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**
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** This file is part of the Qt Messaging Framework.
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****************************************************************************/

#ifndef QMAILCODEC_H
#define QMAILCODEC_H

#include "qmailglobal.h"
#include <QByteArray>
#include <QDataStream>
#include <QString>
#include <QTextStream>

class QTextCodec;
class QMF_EXPORT QMailCodec
{
public:
    enum { ChunkCharacters = 8192 };

    virtual ~QMailCodec();

    virtual QString name() const = 0;

    // Stream conversion interface including character translation
    virtual void encode(QDataStream& out, QTextStream& in, const QByteArray& charset = "UTF-8");
    virtual void decode(QTextStream& out, QDataStream& in, const QByteArray& charset);

    // Stream conversion interface
    virtual void encode(QDataStream& out, QDataStream& in);
    virtual void decode(QDataStream& out, QDataStream& in);

    // Convenience functions to encapsulate stream processing
    QByteArray encode(const QString& in, const QByteArray& charset = "UTF-8");
    QString decode(const QByteArray& in, const QByteArray& charset);

    QByteArray encode(const QByteArray& in);
    QByteArray decode(const QByteArray& in);

    // Static helper functions
    static QTextCodec * codecForName(const QByteArray& charset, bool translateAscii = true);
    static QByteArray bestCompatibleCharset(const QByteArray& charset, bool translateAscii);
    static void copy(QDataStream& out, QDataStream& in);
    static void copy(QTextStream& out, QDataStream& in, const QByteArray& charset = "UTF-8");
    static QString autoDetectEncoding(const QByteArray& text);
    static QString encodeModifiedUtf7(const QString &text);
    static QString decodeModifiedUtf7(const QString &text);

protected:
    // Helper functions to convert stream chunks
    virtual void encodeChunk(QDataStream& out, const unsigned char* in, int length, bool finalChunk) = 0;
    virtual void decodeChunk(QDataStream& out, const char* in, int length, bool finalChunk) = 0;
};

class QMF_EXPORT QMailBase64Codec : public QMailCodec
{
public:
    enum ContentType { Text, Binary };

    QMailBase64Codec(ContentType content, int maximumLineLength = -1);

    QString name() const override;

protected:
    void encodeChunk(QDataStream& out, const unsigned char* in, int length, bool finalChunk) override;
    void decodeChunk(QDataStream& out, const char* in, int length, bool finalChunk) override;

private:
    ContentType _content;
    int _maximumLineLength;

    unsigned char _encodeBuffer[3];
    unsigned char* _encodeBufferOut;
    int _encodeLineCharsRemaining;

    unsigned char _decodeBuffer[4];
    unsigned char* _decodeBufferOut;
    int _decodePaddingCount;

    unsigned char _lastChar;
};

class QMF_EXPORT QMailQuotedPrintableCodec : public QMailCodec
{
public:
    enum ContentType { Text, Binary };
    enum ConformanceType { Rfc2045, Rfc2047 };

    QMailQuotedPrintableCodec(ContentType content, ConformanceType conformance, int maximumLineLength = -1);

    QString name() const override;

protected:
    void encodeChunk(QDataStream& out, const unsigned char* in, int length, bool finalChunk) override;
    void decodeChunk(QDataStream& out, const char* in, int length, bool finalChunk) override;

private:
    ContentType _content;
    ConformanceType _conformance;
    int _maximumLineLength;

    int _encodeLineCharsRemaining;
    unsigned char _encodeLastChar;

    char _decodePrecedingInput;
    unsigned char _decodeLastChar;
};

class QMF_EXPORT QMailPassThroughCodec : public QMailCodec
{
    QString name() const override;

protected:
    void encodeChunk(QDataStream& out, const unsigned char* in, int length, bool finalChunk) override;
    void decodeChunk(QDataStream& out, const char* in, int length, bool finalChunk) override;
};

class QMF_EXPORT QMailLineEndingCodec : public QMailCodec
{
    QString name() const override;

public:
    QMailLineEndingCodec();

protected:
    void encodeChunk(QDataStream& out, const unsigned char* in, int length, bool finalChunk) override;
    void decodeChunk(QDataStream& out, const char* in, int length, bool finalChunk) override;

private:
    unsigned char _lastChar;
};

#endif