#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <time.h>
#include "c24lib/image/image.h"
#include "c24lib/image/draw.h"
#include "c24lib/image/pnm.h"

#include "pcb_draw.h"

int stat[100];

static inline void ray(image_t *i, double x, double y, double dx, double dy, int *out)
{
	pixel_t *p;
	int h = 0, xx, yy;
	do {
		x += dx;
		y += dy;
		xx = round(x);
		yy = round(y);
		p = &image_pix(i, xx, yy);
		h++;

	} while(p->r == 0);

	if (h < *out)
		*out = h;
}

static inline int height(image_t *i, int cx, int cy)
{
	pixel_t *p;
	double dx, dy;
	int h = i->sx + i->sy;
	p = &image_pix(i, cx, cy);
	if (p->r != 0)
		return 0;
	for(dy = -1.0; dy <= 1.0; dy+=0.27)
		for(dx = -1.0; dx <= 1.0; dx+=0.27)
			ray(i, (double)cx, (double)cy, dx, dy, &h);
	return h;
}

static int near(int *hg, int my, double cx, double cy, int width, int clear)
{
	int x1 = round(cx - 1), x2 = round(cx + 1);
	int y1 = round(cy - 1), y2 = round(cy + 1);
	int x, y;
	for(y = y1; y <= y2; y++) {
		for(x = x1; x <= x2; x++) {
			if (hg[x + y*width] == my) {
				if (clear)
					hg[x + y*width] = 0;
				return 1;
			}
		}
	}
	return 0;
}

static int find_line(image_t *trace, int *hg, int my, int cx, int cy, double ang, int width)
{
	double dx, dy, x, y, ex, ey;
	int len = -2;

	dx = cos(ang);
	dy = sin(ang);
	x = cx;
	y = cy;
	do {
		len++;
		x += dx;
		y += dy;
		if (trace != NULL) {
			image_pix(trace, (int)round(x), (int)round(y)) = pixel_blue;
			hg[(int)round(x) + (int)round(y) * width] = 0;
		}
	} while(near(hg, my, x, y, width, trace != NULL));
	ex = x;
	ey = y;
	x = cx;
	y = cy;
	do {
		len++;
		x -= dx;
		y -= dy;
		if (trace != NULL) {
			image_pix(trace, (int)round(x), (int)round(y)) = pixel_blue;
			hg[(int)round(x) + (int)round(y) * width] = 0;
		}
	} while(near(hg, my, x, y, width, trace != NULL));
	if (trace != NULL) {
		printf("stroke %d %d %d %d\n", (int)round(ex), (int)round(ey), (int)round(x), (int)round(y));
	}
	return len;
}

int main(int arc, char *argv[])
{
	image_t *ref;
	int *hg;
	int maxh = 0;
	int x, y, n, cutoff, end;
	char *ref_fn = "l.pnm";

	if (argv[1] != NULL)
		ref_fn = argv[1];

	ref = pnm_load(ref_fn);

	/* height map */
	hg = calloc(sizeof(int), ref->sx * ref->sy);
	for(y = 1; y < ref->sy-1; y++) {
		for(x = 1; x < ref->sy-1; x++) {
			int h = height(ref, x, y);
			if (h > maxh)
				maxh = h;
			stat[h]++;
			printf("%d", h);
			hg[x + y*ref->sx] = h;
		}
		printf("\n");
	}

	cutoff = 0;
	for(n = 1; n <= maxh; n++) {
		printf("h=%d %d\n", n, stat[n]);
		if ((n > 1) && (stat[n] < stat[n-1]/2) && (cutoff == 0)) {
			cutoff = n-1;
		}
	}

	printf("-- cutoff=%d\n", cutoff);
	end = ref->sx * ref->sy;
	for(n = 0; n < end; n++) {
		if (hg[n] == cutoff) {
			ref->pixmap[n] = pixel_red;
		}
		else if (ref->pixmap[n].r != 255) {
			ref->pixmap[n].r = 200;
			ref->pixmap[n].g = 200;
			ref->pixmap[n].b = 200;
		}
	}


	/* brute force lines */
	for(;;) {
		int best_len = 0, bestx, besty;
		double besta;
		for(n = 0; n < end; n++) {
			if (hg[n] == cutoff) {
				double a;
				int x, y;
				x = image_x(ref, ref->pixmap+n);
				y = image_y(ref, ref->pixmap+n);
				for(a = 0; a < M_PI; a+=0.1) {
					int len = find_line(NULL, hg, cutoff, x, y, a, ref->sx);
					if (len > best_len) {
						best_len = len;
						bestx = x;
						besty = y;
						besta = a;
					}
				}
			}
		}
		if (best_len <= cutoff*3)
			break;
		printf("len=%d\n", best_len);
		find_line(ref, hg, cutoff, bestx, besty, besta, ref->sx);
	}

	pnm_save(ref, "OUT.pnm");
}