/*
   Unix SMB/Netbios implementation.
   Version 1.9.
   Samba Web Administration Tool
   
   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., 675 Mass Ave, Cambridge, MA 02139, USA.

   Created by Ryo Kawahara <rkawa@lbe.co.jp> 
*/

#include "includes.h"
/* #include "config.h" */
#include "smbintl.h"

#if I18N_SWAT
/* constants. */
/* it is ok to make them bigger.*/
#define LN_PREFLANG_MAX 10
#define LN_LNAME_LENGTH 8+1+8

#define LN_DEFAULT_LANG I18N_DEFAULT_LANG
#define LN_LANGDESC_DEFAULT -1
#define LN_NO_AVAILABLE_LANG -1

/* ******************************************************************
 * macros for debugging.
 ***************************************************************** */
#ifdef LN_R_NODEBUG

#else
/*
 *#define LN_DEBUG_LOG "/tmp/lndebug.log"
 *void ln_debug_error(const char *info, int nLine)
 *{
 *	FILE* fp;
 *	fp = sys_fopen(LN_DEBUG_LOG, "a");
 *	fprintf(fp, "%s at %d.\n", info, nLine);
 *	fclose(fp);
 *}
 *void rassert_help(BOOL b, int l)
 *{
 *	if(!b)
 *	{
 *		ln_debug_error("language negotiation error.", l);
 *		exit(1);
 *	}
 *}
 */
#endif /* LN_R_NODEBUG */

/* ****************************************************************
 LNNegotiator struct. It contains...
 [aPrefLang]
  the array of strings. each string is the name of
  languages ("ja", "ko"...), given by web browser.
 [nPrefLang]
  the number of the languages in aPrefLang.
 [lOriginalLang]
  == "en": indicates what language the  default(original) files
  are written with.
**************************************************************** */
typedef char lnstring[LN_LNAME_LENGTH + 1];
#define lnstrcpy(d,s) safe_strcpy((d),(s),sizeof(lnstring)-1)

typedef struct tagLNNegotiator
{
	lnstring aPrefLang[LN_PREFLANG_MAX];
	int nPrefLang;
	lnstring lOriginalLang;
}LNNegotiator;

/* **************************************************************
 * some access functions & macros for LNNegotiator struct.
 * ************************************************************ */
#define ln_getPreflangCount(pLn) ((pLn)->nPrefLang)
#define ln_getOriginalLang(pLn) ((pLn)->lOriginalLang)
#define ln_getDefaultPrefLang(pLn) ((pLn)->lDefaultPrefLang)

/* make it inline-expanded (or macro) to get better performance */
static const char* ln_getPreflang(LNNegotiator* pLn, int i)
{
	rassert(i == LN_LANGDESC_DEFAULT
	       || (0 <= i && i < ln_getPreflangCount(pLn)));

	if(i == LN_LANGDESC_DEFAULT)
		return NULL;
	if(0 <= i && i < ln_getPreflangCount(pLn))
		return pLn->aPrefLang[i];
	return NULL;
}
/* initialize structures */
static void ln_resetln(LNNegotiator* pLn)
{
	pLn->nPrefLang = 0;
	/* using fixed memory.*/
}
static BOOL ln_addPreflang(LNNegotiator* pLn, const char* pLang)
{
	int nPref = ln_getPreflangCount(pLn);

	if(nPref >= LN_PREFLANG_MAX)
		return False;

	lnstrcpy(pLn->aPrefLang[nPref], pLang);
	(pLn->nPrefLang)++;
	return True;
}
/* #define I18N_DEFAULT_PREF_LANG "ja" */
/* don't forget to make it configurealable !!! */
static void ln_initln_help(LNNegotiator* pLn)
{
	ln_resetln(pLn);
	lnstrcpy(pLn->lOriginalLang, I18N_ORIGINAL_LANG);
	/* I18N_ORIGINAL_LANG = "en" is hardcoded in
	   webintl.h. */
	if(strcmp(I18N_DEFAULT_PREF_LANG, "") != 0)
		ln_addPreflang(pLn, I18N_DEFAULT_PREF_LANG);
	/* this entry is used only when web browser didn't send
	   ACCEPT-LANGUAGE header. */
}
/* ****************************************************************
 * store acceptable languages into LNNegotiator object.
 * [pstrLangarray] The arguments of "accept-language" http header, 
 * which is like "en-GB, es;q=0.5, ja". "q=0.5" is called quality value,
 * but it is ignored now. wiled card "*" is also ignored. 
 ***************************************************************** */
static BOOL ln_negotiate_language_help(
	LNNegotiator* pLn, const char* pstrLangarray)
{
	char* pToken;
	const char* pDelim = " \n\r\t,;";
	pstring strBuffer;

