#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "gtk/gtk.h"
#include "about_dialog.h"
#include "interface.h"

#define ANIMATION_STEPS 16


static int  about_dialog_load_logo (GtkWidget *window);
static void about_dialog_destroy (void);
static void about_dialog_unmap (void);
static int  about_dialog_logo_expose (GtkWidget *widget, GdkEventExpose *event);
static int  about_dialog_scroll_expose (GtkWidget *widget, GdkEventExpose *event);
static int  about_dialog_button (GtkWidget *widget, GdkEventButton *event);
static int  about_dialog_timer (gpointer data);


static GtkWidget *about_dialog = NULL;
static GtkWidget *logo_area = NULL;
static GtkWidget *scroll_area = NULL;
static GdkPixmap *logo_pixmap = NULL;
static GdkPixmap *scroll_pixmap = NULL;
static unsigned char *dissolve_map = NULL;
static int dissolve_width;
static int dissolve_height;
static int logo_width = 0;
static int logo_height = 0;
static int do_animation = 0;
static int do_scrolling = 0;
static int scroll_state = 0;
static int frame = 0;
static int offset = 0;
static int timer = 0;

static char *scroll_text[] =
{
  "Shawn Admunson",
  "Lauri Alanko",
  "John Beale",
  "Zach Beane",
  "Tom Bech",
  "Marc Bless",
  "Roberto Boyd",
  "Brent Burton",
  "Ed Connel",
  "Andreas Dilger",
  "Larry Ewing",
  "David Forsyth",
  "Jim Geuther",
  "Scott Goehring",
  "Heiko Goller",
  "Michael Hammel",
  "Christoph Hoegl",
  "Jan Hubicka",
  "Simon Janes",
  "Tim Janik",
  "Tuomas Kuosmanen",
  "Karl LaRocca",
  "Jens Lautenbacher",
  "Raph Levien",
  "Adrian Likins",
  "Ingo Luetkebohle",
  "Josh MacDonald",
  "Ed Mackey",
  "Marcelo Malheiros",
  "Ian Main",
  "Torsten Martinsen",
  "Federico Mena",
  "Adam D. Moss",
  "Shuji Narazaki",
  "Stephen Robert Norris",
  "Erik Nygren",
  "Miles O'Neal",
  "Jay Painter",
  "Mike Phillips",
  "Raphael Quinet",
  "James Robinson",
  "Mike Schaeffer",
  "Tracy Scott",
  "Eiichi Takamori",
  "Tristan Tarrant",
  "Owen Taylor",
  "Ian Tester",
  "James Wang",
  "Kris Wehner",
};
static int nscroll_texts = sizeof (scroll_text) / sizeof (scroll_text[0]);
static int scroll_text_widths[100] = { 0 };
static int cur_scroll_text = 0;


void
about_dialog_create (int timeout)
{
  GtkStyle *style;
  GtkWidget *vbox;
  GtkWidget *frame;
  GtkWidget *label;
  GtkWidget *alignment;
  gint max_width;
  gint i;

  if (!about_dialog)
    {
      about_dialog = gtk_window_new (GTK_WINDOW_DIALOG);
      gtk_window_set_title (GTK_WINDOW (about_dialog), "About the GIMP");
      gtk_window_set_policy (GTK_WINDOW (about_dialog), FALSE, FALSE, FALSE);
      gtk_window_position (GTK_WINDOW (about_dialog), GTK_WIN_POS_CENTER);
      gtk_signal_connect (GTK_OBJECT (about_dialog), "destroy",
			  (GtkSignalFunc) about_dialog_destroy, NULL);
      gtk_signal_connect (GTK_OBJECT (about_dialog), "delete_event",
			  (GtkSignalFunc) about_dialog_destroy, NULL);
      gtk_signal_connect (GTK_OBJECT (about_dialog), "unmap_event",
			  (GtkSignalFunc) about_dialog_unmap, NULL);
      gtk_signal_connect (GTK_OBJECT (about_dialog), "button_press_event",
			  (GtkSignalFunc) about_dialog_button, NULL);
      gtk_widget_set_events (about_dialog, GDK_BUTTON_PRESS_MASK);

      if (!about_dialog_load_logo (about_dialog))
	{
	  gtk_widget_destroy (about_dialog);
	  about_dialog = NULL;
	  return;
	}

      vbox = gtk_vbox_new (FALSE, 1);
      gtk_container_border_width (GTK_CONTAINER (vbox), 1);
      gtk_container_add (GTK_CONTAINER (about_dialog), vbox);
      gtk_widget_show (vbox);

      frame = gtk_frame_new (NULL);
      gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_IN);
      gtk_container_border_width (GTK_CONTAINER (frame), 0);
      gtk_box_pack_start (GTK_BOX (vbox), frame, TRUE, TRUE, 0);
      gtk_widget_show (frame);

