/* ************************************************************************** */
/*                                       _____           _                    */
/*  p7screen/args.c                     |_   _|__  _   _| |__   ___ _   _     */
/*  | Project: p7utils                    | |/ _ \| | | | '_ \ / _ \ | | |    */
/*                                        | | (_) | |_| | | | |  __/ |_| |    */
/*  By: thomas <thomas@touhey.fr>         |_|\___/ \__,_|_| |_|\___|\__, |.fr */
/*  Last updated: 2017/01/16 23:55:55                               |___/     */
/*                                                                            */
/* ************************************************************************** */
#include "main.h"
#include <stdlib.h>
#include <ctype.h>
#include <getopt.h>

/* ************************************************************************** */
/*  Help and version messages                                                 */
/* ************************************************************************** */
/* Version message */
static const char version_message[] =
QUOTE(BIN) " - from " QUOTE(NAME) " v" QUOTE(VERSION) " (licensed under GPLv2)\n"
"Maintained by " QUOTE(MAINTAINER) ".\n"
"\n"
"This is free software; see the source for copying conditions.\n"
"There is NO warranty; not even for MERCHANTABILITY or\n"
"FITNESS FOR A PARTICULAR PURPOSE.";

/* Help message */
static const char help_main[] =
"Usage: " QUOTE(BIN) " [--help|-h] [--version|-v]\n"
"       [--com <device>]\n"
"\n"
"Displays the streamed screen from a CASIO fx calculator.\n"
"\n"
"Options are:\n"
"  -h, --help        Display this help page\n"
"  -v, --version     Displays the version\n"
"  --com <device>    The serial device, if you want to communicate with a\n"
"                    calculator connected using a USB-to-serial cable.\n"
"                    If this option isn't used, the program will look for a\n"
"                    calculator connected using direct USB.\n"
"  -z ZOOM           Change the zoom (1 to 16)\n"
"                    By default, the zoom will be " QUOTE(DEFAULT_ZOOM) ".\n"
"\n"
"Report bugs to " QUOTE(MAINTAINER) ".";

/* ************************************************************************** */
/*  Main function                                                             */
/* ************************************************************************** */
/**
 *	parse_args:
 *	Args parsing main function.
 *
 *	Inspired of the edits of my first experiment with getopt.
 *	Interesting, huh?
 *
 *	@arg	ac		the arguments count
 *	@arg	av		the arguments values
 *	@arg	device	pointer to the device
 *	@arg	zoom	pointer the zoom
 *	@arg	args	the parsed args pointer
 *	@return			0 if ok, other if not.
 */

int parse_args(int ac, char **av, const char **com, int *zoom)
{
	/* initialize args */
	*com = 0;
	*zoom = DEFAULT_ZOOM;

	/* define options */
	const char short_options[] = "hvz:";
	const struct option long_options[] = {
		{"help", no_argument, NULL, 'h'},
		{"version", no_argument, NULL, 'v'},
		{"com", required_argument, NULL, 'c'},
		{"zoom", required_argument, NULL, 'z'},
		{NULL, 0, NULL, 0}
	};

	/* get all options */
	int c; opterr = 0;
	int help = 0, version = 0;
	while ((c = getopt_long(ac, av, short_options, long_options, NULL)) != -1) {
		switch (c) {
		/* help */
		case 'h': help = 1; break;
		/* version */
		case 'v': version = 1; break;
		/* com port */
		case 'c': *com = optarg; break;
		/* zoom */
		case 'z':
			*zoom = atoi(optarg);
			if (*zoom <= 0 || *zoom > 16) {
				log("-z, --zoom: should be between 1 and 16");
				return (1);
			}
			break;

		/* error (ignore) */
		case '?':
			if (optopt == 'z')
				log("-z, --zoom: expected an argument\n");
			else if (optopt == 'c')
				log("--com: expected an argument\n");
			else
				break;
			return (1);
		}
	}

	/* check if there is any parameter */
	if (ac - optind)
		help = 1;

	/* print help or version if required, and return */
	if (version) puts(version_message);
	else if (help) puts(help_main);
	else return (0);
	return (1);
}