/*
 * EWeekViewMainItem - displays the background grid and dates for the Week and
 * Month calendar views.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 * Authors:
 *		Damon Chaplin <damon@ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>
#include <glib.h>
#include <glib/gi18n.h>

#include "e-week-view-main-item.h"
#include "ea-calendar.h"
#include "calendar-config.h"

#define E_WEEK_VIEW_MAIN_ITEM_GET_PRIVATE(obj) \
	(G_TYPE_INSTANCE_GET_PRIVATE \
	((obj), E_TYPE_WEEK_VIEW_MAIN_ITEM, EWeekViewMainItemPrivate))

struct _EWeekViewMainItemPrivate {
	EWeekView *week_view;
};

enum {
	PROP_0,
	PROP_WEEK_VIEW
};

static gpointer parent_class;

static gint
gdate_to_cal_weekdays (GDateWeekday wd)
{
	switch (wd) {
	case G_DATE_MONDAY: return CAL_MONDAY;
	case G_DATE_TUESDAY: return CAL_TUESDAY;
	case G_DATE_WEDNESDAY: return CAL_WEDNESDAY;
	case G_DATE_THURSDAY: return CAL_THURSDAY;
	case G_DATE_FRIDAY: return CAL_FRIDAY;
	case G_DATE_SATURDAY: return CAL_SATURDAY;
	case G_DATE_SUNDAY: return CAL_SUNDAY;
	default: break;
	}

	return 0;
}

static void
week_view_main_item_draw_day (EWeekViewMainItem *main_item,
                              gint day,
                              GDate *date,
                              GdkDrawable *drawable,
                              gint x,
                              gint y,
                              gint width,
                              gint height)
{
	EWeekView *week_view;
	GtkStyle *style;
	GdkGC *gc;
	gint right_edge, bottom_edge, date_width, date_x, line_y;
	gboolean show_day_name, show_month_name, selected;
	gchar buffer[128], *format_string;
	gint day_of_week, month, day_of_month, max_width;
	GdkColor *bg_color;
	PangoFontDescription *font_desc;
	PangoContext *pango_context;
	PangoFontMetrics *font_metrics;
	PangoLayout *layout;
	gboolean today = FALSE;
	cairo_t *cr;
	CalWeekdays working_days;

	week_view = e_week_view_main_item_get_week_view (main_item);
	style = gtk_widget_get_style (GTK_WIDGET (week_view));
	gc = week_view->main_gc;
	cr = gdk_cairo_create (drawable);

	/* Set up Pango prerequisites */
	font_desc = pango_font_description_copy (style->font_desc);
	pango_context = gtk_widget_get_pango_context (GTK_WIDGET (week_view));
	font_metrics = pango_context_get_metrics (pango_context, font_desc,
						  pango_context_get_language (pango_context));

	g_return_if_fail (gc != NULL);

	day_of_week = gdate_to_cal_weekdays (g_date_get_weekday (date));
	month = g_date_get_month (date);
	day_of_month = g_date_get_day (date);
	line_y = y + E_WEEK_VIEW_DATE_T_PAD +
		PANGO_PIXELS (pango_font_metrics_get_ascent (font_metrics)) +
		PANGO_PIXELS (pango_font_metrics_get_descent (font_metrics)) +
		E_WEEK_VIEW_DATE_LINE_T_PAD;

	if (!today) {
		struct icaltimetype tt;

		/* Check if we are drawing today */
		tt = icaltime_from_timet_with_zone (time (NULL), FALSE,
						    e_calendar_view_get_timezone (E_CALENDAR_VIEW (week_view)));
		today = g_date_get_year (date) == tt.year
			&& g_date_get_month (date) == tt.month
			&& g_date_get_day (date) == tt.day;
	}

	working_days = calendar_config_get_working_days ();

	/* Draw the background of the day. In the month view odd months are
	   one color and even months another, so you can easily see when each
	   month starts (defaults are white for odd - January, March, ... and
	   light gray for even). In the week view the background is always the
	   same color, the color used for the odd months in the month view. */
	if (today)
		bg_color = &week_view->colors[E_WEEK_VIEW_COLOR_TODAY_BACKGROUND];
	else if ((working_days & day_of_week) == 0)
		bg_color = &week_view->colors[E_WEEK_VIEW_COLOR_MONTH_NONWORKING_DAY];
	else if (week_view->multi_week_view && (month % 2 == 0))
		bg_color = &week_view->colors[E_WEEK_VIEW_COLOR_EVEN_MONTHS];
	else
		bg_color = &week_view->colors[E_WEEK_VIEW_COLOR_ODD_MONTHS];

	cairo_save (cr);
	gdk_cairo_set_source_color (cr, bg_color);
	cairo_rectangle (cr, x, y, width, height);
	cairo_fill (cr);
	cairo_restore (cr);

