/******************************************************************************\
 * Copyright (c) 2004-2006
 *
 * Author(s):
 *	Volker Fischer
 *
 ******************************************************************************
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later 
 * version.
 *
 * This program 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 General Public License for more 
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
\******************************************************************************/

#include "server.h"


/* Implementation *************************************************************/
CServer::CServer() : Socket(&ChannelSet)
{
	vecsSendData.Init(BLOCK_SIZE_SAMPLES);

	/* init moving average buffer for response time evaluation */
	RespTimeMoAvBuf.Init(LEN_MOV_AV_RESPONSE);

	/* connect timer timeout signal */
	QObject::connect(&Timer, SIGNAL(timeout()),	this, SLOT(OnTimer()));
}

void CServer::Start()
{
	/* start main timer */
	Timer.start(BLOCK_DURATION_MS);

	/* init time for response time evaluation */
	TimeLastBlock = QTime::currentTime();
}

void CServer::OnTimer()
{
	CVector<int>				vecChanID;
	CVector<CVector<double> >	vecvecdData(BLOCK_SIZE_SAMPLES);

	/* get data from all connected clients */
	ChannelSet.GetBlockAllConC(vecChanID, vecvecdData);

	/* actual processing of audio data -> mix */
	vecsSendData = ProcessData(vecvecdData);

	/* get number of connected clients from vector size */
	const int iNumClients = vecvecdData.Size();

	/* send the same data to all connected clients */
	for (int i = 0; i < iNumClients; i++)
	{
		Socket.SendPacket(ChannelSet.PrepSendPacket(vecChanID[i], vecsSendData),
			ChannelSet.GetAddress(vecChanID[i]),
			ChannelSet.GetTimeStampIdx(vecChanID[i]));
	}


	/* update response time measurement ------------------------------------- */
	/* add time difference */
	const QTime CurTime = QTime::currentTime();

	/* we want to calculate the standard deviation (we assume that the mean is
	   correct at the block period time) */
	const double dCurAddVal =
		((double) TimeLastBlock.msecsTo(CurTime) - BLOCK_DURATION_MS);

	RespTimeMoAvBuf.Add(dCurAddVal * dCurAddVal); /* add squared value */

	/* store old time value */
	TimeLastBlock = CurTime;
}

CVector<short> CServer::ProcessData(CVector<CVector<double> >& vecvecdData)
{
	CVector<short> vecsOutData;
	vecsOutData.Init(BLOCK_SIZE_SAMPLES);

	const int iNumClients = vecvecdData.Size();

	/* we normalize with sqrt() of N to avoid that the level drops too much
	   in case that a new client connects */
	const double dNorm = sqrt((double) iNumClients);

	/* mix all audio data from all clients together */
	for (int i = 0; i < BLOCK_SIZE_SAMPLES; i++)
	{
		double dMixedData = 0.0;

		for (int j = 0; j < iNumClients; j++)
		{
			dMixedData += vecvecdData[j][i];
		}

		/* normalization and truncating to short */
		vecsOutData[i] = Double2Short(dMixedData / dNorm);
	}

	return vecsOutData;
}