/*
 * drl2gp.c - KiCad drill file to gnuplot converter
 *
 * Written 2010 by Werner Almesberger
 * Copyright 2010 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.
 */

/*
 * KiCad drill files are in the Excellon format. The format is described here:
 *
 * http://www.excellon.com/manuals/program.htm
 *
 * Note that drl2gp currently only implements the subset necessary to process
 * the KiCad drill files encountered in a few projects, may not work correctly
 * for drill files from other projects, and will almost certainly fail in
 * tool-shattering ways when fed excellon files from other sources.
 */


#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <math.h>
#include <assert.h>


#define	MAX_ARGS	3
#define	MAX_TOOL	10

#define	MAX_STEP	0.01	/* max arc step, in mm */


static double tool_d[MAX_TOOL+1];
static FILE *out = NULL;
static int lineno = 1;

static int mill = 0;
static double depth, d0, d1;


#define	IN2MM(in)	((in)*25.4)
#define	MIL2MM(mil)	IN2MM((mil)/1000)


static void header(void)
{
	enum {
		ts_nl,		/* at beginning of line */
		ts_t,		/* seen a ^T */
		ts_metric,	/* parsing METRIC,... */
		ts_inch,	/* parsing INCH,... */
		ts_tc,		/* seen ^T\d+C */
		ts_skip,	/* skip to next \n */
	} state = ts_nl;
	int c, tool;
	double f = 1;
	double tmp;
	const char *next = NULL;
	int metric = 1;

	while ((c = getchar()) != EOF) {
		if (out) {
			if (fputc(c, out) == EOF) {
				perror("write");
				exit(1);
			}
		}
		switch (state) {
		case ts_nl:
			switch (c) {
			case 'T':
				state = ts_t;
				tool = 0;
				break;
			case 'I':
				state = ts_inch;
				next = "NCH";
				break;
			case 'M':
				state = ts_metric;
				next = "ETRIC";
				break;
			case '%':
				return;
			case '\n':
				lineno++;
				break;
			default:
				state = ts_skip;
				break;
			}
			break;
		case ts_inch:
			if (c == ',')
				metric = 0;
			else {
				if (c == *next++)
					break;
			}
			state = ts_skip;
			break;
		case ts_metric:
			if (c == ',')
				metric = 1;
			else {
				if (c == *next++)
					break;
			}
			state = ts_skip;
			break;
		case ts_t:
			if (isdigit(c))
				tool = tool*10+c-'0';
			else if (c != 'C')
				state = ts_skip;
			else {
				assert(c != '\n');
				if (tool > MAX_TOOL) {
					fprintf(stderr,
					    "tool index %d too large (> %d)\n",
					    tool, MAX_TOOL);
					exit(1);
				}
				tool_d[tool] = 0;
				f = 1;
				state = ts_tc;
			}
			break;
		case ts_tc:
			if (isdigit(c)) {
				tmp = c-'0';
				if (!metric)
					tmp = IN2MM(tmp);
				if (f == 1)
					tool_d[tool] =
					    tool_d[tool]*10+tmp;
				else {
					tool_d[tool] += f*tmp;
					f /= 10;
				}
			} else if (c == '.') {
				f = 0.1;
			} else if (c == '\n') {
				lineno++;
				state = ts_nl;
			} else {
				state = ts_skip;
			}
			break;
		default:
			if (c == '\n') {
				lineno++;
				state = ts_nl;
			} else {
				state = ts_skip;
			}
		}
	}
}


static double arc2angle(double arc, double r)
{
	return acos(1-arc*arc/(r*r)/2);
}


static void half_circle(double cx, double cy, double rx, double ry, double s)
{
	double m[4];
	double x = rx, y = ry, tmp;
	double a;

	m[0] = cos(s);
	m[1] = -sin(s);
	m[2] = -m[1];
	m[3] = m[0];

	for (a = 0; a < M_PI; a += s) {
		printf("%f %f %f\n", cx+x, cy+y, -depth);
		tmp = x*m[0]+y*m[1];
		y = x*m[2]+y*m[3];
		x = tmp;
	}
	printf("%f %f %f\n", cx-rx, cy-ry, -depth);
}


static void slot(double xa, double ya, double xb, double yb, double d)
{
	double dx = xb-xa;
	double dy = yb-ya;
	double cr = d/2;
	double tr = d0/2;
	double s = arc2angle(MAX_STEP, cr);
	double nx, ny;
	double f;

	assert(mill);
	f = (cr-tr)/hypot(dx, dy);
	nx = -dy*f;
	ny = dx*f;

	half_circle(xa, ya, nx, ny, s);
	half_circle(xb, yb, -nx, -ny, s);
	printf("%f %f %f\n\n", xa+nx, ya+ny, -depth);
}


static void circle(double cx, double cy, double d)
{
	double cr = d/2;
	double tr = d0/2;
	double s = arc2angle(MAX_STEP, cr);
	double a;

