_preferences,
						  NAUTILUS_PREFERENCES_ICON_VIEW_DEFAULT_ZOOM_LEVEL);

	return CLAMP (default_zoom_level, NAUTILUS_CANVAS_ZOOM_LEVEL_SMALL, NAUTILUS_CANVAS_ZOOM_LEVEL_LARGE);
}

static void
set_up_zoom_level (NautilusDesktopCanvasView *desktop_canvas_view)
{
	NautilusCanvasZoomLevel new_level;

	new_level = get_default_zoom_level ();
	nautilus_canvas_container_set_zoom_level (get_canvas_container (desktop_canvas_view),
                                                  new_level);
}

static void
default_zoom_level_changed (gpointer user_data)
{
	NautilusCanvasZoomLevel new_level;
	NautilusDesktopCanvasView *desktop_canvas_view;
	gint new_icon_size;
	NautilusFile *file;
	gchar *new_icon_size_string;

	desktop_canvas_view = NAUTILUS_DESKTOP_CANVAS_VIEW (user_data);
	file = nautilus_files_view_get_directory_as_file (NAUTILUS_FILES_VIEW (user_data));
	new_level = get_default_zoom_level ();
	new_icon_size = nautilus_canvas_container_get_icon_size_for_zoom_level (new_level);
	new_icon_size_string = g_strdup_printf ("%d", new_icon_size);

	nautilus_file_set_metadata (file, NAUTILUS_METADATA_KEY_DESKTOP_ICON_SIZE,
                                    NULL, new_icon_size_string);
        set_up_zoom_level (desktop_canvas_view);

	g_free (new_icon_size_string);
}

static void
font_changed_callback (gpointer callback_data)
{
 	g_return_if_fail (NAUTILUS_IS_DESKTOP_CANVAS_VIEW (callback_data));
	
	nautilus_desktop_canvas_view_update_canvas_container_fonts (NAUTILUS_DESKTOP_CANVAS_VIEW (callback_data));
}

static void
nautilus_desktop_canvas_view_update_canvas_container_fonts (NautilusDesktopCanvasView *canvas_view)
{
	NautilusCanvasContainer *canvas_container;
	char *font;

	canvas_container = get_canvas_container (canvas_view);
	g_assert (canvas_container != NULL);

	font = g_settings_get_string (nautilus_desktop_preferences,
				      NAUTILUS_PREFERENCES_DESKTOP_FONT);

	nautilus_canvas_container_set_font (canvas_container, font);

	g_free (font);
}

static const gchar *
get_control_center_command (const gchar ** params_out)
{
	gchar *path;
	const gchar *retval;
	const gchar *params;
	const gchar *xdg_current_desktop;
	gchar **desktop_names;
	gboolean is_unity;
	int i;

	path = NULL;
	retval = NULL;
	params = NULL;

	xdg_current_desktop = g_getenv ("XDG_CURRENT_DESKTOP");

	/* Detect the Unity-based environments */
	is_unity = FALSE;
	if (xdg_current_desktop != NULL) {
		desktop_names = g_strsplit (xdg_current_desktop, ":", 0);
		for (i = 0; desktop_names[i]; ++i) {
			if (!g_strcmp0 (desktop_names[i], "Unity")) {
				is_unity = TRUE;
				break;
			}
		}
		g_strfreev (desktop_names);
	}

	/* In Unity look for unity-control-center */
	if (is_unity) {
		path = g_find_program_in_path ("unity-control-center");
		if (path != NULL) {
			retval = "unity-control-center";
			params = "appearance";
			goto out;
		}
	}

	/* Otherwise look for gnome-control-center */
	path = g_find_program_in_path ("gnome-control-center");
	if (path != NULL) {
		retval = "gnome-control-center";
		params = "background";
	}

 out:
	g_free (path);
	if (params_out != NULL) {
		*params_out = params;
	}

	return retval;
}

static void
action_change_background (GSimpleAction *action,
			  GVariant      *state,
			  gpointer       user_data)
{
	const gchar *control_center_cmd, *params;

        g_assert (NAUTILUS_FILES_VIEW (user_data));

	control_center_cmd = get_control_center_command (&params);
	if (control_center_cmd == NULL) {
		return;
	}

	nautilus_launch_application_from_command (gtk_widget_get_screen (GTK_WIDGET (user_data)),
						  control_center_cmd,
						  FALSE,
						  params, NULL);
}

static void
action_empty_trash (GSimpleAction *action,
		    GVariant      *state,
		    gpointer       user_data)
{
	g_assert (NAUTILUS_IS_FILES_VIEW (user_data));

