/* strgutil.c -  string utilities
 *	Copyright (C) 1998, 2000 Free Software Foundation, Inc.
 *
 * This file is part of GnuPG.
 *
 * GnuPG 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.
 *
 * GnuPG 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 <config.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <gcrypt.h>
#include "types.h"
#include "util.h"
#include "memory.h"


static ushort koi8_unicode[128] = {
    0x2500,0x2502,0x250c,0x2510,0x2514,0x2518,0x251c,0x2524,
    0x252c,0x2534,0x253c,0x2580,0x2584,0x2588,0x258c,0x2590,
    0x2591,0x2592,0x2593,0x2320,0x25a0,0x2219,0x221a,0x2248,
    0x2264,0x2265,0x00a0,0x2321,0x00b0,0x00b2,0x00b7,0x00f7,
    0x2550,0x2551,0x2552,0x0451,0x2553,0x2554,0x2555,0x2556,
    0x2557,0x2558,0x2559,0x255a,0x255b,0x255c,0x255d,0x255e,
    0x255f,0x2560,0x2561,0x0401,0x2562,0x2563,0x2564,0x2565,
    0x2566,0x2567,0x2568,0x2569,0x256a,0x256b,0x256c,0x00a9,
    0x044e,0x0430,0x0431,0x0446,0x0434,0x0435,0x0444,0x0433,
    0x0445,0x0438,0x0439,0x043a,0x043b,0x043c,0x043d,0x043e,
    0x043f,0x044f,0x0440,0x0441,0x0442,0x0443,0x0436,0x0432,
    0x044c,0x044b,0x0437,0x0448,0x044d,0x0449,0x0447,0x044a,
    0x042e,0x0410,0x0411,0x0426,0x0414,0x0415,0x0424,0x0413,
    0x0425,0x0418,0x0419,0x041a,0x041b,0x041c,0x041d,0x041e,
    0x041f,0x042f,0x0420,0x0421,0x0422,0x0423,0x0416,0x0412,
    0x042c,0x042b,0x0417,0x0428,0x042d,0x0429,0x0427,0x042a
};

static ushort latin2_unicode[128] = {
    0x0080,0x0081,0x0082,0x0083,0x0084,0x0085,0x0086,0x0087,
    0x0088,0x0089,0x008A,0x008B,0x008C,0x008D,0x008E,0x008F,
    0x0090,0x0091,0x0092,0x0093,0x0094,0x0095,0x0096,0x0097,
    0x0098,0x0099,0x009A,0x009B,0x009C,0x009D,0x009E,0x009F,
    0x00A0,0x0104,0x02D8,0x0141,0x00A4,0x013D,0x015A,0x00A7,
    0x00A8,0x0160,0x015E,0x0164,0x0179,0x00AD,0x017D,0x017B,
    0x00B0,0x0105,0x02DB,0x0142,0x00B4,0x013E,0x015B,0x02C7,
    0x00B8,0x0161,0x015F,0x0165,0x017A,0x02DD,0x017E,0x017C,
    0x0154,0x00C1,0x00C2,0x0102,0x00C4,0x0139,0x0106,0x00C7,
    0x010C,0x00C9,0x0118,0x00CB,0x011A,0x00CD,0x00CE,0x010E,
    0x0110,0x0143,0x0147,0x00D3,0x00D4,0x0150,0x00D6,0x00D7,
    0x0158,0x016E,0x00DA,0x0170,0x00DC,0x00DD,0x0162,0x00DF,
    0x0155,0x00E1,0x00E2,0x0103,0x00E4,0x013A,0x0107,0x00E7,
    0x010D,0x00E9,0x0119,0x00EB,0x011B,0x00ED,0x00EE,0x010F,
    0x0111,0x0144,0x0148,0x00F3,0x00F4,0x0151,0x00F6,0x00F7,
    0x0159,0x016F,0x00FA,0x0171,0x00FC,0x00FD,0x0163,0x02D9
};