	/* Draw the lines on the right and bottom of the cell. The canvas is
	   sized so that the lines on the right & bottom edges will be off the
	   edge of the canvas, so we don't have to worry about them. */
	right_edge = x + width - 1;
	bottom_edge = y + height - 1;

	cairo_save (cr);
	gdk_cairo_set_source_color (cr,  &week_view->colors[E_WEEK_VIEW_COLOR_GRID]);
	cairo_set_line_width (cr, 0.7);
	cairo_move_to (cr, right_edge, y);
	cairo_line_to (cr, right_edge, bottom_edge);
	cairo_move_to (cr, x, bottom_edge);
	cairo_line_to (cr, right_edge, bottom_edge);
	cairo_stroke (cr);
	cairo_restore (cr);

	/* If the day is selected, draw the blue background. */
	cairo_save (cr);
	selected = TRUE;
	if (week_view->selection_start_day == -1
	    || week_view->selection_start_day > day
	    || week_view->selection_end_day < day)
		selected = FALSE;
	if (selected) {
		if (gtk_widget_has_focus (GTK_WIDGET (week_view))) {
			gdk_cairo_set_source_color (cr, &week_view->colors[E_WEEK_VIEW_COLOR_SELECTED]);
		} else {
			gdk_cairo_set_source_color (cr, &week_view->colors[E_WEEK_VIEW_COLOR_SELECTED]);
		}

		if (week_view->multi_week_view) {
			cairo_rectangle (cr, x + 2, y + 1,
					    width - 5,
					    E_WEEK_VIEW_DATE_T_PAD - 1 +
				PANGO_PIXELS (pango_font_metrics_get_ascent (font_metrics)) +
				PANGO_PIXELS (pango_font_metrics_get_descent (font_metrics)));
			cairo_fill (cr);
		} else {
			cairo_rectangle (cr, x + 2, y + 1,
				    width - 5, line_y - y);
			cairo_fill (cr);
		}
	}
	cairo_restore (cr);

	/* Display the date in the top of the cell.
	   In the week view, display the long format "10 January" in all cells,
	   or abbreviate it to "10 Jan" or "10" if that doesn't fit.
	   In the month view, only use the long format for the first cell and
	   the 1st of each month, otherwise use "10". */
	show_day_name = FALSE;
	show_month_name = FALSE;
	if (!week_view->multi_week_view) {
		show_day_name = TRUE;
		show_month_name = TRUE;
	} else if (day == 0 || day_of_month == 1) {
		show_month_name = TRUE;
	}

	/* Now find the longest form of the date that will fit. */
	max_width = width - 4;
	format_string = NULL;
	if (show_day_name) {
		if (week_view->max_day_width + week_view->digit_width * 2
		    + week_view->space_width * 2
		    + week_view->month_widths[month - 1] < max_width)
			/* strftime format %A = full weekday name, %d = day of
			   month, %B = full month name. You can change the
			   order but don't change the specifiers or add
			   anything. */
			format_string = _("%A %d %B");
		else if (week_view->max_abbr_day_width
			 + week_view->digit_width * 2
			 + week_view->space_width * 2
			 + week_view->abbr_month_widths[month - 1] < max_width)
			/* strftime format %a = abbreviated weekday name,
			   %d = day of month, %b = abbreviated month name.
			   You can change the order but don't change the
			   specifiers or add anything. */
			format_string = _("%a %d %b");
	}
	if (!format_string && show_month_name) {
		if (week_view->digit_width * 2 + week_view->space_width
		    + week_view->month_widths[month - 1] < max_width)
			/* strftime format %d = day of month, %B = full
			   month name. You can change the order but don't
			   change the specifiers or add anything. */
			format_string = _("%d %B");
		else if (week_view->digit_width * 2 + week_view->space_width
		    + week_view->abbr_month_widths[month - 1] < max_width)
			/* strftime format %d = day of month, %b = abbreviated
			   month name. You can change the order but don't
			   change the specifiers or add anything. */
			format_string = _("%d %b");
	}

