/*
 * Utility routines
 *
 * Copyright 1998 Bertho A. Stultiens
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include "config.h"

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>

#include "../tools.h"
#include "wrc.h"
#include "winternl.h"
#include "utils.h"
#include "parser.h"

/* #define WANT_NEAR_INDICATION */

#ifdef WANT_NEAR_INDICATION
void make_print(char *str)
{
	while(*str)
	{
		if(!isprint(*str))
			*str = ' ';
		str++;
	}
}
#endif

static void generic_msg(const char *s, const char *t, const char *n, va_list ap)
{
	fprintf(stderr, "%s:%d:%d: %s: ", input_name ? input_name : "stdin", line_number, char_number, t);
	vfprintf(stderr, s, ap);
#ifdef WANT_NEAR_INDICATION
	{
		char *cpy;
		if(n)
		{
			cpy = xstrdup(n);
			make_print(cpy);
			fprintf(stderr, " near '%s'", cpy);
			free(cpy);
		}
	}
#endif
}


int parser_error(const char *s, ...)
{
	va_list ap;
	va_start(ap, s);
	generic_msg(s, "Error", parser_text, ap);
        fputc( '\n', stderr );
	va_end(ap);
	exit(1);
	return 1;
}

int parser_warning(const char *s, ...)
{
	va_list ap;
	va_start(ap, s);
	generic_msg(s, "Warning", parser_text, ap);
	va_end(ap);
	return 0;
}

void fatal_perror( const char *msg, ... )
{
        va_list valist;
        va_start( valist, msg );
	fprintf(stderr, "Error: ");
        vfprintf( stderr, msg, valist );
        perror( " " );
        va_end( valist );
        exit(2);
}

void error(const char *s, ...)
{
	va_list ap;
	va_start(ap, s);
	fprintf(stderr, "Error: ");
	vfprintf(stderr, s, ap);
	va_end(ap);
	exit(2);
}

void warning(const char *s, ...)
{
	va_list ap;
	va_start(ap, s);
	fprintf(stderr, "Warning: ");
	vfprintf(stderr, s, ap);
	va_end(ap);
}

void chat(const char *s, ...)
{
	if(debuglevel & DEBUGLEVEL_CHAT)
	{
		va_list ap;
		va_start(ap, s);
		fprintf(stderr, "FYI: ");
		vfprintf(stderr, s, ap);
		va_end(ap);
	}
}

int compare_striA( const char *str1, const char *str2 )
{
    for (;;)
    {
        /* only the A-Z range is case-insensitive */
        char ch1 = (*str1 >= 'a' && *str1 <= 'z') ? *str1 + 'A' - 'a' : *str1;
        char ch2 = (*str2 >= 'a' && *str2 <= 'z') ? *str2 + 'A' - 'a' : *str2;
        if (!ch1 || ch1 != ch2) return ch1 - ch2;
        str1++;
        str2++;
    }
}

int compare_striW( const WCHAR *str1, const WCHAR *str2 )
{
    for (;;)
    {
        /* only the A-Z range is case-insensitive */
        WCHAR ch1 = (*str1 >= 'a' && *str1 <= 'z') ? *str1 + 'A' - 'a' : *str1;
        WCHAR ch2 = (*str2 >= 'a' && *str2 <= 'z') ? *str2 + 'A' - 'a' : *str2;
        if (!ch1 || ch1 != ch2) return ch1 - ch2;
        str1++;
        str2++;
    }
}

int compare_striAW( const char *str1, const WCHAR *str2 )
{
    for (;;)
    {
        /* only the A-Z range is case-insensitive */
        WCHAR ch1 = (*str1 >= 'a' && *str1 <= 'z') ? *str1 + 'A' - 'a' : (unsigned char)*str1;
        WCHAR ch2 = (*str2 >= 'a' && *str2 <= 'z') ? *str2 + 'A' - 'a' : *str2;
        if (!ch1 || ch1 != ch2) return ch1 - ch2;
        str1++;
        str2++;
    }
}

/*
 *****************************************************************************
 * Function	: compare_name_id
 * Syntax	: int compare_name_id(const name_id_t *n1, const name_id_t *n2)
 * Input	:
 * Output	:
 * Description	:
 * Remarks	:
 *****************************************************************************
*/
int compare_name_id(const name_id_t *n1, const name_id_t *n2)
{
    if (n1->type != n2->type) return n1->type == name_ord ? 1 : -1;
    if (n1->type == name_ord) return n1->name.i_name - n2->name.i_name;

    if (n1->name.s_name->type == str_char)
    {
        if (n2->name.s_name->type == str_char)
            return compare_striA(n1->name.s_name->str.cstr, n2->name.s_name->str.cstr);
        return compare_striAW(n1->name.s_name->str.cstr, n2->name.s_name->str.wstr);
    }
    else
    {
        if (n2->name.s_name->type == str_char)
            return -compare_striAW(n2->name.s_name->str.cstr, n1->name.s_name->str.wstr);
        return compare_striW(n1->name.s_name->str.wstr, n2->name.s_name->str.wstr);
    }
}

