/*
 * Copyright © 2005-2019 Rich Felker, et al.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/* This implementation was taken from musl and modified for RGBDS */

#include <stddef.h>
#include <stdlib.h>
#include <limits.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include "extern/getopt.h"

int __optpos, __optreset;

void musl__getopt_msg(const char *a, const char *b, const char *c, size_t l)
{
	FILE *f = stderr;
	(void)(fputs(a, f)>=0
	&& fwrite(b, strlen(b), 1, f)
	&& fwrite(c, 1, l, f)==l
	&& putc('\n', f));
}

static void permute(char **argv, int dest, int src)
{
	char **av = (char **)argv;
	char *tmp = av[src];
	int i;
	for (i=src; i>dest; i--)
		av[i] = av[i-1];
	av[dest] = tmp;
}

static int musl__getopt_long_core(int argc, char **argv, const char *optstring, const struct option *longopts, int *idx, int longonly);

static int musl__getopt_long(int argc, char **argv, const char *optstring, const struct option *longopts, int *idx, int longonly)
{
	int ret, skipped, resumed;
	if (!optind || __optreset) {
		__optreset = 0;
		__optpos = 0;
		optind = 1;
	}
	if (optind >= argc || !argv[optind]) return -1;
	skipped = optind;
	if (optstring[0] != '+' && optstring[0] != '-') {
		int i;
		for (i=optind; ; i++) {
			if (i >= argc || !argv[i]) return -1;
			if (argv[i][0] == '-' && argv[i][1]) break;
		}
		optind = i;
	}
	resumed = optind;
	ret = musl__getopt_long_core(argc, argv, optstring, longopts, idx, longonly);
	if (resumed > skipped) {
		int i, cnt = optind-resumed;
		for (i=0; i<cnt; i++)
			permute(argv, skipped, optind-1);
		optind = skipped + cnt;
	}
	return ret;
}

static int musl__getopt_long_core(int argc, char **argv, const char *optstring, const struct option *longopts, int *idx, int longonly)
{
	optarg = 0;
	if (longopts && argv[optind][0] == '-' &&
		((longonly && argv[optind][1] && argv[optind][1] != '-') ||
		 (argv[optind][1] == '-' && argv[optind][2])))
	{
		int colon = optstring[optstring[0]=='+'||optstring[0]=='-']==':';
		int i, cnt, match;
		char *arg, *opt, *start = argv[optind]+1;
		for (cnt=i=0; longopts[i].name; i++) {
			const char *name = longopts[i].name;
			opt = start;
			if (*opt == '-') opt++;
			while (*opt && *opt != '=' && *opt == *name)
				name++, opt++;
			if (*opt && *opt != '=') continue;
			arg = opt;
			match = i;
			if (!*name) {
				cnt = 1;
				break;
			}
			cnt++;
		}
		if (cnt==1 && longonly && arg-start == mblen(start, MB_LEN_MAX)) {
			int l = arg-start;
			for (i=0; optstring[i]; i++) {
				int j;
				for (j=0; j<l && start[j]==optstring[i+j]; j++);
				if (j==l) {
					cnt++;
					break;
				}
			}
		}
		if (cnt==1) {
			i = match;
			opt = arg;
			optind++;
			if (*opt == '=') {
				if (!longopts[i].has_arg) {
					optopt = longopts[i].val;
					if (colon || !opterr)
						return '?';
					musl__getopt_msg(argv[0],
						": option does not take an argument: ",
						longopts[i].name,
						strlen(longopts[i].name));
					return '?';
				}
				optarg = opt+1;
			} else if (longopts[i].has_arg == required_argument) {
				if (!(optarg = argv[optind])) {
					optopt = longopts[i].val;
					if (colon) return ':';
					if (!opterr) return '?';
					musl__getopt_msg(argv[0],
						": option requires an argument: ",
						longopts[i].name,
						strlen(longopts[i].name));
					return '?';
				}
				optind++;
			}
			if (idx) *idx = i;
			if (longopts[i].flag) {
				*longopts[i].flag = longopts[i].val;
				return 0;
			}
			return longopts[i].val;
		}
		if (argv[optind][1] == '-') {
			optopt = 0;
			if (!colon && opterr)
				musl__getopt_msg(argv[0], cnt ?
					": option is ambiguous: " :
					": unrecognized option: ",
					argv[optind]+2,
					strlen(argv[optind]+2));
			optind++;
			return '?';
		}
	}
	return getopt(argc, argv, optstring);
}

int musl_getopt_long_only(int argc, char **argv, const char *optstring, const struct option *longopts, int *idx)
{
	return musl__getopt_long(argc, argv, optstring, longopts, idx, 1);
}