/* AbiWord
 * Copyright (C) 2000 AbiSource, Inc.
 * Copyright (C) 2001 Hubert Figuiere
 * 
 * This program 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 Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  
 * 02111-1307, USA.
 */


#include <stdio.h>
#include <stdlib.h>
#include <glib.h>

#include "xap_CocoaEncodingManager.h"
#include "ut_assert.h"
#include "ut_debugmsg.h"
#include "ut_string.h"
#include "ut_string_class.h"

/* We source this file in order not to replace symbols in gnome-libs.
  (if AW is linked with GNOME).
*/

/* Only this function is used. For $LANG=ru_RU.KOI8-R it returns the following
  list:
  
  ru_RU.KOI8-R
  ru_RU
  ru.KOI8-R
  ru
  C
  ""
  
  It's much more powerfull (gives correct result) than plain setlocale since 
  it explicitly reads locale aliases.
*/
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

const GList *
g_i18n_get_language_list (const gchar *category_name);

#ifdef __cplusplus
}
#endif /* __cplusplus */


/*
 * Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation
 * All rights reserved.
 *
 * This file is part of the Gnome Library.
 *
 * The Gnome Library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * The Gnome Library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with the Gnome Library; see the file COPYING.LIB.  If not,
 * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <glib.h>

static GHashTable *alias_table = NULL;
static GHashTable *category_table= NULL;

/*read an alias file for the locales*/
static void
read_aliases (char *file)
{
  FILE *fp;
  char buf[256];
  if (!alias_table)
    alias_table = g_hash_table_new (g_str_hash, g_str_equal);
  fp = fopen (file,"r");
  if (!fp)
    return;
  while (fgets (buf,256,fp))
    {
      char *p;
      g_strstrip(buf);
      if (buf[0]=='#' || buf[0]=='\0')
        continue;
      p = strtok (buf,"\t ");
      if (!p)
	continue;
      p = strtok (NULL,"\t ");
      if(!p)
	continue;
      if (!g_hash_table_lookup (alias_table, buf))
	g_hash_table_insert (alias_table, g_strdup(buf), g_strdup(p));
    }
  fclose (fp);
}

/*return the un-aliased language as a newly allocated string*/
static char *
unalias_lang (char *lang)
{
  char *p;
  int i;
  if (!alias_table)
    {
      read_aliases ("/usr/lib/locale/locale.alias");
      read_aliases ("/usr/local/lib/locale/locale.alias");
      read_aliases ("/usr/share/locale/locale.alias");
      read_aliases ("/usr/local/share/locale/locale.alias");
      read_aliases ("/usr/lib/X11/locale/locale.alias");
      read_aliases ("/usr/openwin/lib/locale/locale.alias");
    }
  i = 0;
  while ((p=(char*)g_hash_table_lookup(alias_table,lang)) && strcmp(p, lang))
    {
      lang = p;
      if (i++ == 30)
        {
          static gboolean said_before = FALSE;
	  if (!said_before)
            g_warning ("Too many alias levels for a locale, "
		       "may indicate a loop");
	  said_before = TRUE;
	  return lang;
	}
    }
  return lang;
}

/* Mask for components of locale spec. The ordering here is from
 * least significant to most significant
 */
enum
{
  COMPONENT_CODESET =   1 << 0,
  COMPONENT_TERRITORY = 1 << 1,
  COMPONENT_MODIFIER =  1 << 2
};

/* Break an X/Open style locale specification into components
 */
static guint
explode_locale (const gchar *locale,
		gchar **language, 
		gchar **territory, 
		gchar **codeset, 
		gchar **modifier)
{
  const gchar *uscore_pos;
  const gchar *at_pos;
  const gchar *dot_pos;

  guint mask = 0;

  uscore_pos = strchr (locale, '_');
  dot_pos = strchr (uscore_pos ? uscore_pos : locale, '.');
  at_pos = strchr (dot_pos ? dot_pos : (uscore_pos ? uscore_pos : locale), '@');

  if (at_pos)
    {
      mask |= COMPONENT_MODIFIER;
      *modifier = g_strdup (at_pos);
    }
  else
    at_pos = locale + strlen (locale);

  if (dot_pos)
    {
      mask |= COMPONENT_CODESET;
      *codeset = g_new (gchar, 1 + at_pos - dot_pos);
      strncpy (*codeset, dot_pos, at_pos - dot_pos);
      (*codeset)[at_pos - dot_pos] = '\0';
    }
  else
    dot_pos = at_pos;

  if (uscore_pos)
    {
      mask |= COMPONENT_TERRITORY;
      *territory = g_new (gchar, 1 + dot_pos - uscore_pos);
      strncpy (*territory, uscore_pos, dot_pos - uscore_pos);
      (*territory)[dot_pos - uscore_pos] = '\0';
    }
  else
    uscore_pos = dot_pos;

