/*

    File:       utf8_decodestr.h

    Contains:   User space implementation of utf8_decodestr.

    Written by: DTS

    Copyright:  Copyright (c) 2006 by Apple Computer, Inc., All Rights Reserved.

    Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.

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    Change History (most recent first):

$Log: utf8_decodestr.c,v $

Revision 1.1  2006/07/27 15:49:36  eskimo1

First checked in.

*/

/////////////////////////////////////////////////////////////////////

// Our prototypes

#include "utf8_decodestr.h"

// We do the working using CF; AFAICT there is no lower-level code that can do 

// this job that's supported for third party use.  Scarily, the routine with the 

// /same name/ that's exported by libiconv.dylib has different parameters!

#include <CoreFoundation/CoreFoundation.h>

/////////////////////////////////////////////////////////////////////

extern int utf8_decodestr(const u_int8_t * utf8p, size_t utf8len, u_int16_t *ucsp, size_t *ucslen,

        size_t buflen, u_int16_t altslash, int flags)

{

    int         err;

    CFStringRef str;

    CFIndex     utf16Count;

    assert(utf8p != NULL);

    assert(ucsp != NULL);

    assert(ucslen != NULL);

    assert(altslash == 0);

    assert(flags == UTF_PRECOMPOSED);

    err = 0;

    str = CFStringCreateWithBytes(NULL, utf8p, utf8len, kCFStringEncodingUTF8, false);

    if (str == NULL) {

        err = EINVAL;

    }

    if (err == 0) {

        CFMutableStringRef  tmpStr;

        tmpStr = CFStringCreateMutableCopy(NULL, 0, str);

        if (tmpStr != NULL) {

            CFStringNormalize(tmpStr, kCFStringNormalizationFormC);

            // Swap tmpStr into str.

            CFRelease(str);

            str = tmpStr;

        }

    }

    if (err == 0) {

        utf16Count = CFStringGetLength(str);

        if (utf16Count > (buflen / 2)) {

            utf16Count = (buflen / 2);

            err = ENAMETOOLONG;

        }

        CFStringGetCharacters(str, CFRangeMake(0, utf16Count), ucsp);

        *ucslen = utf16Count * sizeof(uint16_t);

    }

    if (str != NULL) {

        CFRelease(str);

    }

    return err;

}