/*
 * CMusicHandler.cpp, part of VCMI engine
 *
 * Authors: listed in file AUTHORS in main folder
 *
 * License: GNU General Public License v2.0 or later
 * Full text of license available in license.txt file, in main folder
 *
 */
#include "StdInc.h"
#include "CSoundHandler.h"

#include "../gui/CGuiHandler.h"
#include "../CGameInfo.h"

#include "../lib/filesystem/Filesystem.h"
#include "../lib/CRandomGenerator.h"

#include <SDL_mixer.h>

#define VCMI_SOUND_NAME(x)
#define VCMI_SOUND_FILE(y) #y,

// sounds mapped to soundBase enum
static const std::string soundsList[] = {
	"", // invalid
	"", // todo
	VCMI_SOUND_LIST
};
#undef VCMI_SOUND_NAME
#undef VCMI_SOUND_FILE

void CSoundHandler::onVolumeChange(const JsonNode & volumeNode)
{
	setVolume(volumeNode.Integer());
}

CSoundHandler::CSoundHandler():
	listener(settings.listen["general"]["sound"]),
	ambientConfig(JsonPath::builtin("config/ambientSounds.json"))
{
	listener(std::bind(&CSoundHandler::onVolumeChange, this, _1));

	if(ambientConfig["allocateChannels"].isNumber())
		Mix_AllocateChannels(ambientConfig["allocateChannels"].Integer());

	if(isInitialized())
	{
		Mix_ChannelFinished([](int channel)
		{
			if (CCS)
			{
				CCS->soundh->soundFinishedCallback(channel);
			}
		});
	}
}

CSoundHandler::~CSoundHandler()
{
	if(isInitialized())
	{
		Mix_HaltChannel(-1);

		for(auto & chunk : soundChunks)
		{
			if(chunk.second.first)
				Mix_FreeChunk(chunk.second.first);
		}
	}
}

// Allocate an SDL chunk and cache it.
Mix_Chunk * CSoundHandler::GetSoundChunk(const AudioPath & sound, bool cache)
{
	try
	{
		if(cache && soundChunks.find(sound) != soundChunks.end())
			return soundChunks[sound].first;

		auto data = CResourceHandler::get()->load(sound.addPrefix("SOUNDS/"))->readAll();
		SDL_RWops * ops = SDL_RWFromMem(data.first.get(), data.second);
		Mix_Chunk * chunk = Mix_LoadWAV_RW(ops, 1); // will free ops

		if(cache)
			soundChunks.insert({sound, std::make_pair(chunk, std::move(data.first))});

		return chunk;
	}
	catch(std::exception & e)
	{
		logGlobal->warn("Cannot get sound %s chunk: %s", sound.getOriginalName(), e.what());
		return nullptr;
	}
}

Mix_Chunk * CSoundHandler::GetSoundChunk(std::pair<std::unique_ptr<ui8[]>, si64> & data, bool cache)
{
	try
	{
		std::vector<ui8> startBytes = std::vector<ui8>(data.first.get(), data.first.get() + std::min(static_cast<si64>(100), data.second));

		if(cache && soundChunksRaw.find(startBytes) != soundChunksRaw.end())
			return soundChunksRaw[startBytes].first;

		SDL_RWops * ops = SDL_RWFromMem(data.first.get(), data.second);
		Mix_Chunk * chunk = Mix_LoadWAV_RW(ops, 1); // will free ops

		if(cache)
			soundChunksRaw.insert({startBytes, std::make_pair(chunk, std::move(data.first))});

		return chunk;
	}
	catch(std::exception & e)
	{
		logGlobal->warn("Cannot get sound chunk: %s", e.what());
		return nullptr;
	}
}

int CSoundHandler::ambientDistToVolume(int distance) const
{
	const auto & distancesVector = ambientConfig["distances"].Vector();

	if(distance >= distancesVector.size())
		return 0;

