/*
 * Copyright (C) 2012 - Juan Ferrer Toribio
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include "vn-date-chooser.h"
#include <db/db.h>

/**
 * SECTION:vn-date-chooser
 * @Short_description: an embedded popup date selector
 * @Title: VnDateChooser
 * @See_also: #VnField
 * @Image: date-chooser.png
 *
 * An embedded button and text field that pops-up a #GtkCalendar.
 */
G_DEFINE_TYPE (VnDateChooser, vn_date_chooser, VN_TYPE_FIELD);

/**
 * vn_date_chooser_new:
 *
 * Creates a new #VnDateChooser
 *
 * Return value: a #VnDateChooser
 **/
VnField * vn_date_chooser_new ()
{
	return VN_FIELD (g_object_new (VN_TYPE_DATE_CHOOSER, NULL));
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Private

static void vn_date_chooser_hide_popup (VnDateChooser * obj)
{
	if (obj->device)
	{
		gdk_device_ungrab (obj->device, GDK_CURRENT_TIME);
		gtk_device_grab_remove (obj->popup, obj->device);
	}

	gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (obj->button), FALSE);
	gtk_widget_hide (obj->popup);
}

static void vn_date_chooser_changed (VnDateChooser * obj)
{
	GDate * date = &obj->date;

	if (g_date_valid (date))
	{
		gchar * str;
		GDateWeekday wday;
		GDateMonth month;

		month = g_date_get_month (date);
		wday = g_date_get_weekday (date);
		
		str = g_strdup_printf (_("%s, %u %s %u")
			,GVN_ABR_WDAY[wday]
			,g_date_get_day (date)
			,GVN_ABR_MONTH[month]
			,g_date_get_year (date)
		);
		gtk_label_set_text (obj->label, str);
		g_free (str);
	}
	else
		gtk_label_set_text (obj->label, "");
}

static void vn_date_chooser_set_value (VnDateChooser * obj, const GValue * value)
{
	GDate * date = NULL;

	if (G_VALUE_TYPE (value) != G_TYPE_DATE)
	{
		GValue new_value = {0};
		g_value_init (&new_value, G_TYPE_DATE);
		g_value_transform (value, &new_value);
		date = g_value_get_boxed (&new_value);
	}
	else if (!gvn_value_is_null (value))
		date = g_value_get_boxed (value);
	
	if (date)
		obj->date = *date;
	else
		g_date_clear (&obj->date, 1);
		
	vn_date_chooser_changed (obj);
}

static void vn_date_chooser_on_day_selected (GtkCalendar * calendar, VnDateChooser * obj)
{
	guint year;
	guint month;
	guint day;
	GDate new_date;
	GValue value = {0};

	gtk_calendar_get_date (calendar, &year, &month, &day);
	month++;
	
	g_date_clear (&new_date, 1);
	g_date_set_dmy (&new_date, day, month, year);
	
	if (!g_date_valid (&obj->date) || g_date_compare (&new_date, &obj->date))
	{
		g_date_set_julian (&obj->date, g_date_get_julian (&new_date));
		g_value_init (&value, G_TYPE_DATE);
		g_value_set_boxed (&value, &obj->date);
	}
	else
	{
		g_value_init (&value, GVN_TYPE_NULL);
		g_date_clear (&obj->date, 1);
	}

	VN_FIELD_GET_CLASS (obj)->value_changed (VN_FIELD (obj), &value);
	g_value_unset (&value);

	vn_date_chooser_hide_popup (obj);
	vn_date_chooser_changed (obj);
}

static gboolean vn_date_chooser_on_buton_press (GtkWidget * widget,
	GdkEventButton * event, VnDateChooser * obj)
{
	gint x, y;
	GtkAllocation allocation;

	gdk_window_get_origin (
		gtk_widget_get_window (obj->popup), &x, &y);
	gtk_widget_get_allocation (obj->popup, &allocation);

	if (!( event->x_root >= x && event->x_root <= x + allocation.width
		&& event->y_root >= y && event->y_root <= y + allocation.height))
	{
		vn_date_chooser_hide_popup (obj);
		return TRUE;
	}

	return FALSE;
}

static gboolean vn_date_chooser_on_key_press (GtkWidget * widget,
	GdkEventKey * event, VnDateChooser * obj)
{
	if (event->keyval == GDK_KEY_Escape)
	{
		vn_date_chooser_hide_popup (obj);
		return TRUE;
	}
	
	return FALSE;
}

static void vn_date_chooser_on_toggled (GtkToggleButton * button, VnDateChooser * obj)
{
	if (gtk_toggle_button_get_active (button))
	{
		gint x, y;
		GdkWindow * window;
		GdkScreen * screen;
		GtkRequisition req;
		GdkRectangle monitor;
		GtkAllocation allocation;
		GtkWidget * widget = GTK_WIDGET (button);
		
		// Set the date on the calendar
		
		if (g_date_valid (&obj->date))
		{
			gtk_calendar_select_month (obj->calendar
				 ,g_date_get_month (&obj->date) - 1
				 ,g_date_get_year (&obj->date)
			);
			gtk_calendar_select_day (obj->calendar,
				g_date_get_day (&obj->date));
		}
		else
			gtk_calendar_select_day (obj->calendar, 0);
		
