#include <assert.h>
#include "VideoStream_ReadMotionVector.h"
#include "MpegVideoState.h"
#include "MPEG2/MotionCodeTable.h"
#include "../../../Source/Log.h"
#include "LogSettings.h"

using namespace VideoStream;

ReadMotionVector::ReadMotionVector()
{
	m_hrSize = 0;
	m_vrSize = 0;
}

ReadMotionVector::~ReadMotionVector()
{
}

void ReadMotionVector::SetRSizes(uint8 hsize, uint8 vsize)
{
	m_hrSize = hsize;
	m_vrSize = vsize;
}

void ReadMotionVector::Reset()
{
	m_programState = STATE_INIT;
}

int16 ReadMotionVector::ComputeMotionVector(int16 currentVector, int16 motionCode, uint16 motionResidual, uint8 rsize)
{
	int16 limit = 16 << rsize;

	if(motionCode > 0)
	{
		currentVector += ((motionCode - 1) << rsize) + motionResidual + 1;
		if(currentVector >= limit)
		{
			currentVector -= (limit * 2);
		}
	}
	else if(motionCode < 0)
	{
		currentVector -= ((-motionCode - 1) << rsize) + motionResidual + 1;
		if(currentVector < -limit)
		{
			currentVector += (limit * 2);
		}
	}

	return currentVector;
}

void ReadMotionVector::Execute(void* context, Framework::CBitStream& stream)
{
	MPEG_VIDEO_STATE* state(reinterpret_cast<MPEG_VIDEO_STATE*>(context));
	PICTURE_HEADER& pictureHeader(state->pictureHeader);
	BLOCK_DECODER_STATE& decoderState(state->blockDecoderState);

	while(1)
	{
		switch(m_programState)
		{
		case STATE_INIT:
			goto Label_Init;
		case STATE_READHMOTIONCODE:
			goto Label_ReadHMotionCode;
		case STATE_READHMOTIONRESIDUAL:
			goto Label_ReadHMotionResidual;
		case STATE_READVMOTIONCODE:
			goto Label_ReadVMotionCode;
		case STATE_READVMOTIONRESIDUAL:
			goto Label_ReadVMotionResidual;
		case STATE_DONE:
			goto Label_Done;
		default:
			assert(0);
		}

	Label_Init:
		m_programState = STATE_READHMOTIONCODE;
		continue;

	Label_ReadHMotionCode:
	{
		decoderState.motionCode[0] = static_cast<int16>(MPEG2::CMotionCodeTable::GetInstance()->GetSymbol(&stream));
#ifdef _DECODE_LOGGING
		CLog::GetInstance().Print(DECODE_LOG_NAME, "Symbol(%d, 'motion code') = %d\r\n",
		                          g_currentVdec++, decoderState.motionCode[0]);
#endif
		decoderState.motionResidual[0] = 0;
		if(decoderState.motionCode[0] != 0 && m_hrSize != 0)
		{
			m_programState = STATE_READHMOTIONRESIDUAL;
		}
		else
		{
			m_programState = STATE_READVMOTIONCODE;
		}
	}
		continue;

	Label_ReadHMotionResidual:
	{
		decoderState.motionResidual[0] = static_cast<uint16>(stream.GetBits_MSBF(m_hrSize));
		m_programState = STATE_READVMOTIONCODE;
	}
		continue;

	Label_ReadVMotionCode:
	{
		decoderState.motionCode[1] = static_cast<int16>(MPEG2::CMotionCodeTable::GetInstance()->GetSymbol(&stream));
#ifdef _DECODE_LOGGING
		CLog::GetInstance().Print(DECODE_LOG_NAME, "Symbol(%d, 'motion code') = %d\r\n",
		                          g_currentVdec++, decoderState.motionCode[1]);
#endif
		decoderState.motionResidual[1] = 0;
		if(decoderState.motionCode[1] != 0 && m_vrSize != 0)
		{
			m_programState = STATE_READVMOTIONRESIDUAL;
		}
		else
		{
			m_programState = STATE_DONE;
		}
	}
		continue;

	Label_ReadVMotionResidual:
	{
		decoderState.motionResidual[1] = static_cast<uint16>(stream.GetBits_MSBF(m_vrSize));
		m_programState = STATE_DONE;
	}
		continue;

	Label_Done:
		return;
	}
}