	cairo_save (cr);
	if (selected) {
		gdk_cairo_set_source_color (
			cr, &week_view->colors[E_WEEK_VIEW_COLOR_DATES_SELECTED]);
	} else if (week_view->multi_week_view) {
		if (today) {
			gdk_cairo_set_source_color (
				cr, &week_view->colors[E_WEEK_VIEW_COLOR_TODAY]);
		} else {
			gdk_cairo_set_source_color (
				cr, &week_view->colors[E_WEEK_VIEW_COLOR_DATES]);
		}
	} else {
		gdk_cairo_set_source_color (
			cr, &week_view->colors[E_WEEK_VIEW_COLOR_DATES]);
	}

	if (today) {
		g_date_strftime (
			buffer, sizeof (buffer),
			 format_string ? format_string : "<b>%d</b>", date);
		pango_cairo_update_context (cr, pango_context);
		layout = pango_cairo_create_layout (cr);
		pango_layout_set_font_description (layout, font_desc);
		pango_layout_set_text (layout, buffer, -1);
		pango_layout_set_markup (layout, buffer, strlen (buffer));
	} else {
		g_date_strftime (buffer, sizeof (buffer),
				 format_string ? format_string : "%d", date);
		pango_cairo_update_context (cr, pango_context);
		layout = pango_cairo_create_layout (cr);
		pango_layout_set_font_description (layout, font_desc);
		pango_layout_set_text (layout, buffer, -1);
	}

	pango_layout_get_pixel_size (layout, &date_width, NULL);
	date_x = x + width - date_width - E_WEEK_VIEW_DATE_R_PAD;
	date_x = MAX (date_x, x + 1);

	cairo_translate (cr, date_x, y + E_WEEK_VIEW_DATE_T_PAD);
	pango_cairo_update_layout (cr, layout);
	pango_cairo_show_layout (cr, layout);
	cairo_restore (cr);
	g_object_unref (layout);

	/* Draw the line under the date. */
	if (!week_view->multi_week_view) {
		cairo_save (cr);
		gdk_cairo_set_source_color (
			cr, &week_view->colors[E_WEEK_VIEW_COLOR_GRID]);
		cairo_set_line_width (cr, 0.7);
		cairo_move_to (cr, x + E_WEEK_VIEW_DATE_LINE_L_PAD, line_y);
		cairo_line_to (cr, right_edge, line_y);
		cairo_stroke (cr);
		cairo_restore (cr);
	}
	pango_font_metrics_unref (font_metrics);
	pango_font_description_free (font_desc);
	cairo_destroy (cr);
}

static void
week_view_main_item_set_property (GObject *object,
                                  guint property_id,
                                  const GValue *value,
                                  GParamSpec *pspec)
{
	switch (property_id) {
		case PROP_WEEK_VIEW:
			e_week_view_main_item_set_week_view (
				E_WEEK_VIEW_MAIN_ITEM (object),
				g_value_get_object (value));
			return;
	}

	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
week_view_main_item_get_property (GObject *object,
                                  guint property_id,
                                  GValue *value,
                                  GParamSpec *pspec)
{
	switch (property_id) {
		case PROP_WEEK_VIEW:
			g_value_set_object (
				value, e_week_view_main_item_get_week_view (
				E_WEEK_VIEW_MAIN_ITEM (object)));
			return;
	}

	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
week_view_main_item_dispose (GObject *object)
{
	EWeekViewMainItemPrivate *priv;

	priv = E_WEEK_VIEW_MAIN_ITEM_GET_PRIVATE (object);

	if (priv->week_view != NULL) {
		g_object_unref (priv->week_view);
		priv->week_view = NULL;
	}

	/* Chain up to parent's dispose() method. */
	G_OBJECT_CLASS (parent_class)->dispose (object);
}

static void
week_view_main_item_update (GnomeCanvasItem *item,
                            gdouble *affine,
                            ArtSVP *clip_path,
                            gint flags)
{
	GnomeCanvasItemClass *canvas_item_class;

	/* Chain up to parent's update() method. */
	canvas_item_class = GNOME_CANVAS_ITEM_CLASS (parent_class);
	canvas_item_class->update (item, affine, clip_path, flags);

	/* The item covers the entire canvas area. */
	item->x1 = 0;
	item->y1 = 0;
	item->x2 = INT_MAX;
	item->y2 = INT_MAX;
}

static void
week_view_main_item_draw (GnomeCanvasItem *canvas_item,
                          GdkDrawable *drawable,
                          gint x,
                          gint y,
                          gint width,
                          gint height)
{
	EWeekViewMainItem *main_item;
	EWeekView *week_view;
	GDate date;
	gint num_days, day, day_x, day_y, day_w, day_h;

	main_item = E_WEEK_VIEW_MAIN_ITEM (canvas_item);
	week_view = e_week_view_main_item_get_week_view (main_item);
	g_return_if_fail (week_view != NULL);