		// Setting the position of the popup
		
		window = gtk_widget_get_window (widget);
		
		gtk_widget_get_allocation (widget, &allocation);
		
		gdk_window_get_origin (window, &x, &y);
		x += allocation.x;
		y += allocation.y;

  		screen = gtk_widget_get_screen (widget);
  		gdk_screen_get_monitor_geometry (screen,
  			gdk_screen_get_monitor_at_point (screen, x, y), &monitor);
  		
		gtk_widget_show (GTK_WIDGET (obj->calendar));
  		gtk_widget_get_preferred_size (obj->popup, &req, NULL);
  		
  		if (y - monitor.y > monitor.height)
  			y = monitor.y + monitor.height - req.height;
  		else if ((y - monitor.y) + req.height + allocation.height > monitor.height)
  			y -= req.height;
  		else
  			y += allocation.height;
  			
  		if ((x + allocation.width) - monitor.x > monitor.width)
  			x = monitor.x + monitor.width - req.width; 	
  		else if ((x - monitor.x) + req.width > monitor.width)
  			x -= req.width - allocation.width;

		gtk_window_set_screen (GTK_WINDOW (obj->popup), screen);
		gtk_window_move (GTK_WINDOW (obj->popup), x, y);
		gtk_widget_show_all (obj->popup);
		
		// Graving the focus on the popup window

		obj->device = gtk_get_current_event_device ();

		if (obj->device && gdk_device_get_source (obj->device) == GDK_SOURCE_KEYBOARD)
			obj->device = gdk_device_get_associated_device (obj->device);

		if (!obj->device)
		{
			GList * devices;
			GdkDisplay * display;
			GdkDeviceManager * device_manager;

			display = gtk_widget_get_display (GTK_WIDGET (obj->popup));
			device_manager = gdk_display_get_device_manager (display);

			devices = gdk_device_manager_list_devices (device_manager,
				GDK_DEVICE_TYPE_MASTER);
			obj->device = devices->data;
			g_list_free (devices);
		}

//		gtk_widget_grab_focus (obj->popup);
		gtk_device_grab_add (obj->popup, obj->device, TRUE);
		gdk_device_grab (obj->device
			,gtk_widget_get_window (obj->popup)
			,GDK_OWNERSHIP_WINDOW, TRUE
			,GDK_BUTTON_PRESS_MASK, NULL
			,GDK_CURRENT_TIME
		);
	}
	else
		vn_date_chooser_hide_popup (obj);
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Class

static void vn_date_chooser_init (VnDateChooser * obj)
{
	GtkWidget * image;

	obj->popup = NULL;
	obj->device = NULL;
	g_date_clear (&obj->date, 1);
	
	obj->box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 8);
	gtk_container_add (GTK_CONTAINER (obj), GTK_WIDGET (obj->box));
	VN_FIELD (obj)->field = obj->box;
	
	obj->button = gtk_toggle_button_new ();
	gtk_widget_set_tooltip_text (GTK_WIDGET (obj->button), _("Change date"));
	g_signal_connect (obj->button, "toggled",
		G_CALLBACK (vn_date_chooser_on_toggled), obj);
	gtk_box_pack_start (GTK_BOX (obj->box),
		GTK_WIDGET (obj->button), FALSE, FALSE, 0);
		
	image = gtk_image_new_from_stock (GTK_STOCK_EDIT, GTK_ICON_SIZE_BUTTON);
	gtk_button_set_image (GTK_BUTTON (obj->button), image);
	
	obj->label = GTK_LABEL (gtk_label_new (NULL));
	gtk_misc_set_alignment (GTK_MISC (obj->label), 0, 0.5);
	gtk_box_pack_end (GTK_BOX (obj->box),
		GTK_WIDGET (obj->label), TRUE, TRUE, 0);

	obj->popup = gtk_window_new (GTK_WINDOW_POPUP);		
	g_object_connect (obj->popup
		,"signal::button-press-event", vn_date_chooser_on_buton_press, obj
		,"signal::key-press-event", vn_date_chooser_on_key_press, obj
		,NULL
	);

	obj->calendar = GTK_CALENDAR (gtk_calendar_new ());
	g_signal_connect (obj->calendar, "day-selected-double-click",
		G_CALLBACK (vn_date_chooser_on_day_selected), obj);
	gtk_container_add (GTK_CONTAINER (obj->popup), GTK_WIDGET (obj->calendar));
}

static void vn_date_chooser_finalize (VnDateChooser * obj)
{
	gtk_widget_destroy (obj->popup);
	G_OBJECT_CLASS (vn_date_chooser_parent_class)->finalize (G_OBJECT (obj));
}

static void vn_date_chooser_class_init (VnDateChooserClass * klass)
{
	G_OBJECT_CLASS (klass)->finalize = (GObjectFinalizeFunc) vn_date_chooser_finalize;
	VN_FIELD_CLASS (klass)->set_value = (VnFieldSetValueFunc) vn_date_chooser_set_value;
}