#ifndef CRYPTOPP_GZIP_H
#define CRYPTOPP_GZIP_H

#include "zdeflate.h"
#include "zinflate.h"
#include "crc.h"

NAMESPACE_BEGIN(CryptoPP)

/// GZIP Compression (RFC 1952)
class Gzip : public Deflator
{
public:
	Gzip(BufferedTransformation *attachment=NULL, unsigned int deflateLevel=DEFAULT_DEFLATE_LEVEL, unsigned int log2WindowSize=DEFAULT_LOG2_WINDOW_SIZE, bool detectUncompressible=true)
		: Deflator(attachment, deflateLevel, log2WindowSize, detectUncompressible), m_filetime(0) {}
	Gzip(const NameValuePairs &parameters, BufferedTransformation *attachment=NULL)
		: Deflator(parameters, attachment), m_filetime(0) {}
    
	/*! \param filetime the filetime to set in the header. The application is responsible for setting it.
	 */
	void SetFiletime(word32 filetime) { m_filetime = filetime; }
    
	/*! \param filename the original filename to set in the header. The application is responsible for setting it.
	           RFC 1952 requires a ISO/IEC 8859-1 encoding.
	    \param throwOnEncodingError if throwOnEncodingError is true, then the filename is checked to ensure it is
	           ISO/IEC 8859-1 encoded. If the filename does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat
	           is thrown. If throwOnEncodingError is false then the filename is not checked.
	 */
	void SetFilename(const std::string& filename, bool throwOnEncodingError = false);
    
	/*! \param comment the comment to set in the header. The application is responsible for setting it.
	           RFC 1952 requires a ISO/IEC 8859-1 encoding.
	    \param throwOnEncodingError if throwOnEncodingError is true, then the comment is checked to ensure it is
	           ISO/IEC 8859-1 encoded. If the comment does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat
	           is thrown. If throwOnEncodingError is false then the comment is not checked.
	 */
	void SetComment(const std::string& comment, bool throwOnEncodingError = false);

protected:
	enum {MAGIC1=0x1f, MAGIC2=0x8b,   // flags for the header
		  DEFLATED=8, FAST=4, SLOW=2};
    
	enum FLAG_MASKS {
		FILENAME=8, COMMENTS=16};

	void WritePrestreamHeader();
	void ProcessUncompressedData(const byte *string, size_t length);
	void WritePoststreamTail();

	word32 m_totalLen;
	CRC32 m_crc;
    
	word32 m_filetime;
	std::string m_filename;
	std::string m_comment;
};

/// GZIP Decompression (RFC 1952)
class Gunzip : public Inflator
{
public:
	typedef Inflator::Err Err;
	class HeaderErr : public Err {public: HeaderErr() : Err(INVALID_DATA_FORMAT, "Gunzip: header decoding error") {}};
	class TailErr : public Err {public: TailErr() : Err(INVALID_DATA_FORMAT, "Gunzip: tail too short") {}};
	class CrcErr : public Err {public: CrcErr() : Err(DATA_INTEGRITY_CHECK_FAILED, "Gunzip: CRC check error") {}};
	class LengthErr : public Err {public: LengthErr() : Err(DATA_INTEGRITY_CHECK_FAILED, "Gunzip: length check error") {}};

	/*! \param repeat decompress multiple compressed streams in series
		\param autoSignalPropagation 0 to turn off MessageEnd signal
	*/
	Gunzip(BufferedTransformation *attachment = NULL, bool repeat = false, int autoSignalPropagation = -1);
    
	/*! \return the filetime of the stream as set in the header. The application is responsible for setting it on the decompressed file.
	 */
	word32 GetFiletime() const { return m_filetime; }
    
	/*! \return the filename of the stream as set in the header. The application is responsible for setting it on the decompressed file.
	    \param throwOnEncodingError if throwOnEncodingError is true, then the filename is checked to ensure it is
	           ISO/IEC 8859-1 encoded. If the filename does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat is thrown.
	           If throwOnEncodingError is false then the filename is not checked.
	 */
	const std::string& GetFilename(bool throwOnEncodingError = false) const;
    
	/*! \return the comment of the stream as set in the header.
	    \param throwOnEncodingError if throwOnEncodingError is true, then the comment is checked to ensure it is
	           ISO/IEC 8859-1 encoded. If the comment does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat is thrown.
	           If throwOnEncodingError is false then the comment is not checked.
	 */
	const std::string& GetComment(bool throwOnEncodingError = false) const;

protected:
	enum {MAGIC1=0x1f, MAGIC2=0x8b,   // flags for the header
		DEFLATED=8};

	enum FLAG_MASKS {
		CONTINUED=2, EXTRA_FIELDS=4, FILENAME=8, COMMENTS=16, ENCRYPTED=32};

	unsigned int MaxPrestreamHeaderSize() const {return 1024;}
	void ProcessPrestreamHeader();
	void ProcessDecompressedData(const byte *string, size_t length);
	unsigned int MaxPoststreamTailSize() const {return 8;}
	void ProcessPoststreamTail();

	word32 m_length;
	CRC32 m_crc;

	word32 m_filetime;
	std::string m_filename;
	std::string m_comment;
};

NAMESPACE_END

#endif