static ushort ibm850_unicode[128] = {
    0x00c7,0x00fc,0x00e9,0x00e2,0x00e4,0x00e0,0x00e5,0x00e7,
    0x00ea,0x00eb,0x00e8,0x00ef,0x00ee,0x00ec,0x00c4,0x00c5,
    0x00c9,0x00e6,0x00c6,0x00f4,0x00f6,0x00f2,0x00fb,0x00f9,
    0x00ff,0x00d6,0x00dc,0x00f8,0x00a3,0x00d8,0x00d7,0x0192,
    0x00e1,0x00ed,0x00f3,0x00fa,0x00f1,0x00d1,0x00aa,0x00ba,
    0x00bf,0x00ae,0x00ac,0x00bd,0x00bc,0x00a1,0x00ab,0x00bb,
    0x2591,0x2592,0x2593,0x2502,0x2524,0x00c1,0x00c2,0x00c0,
    0x00a9,0x2563,0x2551,0x2557,0x255d,0x00a2,0x00a5,0x2510,
    0x2514,0x2534,0x252c,0x251c,0x2500,0x253c,0x00e3,0x00c3,
    0x255a,0x2554,0x2569,0x2566,0x2560,0x2550,0x256c,0x00a4,
    0x00f0,0x00d0,0x00ca,0x00cb,0x00c8,0x0131,0x00cd,0x00ce,
    0x00cf,0x2518,0x250c,0x2588,0x2584,0x00a6,0x00cc,0x2580,
    0x00d3,0x00df,0x00d4,0x00d2,0x00f5,0x00d5,0x00b5,0x00fe,
    0x00de,0x00da,0x00db,0x00d9,0x00fd,0x00dd,0x00af,0x00b4,
    0x00ad,0x00b1,0x2017,0x00be,0x00b6,0x00a7,0x00f7,0x00b8,
    0x00b0,0x00a8,0x00b7,0x00b9,0x00b3,0x00b2,0x25a0,0x00a0,
};

static int query_native_charset_done = 0;
static const char *active_charset_name = "iso-8859-1";
static ushort *active_charset = NULL;


void
free_strlist( STRLIST sl )
{
    STRLIST sl2;

    for(; sl; sl = sl2 ) {
	sl2 = sl->next;
	gcry_free(sl);
    }
}


STRLIST
add_to_strlist( STRLIST *list, const char *string )
{
    STRLIST sl;

    sl = gcry_xmalloc( sizeof *sl + strlen(string));
    sl->flags = 0;
    strcpy(sl->d, string);
    sl->next = *list;
    *list = sl;
    return sl;
}

/****************
 * ame as add_to_strlist() but if is_utf8 is *not* set a conversion
 * to UTF8 is done
 */
STRLIST
add_to_strlist2( STRLIST *list, const char *string, int is_utf8 )
{
    STRLIST sl;

    if( is_utf8 )
	sl = add_to_strlist( list, string );
    else {
	char *p = native_to_utf8( string );
	sl = add_to_strlist( list, p );
	gcry_free( p );
    }
    return sl;
}

STRLIST
append_to_strlist( STRLIST *list, const char *string )
{
    STRLIST r, sl;

    sl = gcry_xmalloc( sizeof *sl + strlen(string));
    sl->flags = 0;
    strcpy(sl->d, string);
    sl->next = NULL;
    if( !*list )
	*list = sl;
    else {
	for( r = *list; r->next; r = r->next )
	    ;
	r->next = sl;
    }
    return sl;
}

STRLIST
append_to_strlist2( STRLIST *list, const char *string, int is_utf8 )
{
    STRLIST sl;

    if( is_utf8 )
	sl = append_to_strlist( list, string );
    else {
	char *p = native_to_utf8( string );
	sl = append_to_strlist( list, p );
	gcry_free( p );
    }
    return sl;
}


STRLIST
strlist_prev( STRLIST head, STRLIST node )
{
    STRLIST n;

    for(n=NULL; head && head != node; head = head->next )
	n = head;
    return n;
}

STRLIST
strlist_last( STRLIST node )
{
    if( node )
	for( ; node->next ; node = node->next )
	    ;
    return node;
}



int
string_count_chr( const char *string, int c )
{
    int count;
    for(count=0; *string; string++ )
	if( *string == c )
	    count++;
    return count;
}


static const char*
query_native_charset(void)
{
  #ifdef __MINGW32__
    unsigned int cp;

