/*
 * Copyright (C) 2003-2013 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"
#include "PcmConvert.hxx"
#include "PcmChannels.hxx"
#include "PcmFormat.hxx"
#include "AudioFormat.hxx"
#include "util/ConstBuffer.hxx"
#include "util/Error.hxx"
#include "util/Domain.hxx"

#include <assert.h>
#include <math.h>

const Domain pcm_convert_domain("pcm_convert");

bool
pcm_convert_global_init(Error &error)
{
	return pcm_resample_global_init(error);
}

PcmConvert::PcmConvert()
{
#ifndef NDEBUG
	src_format.Clear();
	dest_format.Clear();
#endif
}

PcmConvert::~PcmConvert()
{
	assert(!src_format.IsValid());
	assert(!dest_format.IsValid());
}

bool
PcmConvert::Open(AudioFormat _src_format, AudioFormat _dest_format,
		 gcc_unused Error &error)
{
	assert(!src_format.IsValid());
	assert(!dest_format.IsValid());
	assert(_src_format.IsValid());
	assert(_dest_format.IsValid());

	src_format = _src_format;
	dest_format = _dest_format;

	is_dsd = src_format.format == SampleFormat::DSD;
	if (is_dsd)
		src_format.format = SampleFormat::FLOAT;

	return true;
}

void
PcmConvert::Close()
{
	dsd.Reset();
	resampler.Reset();

#ifndef NDEBUG
	src_format.Clear();
	dest_format.Clear();
#endif
}

inline const int16_t *
PcmConvert::Convert16(const void *src_buffer, size_t src_size,
		      size_t *dest_size_r,
		      Error &error)
{
	const int16_t *buf;
	size_t len;

	assert(dest_format.format == SampleFormat::S16);

	buf = pcm_convert_to_16(format_buffer, dither,
				src_format.format,
				src_buffer, src_size,
				&len);
	if (buf == nullptr) {
		error.Format(pcm_convert_domain,
			     "Conversion from %s to 16 bit is not implemented",
			     sample_format_to_string(src_format.format));
		return nullptr;
	}

	if (src_format.channels != dest_format.channels) {
		buf = pcm_convert_channels_16(channels_buffer,
					      dest_format.channels,
					      src_format.channels,
					      buf, len, &len);
		if (buf == nullptr) {
			error.Format(pcm_convert_domain,
				     "Conversion from %u to %u channels "
				     "is not implemented",
				     src_format.channels,
				     dest_format.channels);
			return nullptr;
		}
	}

	if (src_format.sample_rate != dest_format.sample_rate) {
		buf = resampler.Resample16(dest_format.channels,
					   src_format.sample_rate, buf, len,
					   dest_format.sample_rate, &len,
					   error);
		if (buf == nullptr)
			return nullptr;
	}

	*dest_size_r = len;
	return buf;
}

inline const int32_t *
PcmConvert::Convert24(const void *src_buffer, size_t src_size,
		      size_t *dest_size_r,
		      Error &error)
{
	const int32_t *buf;
	size_t len;

	assert(dest_format.format == SampleFormat::S24_P32);

	buf = pcm_convert_to_24(format_buffer,
				src_format.format,
				src_buffer, src_size, &len);
	if (buf == nullptr) {
		error.Format(pcm_convert_domain,
			     "Conversion from %s to 24 bit is not implemented",
			     sample_format_to_string(src_format.format));
		return nullptr;
	}

	if (src_format.channels != dest_format.channels) {
		buf = pcm_convert_channels_24(channels_buffer,
					      dest_format.channels,
					      src_format.channels,
					      buf, len, &len);
		if (buf == nullptr) {
			error.Format(pcm_convert_domain,
				     "Conversion from %u to %u channels "
				     "is not implemented",
				     src_format.channels,
				     dest_format.channels);
			return nullptr;
		}
	}

	if (src_format.sample_rate != dest_format.sample_rate) {
		buf = resampler.Resample24(dest_format.channels,
					   src_format.sample_rate, buf, len,
					   dest_format.sample_rate, &len,
					   error);
		if (buf == nullptr)
			return nullptr;
	}

