/*
* my_getopt.c - my re-implementation of getopt.
* Copyright 1997, 2000, 2001, 2002, 2006, Benjamin Sittler
*
* 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.
*/

#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "my_getopt.h"

int my_optind=1, my_opterr=1, my_optopt=0;
char *my_optarg=0;

/* reset argument parser to start-up values */
int my_getopt_reset(void)
{
    my_optind = 1;
    my_opterr = 1;
    my_optopt = 0;
    my_optarg = 0;
    return 0;
}

/* this is the plain old UNIX getopt, with GNU-style extensions. */
/* if you're porting some piece of UNIX software, this is all you need. */
/* this supports GNU-style permution and optional arguments */

int my_getopt(int argc, char * argv[], const char *opts)
{
    static int charind=0;
    const char *s;
    char mode, colon_mode;
    int off = 0, opt = -1;

    if(getenv("POSIXLY_CORRECT")) colon_mode = mode = '+';
    else {
        if((colon_mode = *opts) == ':') off ++;
        if(((mode = opts[off]) == '+') || (mode == '-')) {
            off++;
            if((colon_mode != ':') && ((colon_mode = opts[off]) == ':'))
                off ++;
        }
    }
    my_optarg = 0;
    if(charind) {
        my_optopt = argv[my_optind][charind];
        for(s=opts+off; *s; s++) if(my_optopt == *s) {
            charind++;
            if((*(++s) == ':') || ((my_optopt == 'W') && (*s == ';'))) {
                if(argv[my_optind][charind]) {
                    my_optarg = &(argv[my_optind++][charind]);
                    charind = 0;
                } else if(*(++s) != ':') {
                    charind = 0;
                    if(++my_optind >= argc) {
                        if(my_opterr) fprintf(stderr,
                            "%s: option requires an argument -- %c\n",
                            argv[0], my_optopt);
                        opt = (colon_mode == ':') ? ':' : '?';
                        goto my_getopt_ok;
                    }
                    my_optarg = argv[my_optind++];
                }
            }
            opt = my_optopt;
            goto my_getopt_ok;
        }
        if(my_opterr) fprintf(stderr,
            "%s: illegal option -- %c\n",
            argv[0], my_optopt);
        opt = '?';
        if(argv[my_optind][++charind] == '\0') {
            my_optind++;
            charind = 0;
        }
my_getopt_ok:
        if(charind && ! argv[my_optind][charind]) {
            my_optind++;
            charind = 0;
        }
    } else if((my_optind >= argc) ||
        ((argv[my_optind][0] == '-') &&
        (argv[my_optind][1] == '-') &&
        (argv[my_optind][2] == '\0'))) {
            my_optind++;
            opt = -1;
    } else if((argv[my_optind][0] != '-') ||
        (argv[my_optind][1] == '\0')) {
            char *tmp;
            int i, j, k;

            if(mode == '+') opt = -1;
            else if(mode == '-') {
                my_optarg = argv[my_optind++];
                charind = 0;
                opt = 1;
            } else {
                for(i=j=my_optind; i<argc; i++) if((argv[i][0] == '-') &&
                    (argv[i][1] != '\0')) {
                        my_optind=i;
                        opt=my_getopt(argc, argv, opts);
                        while(i > j) {
                            tmp=argv[--i];
                            for(k=i; k+1<my_optind; k++) argv[k]=argv[k+1];
                            argv[--my_optind]=tmp;
                        }
                        break;
                }
                if(i == argc) opt = -1;
            }
    } else {
        charind++;
        opt = my_getopt(argc, argv, opts);
    }
    if (my_optind > argc) my_optind = argc;
    return opt;
}

/* this is the extended getopt_long{,_only}, with some GNU-like
* extensions. Implements _getopt_internal in case any programs
* expecting GNU libc getopt call it.
*/

int _my_getopt_internal(int argc, char * argv[], const char *shortopts,
                        const struct option *longopts, int *longind,
                        int long_only)
{
    char mode, colon_mode = *shortopts;
    int shortoff = 0, opt = -1;

