#include <stdlib.h>
#include <stdio.h>
#include <gtk/gtk.h>

#include "array.h"
#include "face.h"
#include "level.h"


static void draw_map(GtkWidget *widget, struct face *f)
{
	int x, y, z;
	guchar *rgbbuf, *p;

	rgbbuf = p = calloc(f->sx*f->sy, 3);
	if (!rgbbuf) {
		perror("calloc");
		exit(1);
	}
	for (y = f->sy-1; y >= 0; y--)
		for (x = 0; x != f->sx ; x++) {
			z = get(f->a, x+f->a->min_x, y+f->a->min_y);
			if (z == UNDEF) {
				p += 3;
				continue;
			}
			if (z == f->z_ref) {
				*p++ = 0;
				*p++ = 0;
				*p++ = 255;
				continue;
			}
			if (z < f->z_ref) {
				z = 255.0*(z-f->z_ref)/(f->z_ref-f->a->min_z);
				*p++ = 255;
				*p++ = z;
				*p++ = z;
			} else {
				z = 255.0*(f->z_ref-z)/(f->a->max_z-f->z_ref);
				*p++ = z;
				*p++ = 255;
				*p++ = z;
			}
		}
	gdk_draw_rgb_image(widget->window,
	    widget->style->fg_gc[GTK_STATE_NORMAL],
	    0, 0, f->sx, f->sy, GDK_RGB_DITHER_MAX, rgbbuf, f->sx*3);
	free(rgbbuf);
}


static void draw_image(GtkWidget *da, struct face *f)
{
	fprintf(stderr, "%d\n", f->z_ref);
	draw_map(da, f);
}


static gboolean scroll_event(GtkWidget *widget, GdkEventScroll *event,
    gpointer data)
{
	GtkWidget *da = gtk_bin_get_child(GTK_BIN(widget));
	struct face *f = data;

	switch (event->direction) {
	case GDK_SCROLL_UP:
		if (f->z_ref > f->a->min_z) {
			f->z_ref--;
			draw_image(da, f);
		}
		break;
	case GDK_SCROLL_DOWN:
		if (f->z_ref < f->a->max_z) {
			f->z_ref++;
			draw_image(da, f);
		}
		break;
	default:
		/* ignore */;
	}
	return TRUE;
}


static gboolean expose_event(GtkWidget *widget, GdkEventExpose *event,
    gpointer user_data)
{
	draw_image(widget, user_data);
	return TRUE;
}


static gboolean key_press_event(GtkWidget *widget, GdkEventKey *event,
    gpointer data)
{
	if (event->keyval == 'q')
		gtk_main_quit();
	return TRUE;
}


static void make_screen(GtkWidget *root, struct face *f)
{
	GtkWidget *evbox, *da;

	da = gtk_drawing_area_new();
	gtk_widget_set_size_request(da, f->sx, f->sy);
	evbox = gtk_event_box_new();
	gtk_container_add(GTK_CONTAINER(evbox), da);
	gtk_container_add(GTK_CONTAINER(root), evbox);
	gtk_widget_show_all(root);
	draw_map(da, f);

	g_signal_connect(G_OBJECT(evbox), "scroll-event",
	    G_CALLBACK(scroll_event), f);
	g_signal_connect(G_OBJECT(da), "expose-event",
	    G_CALLBACK(expose_event), f);
	g_signal_connect(G_OBJECT(root), "key-press-event",
	    G_CALLBACK(key_press_event), NULL);
}


void level(struct face *f)
{
	GtkWidget *root;

	root = gtk_window_new(GTK_WINDOW_TOPLEVEL);
	gtk_window_set_position(GTK_WINDOW(root), GTK_WIN_POS_CENTER);

#if 0
	/* get root->window */
	gtk_widget_show_all(root);
#endif

	g_signal_connect(G_OBJECT(root), "destroy",
	    G_CALLBACK(gtk_main_quit), NULL);
	make_screen(root, f);
	gtk_main();
}