// Copyright 2013 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

// Note that this file *and this file only* must include XAudio2.h from the old
// DXSDK instead of other possible places.

#include <XAudio2_7/XAudio2.h>

#include "AudioCommon/AudioCommon.h"
#include "AudioCommon/XAudio2_7Stream.h"
#include "Common/Event.h"

struct StreamingVoiceContext2_7 : public IXAudio2VoiceCallback
{
private:
	CMixer* const m_mixer;
	Common::Event& m_sound_sync_event;
	IXAudio2SourceVoice* m_source_voice;
	std::unique_ptr<BYTE[]> xaudio_buffer;

	void SubmitBuffer(PBYTE buf_data);

public:
	StreamingVoiceContext2_7(IXAudio2 *pXAudio2, CMixer *pMixer, Common::Event& pSyncEvent);

	~StreamingVoiceContext2_7();

	void StreamingVoiceContext2_7::Stop();
	void StreamingVoiceContext2_7::Play();

	STDMETHOD_(void, OnVoiceError) (THIS_ void* pBufferContext, HRESULT Error) {}
	STDMETHOD_(void, OnVoiceProcessingPassStart) (UINT32) {}
	STDMETHOD_(void, OnVoiceProcessingPassEnd) () {}
	STDMETHOD_(void, OnBufferStart) (void*) {}
	STDMETHOD_(void, OnLoopEnd) (void*) {}
	STDMETHOD_(void, OnStreamEnd) () {}

	STDMETHOD_(void, OnBufferEnd) (void* context);
};

const int NUM_BUFFERS = 3;
const int SAMPLES_PER_BUFFER = 96;

const int NUM_CHANNELS = 2;
const int BUFFER_SIZE = SAMPLES_PER_BUFFER * NUM_CHANNELS;
const int BUFFER_SIZE_BYTES = BUFFER_SIZE * sizeof(s16);

void StreamingVoiceContext2_7::SubmitBuffer(PBYTE buf_data)
{
	XAUDIO2_BUFFER buf = {};
	buf.AudioBytes = BUFFER_SIZE_BYTES;
	buf.pContext = buf_data;
	buf.pAudioData = buf_data;

	m_source_voice->SubmitSourceBuffer(&buf);
}

StreamingVoiceContext2_7::StreamingVoiceContext2_7(IXAudio2 *pXAudio2, CMixer *pMixer, Common::Event& pSyncEvent)
	: m_mixer(pMixer)
	, m_sound_sync_event(pSyncEvent)
	, xaudio_buffer(new BYTE[NUM_BUFFERS * BUFFER_SIZE_BYTES]())
{
	WAVEFORMATEXTENSIBLE wfx = {};

	wfx.Format.wFormatTag      = WAVE_FORMAT_EXTENSIBLE;
	wfx.Format.nSamplesPerSec  = m_mixer->GetSampleRate();
	wfx.Format.nChannels       = 2;
	wfx.Format.wBitsPerSample  = 16;
	wfx.Format.nBlockAlign     = wfx.Format.nChannels*wfx.Format.wBitsPerSample / 8;
	wfx.Format.nAvgBytesPerSec = wfx.Format.nSamplesPerSec * wfx.Format.nBlockAlign;
	wfx.Format.cbSize          = sizeof(WAVEFORMATEXTENSIBLE) - sizeof(WAVEFORMATEX);
	wfx.Samples.wValidBitsPerSample = 16;
	wfx.dwChannelMask          = SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT;
	wfx.SubFormat              = KSDATAFORMAT_SUBTYPE_PCM;

	// create source voice
	HRESULT hr;
	if (FAILED(hr = pXAudio2->CreateSourceVoice(&m_source_voice, &wfx.Format, XAUDIO2_VOICE_NOSRC, 1.0f, this)))
	{
		PanicAlert("XAudio2_7 CreateSourceVoice failed: %#X", hr);
		return;
	}

	m_source_voice->Start();