      logo_area = gtk_drawing_area_new ();
      gtk_signal_connect (GTK_OBJECT (logo_area), "expose_event",
			  (GtkSignalFunc) about_dialog_logo_expose, NULL);
      gtk_drawing_area_size (GTK_DRAWING_AREA (logo_area), logo_width, logo_height);
      gtk_widget_set_events (logo_area, GDK_EXPOSURE_MASK);
      gtk_container_add (GTK_CONTAINER (frame), logo_area);
      gtk_widget_show (logo_area);

      gtk_widget_realize (logo_area);
      gdk_window_set_background (logo_area->window, &logo_area->style->black);


      style = gtk_style_new ();
      gdk_font_free (style->font);
      style->font = gdk_font_load ("-Adobe-Helvetica-Medium-R-Normal--*-140-*-*-*-*-*-*");
      gtk_widget_push_style (style);

      label = gtk_label_new ("Version 1.0 brought to you by");
      gtk_box_pack_start (GTK_BOX (vbox), label, FALSE, TRUE, 0);
      gtk_widget_show (label);

      label = gtk_label_new ("Spencer Kimball and Peter Mattis");
      gtk_box_pack_start (GTK_BOX (vbox), label, FALSE, TRUE, 0);
      gtk_widget_show (label);

      gtk_widget_pop_style ();


      alignment = gtk_alignment_new (0.5, 0.5, 0.0, 0.0);
      gtk_box_pack_start (GTK_BOX (vbox), alignment, FALSE, TRUE, 0);
      gtk_widget_show (alignment);

      frame = gtk_frame_new (NULL);
      gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_IN);
      gtk_container_border_width (GTK_CONTAINER (frame), 0);
      gtk_container_add (GTK_CONTAINER (alignment), frame);
      gtk_widget_show (frame);

      max_width = 0;
      for (i = 0; i < nscroll_texts; i++)
	{
	  scroll_text_widths[i] = gdk_string_width (frame->style->font, scroll_text[i]);
	  max_width = MAX (max_width, scroll_text_widths[i]);
	}

      scroll_area = gtk_drawing_area_new ();
      gtk_signal_connect (GTK_OBJECT (scroll_area), "expose_event",
			  (GtkSignalFunc) about_dialog_scroll_expose, NULL);
      gtk_drawing_area_size (GTK_DRAWING_AREA (scroll_area),
			     max_width + 10,
			     frame->style->font->ascent +
			     frame->style->font->descent);
      gtk_widget_set_events (scroll_area, GDK_EXPOSURE_MASK | GDK_BUTTON_PRESS_MASK);
      gtk_container_add (GTK_CONTAINER (frame), scroll_area);
      gtk_widget_show (scroll_area);

      gtk_widget_realize (scroll_area);
      gdk_window_set_background (scroll_area->window, &scroll_area->style->white);
    }

  if (!GTK_WIDGET_VISIBLE (about_dialog))
    {
      gtk_widget_show (about_dialog);

      do_animation = TRUE;
      do_scrolling = FALSE;
      scroll_state = 0;
      frame = 0;
      offset = 0;
    }
}


static int
about_dialog_load_logo (GtkWidget *window)
{
  GtkWidget *preview;
  char buf[1024];
  unsigned char *pixelrow;
  FILE *fp;
  int count;
  int i, j, k;

  if (logo_pixmap)
    return TRUE;

  sprintf (buf, "%s/gimp_logo.ppm", DATADIR);

  fp = fopen (buf, "r");
  if (!fp)
    return 0;

  fgets (buf, 1024, fp);
  if (strcmp (buf, "P6\n") != 0)
    {
      fclose (fp);
      return 0;
    }

  fgets (buf, 1024, fp);
  fgets (buf, 1024, fp);
  sscanf (buf, "%d %d", &logo_width, &logo_height);

  fgets (buf, 1024, fp);
  if (strcmp (buf, "255\n") != 0)
    {
      fclose (fp);
      return 0;
    }

  preview = gtk_preview_new (GTK_PREVIEW_COLOR);
  gtk_preview_size (GTK_PREVIEW (preview), logo_width, logo_height);
  pixelrow = g_new (guchar, logo_width * 3);

  for (i = 0; i < logo_height; i++)
    {
      count = fread (pixelrow, sizeof (unsigned char), logo_width * 3, fp);
      if (count != (logo_width * 3))
	{
	  gtk_widget_destroy (preview);
	  g_free (pixelrow);
	  fclose (fp);
	  return 0;
	}

      gtk_preview_draw_row (GTK_PREVIEW (preview), pixelrow, 0, i, logo_width);
    }

  gtk_widget_realize (window);
  logo_pixmap = gdk_pixmap_new (window->window, logo_width, logo_height, -1);
  gtk_preview_put (GTK_PREVIEW (preview),
		   logo_pixmap, window->style->black_gc,
		   0, 0, 0, 0, logo_width, logo_height);

