/*

 * Copyright (C) 2007 Apple Inc.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#ifndef WTF_UTF8_h

#define WTF_UTF8_h

#include "Unicode.h"

namespace WTF {

  namespace Unicode {

    // Given a first byte, gives the length of the UTF-8 sequence it begins.

    // Returns 0 for bytes that are not legal starts of UTF-8 sequences.

    // Only allows sequences of up to 4 bytes, since that works for all Unicode characters (U-00000000 to U-0010FFFF).

    int UTF8SequenceLength(char);

    // Takes a null-terminated C-style string with a UTF-8 sequence in it and converts it to a character.

    // Only allows Unicode characters (U-00000000 to U-0010FFFF).

    // Returns -1 if the sequence is not valid (including presence of extra bytes).

    int decodeUTF8Sequence(const char*);

    typedef enum {

            conversionOK,       // conversion successful

            sourceExhausted,    // partial character in source, but hit end

            targetExhausted,    // insuff. room in target for conversion

            sourceIllegal       // source sequence is illegal/malformed

    } ConversionResult;

    // These conversion functions take a "strict" argument. When this

    // flag is set to strict, both irregular sequences and isolated surrogates

    // will cause an error.  When the flag is set to lenient, both irregular

    // sequences and isolated surrogates are converted.

    // 

    // Whether the flag is strict or lenient, all illegal sequences will cause

    // an error return. This includes sequences such as: <F4 90 80 80>, <C0 80>,

    // or <A0> in UTF-8, and values above 0x10FFFF in UTF-32. Conformant code

    // must check for illegal sequences.

    // 

    // When the flag is set to lenient, characters over 0x10FFFF are converted

    // to the replacement character; otherwise (when the flag is set to strict)

    // they constitute an error.

    ConversionResult convertUTF8ToUTF16(

                    const char** sourceStart, const char* sourceEnd, 

                    UChar** targetStart, UChar* targetEnd, bool strict = true);

    ConversionResult convertUTF16ToUTF8(

                    const UChar** sourceStart, const UChar* sourceEnd, 

                    char** targetStart, char* targetEnd, bool strict = true);

  }

}

#endif // WTF_UTF8_h