	*dest_size_r = len;
	return buf;
}

inline const int32_t *
PcmConvert::Convert32(const void *src_buffer, size_t src_size,
		      size_t *dest_size_r,
		      Error &error)
{
	const int32_t *buf;
	size_t len;

	assert(dest_format.format == SampleFormat::S32);

	buf = pcm_convert_to_32(format_buffer,
				src_format.format,
				src_buffer, src_size, &len);
	if (buf == nullptr) {
		error.Format(pcm_convert_domain,
			     "Conversion from %s to 32 bit is not implemented",
			     sample_format_to_string(src_format.format));
		return nullptr;
	}

	if (src_format.channels != dest_format.channels) {
		buf = pcm_convert_channels_32(channels_buffer,
					      dest_format.channels,
					      src_format.channels,
					      buf, len, &len);
		if (buf == nullptr) {
			error.Format(pcm_convert_domain,
				     "Conversion from %u to %u channels "
				     "is not implemented",
				     src_format.channels,
				     dest_format.channels);
			return nullptr;
		}
	}

	if (src_format.sample_rate != dest_format.sample_rate) {
		buf = resampler.Resample32(dest_format.channels,
					   src_format.sample_rate, buf, len,
					   dest_format.sample_rate, &len,
					   error);
		if (buf == nullptr)
			return buf;
	}

	*dest_size_r = len;
	return buf;
}

inline const float *
PcmConvert::ConvertFloat(const void *src_buffer, size_t src_size,
			 size_t *dest_size_r,
			 Error &error)
{
	const float *buffer = (const float *)src_buffer;
	size_t size = src_size;

	assert(dest_format.format == SampleFormat::FLOAT);

	/* convert to float now */

	buffer = pcm_convert_to_float(format_buffer,
				      src_format.format,
				      buffer, size, &size);
	if (buffer == nullptr) {
		error.Format(pcm_convert_domain,
			     "Conversion from %s to float is not implemented",
			     sample_format_to_string(src_format.format));
		return nullptr;
	}

	/* convert channels */

	if (src_format.channels != dest_format.channels) {
		buffer = pcm_convert_channels_float(channels_buffer,
						    dest_format.channels,
						    src_format.channels,
						    buffer, size, &size);
		if (buffer == nullptr) {
			error.Format(pcm_convert_domain,
				     "Conversion from %u to %u channels "
				     "is not implemented",
				     src_format.channels,
				     dest_format.channels);
			return nullptr;
		}
	}

	/* resample with float, because this is the best format for
	   libsamplerate */

	if (src_format.sample_rate != dest_format.sample_rate) {
		buffer = resampler.ResampleFloat(dest_format.channels,
						 src_format.sample_rate,
						 buffer, size,
						 dest_format.sample_rate,
						 &size, error);
		if (buffer == nullptr)
			return nullptr;
	}

	*dest_size_r = size;
	return buffer;
}

const void *
PcmConvert::Convert(const void *src, size_t src_size,
		    size_t *dest_size_r,
		    Error &error)
{
	ConstBuffer<void> buffer(src, src_size);

	if (is_dsd) {
		auto s = ConstBuffer<uint8_t>::FromVoid(buffer);
		auto d = dsd.ToFloat(src_format.channels,
				     false, s);
		if (d.IsNull()) {
			error.Set(pcm_convert_domain,
				  "DSD to PCM conversion failed");
			return nullptr;
		}

		buffer = d.ToVoid();
	}

	switch (dest_format.format) {
	case SampleFormat::S16:
		return Convert16(buffer.data, buffer.size,
				 dest_size_r,
				 error);

	case SampleFormat::S24_P32:
		return Convert24(buffer.data, buffer.size,
				 dest_size_r,
				 error);

	case SampleFormat::S32:
		return Convert32(buffer.data, buffer.size,
				 dest_size_r,
				 error);

	case SampleFormat::FLOAT:
		return ConvertFloat(buffer.data, buffer.size,
				    dest_size_r,
				    error);

	default:
		error.Format(pcm_convert_domain,
			     "PCM conversion to %s is not implemented",
			     sample_format_to_string(dest_format.format));
		return nullptr;
	}
}