  gtk_widget_destroy (preview);
  g_free (pixelrow);

  fclose (fp);

  dissolve_width = logo_width / 2;
  dissolve_height = logo_height / 2;

  dissolve_map = g_new (guchar, dissolve_width * dissolve_height);

  srand (time (NULL));

  for (i = 0, k = 0; i < dissolve_height; i++)
    for (j = 0; j < dissolve_width; j++, k++)
      dissolve_map[k] = rand () % ANIMATION_STEPS;

  return TRUE;
}

static void
about_dialog_destroy ()
{
  about_dialog = NULL;
  about_dialog_unmap ();
}

static void
about_dialog_unmap ()
{
  if (timer)
    {
      gtk_timeout_remove (timer);
      timer = 0;
    }
}

static int
about_dialog_logo_expose (GtkWidget      *widget,
			  GdkEventExpose *event)
{
  if (do_animation)
    {
      if (!timer)
	{
	  about_dialog_timer (widget);
	  timer = gtk_timeout_add (75, about_dialog_timer, NULL);
	}
    }
  else
    {
      /* If we draw beyond the boundaries of the pixmap, then X
	 will generate an expose area for those areas, starting
	 an infinite cycle. We now set allow_grow = FALSE, so
	 the drawing area can never be bigger than the preview.
         Otherwise, it would be necessary to intersect event->area
         with the pixmap boundary rectangle. */

      gdk_draw_pixmap (widget->window,
		       widget->style->black_gc,
		       logo_pixmap, 
		       event->area.x, event->area.y,
		       event->area.x, event->area.y,
		       event->area.width, event->area.height);
    }

  return FALSE;
}

static int
about_dialog_scroll_expose (GtkWidget      *widget,
			    GdkEventExpose *event)
{
  if (!scroll_pixmap)
    scroll_pixmap = gdk_pixmap_new (widget->window,
				    widget->allocation.width,
				    widget->allocation.height,
				    -1);

  gdk_window_clear (scroll_area->window);

  return FALSE;
}

static int
about_dialog_button (GtkWidget      *widget,
		     GdkEventButton *event)
{
  if (timer)
    gtk_timeout_remove (timer);
  timer = 0;
  frame = 0;

  gtk_widget_hide (about_dialog);

  return FALSE;
}

static int
about_dialog_timer (gpointer data)
{
  gint i, j, k;
  gint return_val;

  return_val = TRUE;

  if (do_animation)
    {
      for (i = 0, k = 0; i < dissolve_height; i++)
	for (j = 0; j < dissolve_width; j++, k++)
	  if (frame == dissolve_map[k])
	    {
	      gdk_draw_pixmap (logo_area->window,
			       logo_area->style->black_gc,
			       logo_pixmap,
			       j * 2, i * 2, j * 2, i * 2,
			       2, 2);
	    }

      frame += 1;

      if (frame == ANIMATION_STEPS)
	{
	  do_animation = FALSE;
	  do_scrolling = TRUE;
	  frame = 0;

	  timer = gtk_timeout_add (75, about_dialog_timer, NULL);

	  return FALSE;
	}
    }

  if (do_scrolling)
    {
      switch (scroll_state)
	{
	case 1:
	  scroll_state = 2;
	  timer = gtk_timeout_add (700, about_dialog_timer, NULL);
	  return_val = FALSE;
	  break;
	case 2:
	  scroll_state = 3;
	  timer = gtk_timeout_add (75, about_dialog_timer, NULL);
	  return_val = FALSE;
	  break;
	}

      if (offset > (scroll_text_widths[cur_scroll_text] + scroll_area->allocation.width))
	{
	  scroll_state = 0;
	  cur_scroll_text += 1;
	  if (cur_scroll_text == nscroll_texts)
	    cur_scroll_text = 0;

	  offset = 0;
	}

      gdk_draw_rectangle (scroll_pixmap,
			  scroll_area->style->white_gc,
			  TRUE, 0, 0,
			  scroll_area->allocation.width,
			  scroll_area->allocation.height);
      gdk_draw_string (scroll_pixmap,
		       scroll_area->style->font,
		       scroll_area->style->black_gc,
		       scroll_area->allocation.width - offset,
		       scroll_area->style->font->ascent,
		       scroll_text[cur_scroll_text]);
      gdk_draw_pixmap (scroll_area->window,
		       scroll_area->style->black_gc,
		       scroll_pixmap, 0, 0, 0, 0,
		       scroll_area->allocation.width,
		       scroll_area->allocation.height);

      offset += 15;
      if (scroll_state == 0)
	{
	  if (offset > ((scroll_area->allocation.width + scroll_text_widths[cur_scroll_text]) / 2))
	    {
	      scroll_state = 1;
	      offset = (scroll_area->allocation.width + scroll_text_widths[cur_scroll_text]) / 2;
	    }
	}
    }

  return return_val;
}
