/***************************************************************************
 * Copyright 2000-2005 Nobby Noboru Hirano
 * All rights reserved
 *
 * Ntools BSD License
 * Version 1.0 March 2005
 *
 * Nobby Noboru Hirano <nobby@ntools.net>
 ***************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <math.h>

void crcut(char *s)
{
	char *p;

	if ((p = strchr(s, 0x0a)) != NULL) *p = '\0';
	if ((p = strchr(s, 0x0d)) != NULL) *p = '\0';
}

float get_float(char *msg)
{
	char buf[64];

	printf("%s: ", msg); fflush(stdout);
	if (fgets(buf, 63, stdin) == NULL) return -1;
	crcut(buf);
	return atof(buf);
}

int main(int argc, char *argv[])
{
	float diameter = 8;
	float pitch = 6;
	float rpm = 7000;
	float t;
	double g1, g2, th, psp;
	double k = 22.0, fin = 1.0, b = 3.0;
	int c, prop, cont = 0;


	while ((c = getopt (argc, argv, "Aa56Hwf:k:")) != EOF) {
		switch (c) {
		  case 'A': /* APC Peller */
		  case 'a':
			b = 3.08;
			k = 20.75;
			break;
		  case '5':
			diameter = 2.20; pitch = 4.5;
			fin = 3.0; k = 26.0; cont = 1;
			printf("GWS EDF55 default setting.\n");
			break;
		  case '6':
			diameter = 2.50; pitch = 4.0;
			fin = 3.0; k = 24.5; cont = 1;
			printf("GWS EDF64 default setting.\n");
			break;
		  case 'H':
			diameter = 2.20; pitch = 3.5;
			fin = 2.5; k = 31.6; cont = 1;
			printf("Hyperflow 56mm EDF default setting.\n");
			break;
		  case 'w':
			diameter = 3.5433; pitch = 4.3196;
			fin = 3.0; k = 37.0; cont = 1;
			printf("Wemotec Midifan default setting.\n");
			break;
		  case 'f':
			sscanf (optarg, "%dx", &prop);
			fin = (double)prop / 2.0;
			break;
		  case 'k':
			k = atof(optarg);
			break;
		  default:
			fprintf(stderr, "Usage: thrust -f [propeller fin] -k [k]\n");
			fprintf(stderr, "       thrust -A  for APC-E Propeller\n");
			fprintf(stderr, "       thrust -w  for Wemotec MidiFAN(90mm)\n");
			fprintf(stderr, "       thrust -H  for Hyperflow 56mm EDF\n");
			fprintf(stderr, "       thrust -5  for GWS EDF55\n");
			fprintf(stderr, "       thrust -6  for GWS EDF64\n");
			exit (1);
		}
	}

	if (optind < argc) {
		k = atof(argv[optind++]);
	}

	while(1) {
		if (!cont) {
			if ((t = get_float("Diameter")) < 0) break;
			if (t != 0) diameter = t;

			if ((t = get_float("Pitch")) < 0) break;
			if (t != 0) pitch = t;
		}

		if ((t = get_float("RPM")) < 0) break;
		if (t != 0) rpm = t;

		g1 = pow((double)diameter, b); g1 /= 1000.0;
		g2 = ((double)rpm / 1000.0) * ((double)rpm / 1000.0);
		th = ((double)pitch / 10.00) * g1 * g2 * k * fin;
		psp =((double)pitch * 0.0254) * (double)rpm * 60.0;	/* m/h */
		psp /= 1000.0;
		printf("Stationary thrust = %.2f g %.2f oz, speed = %.2fkm/h %.2fmph\n"
		       "diameter = %.2f, pitch = %.2f, %.1f rpm, k = %.1f\n\n", 
		       th, (th / 28.34952313), psp, (psp / 1.609344),
		       diameter, pitch, rpm, k);
	}
	putchar('\n');
	exit(0);
}