/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2013 - Hans-Kristian Arntzen
 * 
 *  RetroArch is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include "getopt_rarch.h"
#include "strl.h"
#include "posix_string.h"

#ifndef HAVE_GETOPT_LONG

#include <string.h>
#include "../boolean.h"
#include <stddef.h>
#include <stdlib.h>
#ifdef _MSC_VER
#include "../msvc/msvc_compat.h"
#endif
#include "../general.h"

char *optarg;
int optind, opterr, optopt;

static bool is_short_option(const char *str)
{
   return str[0] == '-' && str[1] != '-';
}

static bool is_long_option(const char *str)
{
   return str[0] == '-' && str[1] == '-';
}

static int find_short_index(char * const *argv)
{
   for (int index = 0; argv[index]; index++)
   {
      if (is_short_option(argv[index]))
         return index;
   }

   return -1;
}

static int find_long_index(char * const *argv)
{
   for (int index = 0; argv[index]; index++)
   {
      if (is_long_option(argv[index]))
         return index;
   }

   return -1;
}

static int parse_short(const char *optstring, char * const *argv)
{
   char arg = argv[0][1];
   if (arg == ':')
      return '?';

   const char *opt = strchr(optstring, arg);
   if (!opt)
      return '?';

   bool extra_opt = argv[0][2];
   bool takes_arg = opt[1] == ':';

   // If we take an argument, and we see additional characters,
   // this is in fact the argument (i.e. -cfoo is same as -c foo).
   bool embedded_arg = extra_opt && takes_arg;

   if (takes_arg)
   {
      if (embedded_arg)
      {
         optarg = argv[0] + 2;
         optind++;
      }
      else
      {
         optarg = argv[1];
         optind += 2;
      }

      return optarg ? opt[0] : '?';
   }
   else if (embedded_arg) // If we see additional characters, and they don't take arguments, this means we have multiple flags in one.
   {
      memmove(&argv[0][1], &argv[0][2], strlen(&argv[0][2]) + 1);
      return opt[0];
   }
   else
   {
      optind++;
      return opt[0];
   }
}

static int parse_long(const struct option *longopts, char * const *argv)
{
   const struct option *opt = NULL;
   for (size_t indice = 0; longopts[indice].name; indice++)
   {
      if (strcmp(longopts[indice].name, &argv[0][2]) == 0)
      {
         opt = &longopts[indice];
         break;
      }
   }

   if (!opt)
      return '?';
   
   // getopt_long has an "optional" arg, but we don't bother with that.
   if (opt->has_arg && !argv[1])
      return '?';

   if (opt->has_arg)
   {
      optarg = argv[1];
      optind += 2;
   }
   else
      optind++;

   if (opt->flag)
   {
      *opt->flag = opt->val;
      return 0;
   }
   else
      return opt->val;
}

static void shuffle_block(char **begin, char **last, char **end)
{
   ptrdiff_t len = last - begin;
   const char **tmp = (const char**)calloc(len, sizeof(const char*));
   rarch_assert(tmp);

   memcpy(tmp, begin, len * sizeof(const char*));
   memmove(begin, last, (end - last) * sizeof(const char*));
   memcpy(end - len, tmp, len * sizeof(const char*));

   free(tmp);
}

int getopt_long(int argc, char *argv[],
      const char *optstring, const struct option *longopts, int *longindex)
{
   (void)longindex;

   if (optind == 0)
      optind = 1;

   if (argc == 1)
      return -1;

   int short_index = find_short_index(&argv[optind]);
   int long_index  = find_long_index(&argv[optind]);

   // We're done here.
   if (short_index == -1 && long_index == -1)
      return -1;

   // Reorder argv so that non-options come last.
   // Non-POSIXy, but that's what getopt does by default.
   if ((short_index > 0) && ((short_index < long_index) || (long_index == -1)))
   {
      shuffle_block(&argv[optind], &argv[optind + short_index], &argv[argc]);
      short_index = 0;
   }
   else if ((long_index > 0) && ((long_index < short_index) || (short_index == -1)))
   {
      shuffle_block(&argv[optind], &argv[optind + long_index], &argv[argc]);
      long_index = 0;
   }

   rarch_assert(short_index == 0 || long_index == 0);

   if (short_index == 0)
      return parse_short(optstring, &argv[optind]);
   else if (long_index == 0)
      return parse_long(longopts, &argv[optind]);
   else
      return '?';
}

#endif

#ifndef HAVE_STRL

// Implementation of strlcpy()/strlcat() based on OpenBSD.

size_t strlcpy(char *dest, const char *source, size_t size)
{
   size_t src_size = 0;
   size_t n = size;

   if (n)
      while (--n && (*dest++ = *source++)) src_size++;

   if (!n)
   {
      if (size) *dest = '\0';
      while (*source++) src_size++;
   }

   return src_size;
}

size_t strlcat(char *dest, const char *source, size_t size)
{
   size_t len = strlen(dest);
   dest += len;

   if (len > size)
      size = 0;
   else
      size -= len;

   return len + strlcpy(dest, source, size);
}

#endif

#ifdef _WIN32

#undef strcasecmp
#undef strdup
#undef isblank
#undef strtok_r
#include <ctype.h>
#include <stdlib.h>
#include <stddef.h>
#include "strl.h"

#include <string.h>

int rarch_strcasecmp__(const char *a, const char *b)
{
   while (*a && *b)
   {
      int a_ = tolower(*a);
      int b_ = tolower(*b);
      if (a_ != b_)
         return a_ - b_;

      a++;
      b++;
   }

   return tolower(*a) - tolower(*b);
}

char *rarch_strdup__(const char *orig)
{
   size_t len = strlen(orig) + 1;
   char *ret = (char*)malloc(len);
   if (!ret)
      return NULL;

   strlcpy(ret, orig, len);
   return ret;
}

int rarch_isblank__(int c)
{
   return (c == ' ') || (c == '\t');
}

char *rarch_strtok_r__(char *str, const char *delim, char **saveptr)
{
   if (!saveptr || !delim)
      return NULL;

   if (str)
      *saveptr = str;

   char *first = NULL;

   do
   {
      first = *saveptr;
      while (*first && strchr(delim, *first))
         *first++ = '\0';

      if (*first == '\0')
         return NULL;

      char *ptr = first + 1;

      while (*ptr && !strchr(delim, *ptr))
         ptr++;

      *saveptr = ptr + (*ptr ? 1 : 0);
      *ptr     = '\0';
   } while (strlen(first) == 0);

   return first;
}

#endif