	assert(mill);
	for (a = 0; a < 2*M_PI; a += s)
		printf("%f %f %f\n",
		    cx+(cr-tr)*cos(a), cy+(cr-tr)*sin(a), -depth);
	printf("%f %f %f\n\n", cx+(cr-tr), cy, -depth);
}


static void drill(double x, double y)
{
	printf("%f %f %f\n\n", x, y, -depth);
}


static void do_cmd(char cmd, double v, int nl)
{
	static int active = 0;
	static int metric = 1;
	static int slotting = 0;
	static double x = 0, y = 0, x0 = 0, d = 0;
	int n = v;

	switch (cmd) {
	case 'M':
		switch (n) {
		case 30:	/* end of program */
			exit(0);
		case 47:	/* operator message */
			break;
		case 71:	/* metric measuring mode */
			metric = 1;
			break;
		case 72:	/* inch measuring mode */
			metric = 0;
			break;
		default:
			fprintf(stderr,
			    "unrecognized command M%d at line %d\n",
			    n, lineno);
			exit(1);
		}
		break;
	case 'G':
		switch (n) {
		case 5:		/* drill mode */
			break;
		case 85:	/* slot */
			x0 = x;
			slotting = 1;
			break;
		default:
			fprintf(stderr,
			    "unrecognized command G%d at line %d\n",
			    n, lineno);
			exit(1);
		}
		break;
	case 'T':
		if (!n) {
			active = 0;
			break;
		}
		if (n < 1 || n > MAX_TOOL || !tool_d[n]) {
			fprintf(stderr, "invalid tool T%d at line %d\n",
			    n, lineno);
			exit(1);
		}
		d = tool_d[n];
		if (mill)
			active = d >= d0;
		else
			active = d >= d0 && d <= d1;
		break;
	case 'X':
		x = metric ? v : IN2MM(v);
		break;
	case 'Y':
		if (!active) {
			slotting = 0;
			break;
		}
		if (!metric)
			v = IN2MM(v);
		if (slotting) {
			slot(x0, y, x, v, d);
			slotting = 0;
			break;
		}
		if (nl) {
			assert(d);
			if (d > d1)
				circle(x, v, d);
			else
				drill(x, v);
			break;
		}
		y = v;
		break;
	default:
		fprintf(stderr, "unrecognized command \"%c\" at line %d\n",
		    cmd, lineno);
		exit(1);
	}
}


static void body(void)
{
	char cmd = 0;
	double v = 0, f = 1;
	int c, s = 0;

	while ((c = getchar()) != EOF) {
		if (c == '\n') {
			lineno++;
			if (cmd)
				do_cmd(cmd, s ? -v : v, 1);
			cmd = 0;
		} else if (isdigit(c)) {
			if (f == 1)
				v = v*10+c-'0';
			else {
				v += f*(c-'0');
				f /= 10;
			}
		} else if (c == '.') {
			f = 0.1;
		} else if (c == '-') {
			s = !s;
		} else {
			if (cmd)
				do_cmd(cmd, s ? -v : v, 0);
			cmd = c;
			v = 0;
			f = 1;
			s = 0;
		}
	}
}


static void usage(const char *name)
{
	fprintf(stderr,
"usage: %s depth drill_d_min drill_d_max\n"
"usage: %s depth mill_d\n\n"
"  options can be placed anywhere. -i and -m can be repeated.\n\n"
"  -i           set units to imperial (mil)\n"
"  -m           set units to metric (mm, default)\n"
"  -f out-file  write filtered output to out-file\n"
    , name, name);
	exit(1);
}


int main(int argc, char **argv)
{
	const char *filtered = NULL;
	int metric = 1;
	double arg[MAX_ARGS];
	int n_arg = 0;
	char *end;
	double tmp;
	int i;

	for (i = 1; i != argc; i++) {
		if (*argv[i] != '-') {
			if (n_arg == MAX_ARGS)
				usage(*argv);
			tmp = strtod(argv[i], &end);
			if (*end)
				usage(*argv);
			if (!metric)
				tmp = MIL2MM(tmp);
			arg[n_arg++] = tmp;
			continue;
		}
		switch (argv[i][1]) {
		case 'i':
			if (argv[i][2])
				usage(*argv);
			metric = 0;
			break;
		case 'm':
			if (argv[i][2])
				usage(*argv);
			metric = 1;
			break;
		case 'f':
			if (filtered)
				usage(*argv);
			if (argv[i][2])
				filtered = argv[i]+2;
			else {
				i++;
				if (i == argc)
					usage(*argv);
				filtered = argv[i];
			}
			break;
		default:
			usage(*argv);
		}
	}

	depth = arg[0];
	d0 = arg[1];
	d1 = arg[2];

	switch (n_arg) {
	case 2:
		d1 = d0;
		mill = 1;
		break;
	case 3:
		mill = 0;
		break;
	default:
		usage(*argv);
	}

	header();
	body();

	return 0;
}