/** BEGIN COPYRIGHT BLOCK
 * License: GPL (version 3 or any later version).
 * See LICENSE for details.
 * END COPYRIGHT BLOCK **/
/* ***** BEGIN LICENSE BLOCK *****
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998-1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * June 25, 2009 - copied from Mozilla LDAP C SDK - relicensed to use GPLv2
 * with directory server plug-in exception as per the above paragraph
 *
 * ***** END LICENSE BLOCK ***** */

/* the openldap library has utf8 string handling functions, but they
   are somewhat different, and not exposed/exported for use outside
   of the library - therefore, we just copy these from mozldap when
   using openldap
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

/* uft8.c - misc. utf8 "string" functions. */
#include "slapi-plugin.h"

#define register  /* For C97 */

static char UTF8len[64] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
                           1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
                           0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                           2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 5, 6};

int
ldap_utf8len(const char *s)
/* Return the number of char's in the character at *s. */
{
    return ldap_utf8next((char *)s) - s;
}

char *
ldap_utf8next(char *s)
/* Return a pointer to the character immediately following *s.
    Handle any valid UTF-8 character, including '\0' and ASCII.
    Try to handle a misaligned pointer or a malformed character.
     */
{
    register unsigned char *next = (unsigned char *)s;
    switch (UTF8len[(*next >> 2) & 0x3F]) {
    case 0: /* erroneous: s points to the middle of a character. */
    case 6:
        if ((*++next & 0xC0) != 0x80) {
            break;
        }
        /* FALLTHRU */
    case 5:
        if ((*++next & 0xC0) != 0x80) {
            break;
        }
        /* FALLTHRU */
    case 4:
        if ((*++next & 0xC0) != 0x80) {
            break;
        }
        /* FALLTHRU */
    case 3:
        if ((*++next & 0xC0) != 0x80) {
            break;
        }
        /* FALLTHRU */
    case 2:
        if ((*++next & 0xC0) != 0x80) {
            break;
        }
        /* FALLTHRU */
    case 1:
        ++next;
    }
    return (char *)next;
}

char *
ldap_utf8prev(char *s)
/* Return a pointer to the character immediately preceding *s.
    Handle any valid UTF-8 character, including '\0' and ASCII.
    Try to handle a misaligned pointer or a malformed character.
     */
{
    register unsigned char *prev = (unsigned char *)s;
    unsigned char *limit = prev - 6;
    while (((*--prev & 0xC0) == 0x80) && (prev != limit)) {
        ;
    }
    return (char *)prev;
}

/*
 * Return a pointer to the n-th character following *s.
 * Handle any valid UTF-8 character, including '\0' and ASCII.
 * Try to handle a misaligned pointer or a malformed character.
 * If the n-th character is beyond the string, it returns NULL.
 */
char *
ldap_utf8nextn(char *s, int n)
{
    char *endp;
    char *next = s;
    if (!s) {
        return NULL;
    }
    endp = s + strlen(s);
    for (; n > 0; --n) {
        next = ldap_utf8next(next);
        if ((next > endp) && (n > 0)) {
            return NULL;
        }
    }
    return next;
}

/*
 * Return a pointer to the n-th character preceding *from.
 * Handle any valid UTF-8 character, including '\0' and ASCII.
 * Try to handle a misaligned pointer or a malformed character.
 * If the n-th previous character is beyond the start address, it returns NULL.
 */
char *
ldap_utf8prevn(char *s, char *from, int n)
{
    char *prev = from;
    if (!s || !from || (s > from)) {
        return NULL;
    }
    for (; n > 0; --n) {
        prev = ldap_utf8prev(prev);
        if ((n > 0) && (prev < s)) {
            return NULL;
        }
    }
    return prev;
}

int
ldap_utf8copy(char *dst, const char *src)
/* Copy a character from src to dst; return the number of char's copied.
    Handle any valid UTF-8 character, including '\0' and ASCII.
    Try to handle a misaligned pointer or a malformed character.
     */
{
    register const unsigned char *s = (const unsigned char *)src;
    switch (UTF8len[(*s >> 2) & 0x3F]) {
    case 0: /* erroneous: s points to the middle of a character. */
    case 6:
        *dst++ = *s++;
        if ((*s & 0xC0) != 0x80) {
            break;
        }
        /* FALLTHRU */
    case 5:
        *dst++ = *s++;
        if ((*s & 0xC0) != 0x80) {
            break;
        }
        /* FALLTHRU */
    case 4:
        *dst++ = *s++;
        if ((*s & 0xC0) != 0x80) {
            break;
        }
        /* FALLTHRU */
    case 3:
        *dst++ = *s++;
        if ((*s & 0xC0) != 0x80) {
            break;
        }
        /* FALLTHRU */
    case 2:
        *dst++ = *s++;
        if ((*s & 0xC0) != 0x80) {
            break;
        }
        /* FALLTHRU */
    case 1:
        *dst = *s++;
    }
    return s - (const unsigned char *)src;
}

size_t
ldap_utf8characters(const char *src)
/* Return the number of UTF-8 characters in the 0-terminated array s. */
{
    register char *s = (char *)src;
    size_t n;
    for (n = 0; *s; LDAP_UTF8INC(s))
        ++n;
    return n;
}

