/*
 * face.c - Data structure and handling of one face of a part
 *
 * Written 2010 by Werner Almesberger
 * Copyright 2010 by Werner Almesberger
 *
 * This program 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.
 */


#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <math.h>
#include <fcntl.h>
#include <sys/wait.h>

#include "util.h"
#include "array.h"
#include "histo.h"
#include "face.h"


#define	CACHE_DIR	".cache"
#define	DEFAULT_STEP	1		/* 1 mm */
#define	MIN_STEP	0.005		/* 5 um */


struct coord {
	float x, y, z;
};


static struct coord *load_file(const char *name)
{
	FILE *file;
	struct coord *v, *n;
	int s;

	if (!strcmp(name, "-")) {
		file = stdin;
	} else {
		int len;

		len = strlen(name);
		if (len > 4 && !strcmp(name+len-4, ".bz2")) {
			char tmp[1000]; /* @@@ enough */

			sprintf(tmp, "bzcat \"%s\"", name);
			file = popen(tmp, "r");
			if (!file) {
				perror(tmp);
				exit(1);
			}
		} else {
			file = fopen(name, "r");
			if (!file) {
				perror(name);
				exit(1);
			}
		}
	}

	v = n = alloc_type(struct coord);
	s = 1;

	while (fscanf(file, "%f,%f,%f\r\n", &n->x, &n->y, &n->z) == 3) {
		n++;
		if (n-v == s) {
			struct coord *tmp;

			s += s;
			tmp = realloc(v, sizeof(struct coord)*s);
			if (!tmp) {
				perror("realloc");
				exit(1);
			}
			n = n-v+tmp;
			v = tmp;
		}
	}
	if (file != stdin)
		(void) fclose(file);

	n->x = n->y = n->z = 0;
	return v;
}


static void adjust_step(double *step, double delta)
{
	double n = round(delta/MIN_STEP);
	double s = n*MIN_STEP;

	if (n && s < *step)
		*step = s;
}


static struct face *read_file(const char *name)
{
	struct coord *v, *p;
	struct face *f;
	struct histo *h;
	int xi, yi, zi;

	v = load_file(name);

	f = alloc_type(struct face);
	f->a = new_array();

	/*
	 * Hack: the MDX-15 measures bumps along the x axis with 25 um
	 * resolution, so we just ignore the x resultion we find and use the
	 * y resolution instead.
	 */
	f->x_step = f->y_step =f->z_step = DEFAULT_STEP;
	for (p = v; p[1].x || p[1].y || p[1].z; p++) {
		adjust_step(&f->y_step, fabs(p[0].y-p[1].y));
		adjust_step(&f->z_step, fabs(p[0].z-p[1].z));
	}
	f->x_step = f->y_step;

	for (p = v; p->x || p->y || p->z; p++) {
		xi = round(p->x/f->x_step);
		yi = round(p->y/f->y_step);
		zi = round(p->z/f->z_step);
		set(f->a, xi, yi, zi);
	}

	free(v);

	f->sx = f->a->max_x-f->a->min_x+1;
	f->sy = f->a->max_y-f->a->min_y+1;

	f->cx = (f->a->min_x+f->a->max_x)/2;
	f->cy = (f->a->min_y+f->a->max_y)/2;

	h = make_histo(f->a);
	f->z_ref = f->a->min_z+median(h);
	free_histo(h);
	f->fx = f->fy = 0;

	f->m.a[0][0] = f->m.a[1][1] = 1;
	f->m.a[0][1] = f->m.a[1][0] = 0;
	f->m.b[0] = f->m.b[1] = 0;

	fprintf(stderr, "%g %g %g\n", f->x_step, f->y_step, f->z_step);
	fprintf(stderr, "%d-%d / %d-%d / %d-%d\n",
	    f->a->min_x, f->a->max_x, f->a->min_y, f->a->max_y,
	    f->a->min_z, f->a->max_z);

	return f;
}


struct face *read_face(const char *name)
{
	const char *p;
	int cwd;
	struct face *face;

	if (strncmp(name, "http:", 5) && strncmp(name, "https:", 6))
		return read_file(name);
	p = strrchr(name, '/');
	if (!p || !p[1]) {
		fprintf(stderr, "malformed URL: \"%s\"\n", name);
		exit(1);
	}
	cwd = open(".", O_RDONLY);
	if (cwd < 0) {
		perror(".");
		exit(1);
	}
	if (chdir(CACHE_DIR) < 0) {
		perror(CACHE_DIR);
		exit(1);
	}
	if (access(p+1, R_OK) < 0) {
		char tmp[1000]; /* @@@ enough */
		int res;

		sprintf(tmp, "wget '%s'", name);
		res = system(tmp);
		if (res < 0) {
			perror("system");
			exit(1);
		}
		if (!WIFEXITED(res) || WEXITSTATUS(res)) {
			fprintf(stderr, "%s: status %d\n", tmp, res);
			exit(1);
		}
	}
	face = read_file(p+1);
	if (fchdir(cwd) < 0) {
		perror("fchdir");
		exit(1);
	}
	return face;
}