  *language = g_new (gchar, 1 + uscore_pos - locale);
  strncpy (*language, locale, uscore_pos - locale);
  (*language)[uscore_pos - locale] = '\0';

  return mask;
}

/*
 * Compute all interesting variants for a given locale name -
 * by stripping off different components of the value.
 *
 * For simplicity, we assume that the locale is in
 * X/Open format: language[_territory][.codeset][@modifier]
 *
 * TODO: Extend this to handle the CEN format (see the GNUlibc docs)
 *       as well. We could just copy the code from glibc wholesale
 *       but it is big, ugly, and complicated, so I'm reluctant
 *       to do so when this should handle 99% of the time...
 */
static GList *
compute_locale_variants (const gchar *locale)
{
  GList *retval = NULL;

  gchar *language;
  gchar *territory;
  gchar *codeset;
  gchar *modifier;

  guint mask;
  guint i;

  g_return_val_if_fail (locale != NULL, NULL);

  mask = explode_locale (locale, &language, &territory, &codeset, &modifier);

  /* Iterate through all possible combinations, from least attractive
   * to most attractive.
   */
  for (i=0; i<=mask; i++)
    if ((i & ~mask) == 0)
      {
	gchar *val = g_strconcat(language,
				 (i & COMPONENT_TERRITORY) ? territory : "",
				 (i & COMPONENT_CODESET) ? codeset : "",
				 (i & COMPONENT_MODIFIER) ? modifier : "",
				 NULL);
	retval = g_list_prepend (retval, val);
      }

  g_free (language);
  if (mask & COMPONENT_CODESET)
    g_free (codeset);
  if (mask & COMPONENT_TERRITORY)
    g_free (territory);
  if (mask & COMPONENT_MODIFIER)
    g_free (modifier);

  return retval;
}

/* The following is (partly) taken from the gettext package.
   Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.  */

static const gchar *
guess_category_value (const gchar *categoryname)
{
  const gchar *retval;

  /* The highest priority value is the `LANGUAGE' environment
     variable.  This is a GNU extension.  */
  retval = g_getenv ("LANGUAGE");
  if (retval != NULL && retval[0] != '\0')
    return retval;

  /* `LANGUAGE' is not set.  So we have to proceed with the POSIX
     methods of looking to `LC_ALL', `LC_xxx', and `LANG'.  On some
     systems this can be done by the `setlocale' function itself.  */

  /* Setting of LC_ALL overwrites all other.  */
  retval = g_getenv ("LC_ALL");  
  if (retval != NULL && retval[0] != '\0')
    return retval;

  /* Next comes the name of the desired category.  */
  retval = g_getenv (categoryname);
  if (retval != NULL && retval[0] != '\0')
    return retval;

  /* Last possibility is the LANG environment variable.  */
  retval = g_getenv ("LANG");
  if (retval != NULL && retval[0] != '\0')
    return retval;

  return NULL;
}

/**
 * g_i18n_get_language_list:
 * @category_name: Name of category to look up, e.g. "LC_MESSAGES".
 * 
 * This computes a list of language strings.  It searches in the
 * standard environment variables to find the list, which is sorted
 * in order from most desirable to least desirable.  The `C' locale
 * is appended to the list if it does not already appear (other routines depend on this behaviour).
 * If @category_name is %NULL, then LC_ALL is assumed.
 * 
 * Return value: the list of languages, this list should not be freed as it is owned by gnome-i18n
 **/
const GList *
g_i18n_get_language_list (const gchar *category_name)
{
  GList *list;

  if (!category_name)
    category_name= "LC_ALL";

  if (category_table)
    {
#if 0
	  // we want a fresh reading of the LANG variable every time so we can
	  // work out the 8bit encoding under utf-8 locale
      list= (GList *)g_hash_table_lookup (category_table, (const gpointer) category_name);
#else
		xxx_UT_DEBUGMSG(("recreating hash table\n"));
		g_hash_table_destroy (category_table);
        category_table= g_hash_table_new (g_str_hash, g_str_equal);
        list= NULL;
		
#endif
    }
  else
    {
      category_table= g_hash_table_new (g_str_hash, g_str_equal);
      list= NULL;
    }

  if (!list)
    {
      gint c_locale_defined= FALSE;
  
      const gchar *category_value;
      gchar *category_memory, *orig_category_memory;

      category_value = guess_category_value (category_name);
      if (! category_value)
	category_value = "C";
      orig_category_memory = category_memory =
	(gchar*) g_malloc (strlen (category_value)+1);
      
      while (category_value[0] != '\0')
	{
	  while (category_value[0] != '\0' && category_value[0] == ':')
	    ++category_value;
	  
	  if (category_value[0] != '\0')
	    {
	      char *cp= category_memory;
	      
	      while (category_value[0] != '\0' && category_value[0] != ':')
		*category_memory++= *category_value++;
	      
	      category_memory[0]= '\0'; 
	      category_memory++;
	      
	      cp = unalias_lang(cp);
	      
	      if (strcmp (cp, "C") == 0)
		c_locale_defined= TRUE;
	      
	      list= g_list_concat (list, compute_locale_variants (cp));
	    }
	}

      g_free (orig_category_memory);
      
      if (!c_locale_defined)
	list= g_list_append (list, (void*)"C");