unsigned long
ldap_utf8getcc(const char **src)
{
    register unsigned long c = 0;
    register const unsigned char *s = (const unsigned char *)*src;
    switch (UTF8len[(*s >> 2) & 0x3F]) {
    case 0: /* erroneous: s points to the middle of a character. */
        c = (*s++) & 0x3F;
        goto more5;
    case 1:
        c = (*s++);
        break;
    case 2:
        c = (*s++) & 0x1F;
        goto more1;
    case 3:
        c = (*s++) & 0x0F;
        goto more2;
    case 4:
        c = (*s++) & 0x07;
        goto more3;
    case 5:
        c = (*s++) & 0x03;
        goto more4;
    case 6:
        c = (*s++) & 0x01;
        goto more5;
    more5:
        if ((*s & 0xC0) != 0x80)
            break;
        c = (c << 6) | ((*s++) & 0x3F);
    more4:
        if ((*s & 0xC0) != 0x80)
            break;
        c = (c << 6) | ((*s++) & 0x3F);
    more3:
        if ((*s & 0xC0) != 0x80)
            break;
        c = (c << 6) | ((*s++) & 0x3F);
    more2:
        if ((*s & 0xC0) != 0x80)
            break;
        c = (c << 6) | ((*s++) & 0x3F);
    more1:
        if ((*s & 0xC0) != 0x80)
            break;
        c = (c << 6) | ((*s++) & 0x3F);
        break;
    }
    *src = (const char *)s;
    return c;
}

char *
ldap_utf8strtok_r(char *sp, const char *brk, char **next)
{
    const char *bp;
    unsigned long sc, bc;
    char *tok;

    if (sp == NULL && (sp = *next) == NULL)
        return NULL;

/* Skip leading delimiters; roughly, sp += strspn(sp, brk) */
cont:
    sc = LDAP_UTF8GETC(sp);
    for (bp = brk; (bc = LDAP_UTF8GETCC(bp)) != 0;) {
        if (sc == bc)
            goto cont;
    }

    if (sc == 0) { /* no non-delimiter characters */
        *next = NULL;
        return NULL;
    }
    tok = LDAP_UTF8PREV(sp);

    /* Scan token; roughly, sp += strcspn(sp, brk)
     * Note that brk must be 0-terminated; we stop if we see that, too.
     */
    while (1) {
        sc = LDAP_UTF8GETC(sp);
        bp = brk;
        do {
            if ((bc = LDAP_UTF8GETCC(bp)) == sc) {
                if (sc == 0) {
                    *next = NULL;
                } else {
                    *next = sp;
                    *(LDAP_UTF8PREV(sp)) = 0;
                }
                return tok;
            }
        } while (bc != 0);
    }
    /* NOTREACHED */
}

int
ldap_utf8isalnum(char *s)
{
    register unsigned char c = *(unsigned char *)s;
    if (0x80 & c)
        return 0;
    if (c >= 'A' && c <= 'Z')
        return 1;
    if (c >= 'a' && c <= 'z')
        return 1;
    if (c >= '0' && c <= '9')
        return 1;
    return 0;
}

int
ldap_utf8isalpha(char *s)
{
    register unsigned char c = *(unsigned char *)s;
    if (0x80 & c)
        return 0;
    if (c >= 'A' && c <= 'Z')
        return 1;
    if (c >= 'a' && c <= 'z')
        return 1;
    return 0;
}

int
ldap_utf8isdigit(char *s)
{
    register unsigned char c = *(unsigned char *)s;
    if (0x80 & c)
        return 0;
    if (c >= '0' && c <= '9')
        return 1;
    return 0;
}

int
ldap_utf8isxdigit(char *s)
{
    register unsigned char c = *(unsigned char *)s;
    if (0x80 & c)
        return 0;
    if (c >= '0' && c <= '9')
        return 1;
    if (c >= 'A' && c <= 'F')
        return 1;
    if (c >= 'a' && c <= 'f')
        return 1;
    return 0;
}

int
ldap_utf8isspace(char *s)
{
    register unsigned char *c = (unsigned char *)s;
    int len = ldap_utf8len(s);

    if (len == 0) {
        return 0;
    } else if (len == 1) {
        switch (*c) {
        case 0x09:
        case 0x0A:
        case 0x0B:
        case 0x0C:
        case 0x0D:
        case 0x20:
            return 1;
        default:
            return 0;
        }
    } else if (len == 2) {
        if (*c == 0xc2) {
            return *(c + 1) == 0x80;
        }
    } else if (len == 3) {
        if (*c == 0xE2) {
            c++;
            if (*c == 0x80) {
                c++;
                return (*c >= 0x80 && *c <= 0x8a);
            }
        } else if (*c == 0xE3) {
            return (*(c + 1) == 0x80) && (*(c + 2) == 0x80);
        } else if (*c == 0xEF) {
            return (*(c + 1) == 0xBB) && (*(c + 2) == 0xBF);
        }
        return 0;
    }

    /* should never reach here */
    return 0;
}