/*

    Copyright (C) 1999 Lars Knoll (knoll@mpi-hd.mpg.de)

    Copyright (C) 2006 Alexey Proskuryakov (ap@nypop.com)

    Copyright (C) 2006, 2008 Apple Inc. All rights reserved.

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Library General Public

    License as published by the Free Software Foundation; either

    version 2 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

    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License

    along with this library; see the file COPYING.LIB.  If not, write to

    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

    Boston, MA 02110-1301, USA.

*/

#ifndef TextResourceDecoder_h

#define TextResourceDecoder_h

#include "TextEncoding.h"

namespace WebCore {

class TextResourceDecoder : public RefCounted<TextResourceDecoder> {

public:

    enum EncodingSource {

        DefaultEncoding,

        AutoDetectedEncoding,

        EncodingFromXMLHeader,

        EncodingFromMetaTag,

        EncodingFromCSSCharset,

        EncodingFromHTTPHeader,

        UserChosenEncoding,

        EncodingFromParentFrame

    };

    static PassRefPtr<TextResourceDecoder> create(const String& mimeType, const TextEncoding& defaultEncoding = TextEncoding(), bool usesEncodingDetector = false)

    {

        return adoptRef(new TextResourceDecoder(mimeType, defaultEncoding, usesEncodingDetector));

    }

    ~TextResourceDecoder();

    void setEncoding(const TextEncoding&, EncodingSource);

    const TextEncoding& encoding() const { return m_encoding; }

    String decode(const char* data, size_t length);

    String flush();

    void setHintEncoding(const TextResourceDecoder* hintDecoder)

    {

        // hintEncoding is for use with autodetection, which should be 

        // only invoked when hintEncoding comes from auto-detection.

        if (hintDecoder && hintDecoder->m_source == AutoDetectedEncoding)

            m_hintEncoding = hintDecoder->encoding().name();

    }

    void useLenientXMLDecoding() { m_useLenientXMLDecoding = true; }

    bool sawError() const { return m_sawError; }

private:

    TextResourceDecoder(const String& mimeType, const TextEncoding& defaultEncoding,

                        bool usesEncodingDetector);

    enum ContentType { PlainText, HTML, XML, CSS }; // PlainText only checks for BOM.

    static ContentType determineContentType(const String& mimeType);

    static const TextEncoding& defaultEncoding(ContentType, const TextEncoding& defaultEncoding);

    size_t checkForBOM(const char*, size_t);

    bool checkForCSSCharset(const char*, size_t, bool& movedDataToBuffer);

    bool checkForHeadCharset(const char*, size_t, bool& movedDataToBuffer);

    void detectJapaneseEncoding(const char*, size_t);

    bool shouldAutoDetect() const;

    ContentType m_contentType;

    TextEncoding m_encoding;

    OwnPtr<TextCodec> m_codec;

    EncodingSource m_source;

    const char* m_hintEncoding;

    Vector<char> m_buffer;

    bool m_checkedForBOM;

    bool m_checkedForCSSCharset;

    bool m_checkedForHeadCharset;

    bool m_useLenientXMLDecoding; // Don't stop on XML decoding errors.

    bool m_sawError;

    bool m_usesEncodingDetector;

};

}

#endif