	int volumeByDistance = static_cast<int>(distancesVector[distance].Integer());
	return volumeByDistance * ambientConfig["volume"].Integer() / 100;
}

void CSoundHandler::ambientStopSound(const AudioPath & soundId)
{
	stopSound(ambientChannels[soundId]);
	setChannelVolume(ambientChannels[soundId], volume);
}

uint32_t CSoundHandler::getSoundDurationMilliseconds(const AudioPath & sound)
{
	if(!isInitialized() || sound.empty())
		return 0;

	auto resourcePath = sound.addPrefix("SOUNDS/");

	if(!CResourceHandler::get()->existsResource(resourcePath))
		return 0;

	auto data = CResourceHandler::get()->load(resourcePath)->readAll();

	SDL_AudioSpec spec;
	uint32_t audioLen;
	uint8_t * audioBuf;
	uint32_t milliseconds = 0;

	if(SDL_LoadWAV_RW(SDL_RWFromMem(data.first.get(), data.second), 1, &spec, &audioBuf, &audioLen) != nullptr)
	{
		SDL_FreeWAV(audioBuf);
		uint32_t sampleSize = SDL_AUDIO_BITSIZE(spec.format) / 8;
		uint32_t sampleCount = audioLen / sampleSize;
		uint32_t sampleLen = sampleCount / spec.channels;
		milliseconds = 1000 * sampleLen / spec.freq;
	}

	return milliseconds;
}

// Plays a sound, and return its channel so we can fade it out later
int CSoundHandler::playSound(soundBase::soundID soundID, int repeats)
{
	assert(soundID < soundBase::sound_after_last);
	auto sound = AudioPath::builtin(soundsList[soundID]);
	logGlobal->trace("Attempt to play sound %d with file name %s with cache", soundID, sound.getOriginalName());

	return playSound(sound, repeats, true);
}

int CSoundHandler::playSound(const AudioPath & sound, int repeats, bool cache)
{
	if(!isInitialized() || sound.empty())
		return -1;

	int channel;
	Mix_Chunk * chunk = GetSoundChunk(sound, cache);

	if(chunk)
	{
		channel = Mix_PlayChannel(-1, chunk, repeats);
		if(channel == -1)
		{
			logGlobal->error("Unable to play sound file %s , error %s", sound.getOriginalName(), Mix_GetError());
			if(!cache)
				Mix_FreeChunk(chunk);
		}
		else if(cache)
			initCallback(channel);
		else
			initCallback(channel, [chunk](){ Mix_FreeChunk(chunk);});
	}
	else
		channel = -1;

	return channel;
}

int CSoundHandler::playSound(std::pair<std::unique_ptr<ui8[]>, si64> & data, int repeats, bool cache)
{
	int channel = -1;
	if(Mix_Chunk * chunk = GetSoundChunk(data, cache))
	{
		channel = Mix_PlayChannel(-1, chunk, repeats);
		if(channel == -1)
		{
			logGlobal->error("Unable to play sound, error %s", Mix_GetError());
			if(!cache)
				Mix_FreeChunk(chunk);
		}
		else if(cache)
			initCallback(channel);
		else
			initCallback(channel, [chunk](){ Mix_FreeChunk(chunk);});
	}
	return channel;
}

// Helper. Randomly select a sound from an array and play it
int CSoundHandler::playSoundFromSet(std::vector<soundBase::soundID> & sound_vec)
{
	return playSound(*RandomGeneratorUtil::nextItem(sound_vec, CRandomGenerator::getDefault()));
}

void CSoundHandler::stopSound(int handler)
{
	if(isInitialized() && handler != -1)
		Mix_HaltChannel(handler);
}

ui32 CSoundHandler::getVolume() const
{
	return volume;
}

// Sets the sound volume, from 0 (mute) to 100
void CSoundHandler::setVolume(ui32 percent)
{
	volume = std::min(100u, percent);

	if(isInitialized())
	{
		setChannelVolume(-1, volume);

		for(const auto & channel : channelVolumes)
			updateChannelVolume(channel.first);
	}
}

void CSoundHandler::updateChannelVolume(int channel)
{
	if(channelVolumes.count(channel))
		setChannelVolume(channel, getVolume() * channelVolumes[channel] / 100);
	else
		setChannelVolume(channel, getVolume());
}