	// start buffers with silence
	for (int i = 0; i != NUM_BUFFERS; ++i)
		SubmitBuffer(xaudio_buffer.get() + (i * BUFFER_SIZE_BYTES));
}

StreamingVoiceContext2_7::~StreamingVoiceContext2_7()
{
	if (m_source_voice)
	{
		m_source_voice->Stop();
		m_source_voice->DestroyVoice();
	}
}

void StreamingVoiceContext2_7::Stop()
{
	if (m_source_voice)
		m_source_voice->Stop();
}

void StreamingVoiceContext2_7::Play()
{
	if (m_source_voice)
		m_source_voice->Start();
}

void StreamingVoiceContext2_7::OnBufferEnd(void* context)
{
	//  buffer end callback; gets SAMPLES_PER_BUFFER samples for a new buffer

	if (!m_source_voice || !context)
		return;

	//m_sound_sync_event->Wait(); // sync
	//m_sound_sync_event->Spin(); // or tight sync

	m_mixer->Mix(static_cast<short*>(context), SAMPLES_PER_BUFFER);
	SubmitBuffer(static_cast<BYTE*>(context));
}

HMODULE XAudio2_7::m_xaudio2_dll = nullptr;

void XAudio2_7::ReleaseIXAudio2(IXAudio2* ptr)
{
	ptr->Release();
}

bool XAudio2_7::InitLibrary()
{
	if (m_xaudio2_dll)
	{
		return true;
	}

	m_xaudio2_dll = ::LoadLibrary(TEXT("xaudio2_7.dll"));

	return m_xaudio2_dll != nullptr;
}

XAudio2_7::XAudio2_7()
	: m_mastering_voice(nullptr)
	, m_volume(1.0f)
	, m_cleanup_com(SUCCEEDED(CoInitializeEx(nullptr, COINIT_MULTITHREADED)))
{
}

XAudio2_7::~XAudio2_7()
{
	Stop();
	if (m_cleanup_com)
		CoUninitialize();
}

bool XAudio2_7::Start()
{
	HRESULT hr;

	// callback doesn't seem to run on a specific CPU anyways
	IXAudio2* xaudptr;
	if (FAILED(hr = XAudio2Create(&xaudptr, 0, XAUDIO2_DEFAULT_PROCESSOR)))
	{
		PanicAlert("XAudio2_7 init failed: %#X", hr);
		Stop();
		return false;
	}
	m_xaudio2 = std::unique_ptr<IXAudio2, Releaser>(xaudptr);

	// XAudio2 master voice
	// XAUDIO2_DEFAULT_CHANNELS instead of 2 for expansion?
	if (FAILED(hr = m_xaudio2->CreateMasteringVoice(&m_mastering_voice, 2, m_mixer->GetSampleRate())))
	{
		PanicAlert("XAudio2_7 master voice creation failed: %#X", hr);
		Stop();
		return false;
	}

	// Volume
	m_mastering_voice->SetVolume(m_volume);

	m_voice_context = std::unique_ptr<StreamingVoiceContext2_7>
		(new StreamingVoiceContext2_7(m_xaudio2.get(), m_mixer.get(), m_sound_sync_event));

	return true;
}

void XAudio2_7::SetVolume(int volume)
{
	//linear 1- .01
	m_volume = (float)volume / 100.f;

	if (m_mastering_voice)
		m_mastering_voice->SetVolume(m_volume);
}

void XAudio2_7::Clear(bool mute)
{
	m_muted = mute;

	if (m_voice_context)
	{
		if (m_muted)
			m_voice_context->Stop();
		else
			m_voice_context->Play();
	}
}

void XAudio2_7::Stop()
{
	//m_sound_sync_event.Set();

	m_voice_context.reset();

	if (m_mastering_voice)
	{
		m_mastering_voice->DestroyVoice();
		m_mastering_voice = nullptr;
	}

	m_xaudio2.reset(); // release interface

	if (m_xaudio2_dll)
	{
		::FreeLibrary(m_xaudio2_dll);
		m_xaudio2_dll = nullptr;
	}
}