#ifdef _WIN32

int is_valid_codepage(int id)
{
    return IsValidCodePage( id );
}

static WCHAR *codepage_to_unicode( int codepage, const char *src, int srclen, int *dstlen )
{
    WCHAR *dst = xmalloc( (srclen + 1) * sizeof(WCHAR) );
    DWORD ret = MultiByteToWideChar( codepage, MB_ERR_INVALID_CHARS, src, srclen, dst, srclen );
    if (!ret) return NULL;
    dst[ret] = 0;
    *dstlen = ret;
    return dst;
}

int get_language_codepage( language_t lang )
{
    DWORD codepage;

    if (!lang) return 1252;
    if (!GetLocaleInfoW( lang, LOCALE_IDEFAULTANSICODEPAGE | LOCALE_RETURN_NUMBER,
                         (WCHAR *)&codepage, sizeof(codepage)/sizeof(WCHAR) )) return -1;
    return codepage;
}

#else  /* _WIN32 */

struct nls_info
{
    unsigned short  codepage;
    unsigned short  unidef;
    unsigned short  trans_unidef;
    unsigned short *cp2uni;
    unsigned short *dbcs_offsets;
};

static struct nls_info nlsinfo[128];

static void init_nls_info( struct nls_info *info, unsigned short *ptr )
{
    unsigned short hdr_size = ptr[0];

    info->codepage      = ptr[1];
    info->unidef        = ptr[4];
    info->trans_unidef  = ptr[6];
    ptr += hdr_size;
    info->cp2uni = ++ptr;
    ptr += 256;
    if (*ptr++) ptr += 256;  /* glyph table */
    info->dbcs_offsets  = *ptr ? ptr + 1 : NULL;
}

static const struct nls_info *get_nls_info( unsigned int codepage )
{
    unsigned short *data;
    char *path;
    unsigned int i;
    size_t size;

    for (i = 0; i < ARRAY_SIZE(nlsinfo) && nlsinfo[i].codepage; i++)
        if (nlsinfo[i].codepage == codepage) return &nlsinfo[i];

    assert( i < ARRAY_SIZE(nlsinfo) );

    for (i = 0; nlsdirs[i]; i++)
    {
        path = strmake( "%s/c_%03u.nls", nlsdirs[i], codepage );
        if ((data = read_file( path, &size )))
        {
            free( path );
            init_nls_info( &nlsinfo[i], data );
            return &nlsinfo[i];
        }
        free( path );
    }
    return NULL;
}

int is_valid_codepage(int cp)
{
    return cp == CP_UTF8 || get_nls_info( cp );
}

static WCHAR *codepage_to_unicode( int codepage, const char *src, int srclen, int *dstlen )
{
    const struct nls_info *info = get_nls_info( codepage );
    unsigned int i;
    WCHAR dbch, *dst = xmalloc( (srclen + 1) * sizeof(WCHAR) );

    if (!info) error( "codepage %u not supported\n", codepage );

    if (info->dbcs_offsets)
    {
        for (i = 0; srclen; i++, srclen--, src++)
        {
            unsigned short off = info->dbcs_offsets[(unsigned char)*src];
            if (off)
            {
                if (srclen == 1) return NULL;
                dbch = (src[0] << 8) | (unsigned char)src[1];
                src++;
                srclen--;
                dst[i] = info->dbcs_offsets[off + (unsigned char)*src];
                if (dst[i] == info->unidef && dbch != info->trans_unidef) return NULL;
            }
            else
            {
                dst[i] = info->cp2uni[(unsigned char)*src];
                if (dst[i] == info->unidef && *src != info->trans_unidef) return NULL;
            }
        }
    }
    else
    {
        for (i = 0; i < srclen; i++)
        {
            dst[i] = info->cp2uni[(unsigned char)src[i]];
            if (dst[i] == info->unidef && src[i] != info->trans_unidef) return NULL;
        }
    }
    dst[i] = 0;
    *dstlen = i;
    return dst;
}

static const NLS_LOCALE_LCID_INDEX *lcids_index;
static const NLS_LOCALE_HEADER *locale_table;
static const NLS_LOCALE_LCNAME_INDEX *lcnames_index;
static const WCHAR *locale_strings;