	/* Step through each of the days. */
	date = week_view->first_day_shown;

	/* If no date has been set, we just use Dec 1999/January 2000. */
	if (!g_date_valid (&date))
		g_date_set_dmy (&date, 27, 12, 1999);

	num_days = week_view->multi_week_view ? week_view->weeks_shown * 7 : 7;
	for (day = 0; day < num_days; day++) {
		e_week_view_get_day_position (week_view, day,
					      &day_x, &day_y,
					      &day_w, &day_h);
		/* Skip any days which are outside the area. */
		if (day_x < x + width && day_x + day_w >= x
		    && day_y < y + height && day_y + day_h >= y) {
			week_view_main_item_draw_day (
				main_item, day, &date, drawable,
				day_x - x, day_y - y, day_w, day_h);
		}
		g_date_add_days (&date, 1);
	}
}

static gdouble
week_view_main_item_point (GnomeCanvasItem *item,
                           gdouble x,
                           gdouble y,
                           gint cx,
                           gint cy,
                           GnomeCanvasItem **actual_item)
{
	/* This is supposed to return the nearest item the the point
	 * and the distance.  Since we are the only item we just return
	 * ourself and 0 for the distance.  This is needed so that we
	 * get button/motion events. */
	*actual_item = item;

	return 0.0;
}

static void
week_view_main_item_class_init (EWeekViewMainItemClass *class)
{
	GObjectClass  *object_class;
	GnomeCanvasItemClass *item_class;

	parent_class = g_type_class_peek_parent (class);
	g_type_class_add_private (class, sizeof (EWeekViewMainItemPrivate));

	object_class = G_OBJECT_CLASS (class);
	object_class->set_property = week_view_main_item_set_property;
	object_class->get_property = week_view_main_item_get_property;
	object_class->dispose = week_view_main_item_dispose;

	item_class = GNOME_CANVAS_ITEM_CLASS (class);
	item_class->update = week_view_main_item_update;
	item_class->draw = week_view_main_item_draw;
	item_class->point = week_view_main_item_point;

	g_object_class_install_property (
		object_class,
		PROP_WEEK_VIEW,
		g_param_spec_object (
			"week-view",
			"Week View",
			NULL,
			E_TYPE_WEEK_VIEW,
			G_PARAM_READWRITE));

	/* init the accessibility support for e_week_view_main_item */
	e_week_view_main_item_a11y_init ();
}

static void
week_view_main_item_init (EWeekViewMainItem *main_item)
{
	main_item->priv = E_WEEK_VIEW_MAIN_ITEM_GET_PRIVATE (main_item);
}

GType
e_week_view_main_item_get_type (void)
{
	static GType type = 0;

	if (G_UNLIKELY (type == 0)) {
		const GTypeInfo type_info = {
			sizeof (EWeekViewMainItemClass),
			(GBaseInitFunc) NULL,
			(GBaseFinalizeFunc) NULL,
			(GClassInitFunc) week_view_main_item_class_init,
			(GClassFinalizeFunc) NULL,
			NULL,  /* class_data */
			sizeof (EWeekViewMainItem),
			0,     /* n_preallocs */
			(GInstanceInitFunc) week_view_main_item_init,
			NULL   /* value_table */
		};

		type = g_type_register_static (
			GNOME_TYPE_CANVAS_ITEM, "EWeekViewMainItem",
			&type_info, 0);
	}

	return type;
}

EWeekView *
e_week_view_main_item_get_week_view (EWeekViewMainItem *main_item)
{
	g_return_val_if_fail (E_IS_WEEK_VIEW_MAIN_ITEM (main_item), NULL);

	return main_item->priv->week_view;
}

void
e_week_view_main_item_set_week_view (EWeekViewMainItem *main_item,
                                     EWeekView *week_view)
{
	g_return_if_fail (E_IS_WEEK_VIEW_MAIN_ITEM (main_item));
	g_return_if_fail (E_IS_WEEK_VIEW (week_view));

	if (main_item->priv->week_view != NULL)
		g_object_unref (main_item->priv->week_view);

	main_item->priv->week_view = g_object_ref (week_view);

	g_object_notify (G_OBJECT (main_item), "week-view");
}