/*
 * gp2rml.c - Convert from gnuplot to RML
 *
 * Written 2010-2013, 2015 by Werner Almesberger
 * Copyright 2010-2013, 2015 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.
 */

/*
 * When setting the pen up and pen down positions (!PZ), pen up must be a
 * zero or positive coordinate relative to Z0 and pen down must be negative
 * or zero.
 *
 * Our pen up position is defined as the maximum pen down height plus some
 * clearance. All Z coordinates are relative to Z0.
 *
 * All this means that we have to set Z0 (with !ZO, that's zet-oh) such that
 * it is between the maximum pen down and pen up. Since pen up is also defined
 * via the maximum pen down, we have to read all coordinates before we can
 * calculate Z0 and then emit the correct positioning commands. Yuck.
 *
 * We choose Z0 = maximum pen down.
 */

/*
 * @@@ speed selection anomaly:
 *
 * Seems that !ZZ movements of the MDX-15 only use !VZ and VS is completely
 * ignored.
 */

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <math.h>


#define	V_MAX	15.0


struct segment {
	double x, y, z;
	struct segment *next;
};

struct path {
	struct segment *segments;
	struct path *next;
};


static struct path *paths = NULL, *curr_path;
static struct segment **next_seg;
static double z_max = -1e6; /* -1 km :) */
static double z_scale = 1; /* < 1: compress; > 1: stretch */


#define units(mm)	((int) round((mm) * 40.0))


#define alloc_type(t) \
    ({	t *alloc_tmp = malloc(sizeof(t));	\
	if (!alloc_tmp)				\
		abort();			\
	alloc_tmp; })


static void new_path(void)
{
	struct path *new;

	new = alloc_type(struct path);
	if (paths)
		curr_path->next = new;
	else
		paths = new;
	curr_path = new;
	new->segments = NULL;
	new->next = NULL;
	next_seg = &new->segments;
}


static void process_file(FILE *file)
{
	int lineno = 0;
	char buf[1024];
	double x, y, z;
	int n;
	struct segment *seg;

	new_path();
	while (fgets(buf, sizeof(buf), file)) {
		lineno++;
		if (*buf == '!' || *buf == '#')
			continue;
		n = sscanf(buf, "%lf %lf %lf\n", &x, &y, &z);
		switch (n) {
		case -1:
			if (curr_path->segments)
				new_path();
			continue;
		case 2:
			z = 0;
			/* fall through */
		case 3:
			break;
		default:
			fprintf(stderr, "invalid data at line %d\n", lineno);
			exit(1);
		}
		seg = alloc_type(struct segment);
		seg->x = x;
		seg->y = y;
		seg->z = z;
		seg->next = NULL;
		*next_seg = seg;
		next_seg = &seg->next;
		if (z_max < z)
			z_max = z;
	}
}


static void output_paths(double z_clear, double xy_speed, double z_speed)
{
	const struct path *path;
	const struct segment *seg;
	double x = 0, y = 0, z = 0;
	double d, s = 0, t = 0;
	double txy, tz;

	printf("IN;!MC1;PA\n");
	printf("!ZO%d;!PZ0,%d;PU\n", units(z_max), units(z_clear));
	printf("VS%f;!VZ%f\n", xy_speed, z_speed);

	for (path = paths; path; path = path->next) {
		seg = path->segments; 
		if (!seg)
			continue;
		printf("!PZ%d,%d;PA%d,%d;PD\n",
		    units(seg->z-z_max), units(z_clear),
		    units(seg->x), units(seg->y));
		d = hypot(x - seg->x, y - seg->y);
		s += d;
		s += z - z_max;
		t += d / V_MAX;
		t += (z - z_max) / z_speed;
		x = seg->x;
		y = seg->y;
		z = seg->z;
		seg = seg->next;
		while (seg) {
			printf("!ZZ%d,%d,%d\n", units(seg->x), units(seg->y),
			    units((seg->z - z_max) * z_scale));
			d = hypot(x - seg->x, y - seg->y);
			txy = d / xy_speed;
			tz = fabs(z - seg->z) / z_speed;
			t += txy > tz ? txy : tz;
			d = hypot(d, z - seg->z);
			s += d;
			x = seg->x;
			y = seg->y;
			z = seg->z;
			seg = seg->next;
		}
		printf("PU\n");
		d = z_max + z_clear - z;
		s += d;
		t += d / V_MAX;
		z = z_max + z_clear;
	}

	printf("!MC0;!ZO0;!PZ0,0;PU0,0;IN\n");
	d = -z + hypot(x, y);
	s += d;
	t += d / V_MAX;
	fprintf(stderr, "Distance %.1f mm, time %.1f s\n", s, t);
}


static void usage(const char *name)
{
	fprintf(stderr,
"usage: %s [-s z_scale] z_clear[mm] xy_speed z_speed [file]\n\n"
"  -s z_scale scale Z axis by z_scale (default: 1.0)\n"
"  z_clear    clearance above the highest peak, in mm (must be > 0)\n"
"             Unit (\"mm\") can optionally be specified\n"
"  xy_speed   cutting speed, in mm/s\n"
"  z_speed    vertical speed when lowering the pen, in mm/s\n"
    , name);
	exit(1);
}


int main(int argc, char *const *argv)
{
	FILE *file;
	char *end;
	int i;
	double p[3];
	int c;

	 while ((c = getopt(argc, argv, "s:")) != EOF)
		switch (c) {
		case 's':
			z_scale = strtod(optarg &end);
			if (*end)
				usage(*argv);
			break;
		default:
			usage(*argv);
		}

	switch (argc - optind) {
	case 3:
		file = stdin;
		break;
	case 4:
		file = fopen(argv[optind + 3], "r");
		if (!file) {
			perror(argv[optind + 3]);
			return 1;
		}
		break;
	default:
		usage(*argv);
	}
	for (i = 0; i != 3; i++) {
		p[i] = strtod(argv[optind + i], &end);
		/*
		 * Allow the clearance to have a unit, for consistency in
		 * mkmk-simple
		 */
		if (!i && *end && !strcmp(end, "mm"))
			continue;
		if (*end || p[i] <= 0)
			usage(*argv);
	}

	process_file(file);
	output_paths(p[0], p[1], p[2]);

	if (ferror(stdout))
		perror("stdout");
	if (fclose(stdout) == EOF)
		perror("stdout");

	return 0;
}