#include "libc.h"
#include "locale_impl.h"
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <wchar.h>

char* optarg;
int optind = 1, opterr = 1, optopt, __optpos, __optreset = 0;

#define optpos __optpos
weak_alias(__optreset, optreset);

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

int getopt(int argc, char* const argv[], const char* optstring) {
    int i;
    wchar_t c, d;
    int k, l;
    char* optchar;

    if (!optind || __optreset) {
        __optreset = 0;
        __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++;
    if ((k = mbtowc(&c, argv[optind] + optpos, MB_LEN_MAX)) < 0) {
        k = 1;
        c = 0xfffd; /* replacement char */
    }
    optchar = argv[optind] + optpos;
    optopt = c;
    optpos += k;

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

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

    i = 0;
    d = 0;
    do {
        l = mbtowc(&d, optstring + i, MB_LEN_MAX);
        if (l > 0)
            i += l;
        else
            i++;
    } while (l && d != c);

    if (d != c) {
        if (optstring[0] != ':' && opterr)
            __getopt_msg(argv[0], ": unrecognized option: ", optchar, k);
        return '?';
    }
    if (optstring[i] == ':') {
        if (optstring[i + 1] == ':')
            optarg = 0;
        else if (optind >= argc) {
            if (optstring[0] == ':')
                return ':';
            if (opterr)
                __getopt_msg(argv[0], ": option requires an argument: ", optchar, k);
            return '?';
        }
        if (optstring[i + 1] != ':' || optpos) {
            optarg = argv[optind++] + optpos;
            optpos = 0;
        }
    }
    return c;
}

weak_alias(getopt, __posix_getopt);