/*
 * Connection.cpp, part of VCMI engine
 *
 * Authors: listed in file AUTHORS in main folder
 *
 * License: GNU General Public License v2.0 or later
 * Full text of license available in license.txt file, in main folder
 *
 */
#include "StdInc.h"
#include "Connection.h"

#include "BinaryDeserializer.h"
#include "BinarySerializer.h"

#include "../networkPacks/NetPacksBase.h"
#include "../network/NetworkConnection.h"

VCMI_LIB_NAMESPACE_BEGIN

class DLL_LINKAGE ConnectionPackWriter final : public IBinaryWriter
{
public:
	std::vector<uint8_t> buffer;

	int write(const void * data, unsigned size) final;
};

class DLL_LINKAGE ConnectionPackReader final : public IBinaryReader
{
public:
	const std::vector<uint8_t> * buffer;
	size_t position;

	int read(void * data, unsigned size) final;
};

int ConnectionPackWriter::write(const void * data, unsigned size)
{
	const uint8_t * begin_ptr = static_cast<const uint8_t *>(data);
	const uint8_t * end_ptr = begin_ptr + size;
	buffer.insert(buffer.end(), begin_ptr, end_ptr);
	return size;
}

int ConnectionPackReader::read(void * data, unsigned size)
{
	if (position + size > buffer->size())
		throw std::runtime_error("End of file reached when reading received network pack!");

	uint8_t * begin_ptr = static_cast<uint8_t *>(data);

	std::copy_n(buffer->begin() + position, size, begin_ptr);
	position += size;
	return size;
}

CConnection::CConnection(std::weak_ptr<NetworkConnection> networkConnection)
	: networkConnection(networkConnection)
	, packReader(std::make_unique<ConnectionPackReader>())
	, packWriter(std::make_unique<ConnectionPackWriter>())
	, deserializer(std::make_unique<BinaryDeserializer>(packReader.get()))
	, serializer(std::make_unique<BinarySerializer>(packWriter.get()))
	, connectionID(-1)
{
	assert(networkConnection.lock() != nullptr);

	enableSmartPointerSerialization();
	disableStackSendingByID();
	deserializer->fileVersion = SERIALIZATION_VERSION;
}

CConnection::~CConnection() = default;

void CConnection::sendPack(const CPack * pack)
{
	auto connectionPtr = networkConnection.lock();

	if (!connectionPtr)
		throw std::runtime_error("Attempt to send packet on a closed connection!");

	*serializer & pack;

	logNetwork->trace("Sending a pack of type %s", typeid(*pack).name());

	connectionPtr->sendPacket(packWriter->buffer);
	packWriter->buffer.clear();
}

CPack * CConnection::retrievePack(const std::vector<uint8_t> & data)
{
	CPack * result;

	packReader->buffer = &data;
	packReader->position = 0;

	*deserializer & result;

	logNetwork->trace("Received CPack of type %s", (result ? typeid(*result).name() : "nullptr"));
	return result;
}

bool CConnection::isMyConnection(const std::shared_ptr<NetworkConnection> & otherConnection) const
{
	return otherConnection != nullptr && networkConnection.lock() == otherConnection;
}

void CConnection::disableStackSendingByID()
{
	packReader->sendStackInstanceByIds = false;
	packWriter->sendStackInstanceByIds = false;
}

void CConnection::enableStackSendingByID()
{
	packReader->sendStackInstanceByIds = true;
	packWriter->sendStackInstanceByIds = true;
}

void CConnection::enterLobbyConnectionMode()
{
	deserializer->loadedPointers.clear();
	serializer->savedPointers.clear();
	disableSmartVectorMemberSerialization();
	disableSmartPointerSerialization();
	disableStackSendingByID();
}

void CConnection::enterGameplayConnectionMode(CGameState * gs)
{
	enableStackSendingByID();
	disableSmartPointerSerialization();

	packReader->addStdVecItems(gs);
	packWriter->addStdVecItems(gs);
}

void CConnection::disableSmartPointerSerialization()
{
	deserializer->smartPointerSerialization = false;
	serializer->smartPointerSerialization = false;
}

void CConnection::enableSmartPointerSerialization()
{
	deserializer->smartPointerSerialization = true;
	serializer->smartPointerSerialization = true;
}

void CConnection::disableSmartVectorMemberSerialization()
{
	packReader->smartVectorMembersSerialization = false;
	packWriter->smartVectorMembersSerialization = false;
}

void CConnection::enableSmartVectorMemberSerializatoin()
{
	packReader->smartVectorMembersSerialization = true;
	packWriter->smartVectorMembersSerialization = true;
}

VCMI_LIB_NAMESPACE_END