/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
 * getopt function definitions for NOLIBC, adapted from musl libc
 * Copyright (C) 2005-2020 Rich Felker, et al.
 * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net>
 */

/* make sure to include all global symbols */
#include "nolibc.h"

#ifndef _NOLIBC_GETOPT_H
#define _NOLIBC_GETOPT_H

struct FILE;
static struct FILE *const stderr;
static int fprintf(struct FILE *stream, const char *fmt, ...);

__attribute__((weak,unused,section(".data.nolibc_getopt")))
char *optarg;

__attribute__((weak,unused,section(".data.nolibc_getopt")))
int optind = 1, opterr = 1, optopt;

static __attribute__((unused))
int getopt(int argc, char * const argv[], const char *optstring)
{
        static int __optpos;
        int i;
        char c, d;
        char *optchar;

        if (!optind) {
                __optpos = 0;
                optind = 1;
        }

        if (optind >= argc || !argv[optind])
                return -1;

        if (argv[optind][0] != '-') {
                if (optstring[0] == '-') {
                        optarg = argv[optind++];
                        return 1;
                }
                return -1;
        }

        if (!argv[optind][1])
                return -1;

        if (argv[optind][1] == '-' && !argv[optind][2])
                return optind++, -1;

        if (!__optpos)
                __optpos++;
        c = argv[optind][__optpos];
        optchar = argv[optind] + __optpos;
        __optpos++;

        if (!argv[optind][__optpos]) {
                optind++;
                __optpos = 0;
        }

        if (optstring[0] == '-' || optstring[0] == '+')
                optstring++;

        i = 0;
        d = 0;
        do {
                d = optstring[i++];
        } while (d && d != c);

        if (d != c || c == ':') {
                optopt = c;
                if (optstring[0] != ':' && opterr)
                        fprintf(stderr, "%s: unrecognized option: %c\n", argv[0], *optchar);
                return '?';
        }
        if (optstring[i] == ':') {
                optarg = NULL;
                if (optstring[i + 1] != ':' || __optpos) {
                        optarg = argv[optind++];
                        if (__optpos)
                                optarg += __optpos;
                        __optpos = 0;
                }
                if (optind > argc) {
                        optopt = c;
                        if (optstring[0] == ':')
                                return ':';
                        if (opterr)
                                fprintf(stderr, "%s: option requires argument: %c\n",
                                        argv[0], *optchar);
                        return '?';
                }
        }
        return c;
}

#endif /* _NOLIBC_GETOPT_H */