    cp = GetConsoleOutputCP();
    if( cp != GetConsoleCP() ) {
	/* The input cgarset is not equal to the output charset
	 * our system depends on it and therefore we will set
	 * same the same (this won't work on Windows 95) */
	if( !SetConsoleCP( cp ) )
	    log_info("can't set Input-CP to Output-CP: %d\n",
						    (int)GetLastError() );
    }
    /* we could read the registry, but this seems to be too much work */
    switch( cp ) {
      case 850:  return "ibm850";
      case 437:  return "ibm437";
      case 1252: return "iso-8859-1";
      default:
	log_info("unknown MS-Windows CodePage %u "
		 "- trying to switch to Latin-1\n", cp );
	/* try to set latin-1 */
	if( !SetConsoleOutputCP( 1252 ) ) {
	    if( !SetConsoleCP( 1252 ) )
		return "iso-8859-1";
	    else /* back off */
		SetConsoleOutputCP( cp );
	}
	log_info("no information about MS-Windows CodePage %u\n", cp );
	return NULL;
    }
  #else
    return NULL; /* unknown */
  #endif
}


const char*
get_native_charset()
{
    if( !query_native_charset_done ) {
	const char *s;

	query_native_charset_done = 1;
	s = query_native_charset();
	if( s )
	    set_native_charset(s);
    }

    return active_charset_name;
}


int
set_native_charset( const char *newset )
{
    query_native_charset_done = 1; /* don't do this when we want to set one*/
    if( !stricmp( newset, "iso-8859-1" ) ) {
	active_charset_name = "iso-8859-1";
	active_charset = NULL;
    }
    else if( !stricmp( newset, "iso-8859-2" ) ) {
	active_charset_name = "iso-8859-2";
	active_charset = latin2_unicode;
    }
    else if( !stricmp( newset, "koi8-r" ) ) {
	active_charset_name = "koi8-r";
	active_charset = koi8_unicode;
    }
    else if( !stricmp( newset, "ibm850" ) || !stricmp( newset, "ibm437" ) ) {
	active_charset_name = "ibm850";
	active_charset = ibm850_unicode;
    }
    else
	return GPGERR_GENERAL;
    return 0;
}


/****************
 * Convert string, which is in native encoding to UTF8 and return the
 * new allocated UTF8 string.
 */
char *
native_to_utf8( const char *string )
{
    const byte *s;
    char *buffer;
    byte *p;
    size_t length=0;

    if( active_charset ) {
	for(s=string; *s; s++ ) {
	    length++;
	    if( *s & 0x80 )
		length += 2; /* we may need 3 bytes */
	}
	buffer = gcry_xmalloc( length + 1 );
	for(p=buffer, s=string; *s; s++ ) {
	    if( *s & 0x80 ) {
		ushort val = active_charset[ *s & 0x7f ];
		if( val < 0x0800 ) {
		    *p++ = 0xc0 | ( (val >> 6) & 0x1f );
		    *p++ = 0x80 | (  val & 0x3f );
		}
		else {
		    *p++ = 0xe0 | ( (val >> 12) & 0x0f );
		    *p++ = 0x80 | ( (val >>  6) & 0x3f );
		    *p++ = 0x80 | (  val & 0x3f );
		}
	    }
	    else
		*p++ = *s;
	}
	*p = 0;
    }
    else {
	for(s=string; *s; s++ ) {
	    length++;
	    if( *s & 0x80 )
		length++;
	}
	buffer = gcry_xmalloc( length + 1 );
	for(p=buffer, s=string; *s; s++ ) {
	    if( *s & 0x80 ) {
		*p++ = 0xc0 | ((*s >> 6) & 3);
		*p++ = 0x80 | ( *s & 0x3f );
	    }
	    else
		*p++ = *s;
	}
	*p = 0;
    }
    return buffer;
}


/****************
 * Convert string, which is in UTF8 to native encoding.
 * illegal encodings by some "\xnn" and quote all control characters
 */
char *
utf8_to_native( const char *string, size_t length )
{
    int nleft;
    int i;
    byte encbuf[7];
    int encidx;
    const byte *s;
    size_t n;
    byte *buffer = NULL, *p = NULL;
    unsigned long val = 0;
    size_t slen;
    int resync = 0;

