/*
 * $Id$
 *
 * ***** BEGIN LGPL LICENSE BLOCK *****
 *
 * Copyright 2009 Jörg Hermann Müller
 *
 * This file is part of AudaSpace.
 *
 * AudaSpace is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * AudaSpace 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with AudaSpace.  If not, see <http://www.gnu.org/licenses/>.
 *
 * ***** END LGPL LICENSE BLOCK *****
 */

#include "AUD_DoubleReader.h"

#include <cstring>

static const char* specs_error = "AUD_DoubleReader: Both readers have to have "
								 "the same specs.";

AUD_DoubleReader::AUD_DoubleReader(AUD_IReader* reader1,
								   AUD_IReader* reader2) :
		m_reader1(reader1), m_reader2(reader2), m_finished1(false)
{
	AUD_Specs s1, s2;
	s1 = reader1->getSpecs();
	s2 = reader2->getSpecs();
	if(memcmp(&s1, &s2, sizeof(AUD_Specs)) != 0)
	{
		delete reader1;
		delete reader2;
		AUD_THROW(AUD_ERROR_SPECS, specs_error);
	}
}

AUD_DoubleReader::~AUD_DoubleReader()
{
	delete m_reader1;
	delete m_reader2;
}

bool AUD_DoubleReader::isSeekable() const
{
	return m_reader1->isSeekable() && m_reader2->isSeekable();
}

void AUD_DoubleReader::seek(int position)
{
	m_reader1->seek(position);

	int pos1 = m_reader1->getPosition();

	if((m_finished1 = (pos1 < position)))
		m_reader2->seek(position - pos1);
	else
		m_reader2->seek(0);
}

int AUD_DoubleReader::getLength() const
{
	int len1 = m_reader1->getLength();
	int len2 = m_reader2->getLength();
	if(len1 < 0 || len2 < 0)
		return -1;
	return len1 + len2;
}

int AUD_DoubleReader::getPosition() const
{
	return m_reader1->getPosition() + m_reader2->getPosition();
}

AUD_Specs AUD_DoubleReader::getSpecs() const
{
	return m_reader1->getSpecs();
}

void AUD_DoubleReader::read(int & length, sample_t* & buffer)
{
	if(!m_finished1)
	{
		int len = length;
		m_reader1->read(len, buffer);

		if(len < length)
		{
			AUD_Specs specs = m_reader1->getSpecs();
			int samplesize = AUD_SAMPLE_SIZE(specs);

			if(m_buffer.getSize() < length * samplesize)
				m_buffer.resize(length * samplesize);

			sample_t* buf = buffer;
			buffer = m_buffer.getBuffer();

			memcpy(buffer, buf, len * samplesize);

			len = length - len;
			length -= len;
			m_reader2->read(len, buf);

			memcpy(buffer + length * specs.channels, buf,
				   len * samplesize);

			length += len;

			m_finished1 = true;
		}
	}
	else
	{
		m_reader2->read(length, buffer);
	}
}