	rassert(pstrLangarray);
	rassert(pLn);

	ln_resetln(pLn);
	pstrcpy(strBuffer, pstrLangarray);
	pToken = strtok(strBuffer, pDelim);
	while(pToken != NULL)
	{
		if(strncmp(pToken, "q=", strlen("q=")) == 0)
		{
			pToken = strtok(NULL, pDelim);
			continue;
		}
		if(!ln_addPreflang(pLn, pToken))
			break;
		pToken = strtok(NULL, pDelim);
	}
	rassert(ln_getPreflangCount(pLn) != 0);
	return (ln_getPreflangCount(pLn) != 0);
}
/* parse catalog file header and get encoding information.*/
static BOOL parse_po_header(const char* pheader, pstring* pencoding_name)
{
	const char *ap_i_v;
	const char *acharset;
	char* penc;
	int nenc;

	ap_i_v = "Project-Id-Version:";
	acharset = "charset=";
	if(pheader == NULL || pencoding_name == NULL ||
	   strcmp(pheader, "") == 0)
	{
		/* error or catalog is not available. */
		pstrcpy(*pencoding_name, "");
		return False;
	}
	penc = strstr(pheader, acharset);
	if(strncmp(pheader, ap_i_v, strlen(ap_i_v)) != 0 || penc == NULL)
	{
		/* catalog file exists, but header is not good.*/
		pstrcpy(*pencoding_name, "");
		return True;
	}
	nenc = strcspn(penc + strlen(acharset), "\n");
	strncpy(*pencoding_name,
		 penc + strlen(acharset), nenc);
	return True;
}
/* ad-hoc mime charset -> samba encoding name converter.
   character conversion is done when internal samba data,
   such as paramters, open files, share names, are going to be displayed.
   it is only valid for japanese encodings because samba-2.0.7 only has
   these three character convertors.
   so other .po file(catalog file) should be encoded with one which
   samba can deal with (i.e same as DOS codepage).

   display-time conversion is deleted on this version because
   all catalog files are encoded with samba internal encoding (DOS codepage).
*/
#define LN_SAMBA_ENCODINGS 3
static const char* get_samba_enc(const char* penc)
{
	int i;
	static const fstring fdefault = "";
	static const fstring fmimeenc[LN_SAMBA_ENCODINGS] =
	{
		"EUC-JP", "Shift_JIS", "ISO-2022-JP"
	};
	static const fstring fsambaenc[LN_SAMBA_ENCODINGS] =
	{
		"euc",    "sjis",      "jis"
	};
	for(i = 0; i < LN_SAMBA_ENCODINGS; i++)
	{
		if(strcasecmp(penc, fmimeenc[i]) == 0)
			return fsambaenc[i];
	}
	return fdefault;
}
/* ************************************************************
 find a better language.
 if the language specified by web browser matches to a language
 which is supported by the swat server, this function returns it.
 *********************************************************** */
static void set_a_language(const char* planguage)
{
	/* included gettext source is affected by
	   these env.variables without locale settings.
	*/
	/*
	   putenv(env) will not duplicate env argument
	   but smbw_setenv() does this.
	   some system doesn't have setenv(), do not use it.
	*/

	smbw_setenv("LANGUAGE", planguage);
	smbw_setenv("LANG", planguage);

	bindtextdomain(SWAT_I18N_PACKAGE, SWAT_I18N_LOCALEDIR);
	textdomain(SWAT_I18N_PACKAGE);
}
static int ln_set_pref_language(LNNegotiator* pLn)
{
	int j;
	pstring enc_name[1];

