#include "stdafx.h"
#include "SpBase.h"
#include "volumekeeper.h"

#include <audioclient.h>
#include <MMDeviceApi.h>
#include <AudioEngineEndPoint.h>
#include <DeviceTopology.h>
#include <EndpointVolume.h>
#include <functiondiscoverykeys.h>

#define EXIT_ON_ERROR(x) if (FAILED(x)) {goto Exit;}
#define RETURN_ERROR(x)   FAILED(x)?false:true   

class volume_keeper_t : public IAudioEndpointVolumeCallback
{
private:
	char m_dev_key[MAX_PATH];
	int m_in_dev;
	ULONG m_lRef;

public:
	IAudioEndpointVolume *m_pAudioEndpointVolume;
	GUID m_guidContext;
	float m_kept_value;

	volume_keeper_t(const char *dev_key, int in_dev, int kept_value) : m_lRef(1), m_kept_value(kept_value/100.0f), m_pAudioEndpointVolume(NULL), m_in_dev(in_dev)
	{
		strcpy(m_dev_key, dev_key);
	}

	HRESULT Init()
	{
		IMMDeviceEnumerator *pEnumerator = NULL;
		IMMDeviceCollection *pDeviceCollection = NULL;
		
		HRESULT hr;

		hr = CoCreateGuid(&m_guidContext);
		EXIT_ON_ERROR(hr);

		hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL, CLSCTX_INPROC_SERVER, __uuidof(IMMDeviceEnumerator), (void**)&pEnumerator);
		EXIT_ON_ERROR(hr);

		hr = pEnumerator->EnumAudioEndpoints(m_in_dev ? eCapture : eRender, DEVICE_STATE_ACTIVE, &pDeviceCollection);
		EXIT_ON_ERROR(hr);

		UINT nCount = 0;
		hr = pDeviceCollection->GetCount(&nCount);
		EXIT_ON_ERROR(hr);

		for (UINT i = 0; i < nCount; ++i) {
			IMMDevice *pDevice = NULL;
			hr = pDeviceCollection->Item(i, &pDevice);
			if (SUCCEEDED(hr)) {
				char name[260];
				IPropertyStore *pPS = NULL;
				PROPVARIANT value;
				PropVariantInit(&value);
				pDevice->OpenPropertyStore(STGM_READ, &pPS);
				pPS->GetValue(PKEY_Device_FriendlyName, &value);
				WideCharToMultiByte(CP_ACP, 0, value.pwszVal, -1, name, sizeof(name)-1, 0, 0);
				PropVariantClear(&value);
				pPS->Release();
				if (strstr(name, m_dev_key)) {
					hr = pDevice->Activate(__uuidof(IAudioEndpointVolume), CLSCTX_INPROC_SERVER, NULL, (void**)&m_pAudioEndpointVolume);
					if (SUCCEEDED(hr)) {
						hr = m_pAudioEndpointVolume->RegisterControlChangeNotify(this);
						m_pAudioEndpointVolume->SetMasterVolumeLevelScalar(m_kept_value, &m_guidContext);
					}
					pDevice->Release();
					break;
				} else {
					pDevice->Release();
				}
			} else {
				break;
			}
		}

Exit:

		if (pDeviceCollection) {
			pDeviceCollection->Release();
		}
		if (pEnumerator) {
			pEnumerator->Release();
		}

		return hr;

	}

	void Term()
	{
		if (m_pAudioEndpointVolume) {
			m_pAudioEndpointVolume->UnregisterControlChangeNotify(this);
			m_pAudioEndpointVolume->Release();
		}
	}

	void ChangeValue(int nValue)
	{
		m_kept_value=nValue/100.f;
	}

	ULONG STDMETHODCALLTYPE AddRef()
	{
		return InterlockedIncrement(&m_lRef);
	}

	ULONG STDMETHODCALLTYPE Release()
	{
		ULONG ulRef = InterlockedDecrement(&m_lRef);
		if (0 == ulRef) {
			delete this;
		}
		return ulRef;
	}

	HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, VOID **ppvInterface)
	{
		if (IID_IUnknown == riid) { 
			AddRef();
			*ppvInterface = (IUnknown*)this;
		} else if (__uuidof(IAudioEndpointVolumeCallback) == riid) {
			AddRef();
			*ppvInterface = (IAudioEndpointVolumeCallback*)this;
		} else {
			*ppvInterface = NULL;
			return E_NOINTERFACE;
		}
		return S_OK;
	}

	// Callback method for endpoint-volume-change notifications.

	HRESULT STDMETHODCALLTYPE OnNotify(PAUDIO_VOLUME_NOTIFICATION_DATA pNotify)
	{
		if (pNotify == NULL) {
			return E_INVALIDARG;
		}

		if (pNotify->guidEventContext != m_guidContext) {
			if (pNotify->fMasterVolume != m_kept_value) {
				m_pAudioEndpointVolume->SetMasterVolumeLevelScalar(m_kept_value, &m_guidContext);
			}
		}

		return S_OK;
	}
};

void *volume_keeper_create(const char *dev_key_name, int in_dev, int kept_value)
{
	if (!dev_key_name) {
		return NULL;
	}
		
	if (kept_value < 0 || kept_value > 100) {
		return NULL;
	}

	volume_keeper_t *inst = new volume_keeper_t(dev_key_name, in_dev, kept_value);
	if (SUCCEEDED(inst->Init())) 
	{
		return inst;
	} 
	else 
	{
		inst->Release();
	}

	return NULL;
}

void volume_keeper_destroy(void *inst)
{
	volume_keeper_t *keeper = (volume_keeper_t*)inst;
	keeper->Term();
	keeper->Release();
}

void volume_keeper_change(void *inst,int change_value)
{
	volume_keeper_t *keeper = (volume_keeper_t*)inst;
	float fCurValue = 0.0;
	keeper->m_kept_value =(change_value/100.0f);
	if (keeper->m_kept_value>1)
	{
		keeper->m_kept_value = 1;
	}
	else if (keeper->m_kept_value<0)
	{
		keeper->m_kept_value = 0;
	}

	if (NULL != keeper->m_pAudioEndpointVolume){
		keeper->m_pAudioEndpointVolume->SetMasterVolumeLevelScalar(keeper->m_kept_value,&keeper->m_guidContext);
	}
	
}


bool get_audiodevice_volumn(void *inst,int*nvalue)
{
	volume_keeper_t *keeper = (volume_keeper_t*)inst;
	float fValue = 0.0;
	if (NULL != keeper->m_pAudioEndpointVolume){
		keeper->m_pAudioEndpointVolume->GetMasterVolumeLevelScalar(&fValue);
	}
	*nvalue = fValue*100;
	return true;
}