/*

	getlopt: command line option/parameter parsing

	copyright ?-2008 by the mpg123 project - free software under the terms of the LGPL 2.1

	see COPYING and AUTHORS files in distribution or http://mpg123.org

	initially written Oliver Fromme

	old timestamp: Tue Apr  8 07:15:13 MET DST 1997

*/

#include "config.h"

#include "compat.h"

#include "getlopt.h"

#include "debug.h"

int loptind = 1;	/* index in argv[] */

int loptchr = 0;	/* index in argv[loptind] */

char *loptarg;		/* points to argument if present, else to option */

topt *findopt (int islong, char *opt, topt *opts)

{

	if (!opts)

		return (0);

	while (opts->lname) {

		if (islong) {

			if (!strcmp(opts->lname, opt))

				return (opts);

		}

		else

			if (opts->sname == *opt)

				return (opts);

		opts++;

	}

	return (0);

}

static int performoption (int argc, char *argv[], topt *opt)

{

	int result = GLO_CONTINUE;

	/* this really is not supposed to happen, so the exit may be justified to create asap ficing pressure */

	#define prog_error() \

	{ \

		fprintf(stderr, __FILE__ ":%i Option without type flag! This is a programming error! Developer: fix this ASAP to regain your honor.\n", __LINE__); \

		exit(1); \

	}

	debug2("performoption on %c / %s"

	,	opt->sname ? opt->sname : '_', opt->lname ? opt->lname : "");

	if (!(opt->flags & GLO_ARG)) { /* doesn't take argument */

		if (opt->var) {

			if (opt->flags & GLO_CHAR) /* var is *char */

			{

				debug1("char at %p", opt->var);

				*((char *) opt->var) = (char) opt->value;\

			}

			else if(opt->flags & GLO_LONG)

			{

				debug1("long at %p", opt->var);

				*( (long *) opt->var ) = opt->value;

			}

			else if(opt->flags & GLO_INT)

			{

				debug1("int at %p", opt->var);

				*( (int *) opt->var ) = (int) opt->value;

			}

			/* GLO_DOUBLE is not supported here */

			else prog_error();

			debug("casting assignment done");

		}

#if 0 /* Oliver: What was this for?! --ThOr */

		else

			result = opt->value ? opt->value : opt->sname;

#endif

	}

	else { /* requires argument */

		debug("argument required");

		if (loptind >= argc)

			return (GLO_NOARG);

		loptarg = argv[loptind++]+loptchr;

		loptchr = 0;

		if (opt->var) {

			if (opt->flags & GLO_CHAR) /* var is *char */

				*((char **) opt->var) = compat_strdup(loptarg); /* valgrind claims lost memory here */

			else if(opt->flags & GLO_LONG)

				*((long *) opt->var) = atol(loptarg);

			else if(opt->flags & GLO_INT)

				*((int *) opt->var) = atoi(loptarg);

			else if(opt->flags & GLO_DOUBLE)

				*((double *) opt->var) = atof(loptarg);

			else prog_error();

		}

#if 0 /* Oliver: What was this for?! --ThOr */

		else

			result = opt->value ? opt->value : opt->sname;

#endif

	}

	if (opt->func)

		opt->func(loptarg);

	debug4("result: %i (%p, %li, %i)", result, opt->var, opt->value, opt->sname);

	return (result);

}

int getsingleopt (int argc, char *argv[], topt *opts)

{

	char *thisopt;

	topt *opt;

	static char shortopt[2] = {0, 0};

	if (loptind >= argc)

		return (GLO_END);

	thisopt = argv[loptind];

	debug1("getsingleopt: %s", thisopt);

	if (!loptchr) { /* start new option string */

		if (thisopt[0] != '-' || !thisopt[1]) /* no more options */

			return (GLO_END);

		if (thisopt[1] == '-') { /* "--" */

			if (thisopt[2]) { /* long option */

				loptarg = thisopt+2;

				loptind++;

				if (!(opt = findopt(1, thisopt+2, opts)))

					return (GLO_UNKNOWN);

				else

					return (performoption(argc, argv, opt));

			}

			else { /* "--" == end of options */

				loptind++;

				return (GLO_END);

			}

		}

		else /* start short option(s) */

			loptchr = 1;

	}

	shortopt[0] = thisopt[loptchr];

	loptarg = shortopt;

	opt = findopt(0, thisopt+(loptchr++), opts);

	if (!thisopt[loptchr]) {

		loptind++;

		loptchr = 0;

	}

	if (!opt)

		return (GLO_UNKNOWN);

	else

		return (performoption(argc, argv, opt));

}

int getlopt (int argc, char *argv[], topt *opts)

{

	int result;

	while ((result = getsingleopt(argc, argv, opts)) == GLO_CONTINUE);

	return (result);

}

/* EOF */