/*
 * Compilation Copyright (c) 1995-2019 by Wei Dai.  All rights reserved.
 *	This copyright applies only to this software distribution package
 *	as a compilation, and does not imply a copyright on any particular
 *	file in the package.
 * 
 *	Boost Software License - Version 1.0 - August 17th, 2003
 *
 *	Permission is hereby granted, free of charge, to any person or organization
 *	obtaining a copy of the software and accompanying documentation covered by
 *	this license (the "Software") to use, reproduce, display, distribute,
 *	execute, and transmit the Software, and to prepare derivative works of the
 *	Software, and to permit third-parties to whom the Software is furnished to
 *	do so, all subject to the following:
 * 
 *	The copyright notices in the Software and this entire statement, including
 *	the above license grant, this restriction and the following disclaimer,
 *	must be included in all copies of the Software, in whole or in part, and
 *	all derivative works of the Software, unless such copies or derivative
 *	works are solely in the form of machine-executable object code generated by
 *	a source language processor.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *	FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
 *	SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
 *	FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
 *	ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 *	DEALINGS IN THE SOFTWARE.
 */

#ifndef CRYPTOPP_MQUEUE_H
#define CRYPTOPP_MQUEUE_H

#include "cryptlib.h"
#include "queue.h"
#include "filters.h"
#include "misc.h"

#include <deque>

NAMESPACE_BEGIN(CryptoPP)

/// Message Queue
class CRYPTOPP_DLL MessageQueue : public AutoSignaling<BufferedTransformation>
{
public:
	MessageQueue(unsigned int nodeSize=256);

	void IsolatedInitialize(const NameValuePairs &parameters)
		{m_queue.IsolatedInitialize(parameters); m_lengths.assign(1, 0U); m_messageCounts.assign(1, 0U);}
	size_t Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
	{
		CRYPTOPP_UNUSED(blocking);
		m_queue.Put(begin, length);
		m_lengths.back() += length;
		if (messageEnd)
		{
			m_lengths.push_back(0);
			m_messageCounts.back()++;
		}
		return 0;
	}
	bool IsolatedFlush(bool hardFlush, bool blocking)
		{CRYPTOPP_UNUSED(hardFlush), CRYPTOPP_UNUSED(blocking); return false;}
	bool IsolatedMessageSeriesEnd(bool blocking)
		{CRYPTOPP_UNUSED(blocking); m_messageCounts.push_back(0); return false;}

	lword MaxRetrievable() const
		{return m_lengths.front();}
	bool AnyRetrievable() const
		{return m_lengths.front() > 0;}

	size_t TransferTo2(BufferedTransformation &target, lword &transferBytes, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true);
	size_t CopyRangeTo2(BufferedTransformation &target, lword &begin, lword end=LWORD_MAX, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true) const;

	lword TotalBytesRetrievable() const
		{return m_queue.MaxRetrievable();}
	unsigned int NumberOfMessages() const
		{return (unsigned int)m_lengths.size()-1;}
	bool GetNextMessage();

	unsigned int NumberOfMessagesInThisSeries() const
		{return m_messageCounts[0];}
	unsigned int NumberOfMessageSeries() const
		{return (unsigned int)m_messageCounts.size()-1;}

	unsigned int CopyMessagesTo(BufferedTransformation &target, unsigned int count=UINT_MAX, const std::string &channel=DEFAULT_CHANNEL) const;

	const byte * Spy(size_t &contiguousSize) const;

	void swap(MessageQueue &rhs);

private:
	ByteQueue m_queue;
	std::deque<lword> m_lengths;
	std::deque<unsigned int> m_messageCounts;
};


/// A filter that checks messages on two channels for equality
class CRYPTOPP_DLL EqualityComparisonFilter : public Unflushable<Multichannel<Filter> >
{
public:
	struct MismatchDetected : public Exception {MismatchDetected() : Exception(DATA_INTEGRITY_CHECK_FAILED, "EqualityComparisonFilter: did not receive the same data on two channels") {}};

	/*! if throwIfNotEqual is false, this filter will output a '\\0' byte when it detects a mismatch, '\\1' otherwise */
	EqualityComparisonFilter(BufferedTransformation *attachment=NULLPTR, bool throwIfNotEqual=true, const std::string &firstChannel="0", const std::string &secondChannel="1")
		: m_throwIfNotEqual(throwIfNotEqual), m_mismatchDetected(false)
		, m_firstChannel(firstChannel), m_secondChannel(secondChannel)
		{Detach(attachment);}

	size_t ChannelPut2(const std::string &channel, const byte *begin, size_t length, int messageEnd, bool blocking);
	bool ChannelMessageSeriesEnd(const std::string &channel, int propagation=-1, bool blocking=true);

private:
	unsigned int MapChannel(const std::string &channel) const;
	bool HandleMismatchDetected(bool blocking);

	bool m_throwIfNotEqual, m_mismatchDetected;
	std::string m_firstChannel, m_secondChannel;
	MessageQueue m_q[2];
};

NAMESPACE_END

#ifndef __BORLANDC__
NAMESPACE_BEGIN(std)
template<> inline void swap(CryptoPP::MessageQueue &a, CryptoPP::MessageQueue &b)
{
	a.swap(b);
}
NAMESPACE_END
#endif

#endif
