/*
 * Copyright (C) 2007-2010 Nick Schermer <nick@xfce.org>
 *
 * This library 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 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 General Public License for
 * more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

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

#ifdef HAVE_MATH_H
#include <math.h>
#endif
#ifdef HAVE_TIME_H
#include <time.h>
#endif

#include <gtk/gtk.h>
#include <cairo/cairo.h>

#include "clock.h"
#include "clock-analog.h"

#define CLOCK_SCALE 0.1
#define TICKS_TO_RADIANS(x)   (G_PI - (G_PI / 30.0) * (x))
#define HOURS_TO_RADIANS(x,y) (G_PI - (G_PI / 6.0) * (((x) > 12 ? (x) - 12 : (x)) + (y) / 60.0))



static void      xfce_clock_analog_set_property  (GObject              *object,
                                                  guint                 prop_id,
                                                  const GValue         *value,
                                                  GParamSpec           *pspec);
static void      xfce_clock_analog_get_property  (GObject              *object,
                                                  guint                 prop_id,
                                                  GValue               *value,
                                                  GParamSpec           *pspec);
static void      xfce_clock_analog_finalize      (GObject              *object);
static gboolean  xfce_clock_analog_expose_event  (GtkWidget            *widget,
                                                  GdkEventExpose       *event);
static void      xfce_clock_analog_draw_ticks    (cairo_t              *cr,
                                                  gdouble               xc,
                                                  gdouble               yc,
                                                  gdouble               radius);
static void      xfce_clock_analog_draw_pointer  (cairo_t              *cr,
                                                  gdouble               xc,
                                                  gdouble               yc,
                                                  gdouble               radius,
                                                  gdouble               angle,
                                                  gdouble               scale,
                                                  gboolean              line);
static gboolean  xfce_clock_analog_update        (gpointer              user_data);



enum
{
  PROP_0,
  PROP_SHOW_SECONDS,
  PROP_SIZE_RATIO,
  PROP_ORIENTATION
};

struct _XfceClockAnalogClass
{
  GtkImageClass __parent__;
};

struct _XfceClockAnalog
{
  GtkImage __parent__;

  ClockPluginTimeout *timeout;

  guint               show_seconds : 1;
};



XFCE_PANEL_DEFINE_TYPE (XfceClockAnalog, xfce_clock_analog, GTK_TYPE_IMAGE)



static void
xfce_clock_analog_class_init (XfceClockAnalogClass *klass)
{
  GObjectClass   *gobject_class;
  GtkWidgetClass *gtkwidget_class;

  gobject_class = G_OBJECT_CLASS (klass);
  gobject_class->set_property = xfce_clock_analog_set_property;
  gobject_class->get_property = xfce_clock_analog_get_property;
  gobject_class->finalize = xfce_clock_analog_finalize;

  gtkwidget_class = GTK_WIDGET_CLASS (klass);
  gtkwidget_class->expose_event = xfce_clock_analog_expose_event;

  g_object_class_install_property (gobject_class,
                                   PROP_SIZE_RATIO,
                                   g_param_spec_double ("size-ratio", NULL, NULL,
                                                        -1, G_MAXDOUBLE, 1.0,
                                                        G_PARAM_READABLE
                                                        | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_class,
                                   PROP_ORIENTATION,
                                   g_param_spec_enum ("orientation", NULL, NULL,
                                                      GTK_TYPE_ORIENTATION,
                                                      GTK_ORIENTATION_HORIZONTAL,
                                                      G_PARAM_WRITABLE
                                                      | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_class,
                                   PROP_SHOW_SECONDS,
                                   g_param_spec_boolean ("show-seconds", NULL, NULL,
                                                         FALSE,
                                                         G_PARAM_READWRITE
                                                         | G_PARAM_STATIC_STRINGS));
}



static void
xfce_clock_analog_init (XfceClockAnalog *analog)
{
  analog->show_seconds = FALSE;
  analog->timeout = clock_plugin_timeout_new (CLOCK_INTERVAL_MINUTE,
                                              xfce_clock_analog_update,
                                              analog);
}



static void
xfce_clock_analog_set_property (GObject      *object,
                                guint         prop_id,
                                const GValue *value,
                                GParamSpec   *pspec)
{
  XfceClockAnalog *analog = XFCE_CLOCK_ANALOG (object);

  switch (prop_id)
    {
    case PROP_ORIENTATION:
      break;

    case PROP_SHOW_SECONDS:
      analog->show_seconds = g_value_get_boolean (value);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }

  /* reschedule the timeout and redraw */
  clock_plugin_timeout_set_interval (analog->timeout,
      analog->show_seconds ? CLOCK_INTERVAL_SECOND : CLOCK_INTERVAL_MINUTE);
  xfce_clock_analog_update (analog);
}



static void
xfce_clock_analog_get_property (GObject    *object,
                                guint       prop_id,
                                GValue     *value,
                                GParamSpec *pspec)
{
  XfceClockAnalog *analog = XFCE_CLOCK_ANALOG (object);

  switch (prop_id)
    {
    case PROP_SHOW_SECONDS:
      g_value_set_boolean (value, analog->show_seconds);
      break;

    case PROP_SIZE_RATIO:
      g_value_set_double (value, 1.0);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }
}



static void
xfce_clock_analog_finalize (GObject *object)
{
  /* stop the timeout */
  clock_plugin_timeout_free (XFCE_CLOCK_ANALOG (object)->timeout);