static void load_locale_nls(void)
{
    struct
    {
        unsigned int ctypes;
        unsigned int unknown1;
        unsigned int unknown2;
        unsigned int unknown3;
        unsigned int locales;
        unsigned int charmaps;
        unsigned int geoids;
        unsigned int scripts;
    } *header;
    char *path;
    unsigned int i;
    size_t size;

    for (i = 0; nlsdirs[i]; i++)
    {
        path = strmake( "%s/locale.nls", nlsdirs[i] );
        header = read_file( path, &size );
        free( path );
        if (!header) continue;
        locale_table = (const NLS_LOCALE_HEADER *)((char *)header + header->locales);
        lcids_index = (const NLS_LOCALE_LCID_INDEX *)((char *)locale_table + locale_table->lcids_offset);
        lcnames_index = (const NLS_LOCALE_LCNAME_INDEX *)((char *)locale_table + locale_table->lcnames_offset);
        locale_strings = (const WCHAR *)((char *)locale_table + locale_table->strings_offset);
        return;
    }
    error( "unable to load locale.nls\n" );
}

static const NLS_LOCALE_LCID_INDEX *find_lcid_entry( LCID lcid )
{
    int min = 0, max = locale_table->nb_lcids - 1;

    while (min <= max)
    {
        int pos = (min + max) / 2;
        if (lcid < lcids_index[pos].id) max = pos - 1;
        else if (lcid > lcids_index[pos].id) min = pos + 1;
        else return &lcids_index[pos];
    }
    return NULL;
}

static const NLS_LOCALE_DATA *get_locale_data( UINT idx )
{
    ULONG offset = locale_table->locales_offset + idx * locale_table->locale_size;
    return (const NLS_LOCALE_DATA *)((const char *)locale_table + offset);
}

int get_language_codepage( language_t lang )
{
    const NLS_LOCALE_LCID_INDEX *entry;

    if (!lang) return 1252;
    if (lang == MAKELANGID( LANG_ENGLISH, SUBLANG_DEFAULT )) return 1252;
    if (!locale_table) load_locale_nls();
    if (!(entry = find_lcid_entry( lang ))) return -1;
    return get_locale_data( entry->idx )->idefaultansicodepage;
}

#endif  /* _WIN32 */

static WCHAR *utf8_to_unicode( const char *src, int srclen, int *dstlen )
{
    static const char utf8_length[128] =
    {
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x80-0x8f */
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x90-0x9f */
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0xa0-0xaf */
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0xb0-0xbf */
        0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* 0xc0-0xcf */
        1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* 0xd0-0xdf */
        2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, /* 0xe0-0xef */
        3,3,3,3,3,0,0,0,0,0,0,0,0,0,0,0  /* 0xf0-0xff */
    };
    static const unsigned char utf8_mask[4] = { 0x7f, 0x1f, 0x0f, 0x07 };

    const char *srcend = src + srclen;
    int len, res;
    WCHAR *ret, *dst;

    dst = ret = xmalloc( (srclen + 1) * sizeof(WCHAR) );
    while (src < srcend)
    {
        unsigned char ch = *src++;
        if (ch < 0x80)  /* special fast case for 7-bit ASCII */
        {
            *dst++ = ch;
            continue;
        }
        len = utf8_length[ch - 0x80];
        if (len && src + len <= srcend)
        {
            res = ch & utf8_mask[len];
            switch (len)
            {
            case 3:
                if ((ch = *src ^ 0x80) >= 0x40) break;
                res = (res << 6) | ch;
                src++;
                if (res < 0x10) break;
            case 2:
                if ((ch = *src ^ 0x80) >= 0x40) break;
                res = (res << 6) | ch;
                if (res >= 0x110000 >> 6) break;
                src++;
                if (res < 0x20) break;
                if (res >= 0xd800 >> 6 && res <= 0xdfff >> 6) break;
            case 1:
                if ((ch = *src ^ 0x80) >= 0x40) break;
                res = (res << 6) | ch;
                src++;
                if (res < 0x80) break;
                if (res <= 0xffff) *dst++ = res;
                else
                {
                    res -= 0x10000;
                    *dst++ = 0xd800 | (res >> 10);
                    *dst++ = 0xdc00 | (res & 0x3ff);
                }
                continue;
            }
        }
        *dst++ = 0xfffd;
    }
    *dst = 0;
    *dstlen = dst - ret;
    return ret;
}

static char *unicode_to_utf8( const WCHAR *src, int srclen, int *dstlen )
{
    char *ret, *dst;