// Sets the sound volume, from 0 (mute) to 100
void CSoundHandler::setChannelVolume(int channel, ui32 percent)
{
	Mix_Volume(channel, (MIX_MAX_VOLUME * percent) / 100);
}

void CSoundHandler::setCallback(int channel, std::function<void()> function)
{
	boost::mutex::scoped_lock lockGuard(mutexCallbacks);

	auto iter = callbacks.find(channel);

	//channel not found. It may have finished so fire callback now
	if(iter == callbacks.end())
		function();
	else
		iter->second.push_back(function);
}

void CSoundHandler::resetCallback(int channel)
{
	boost::mutex::scoped_lock lockGuard(mutexCallbacks);

	callbacks.erase(channel);
}

void CSoundHandler::soundFinishedCallback(int channel)
{
	boost::mutex::scoped_lock lockGuard(mutexCallbacks);

	if(callbacks.count(channel) == 0)
		return;

	// store callbacks from container locally - SDL might reuse this channel for another sound
	// but do actually execution in separate thread, to avoid potential deadlocks in case if callback requires locks of its own
	auto callback = callbacks.at(channel);
	callbacks.erase(channel);

	if(!callback.empty())
	{
		GH.dispatchMainThread(
			[callback]()
			{
				for(const auto & entry : callback)
					entry();
			}
			);
	}
}

void CSoundHandler::initCallback(int channel)
{
	boost::mutex::scoped_lock lockGuard(mutexCallbacks);
	assert(callbacks.count(channel) == 0);
	callbacks[channel] = {};
}

void CSoundHandler::initCallback(int channel, const std::function<void()> & function)
{
	boost::mutex::scoped_lock lockGuard(mutexCallbacks);
	assert(callbacks.count(channel) == 0);
	callbacks[channel].push_back(function);
}

int CSoundHandler::ambientGetRange() const
{
	return ambientConfig["range"].Integer();
}

void CSoundHandler::ambientUpdateChannels(std::map<AudioPath, int> soundsArg)
{
	boost::mutex::scoped_lock guard(mutex);

	std::vector<AudioPath> stoppedSounds;
	for(const auto & pair : ambientChannels)
	{
		const auto & soundId = pair.first;
		const int channel = pair.second;

		if(!vstd::contains(soundsArg, soundId))
		{
			ambientStopSound(soundId);
			stoppedSounds.push_back(soundId);
		}
		else
		{
			int channelVolume = ambientDistToVolume(soundsArg[soundId]);
			channelVolumes[channel] = channelVolume;
			updateChannelVolume(channel);
		}
	}
	for(const auto & soundId : stoppedSounds)
	{
		channelVolumes.erase(ambientChannels[soundId]);
		ambientChannels.erase(soundId);
	}

	for(const auto & pair : soundsArg)
	{
		const auto & soundId = pair.first;
		const int distance = pair.second;

		if(!vstd::contains(ambientChannels, soundId))
		{
			int channel = playSound(soundId, -1);
			int channelVolume = ambientDistToVolume(distance);
			channelVolumes[channel] = channelVolume;

			updateChannelVolume(channel);
			ambientChannels[soundId] = channel;
		}
	}
}

void CSoundHandler::ambientStopAllChannels()
{
	boost::mutex::scoped_lock guard(mutex);

	for(const auto & ch : ambientChannels)
	{
		ambientStopSound(ch.first);
	}
	channelVolumes.clear();
	ambientChannels.clear();
}