/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
 *            cacheaudiofile.cc
 *
 *  Thu Dec 24 12:17:58 CET 2015
 *  Copyright 2015 Bent Bisballe Nyeng
 *  deva@aasimon.org
 ****************************************************************************/

/*
 *  This file is part of DrumGizmo.
 *
 *  DrumGizmo 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.
 *
 *  DrumGizmo 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 DrumGizmo; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */
#include "audiocachefile.h"

#include <cassert>
#include <cstring>
#include <functional>

#include <hugin.hpp>

AudioCacheFile::AudioCacheFile(const std::string& filename,
                               std::vector<sample_t>& read_buffer)
	: filename(filename)
	, read_buffer(read_buffer)
{
	fh = sf_open(filename.c_str(), SFM_READ, &sf_info);
	if(fh == nullptr)
	{
		ERR(audiofile,"SNDFILE Error (%s): %s\n",
		    filename.c_str(), sf_strerror(fh));
		return;
	}

	if(sf_info.frames == 0)
	{
		WARN(cache, "sf_info.frames == 0\n");
	}
}

AudioCacheFile::~AudioCacheFile()
{
	if(fh != nullptr)
	{
		sf_close(fh);
		fh = nullptr;
	}
}

size_t AudioCacheFile::getSize() const
{
	return sf_info.frames;
}

const std::string& AudioCacheFile::getFilename() const
{
	return filename;
}

size_t AudioCacheFile::getChannelCount() const
{
	return sf_info.channels;
}

void AudioCacheFile::readChunk(const CacheChannels& channels,
                               std::size_t pos, std::size_t num_samples)
{
	//assert(fh != nullptr); // File handle must never be nullptr
	if(fh == nullptr)
	{
		return;
	}

	if((int)pos > sf_info.frames)
	{
		WARN(cache, "pos (%d) > sf_info.frames (%d)\n",
		     (int)pos, (int)sf_info.frames);
		return;
	}

	sf_seek(fh, static_cast<sf_count_t>(pos), SEEK_SET);

	auto size = sf_info.frames - pos;
	if(size > num_samples)
	{
		size = num_samples;
	}

	if((size * sf_info.channels) > read_buffer.size())
	{
		read_buffer.resize(size * sf_info.channels);
	}

	const size_t read_size = sf_readf_float(fh, read_buffer.data(),
	                                        static_cast<sf_count_t>(size));
	assert(read_size == size);

	for(const auto& channel : channels)
	{
		auto channel_index = channel.channel_index;
		auto* data = channel.samples;
		for (size_t i = 0; i < size; ++i)
		{
			data[i] = read_buffer[(i * sf_info.channels) + channel_index]; // NOLINT: will be fixed with std::span
		}
	}

	for(const auto & channel : channels)
	{
		*(channel.ready) = true;
	}
}

AudioCacheFile& AudioCacheFiles::getFile(const std::string& filename)
{
	const std::lock_guard<std::mutex> lock(mutex);

	auto audiofile_it = audiofiles.find(filename);
	if(audiofile_it == audiofiles.end())
	{
		// Construct a new AudioCacheFile in place. The in place construction is relevant.
		audiofile_it =
			audiofiles.emplace(std::piecewise_construct,
			                   std::make_tuple(filename),
			                   std::make_tuple(filename,
			                                   std::ref(read_buffer))).first; // FIXME: This must be possible to do in a more easy-to-read way!
	}

	auto& cache_audio_file = audiofile_it->second;

	// Increase ref count.
	++cache_audio_file.ref;

	return cache_audio_file;
}

void AudioCacheFiles::releaseFile(const std::string& filename)
{
	const std::lock_guard<std::mutex> lock(mutex);

	auto audiofile_it = audiofiles.find(filename);
	if(audiofile_it == audiofiles.end())
	{
		assert(false); // This should never happen!
		return; // not open
	}

	auto& audiofile = audiofile_it->second;

	assert(audiofile.ref); // If ref is not > 0 it shouldn't be in the map.

	--audiofile.ref;
	if(audiofile.ref == 0)
	{
		audiofiles.erase(audiofile_it);
	}
}