    dst = ret = xmalloc( srclen * 3 + 1 );
    for ( ; srclen; srclen--, src++)
    {
        unsigned int ch = *src;

        if (ch < 0x80)  /* 0x00-0x7f: 1 byte */
        {
            *dst++ = ch;
            continue;
        }
        if (ch < 0x800)  /* 0x80-0x7ff: 2 bytes */
        {
            dst[1] = 0x80 | (ch & 0x3f);
            ch >>= 6;
            dst[0] = 0xc0 | ch;
            dst += 2;
            continue;
        }
        if (ch >= 0xd800 && ch <= 0xdbff && srclen > 1 && src[1] >= 0xdc00 && src[1] <= 0xdfff)
        {
            /* 0x10000-0x10ffff: 4 bytes */
            ch = 0x10000 + ((ch & 0x3ff) << 10) + (src[1] & 0x3ff);
            dst[3] = 0x80 | (ch & 0x3f);
            ch >>= 6;
            dst[2] = 0x80 | (ch & 0x3f);
            ch >>= 6;
            dst[1] = 0x80 | (ch & 0x3f);
            ch >>= 6;
            dst[0] = 0xf0 | ch;
            dst += 4;
            src++;
            srclen--;
            continue;
        }
        if (ch >= 0xd800 && ch <= 0xdfff) ch = 0xfffd;  /* invalid surrogate pair */

        /* 0x800-0xffff: 3 bytes */
        dst[2] = 0x80 | (ch & 0x3f);
        ch >>= 6;
        dst[1] = 0x80 | (ch & 0x3f);
        ch >>= 6;
        dst[0] = 0xe0 | ch;
        dst += 3;
    }
    *dst = 0;
    *dstlen = dst - ret;
    return ret;
}

string_t *convert_string_unicode( const string_t *str, int codepage )
{
    string_t *ret = xmalloc(sizeof(*ret));

    ret->type = str_unicode;
    ret->loc = str->loc;

    if (str->type == str_char)
    {
        if (!codepage) parser_error( "Current language is Unicode only, cannot convert string" );

        if (codepage == CP_UTF8)
            ret->str.wstr = utf8_to_unicode( str->str.cstr, str->size, &ret->size );
        else
            ret->str.wstr = codepage_to_unicode( codepage, str->str.cstr, str->size, &ret->size );
        if (!ret->str.wstr) parser_error( "Invalid character in string '%.*s' for codepage %u",
                                          str->size, str->str.cstr, codepage );
    }
    else
    {
        ret->size     = str->size;
        ret->str.wstr = xmalloc(sizeof(WCHAR)*(ret->size+1));
        memcpy( ret->str.wstr, str->str.wstr, ret->size * sizeof(WCHAR) );
        ret->str.wstr[ret->size] = 0;
    }
    return ret;
}

char *convert_string_utf8( const string_t *str, int codepage )
{
    int len;
    string_t *wstr = convert_string_unicode( str, codepage );
    char *ret = unicode_to_utf8( wstr->str.wstr, wstr->size, &len );
    free_string( wstr );
    return ret;
}

void free_string(string_t *str)
{
    if (str->type == str_unicode) free( str->str.wstr );
    else free( str->str.cstr );
    free( str );
}

/* check if the string is valid utf8 despite a different codepage being in use */
int check_valid_utf8( const string_t *str, int codepage )
{
    int i, count;
    WCHAR *wstr;

    if (!check_utf8) return 0;
    if (!codepage) return 0;
    if (codepage == CP_UTF8) return 0;
    if (!is_valid_codepage( codepage )) return 0;

    for (i = count = 0; i < str->size; i++)
    {
        if ((unsigned char)str->str.cstr[i] >= 0xf5) goto done;
        if ((unsigned char)str->str.cstr[i] >= 0xc2) { count++; continue; }
        if ((unsigned char)str->str.cstr[i] >= 0x80) goto done;
    }
    if (!count) return 0;  /* no 8-bit chars at all */

    wstr = utf8_to_unicode( str->str.cstr, str->size, &count );
    for (i = 0; i < count; i++) if (wstr[i] == 0xfffd) break;
    free( wstr );
    return (i == count);

done:
    check_utf8 = 0;  /* at least one 8-bit non-utf8 string found, stop checking */
    return 0;
}

const char *get_nameid_str(const name_id_t *n)
{
    int len;

    if (!n) return "<none>";
    if (n->type == name_ord) return strmake( "%u", n->name.i_name );
    if (n->name.s_name->type == str_char) return n->name.s_name->str.cstr;
    return unicode_to_utf8( n->name.s_name->str.wstr, n->name.s_name->size, &len );
}