#define _XOPEN_SOURCE /* glibc2 needs this */
#include <time.h>
#include <sys/time.h>
#include <glib/gprintf.h>
#include <gdk/gdkkeysyms.h>
#include <gtk/gtk.h>
#include <cairo.h>
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>

#define SECOND_INTERVAL  1000

#define DEFAULT_WIDTH  200
#define DEFAULT_HEIGHT 15

struct private {
	time_t time;
	time_t von_arrives;
	struct timeval tv_now;
	gchar  *ts;
	gchar  *msg;
	gfloat s;
};

static gboolean time_handler (GtkWidget* w)
{
	gtk_widget_queue_draw (w);
	return TRUE;
}

gboolean on_key_press (GtkWidget *widget, GdkEventKey *key, gpointer p) {
	if (key->type == GDK_KEY_PRESS)
	{
		switch (key->keyval)
		{
			case GDK_Escape :
				gtk_main_quit ();
			break;
		}
	}

	return FALSE;
}

static void paint (GtkWidget *widget, GdkEventExpose *eev, struct private *p) {
	gint width, height;
	cairo_t *cr;

	gint sec, min, hour, day;

	p->time = p->von_arrives - time(NULL);
	gettimeofday(&p->tv_now, NULL);
	
	localtime (&p->tv_now.tv_sec);
	
	day  = p->time / (3600*24);
	p->time -= day*(3600*24);

	hour = p->time / 3600;
	p->time -= hour*3600;
       
	min  = p->time/60;
	p->time -= min*60;

	sec  = p->time;

	g_sprintf(p->ts,
		  "Von arrives in %02dd %02d:%02d:%02d:%02d", 
		  day,  hour, min,  sec, 
		  (int) (99 - ((p->tv_now.tv_usec)/10e3)));
	
	width  = widget->allocation.width;
	height = widget->allocation.height;

	cr = gdk_cairo_create (widget->window);
	cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);

	
	cairo_set_source_rgba (cr, 1.0f, 1.0f, 1.0f, 0.4f);
	cairo_paint (cr);

	cairo_select_font_face (cr, "Sans", CAIRO_FONT_SLANT_NORMAL,
				            CAIRO_FONT_WEIGHT_BOLD);
		
	cairo_save (cr);
	  cairo_set_font_size (cr, 10*p->s);
	  cairo_move_to (cr, 10*p->s, 10*p->s);
	  cairo_set_source_rgba (cr, 0.0f, 0.0f, 0.0f, 1.0f);
	  cairo_show_text (cr, p->ts);
	cairo_restore (cr);

	cairo_destroy (cr);
}

static void install_colormap (GtkWidget *w) {
	GdkScreen* screen     = gtk_widget_get_screen (w);
	GdkColormap* colormap = gdk_screen_get_rgba_colormap (screen);

	if (!colormap)
		colormap = gdk_screen_get_rgb_colormap (screen);

	gtk_widget_set_colormap (w, colormap);
}	       


inline int parse_time (char *time, char *fmt, struct tm *tm) {
	char *s_res = NULL;
	if (time) {
		if ((s_res = strptime(time, fmt, tm)) == NULL) {
			printf("WARNING: couldn't parse time '%s' with format '%s'.\n",
			       time, fmt);
			return -1;
		} if (*s_res != '\0') {
			printf("WARNING: processing stoped at '%s'\n", s_res);
			return time - s_res;
		}
		return 0;
	}
	return -2;
}

gint usage (char *name) {
	return printf ("usage: %s [TIME[+FMT]].\n", name);
}

#define DFMT "%Y-%m-%d"
#define SFMT "%H:%M"

gint main (gint argc, gchar **argv) { 
	int c, option_index = 0;
	static struct option long_options[] ={
		{"date", 1, 0, 'd'},
		{"time", 1, 0, 't'},
		{"format", 1, 0, 'f'},
		{"size", 1, 0, 's'},
		{"help", 0, 0, 'h'},
		{0, 0, 0, 0}
	};
	
	char *s_time = NULL;
	char *s_full = NULL;
	char *s_date = NULL;

	char *s_dfmt = DFMT;
	char *s_tfmt = SFMT;
	char *s_fmt  = DFMT "-" SFMT; /* HACK HERE */

	GtkWidget *window;     

	struct private *p = malloc(sizeof(struct private));

	struct tm von_time = {
		.tm_min   = 40,
		.tm_hour  = 9,
		.tm_mday  = 14,
		.tm_mon   = 1,
		.tm_year  = 107,
	};       
	
	while ((c = getopt_long (argc, argv, "d:t:f:s:h",
				 long_options, &option_index)) != -1) {
		switch (c) {
		case 'd':
			s_date = optarg;
			break;
		case 't':
			s_time = optarg;
			break;
		case 'f':
			s_fmt  = optarg;
			break;
		case 's': 
			p->s   = strtod(optarg, NULL);
			break;
		case 'h':
		case '?':
			return usage(argv[0]);
		default:
			printf ("given %d (%c)\n", c, c);
		}
	}

	for (;optind < argc; optind++) {
		switch (*argv[optind]) {
		case '+':
			s_fmt = argv[optind] + 1;
			break;
		default: 
			if (s_time != NULL) 
				printf ("WARNING: overriding previously given time \n"
					"'%s'\n"
					"with '%s'.\n", s_time, argv[optind]);
			s_full = argv[optind];
		}
	}


	parse_time(s_date, s_dfmt, &von_time);
	parse_time(s_time, s_tfmt, &von_time);
	parse_time(s_full, s_fmt,  &von_time);
	
	if (time(NULL) > mktime(&von_time))
		printf("WARNING: given a date in the past !\n");

	p->ts =  g_strdup_printf("Von arrives in 00d 00:00:00:00");

	p->von_arrives =  mktime(&von_time);
	
	gtk_init(&argc, &argv);
	
	window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

	gtk_window_stick (GTK_WINDOW (window));
	gtk_window_set_keep_below (GTK_WINDOW (window), TRUE);

        gtk_window_set_skip_taskbar_hint (GTK_WINDOW (window), TRUE);
	gtk_window_set_skip_pager_hint   (GTK_WINDOW (window), TRUE);
	gtk_window_set_accept_focus      (GTK_WINDOW (window), FALSE);

	gtk_window_set_decorated (GTK_WINDOW (window), FALSE);
	gtk_window_set_resizable (GTK_WINDOW (window), TRUE);
	gtk_widget_set_app_paintable (window, TRUE);
	
	gtk_window_set_default_size (GTK_WINDOW (window),
				     DEFAULT_WIDTH*p->s,
				     DEFAULT_HEIGHT*p->s);

	install_colormap(window);
	
	gtk_widget_add_events (window, GDK_BUTTON_PRESS_MASK);

	g_signal_connect (G_OBJECT (window), "expose-event",
			  G_CALLBACK (paint),
			  p);
	
	g_signal_connect (G_OBJECT (window),
			  "key-press-event",
			  G_CALLBACK (on_key_press),
			  NULL);

	gtk_widget_show_all (window);

	gtk_timeout_add (SECOND_INTERVAL/9, (GtkFunction) time_handler, window);

	gtk_main ();
	
	g_free(p->ts);
	free(p);

	return 0;
}