	nautilus_file_operations_empty_trash (GTK_WIDGET (user_data));
}

static void
action_stretch (GSimpleAction *action,
		GVariant      *state,
		gpointer       user_data)
{
	nautilus_canvas_container_show_stretch_handles
		(get_canvas_container (user_data));
}

static void
action_unstretch (GSimpleAction *action,
		  GVariant      *state,
		  gpointer       user_data)
{
	nautilus_canvas_container_unstretch (get_canvas_container (user_data));
}

static void
action_organize_desktop_by_name (GSimpleAction *action,
				 GVariant      *state,
				 gpointer       user_data)
{
	nautilus_canvas_view_clean_up_by_name (NAUTILUS_CANVAS_VIEW (user_data));
}

static gboolean
trash_link_is_selection (NautilusFilesView *view)
{
	GList *selection;
	NautilusDesktopLink *link;
	gboolean result;

	result = FALSE;
	
	selection = nautilus_view_get_selection (NAUTILUS_VIEW (view));

	if ((g_list_length (selection) == 1) &&
	    NAUTILUS_IS_DESKTOP_ICON_FILE (selection->data)) {
		link = nautilus_desktop_icon_file_get_link (NAUTILUS_DESKTOP_ICON_FILE (selection->data));
		/* link may be NULL if the link was recently removed (unmounted) */
		if (link != NULL &&
		    nautilus_desktop_link_get_link_type (link) == NAUTILUS_DESKTOP_LINK_TRASH) {
			result = TRUE;
		}
		if (link) {
			g_object_unref (link);
		}
	}
	
	nautilus_file_list_free (selection);

	return result;
}

const GActionEntry desktop_view_entries[] = {
	{ "change-background", action_change_background },
	{ "organize-desktop-by-name", action_organize_desktop_by_name },
	{ "empty-trash", action_empty_trash },
	{ "stretch", action_stretch },
	{ "unstretch", action_unstretch },
};

static void
real_check_empty_states (NautilusFilesView *view)
{
        /* Do nothing */
}

static char*
real_get_backing_uri (NautilusFilesView *view)
{
        gchar *uri;
        NautilusDirectory *directory;
        NautilusDirectory *model;

        g_return_val_if_fail (NAUTILUS_IS_FILES_VIEW (view), NULL);

        model = nautilus_files_view_get_model (view);

        if (model == NULL) {
                return NULL;
        }

        directory = nautilus_desktop_directory_get_real_directory (NAUTILUS_DESKTOP_DIRECTORY (model));

        uri = nautilus_directory_get_uri (directory);

        nautilus_directory_unref (directory);

        return uri;
}

static void
real_update_context_menus (NautilusFilesView *view)
{
	NautilusCanvasContainer *canvas_container;
	NautilusDesktopCanvasView *desktop_view;
	GAction *action;
	GActionGroup *view_action_group;
        GList *selection;
	int selection_count;

	g_assert (NAUTILUS_IS_DESKTOP_CANVAS_VIEW (view));

	NAUTILUS_FILES_VIEW_CLASS (nautilus_desktop_canvas_view_parent_class)->update_context_menus (view);

	view_action_group = nautilus_files_view_get_action_group (view);
	desktop_view = NAUTILUS_DESKTOP_CANVAS_VIEW (view);
        selection = nautilus_view_get_selection (NAUTILUS_VIEW (view));
	selection_count = g_list_length (selection);

	action = g_action_map_lookup_action (G_ACTION_MAP (view_action_group), "empty-trash");
	g_simple_action_set_enabled (G_SIMPLE_ACTION (action), trash_link_is_selection (view));

	action = g_action_map_lookup_action (G_ACTION_MAP (view_action_group), "keep-aligned");
	g_simple_action_set_enabled (G_SIMPLE_ACTION (action), TRUE);

	action = g_action_map_lookup_action (G_ACTION_MAP (view_action_group), "organize-desktop-by-name");
	g_simple_action_set_enabled (G_SIMPLE_ACTION (action), TRUE);

	action = g_action_map_lookup_action (G_ACTION_MAP (view_action_group), "change-background");
	g_simple_action_set_enabled (G_SIMPLE_ACTION (action), TRUE);

	action = g_action_map_lookup_action (G_ACTION_MAP (view_action_group), "properties");
	g_simple_action_set_enabled (G_SIMPLE_ACTION (action), selection_count > 0);