	for(j = 0; j < ln_getPreflangCount(pLn); j++)
	{
		set_a_language(ln_getPreflang(pLn, j));
		/* then check for _("") special entry which has
		   a lot of information about .po file. */
		if (parse_po_header(_(""), enc_name))
		{
			/* the catalog file must exist and may have
			   encoding information .*/
			/*
			  but in this version, catalog files must be
			  written with samba-internal encoding (i.e.
			  dos encoding, dos codepage)
			  so there is no need to convert.
			  ln_init_swat_encoding(get_samba_enc(enc_name[0]));
			*/
			return j;
		}
	}
	return LN_NO_AVAILABLE_LANG;
	/* no available or return the default? */
}
/* **************************************************************
 initialize gettext. Before this, cgi_setup() should be done. 
 cgi_setup() calls ln_negotiate_language() if the user specifies
 languages in web browser. Then, ln_set_pref_language() will work.
 ************************************************************* */
static BOOL ln_init_lang_env_help(LNNegotiator* pLn)
{
#if I18N_GETTEXT
	int nLang;

	nLang = ln_set_pref_language(pLn);
	rstrace(getenv("LANGUAGE"));
#endif /* I18N_GETTEXT */
	return True;
}
/* *****************************************************************
 * This function searches for the "PrefLang" version of pFile.
 * if not available, returns pFile.
 * [pFile] the filename.
 * [pst] the address of a struct. it will be filled with the information
 *  of the file.
 * [pLangDesc] The address of an integer. a value which indicates the
 * language of the returned value is written to the address. the value
 * is used in ln_get_lang().
 * [return value] address of the name of the language version of the file.
 * It is static object so it will be destroyed at the time ln_get_pref_file()
 * is called.
 **************************************************************** */
static void ln_make_filename(
	pstring afname, const char* pFile, const char* pAdd)
{
#if LANG_PREFIX
	/* maybe, foo.html.ja */
	pstrcpy(afname, pFile);
	pstrcat(afname, ".");
	pstrcat(afname, pAdd);
#else
	/* maybe, ja/foo.html */
	pstrcpy(afname, pAdd);
	pstrcat(afname, "/");
	pstrcat(afname, pFile);
#endif
}
static const char* ln_get_pref_file_help(
	LNNegotiator* pLn, const char* pFile,
	 SMB_STRUCT_STAT* pst, int* pLangDesc)
{
	static pstring afname;
	int i;

	for(i = 0; i < ln_getPreflangCount(pLn); i++)
	{
		if(strcmp(ln_getPreflang(pLn, i), ln_getOriginalLang(pLn))
			  == 0)
			break;
		ln_make_filename(afname, pFile, ln_getPreflang(pLn, i));
		if(file_exist(afname, pst))
		{
			*pLangDesc = i;
			return afname;
		}
	}
	pstrcpy(afname, pFile);
	file_exist(afname, pst);
	*pLangDesc = LN_LANGDESC_DEFAULT;
	return afname;
}
/* *******************************************************************
 * file scope variables. this variable is not locked.
 * (not multithread-safe)
 ******************************************************************** */
static LNNegotiator lnLanguagenegotiator;

/* *******************************************************************
 * interfaces to the outside of this file.
 ******************************************************************** */
void ln_initln(void)
{
	ln_initln_help(&lnLanguagenegotiator);
}
BOOL ln_init_lang_env(void)
{
	return ln_init_lang_env_help(&lnLanguagenegotiator);
}
const char* ln_get_lang(int nLangDesc)
{
	return ln_getPreflang(&lnLanguagenegotiator, nLangDesc);
}
const char* ln_get_pref_file(const char* pFile,
			  SMB_STRUCT_STAT* pst, int* pLangDesc)
{
	return ln_get_pref_file_help(
		&lnLanguagenegotiator, pFile, pst, pLangDesc);
}
BOOL ln_negotiate_language(const char* pstrLangarray)
{
	return ln_negotiate_language_help(
		&lnLanguagenegotiator, pstrLangarray);
}
const char* ln_get_pref_file_n_o(const char* pFile)
{
	SMB_STRUCT_STAT st;
	int nLangDesc;
	return ln_get_pref_file(pFile, &st, &nLangDesc);
}
#endif /* I18N_SWAT */
