#include <glib.h>
#include <string.h>
#include <unicode.h>
#include <errno.h>

typedef char utfchar;


int get_local_charset(char **charset) 
{

    char *cst = "ISO-8859-1";
    *charset = cst;
    
    return 0;
}


static unicode_iconv_t conv_u2l = (unicode_iconv_t)0;
static int local_is_utf8 = 0;

static void 
check_conv_u2l(void){
  char *charset = NULL;
  
  if (local_is_utf8 || (conv_u2l!=(unicode_iconv_t)0)) return;
  local_is_utf8 = get_local_charset(&charset);
  if (local_is_utf8) return;

  conv_u2l = unicode_iconv_open(charset,"UTF-8");
}
  
extern gchar *
charconv_utf8_to_local8(const utfchar *utf)
{
  const utfchar *u = utf;
  int uleft = strlen(utf);
  gchar *local,*l,*lres;
  int lleft;
  int lost = 0;

  g_assert(utf);
  if (!utf) return NULL; /* GIGO */

  check_conv_u2l();
  if (local_is_utf8) return g_strdup(utf);

  lleft = uleft +2;
  l = local = g_malloc(lleft+2);
  *l = 0;
  unicode_iconv(conv_u2l,NULL,NULL,NULL,NULL); /* reset the state machines */
  while ((uleft) && (lleft)) {
    ssize_t res = unicode_iconv(conv_u2l,
                                &u,&uleft,
                                &l,&lleft);
    *l = 0;
    if (res==(ssize_t)-1) {
      g_warning("unicode_iconv(u2l,...) failed, because '%s'",
                strerror(errno));
      break;
    } else {
      lost += (int)res; /* lost chars in the process. */
    }
  }
  lres = g_strdup(local); /* get the actual size. */
  g_free(local); 
  return lres;
}

utfchar *test0_data = "pépère"; // latin1
utfchar *test_data = "これは日本語のテストです";
utfchar *test2_data = "ｺﾚﾊﾊﾝｶｸｶﾀｶﾅﾉﾃｽﾄﾃﾞｽ";
utfchar *test3_data = "Mélange hétérogène d'€ et de £.";

int main(int argc, char **argv) {
    gchar *charset = NULL;
    
    get_local_charset(&charset);
    printf("Current charset: %s\n",charset);
    
    printf("test0=%s\ntest=%s\ntest2=%s\ntest3=%s\n",
           charconv_utf8_to_local8(test0_data),
           charconv_utf8_to_local8(test_data),
           charconv_utf8_to_local8(test2_data),
           charconv_utf8_to_local8(test3_data));
    return 0;
}