  (*G_OBJECT_CLASS (xfce_clock_analog_parent_class)->finalize) (object);
}



static gboolean
xfce_clock_analog_expose_event (GtkWidget      *widget,
                                GdkEventExpose *event)
{
  XfceClockAnalog *analog = XFCE_CLOCK_ANALOG (widget);
  gdouble          xc, yc;
  gdouble          angle, radius;
  cairo_t         *cr;
  struct tm        tm;

  panel_return_val_if_fail (XFCE_CLOCK_IS_ANALOG (analog), FALSE);

  /* get center of the widget and the radius */
  xc = (widget->allocation.width / 2.0);
  yc = (widget->allocation.height / 2.0);
  radius = MIN (xc, yc);

  /* add the window offset */
  xc += widget->allocation.x;
  yc += widget->allocation.y;

  /* get the cairo context */
  cr = gdk_cairo_create (widget->window);

  if (G_LIKELY (cr != NULL))
    {
      /* clip the drawing region */
      gdk_cairo_rectangle (cr, &event->area);
      cairo_clip (cr);

      /* get the local time */
      clock_plugin_get_localtime (&tm);

      /* set the line properties */
      cairo_set_line_width (cr, 1);
      gdk_cairo_set_source_color (cr, &widget->style->fg[GTK_WIDGET_STATE (widget)]);

      /* draw the ticks */
      xfce_clock_analog_draw_ticks (cr, xc, yc, radius);

      if (analog->show_seconds)
        {
          /* second pointer */
          angle = TICKS_TO_RADIANS (tm.tm_sec);
          xfce_clock_analog_draw_pointer (cr, xc, yc, radius, angle, 0.7, TRUE);
        }

      /* minute pointer */
      angle = TICKS_TO_RADIANS (tm.tm_min);
      xfce_clock_analog_draw_pointer (cr, xc, yc, radius, angle, 0.8, FALSE);

      /* hour pointer */
      angle = HOURS_TO_RADIANS (tm.tm_hour, tm.tm_min);
      xfce_clock_analog_draw_pointer (cr, xc, yc, radius, angle, 0.5, FALSE);

      /* cleanup */
      cairo_destroy (cr);
    }

  return FALSE;
}



static void
xfce_clock_analog_draw_ticks (cairo_t *cr,
                              gdouble  xc,
                              gdouble  yc,
                              gdouble  radius)
{
  gint    i;
  gdouble x, y, angle;

  for (i = 0; i < 12; i++)
    {
      /* calculate */
      angle = HOURS_TO_RADIANS (i, 0);
      x = xc + sin (angle) * (radius * (1.0 - CLOCK_SCALE));
      y = yc + cos (angle) * (radius * (1.0 - CLOCK_SCALE));

      /* draw arc */
      cairo_move_to (cr, x, y);
      cairo_arc (cr, x, y, radius * CLOCK_SCALE, 0, 2 * G_PI);
      cairo_close_path (cr);
    }

  /* fill the arcs */
  cairo_fill (cr);
}



static void
xfce_clock_analog_draw_pointer (cairo_t *cr,
                                gdouble  xc,
                                gdouble  yc,
                                gdouble  radius,
                                gdouble  angle,
                                gdouble  scale,
                                gboolean line)
{
  gdouble xs, ys;
  gdouble xt, yt;

  /* calculate tip position */
  xt = xc + sin (angle) * radius * scale;
  yt = yc + cos (angle) * radius * scale;

  if (line)
    {
      /* draw the line */
      cairo_move_to (cr, xc, yc);
      cairo_line_to (cr, xt, yt);

      /* draw the line */
      cairo_stroke (cr);
    }
  else
    {
      /* calculate start position */
      xs = xc + sin (angle - 0.5 * G_PI) * radius * CLOCK_SCALE;
      ys = yc + cos (angle - 0.5 * G_PI) * radius * CLOCK_SCALE;

      /* draw the pointer */
      cairo_move_to (cr, xs, ys);
      cairo_arc (cr, xc, yc, radius * CLOCK_SCALE, -angle + G_PI, -angle);
      cairo_line_to (cr, xt, yt);
      cairo_close_path (cr);

      /* fill the pointer */
      cairo_fill (cr);
    }
}



static gboolean
xfce_clock_analog_update (gpointer user_data)
{
  GtkWidget *widget = GTK_WIDGET (user_data);

  panel_return_val_if_fail (XFCE_CLOCK_IS_ANALOG (user_data), FALSE);

  /* update if the widget if visible */
  if (G_LIKELY (GTK_WIDGET_VISIBLE (widget)))
    gtk_widget_queue_draw (widget);

  return TRUE;
}



GtkWidget *
xfce_clock_analog_new (void)
{
  return g_object_new (XFCE_CLOCK_TYPE_ANALOG, NULL);
}