	/* Stretch */
	canvas_container = get_canvas_container (desktop_view);

	action = g_action_map_lookup_action (G_ACTION_MAP (view_action_group), "stretch");
	g_simple_action_set_enabled (G_SIMPLE_ACTION (action), selection_count == 1 &&
							       canvas_container != NULL &&
							       !nautilus_canvas_container_has_stretch_handles (canvas_container));

        nautilus_file_list_free (selection);

	/* Unstretch */
	action = g_action_map_lookup_action (G_ACTION_MAP (view_action_group), "unstretch");
	g_simple_action_set_enabled (G_SIMPLE_ACTION (action), canvas_container != NULL &&
							       nautilus_canvas_container_is_stretched (canvas_container));
}

static void
nautilus_desktop_canvas_view_init (NautilusDesktopCanvasView *desktop_canvas_view)
{
	NautilusCanvasContainer *canvas_container;
	GtkAllocation allocation;
	GActionGroup *view_action_group;
	GtkAdjustment *hadj, *vadj;

	desktop_canvas_view->details = G_TYPE_INSTANCE_GET_PRIVATE (desktop_canvas_view,
								  NAUTILUS_TYPE_DESKTOP_CANVAS_VIEW,
								  NautilusDesktopCanvasViewDetails);

	if (desktop_directory == NULL) {
		desktop_directory = nautilus_get_desktop_directory ();
	}

	canvas_container = get_canvas_container (desktop_canvas_view);

	nautilus_canvas_container_set_is_fixed_size (canvas_container, TRUE);
	nautilus_canvas_container_set_is_desktop (canvas_container, TRUE);
	nautilus_canvas_container_set_store_layout_timestamps (canvas_container, TRUE);

	/* Set allocation to be at 0, 0 */
	gtk_widget_get_allocation (GTK_WIDGET (canvas_container), &allocation);
	allocation.x = 0;
	allocation.y = 0;
	gtk_widget_set_allocation (GTK_WIDGET (canvas_container), &allocation);

	gtk_widget_queue_resize (GTK_WIDGET (canvas_container));

	hadj = gtk_scrollable_get_hadjustment (GTK_SCROLLABLE (canvas_container));
	vadj = gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (canvas_container));

	gtk_adjustment_set_value (hadj, 0);
	gtk_adjustment_set_value (vadj, 0);

	nautilus_files_view_ignore_hidden_file_preferences
		(NAUTILUS_FILES_VIEW (desktop_canvas_view));

	nautilus_files_view_set_show_foreign (NAUTILUS_FILES_VIEW (desktop_canvas_view),
					FALSE);

	g_signal_connect_object (canvas_container, "realize",
				 G_CALLBACK (desktop_canvas_container_realize), desktop_canvas_view, 0);

	g_signal_connect_swapped (nautilus_icon_view_preferences,
				  "changed::" NAUTILUS_PREFERENCES_ICON_VIEW_DEFAULT_ZOOM_LEVEL,
				  G_CALLBACK (default_zoom_level_changed),
				  desktop_canvas_view);

	g_signal_connect_swapped (nautilus_desktop_preferences,
				  "changed::" NAUTILUS_PREFERENCES_DESKTOP_FONT,
				  G_CALLBACK (font_changed_callback),
				  desktop_canvas_view);

	set_up_zoom_level (desktop_canvas_view);
	nautilus_desktop_canvas_view_update_canvas_container_fonts (desktop_canvas_view);

	g_signal_connect_swapped (gnome_lockdown_preferences,
				  "changed::" NAUTILUS_PREFERENCES_LOCKDOWN_COMMAND_LINE,
				  G_CALLBACK (nautilus_files_view_update_context_menus),
				  desktop_canvas_view);

	view_action_group = nautilus_files_view_get_action_group (NAUTILUS_FILES_VIEW (desktop_canvas_view));

	g_action_map_add_action_entries (G_ACTION_MAP (view_action_group),
					 desktop_view_entries,
					 G_N_ELEMENTS (desktop_view_entries),
					 NAUTILUS_FILES_VIEW (desktop_canvas_view));
}

NautilusFilesView *
nautilus_desktop_canvas_view_new (NautilusWindowSlot *slot)
{
	return g_object_new (NAUTILUS_TYPE_DESKTOP_CANVAS_VIEW,
			     "window-slot", slot,
			     "supports-zooming", FALSE,
			     "supports-auto-layout", FALSE,
			     "supports-manual-layout", TRUE,
			     "supports-scaling", TRUE,
			     "supports-keep-aligned", TRUE,
			     NULL);
}