      g_hash_table_insert (category_table, (gpointer) category_name, list);
    }
  
  return list;
}


/************************************************************/

XAP_EncodingManager *XAP_EncodingManager::get_instance()
{
	if (_instance == 0)
	{
		UT_DEBUGMSG(("Building XAP_EncodingManager\n"));
		_instance = new XAP_CocoaEncodingManager();
		_instance->initialize();
		UT_DEBUGMSG(("XAP_EncodingManager built\n"));
	}

	return _instance;
}

/************************************************************/

XAP_CocoaEncodingManager::XAP_CocoaEncodingManager() 
{
}

XAP_CocoaEncodingManager::~XAP_CocoaEncodingManager() {}

static const char * NativeEncodingName;
static const char * NativeUnicodeEncodingName;
static const char * Native8BitEncodingName;
static const char * LanguageISOName;
static const char * LanguageISOTerritory;

const char* XAP_CocoaEncodingManager::getNativeEncodingName() const
{     
  return NativeEncodingName; 
}

const char* XAP_CocoaEncodingManager::getNativeUnicodeEncodingName() const
{     
  return NativeEncodingName; 
}

const char* XAP_CocoaEncodingManager::getNative8BitEncodingName() const
{     
  return Native8BitEncodingName;
}

const char* XAP_CocoaEncodingManager::getLanguageISOName() const
{
 	return LanguageISOName; 
}

const char* XAP_CocoaEncodingManager::getLanguageISOTerritory() const
{ 	
  return LanguageISOTerritory; 
}

void  XAP_CocoaEncodingManager::initialize()
{	
	const GList* lst = g_i18n_get_language_list ("LANG");
	const char* locname = (char*)lst->data;

	NativeEncodingName = "ISO-8859-1";
	Native8BitEncodingName = "ISO-8859-1";
	NativeUnicodeEncodingName = "UTF-8";
	LanguageISOName = "en";
	LanguageISOTerritory = "US";
	
	if (!*locname || !strcmp(locname,"C"))
	{ 	/* paranoic case - broken system */
		; /*already initialized*/
	}
	else
	{
		char* lang,*terr,*cs,*mod;
		int mask = explode_locale (locname,&lang,&terr,&cs,&mod);
		LanguageISOName = lang;
		if (mask & COMPONENT_TERRITORY)
		{
			LanguageISOTerritory = terr+1;/*yes, +1*/
		}
		if (mask & COMPONENT_CODESET)
		{
			NativeEncodingName = cs+1;
			if (!strncmp(cs+1,"ISO8859",strlen("ISO8859"))) {
				/*
			 	work around glibc bug - its iconv doesn't know
			 	ISO8859-* - ISO-8859-1 should be used (we encounter this 
			 	since locale.alias aliases en_US.ISO8859-1 to 'en'
			 	PS: This is true for my RH6.0 system - VH
				*/
				static char buf[40];
				strcpy(buf,"ISO-");
				strcat(buf,cs+1+3);
				NativeEncodingName = buf;
			}
			Native8BitEncodingName = NativeEncodingName;
			
			// need to get 8bit encoding if encoding is utf-8
			if(!strcmp(NativeEncodingName, "utf-8") || !strcmp(NativeEncodingName, "UTF-8"))
			{
				// we want to get the encoding that would be used for the given
				// language/territory if the utf-8 encoding was not specified
				// by LANG

			  UT_String OLDLANG (getenv("LANG"));
#if defined(SETENV_MISSING) 
			  UT_String MYLANG ("LANG=");
			  
			  MYLANG += LanguageISOName;
			  MYLANG += "_";
			  MYLANG += LanguageISOTerritory;
			  putenv(MYLANG.c_str());
#else
			  UT_String MYLANG (LanguageISOName);
			  MYLANG += "_";
			  MYLANG += LanguageISOTerritory;
			  setenv ("LANG", MYLANG.c_str(), 1);
#endif
			
				const GList* my_lst = g_i18n_get_language_list ("LANG");
				const char* my_locname = (char*)my_lst->data;
				
	    		char* my_lang,*my_terr,*my_cs,*my_mod;
    			int my_mask = explode_locale (my_locname,&my_lang,&my_terr,&my_cs,&my_mod);
				
				if (my_mask & COMPONENT_CODESET)
				{
					Native8BitEncodingName = my_cs+1;
					xxx_UT_DEBUGMSG(("Native8BitEncodingName (1) %s\n", Native8BitEncodingName));
					if (!strncmp(my_cs+1,"ISO8859",strlen("ISO8859")))
					{
						static char buf[40];
						strcpy(buf,"ISO-");
						strcat(buf,my_cs+1+3);
						Native8BitEncodingName = buf;
					}
					xxx_UT_DEBUGMSG(("Native8BitEncodingName (2) %s\n", Native8BitEncodingName));
				
				}

#if defined(SETENV_MISSING)
				MYLANG = "LANG=";
				MYLANG += OLDLANG;
				putenv(MYLANG.c_str());
#else
				setenv("LANG", OLDLANG.c_str(), 1);
#endif			
			}
		}
	};	
	XAP_EncodingManager::initialize();
	describe();
};