    if(getenv("POSIXLY_CORRECT")) colon_mode = mode = '+';
    else {
        if((colon_mode = *shortopts) == ':') shortoff ++;
        if(((mode = shortopts[shortoff]) == '+') || (mode == '-')) {
            shortoff++;
            if((colon_mode != ':') && ((colon_mode = shortopts[shortoff]) == ':'))
                shortoff ++;
        }
    }
    my_optarg = 0;
    if((my_optind >= argc) ||
        ((argv[my_optind][0] == '-') &&
        (argv[my_optind][1] == '-') &&
        (argv[my_optind][2] == '\0'))) {
            my_optind++;
            opt = -1;
    } else if((argv[my_optind][0] != '-') ||
        (argv[my_optind][1] == '\0')) {
            char *tmp;
            int i, j, k;

            opt = -1;
            if(mode == '+') return -1;
            else if(mode == '-') {
                my_optarg = argv[my_optind++];
                return 1;
            }
            for(i=j=my_optind; i<argc; i++) if((argv[i][0] == '-') &&
                (argv[i][1] != '\0')) {
                    my_optind=i;
                    opt=_my_getopt_internal(argc, argv, shortopts,
                        longopts, longind,
                        long_only);
                    while(i > j) {
                        tmp=argv[--i];
                        for(k=i; k+1<my_optind; k++)
                            argv[k]=argv[k+1];
                        argv[--my_optind]=tmp;
                    }
                    break;
            }
    } else if((!long_only) && (argv[my_optind][1] != '-'))
        opt = my_getopt(argc, argv, shortopts);
    else {
        int charind, offset;
        int found = 0, ind, hits = 0;

        if(((my_optopt = argv[my_optind][1]) != '-') && ! argv[my_optind][2]) {
            int c;

            ind = shortoff;
            while((c = shortopts[ind++])) {
                if(((shortopts[ind] == ':') ||
                    ((c == 'W') && (shortopts[ind] == ';'))) &&
                    (shortopts[++ind] == ':'))
                    ind ++;
                if(my_optopt == c) return my_getopt(argc, argv, shortopts);
            }
        }
        offset = 2 - (argv[my_optind][1] != '-');
        for(charind = offset;
            (argv[my_optind][charind] != '\0') &&
            (argv[my_optind][charind] != '=');
        charind++);
        for(ind = 0; longopts[ind].name && !hits; ind++)
            if((strlen(longopts[ind].name) == (size_t) (charind - offset)) &&
                (strncmp(longopts[ind].name,
                argv[my_optind] + offset, charind - offset) == 0))
                found = ind, hits++;
        if(!hits) for(ind = 0; longopts[ind].name; ind++)
            if(strncmp(longopts[ind].name,
                argv[my_optind] + offset, charind - offset) == 0)
                found = ind, hits++;
        if(hits == 1) {
            opt = 0;

            if(argv[my_optind][charind] == '=') {
                if(longopts[found].has_arg == 0) {
                    opt = '?';
                    if(my_opterr) fprintf(stderr,
                        "%s: option `--%s' doesn't allow an argument\n",
                        argv[0], longopts[found].name);
                } else {
                    my_optarg = argv[my_optind] + ++charind;
                    charind = 0;
                }
            } else if(longopts[found].has_arg == 1) {
                if(++my_optind >= argc) {
                    opt = (colon_mode == ':') ? ':' : '?';
                    if(my_opterr) fprintf(stderr,
                        "%s: option `--%s' requires an argument\n",
                        argv[0], longopts[found].name);
                } else my_optarg = argv[my_optind];
            }
            if(!opt) {
                if (longind) *longind = found;
                if(!longopts[found].flag) opt = longopts[found].val;
                else *(longopts[found].flag) = longopts[found].val;
            }
            my_optind++;
        } else if(!hits) {
            if(offset == 1) opt = my_getopt(argc, argv, shortopts);
            else {
                opt = '?';
                if(my_opterr) fprintf(stderr,
                    "%s: unrecognized option `%s'\n",
                    argv[0], argv[my_optind++]);
            }
        } else {
            opt = '?';
            if(my_opterr) fprintf(stderr,
                "%s: option `%s' is ambiguous\n",
                argv[0], argv[my_optind++]);
        }
    }
    if (my_optind > argc) my_optind = argc;
    return opt;
}

int my_getopt_long(int argc, char * argv[], const char *shortopts,
                   const struct option *longopts, int *longind)
{
    return _my_getopt_internal(argc, argv, shortopts, longopts, longind, 0);
}

int my_getopt_long_only(int argc, char * argv[], const char *shortopts,
                        const struct option *longopts, int *longind)
{
    return _my_getopt_internal(argc, argv, shortopts, longopts, longind, 1);
}