    /* 1. pass (p==NULL): count the extended utf-8 characters */
    /* 2. pass (p!=NULL): create string */
    for( ;; ) {
	for( slen=length, nleft=encidx=0, n=0, s=string; slen; s++, slen-- ) {
	    if( resync ) {
		if( !(*s < 128 || (*s >= 0xc0 && *s <= 0xfd)) ) {
		    /* still invalid */
		    if( p ) {
			sprintf(p, "\\x%02x", *s );
			p += 4;
		    }
		    n += 4;
		    continue;
		}
		resync = 0;
	    }
	    if( !nleft ) {
		if( !(*s & 0x80) ) { /* plain ascii */
		    if( iscntrl( *s ) ) {
			n++;
			if( p )
			    *p++ = '\\';
			switch( *s ) {
			  case '\n': n++; if( p ) *p++ = 'n'; break;
			  case '\r': n++; if( p ) *p++ = 'r'; break;
			  case '\f': n++; if( p ) *p++ = 'f'; break;
			  case '\v': n++; if( p ) *p++ = 'v'; break;
			  case '\b': n++; if( p ) *p++ = 'b'; break;
			  case	 0 : n++; if( p ) *p++ = '0'; break;
			  default: n += 3;
				   sprintf( p, "x%02x", *s );
                                   if ( p )
                                       p += 3;
				   break;
			}
		    }
		    else {
			if( p ) *p++ = *s;
			n++;
		    }
		}
		else if( (*s & 0xe0) == 0xc0 ) { /* 110x xxxx */
		    val = *s & 0x1f;
		    nleft = 1;
		    encbuf[encidx=0] = *s;
		}
		else if( (*s & 0xf0) == 0xe0 ) { /* 1110 xxxx */
		    val = *s & 0x0f;
		    nleft = 2;
		    encbuf[encidx=0] = *s;
		}
		else if( (*s & 0xf8) == 0xf0 ) { /* 1111 0xxx */
		    val = *s & 0x07;
		    nleft = 3;
		    encbuf[encidx=0] = *s;
		}
		else if( (*s & 0xfc) == 0xf8 ) { /* 1111 10xx */
		    val = *s & 0x03;
		    nleft = 4;
		    encbuf[encidx=0] = *s;
		}
		else if( (*s & 0xfe) == 0xfc ) { /* 1111 110x */
		    val = *s & 0x01;
		    nleft = 5;
		    encbuf[encidx=0] = *s;
		}
		else {	/* invalid encoding: print as \xnn */
		    if( p ) {
			sprintf(p, "\\x%02x", *s );
			p += 4;
		    }
		    n += 4;
		    resync = 1;
		}
	    }
	    else if( *s < 0x80 || *s >= 0xc0 ) { /* invalid */
		if( p ) {
		    sprintf(p, "\\x%02x", *s );
		    p += 4;
		}
		n += 4;
		nleft = 0;
		resync = 1;
	    }
	    else {
		encbuf[++encidx] = *s;
		val <<= 6;
		val |= *s & 0x3f;
		if( !--nleft ) { /* ready */
		    if( active_charset ) { /* table lookup */
			for(i=0; i < 128; i++ ) {
			    if( active_charset[i] == val )
				break;
			}
			if( i < 128 ) { /* we can print this one */
			    if( p ) *p++ = i+128;
			    n++;
			}
			else { /* we do not have a translation: print utf8 */
			    if( p ) {
				for(i=0; i < encidx; i++ ) {
				    sprintf(p, "\\x%02x", encbuf[i] );
				    p += 4;
				}
			    }
			    n += encidx*4;
			}
		    }
		    else { /* native set */
			if( val >= 0x80 && val < 256 ) {
			    n++;    /* we can simply print this character */
			    if( p ) *p++ = val;
			}
			else { /* we do not have a translation: print utf8 */
			    if( p ) {
				for(i=0; i < encidx; i++ ) {
				    sprintf(p, "\\x%02x", encbuf[i] );
				    p += 4;
				}
			    }
			    n += encidx*4;
			}
		    }

		}

	    }
	}
	if( !buffer ) { /* allocate the buffer after the first pass */
	    buffer = p = gcry_xmalloc( n + 1 );
	}
	else {
	    *p = 0; /* make a string */
	    return buffer;
	}
    }
}