// ----------------------------------------------------------------------------
// PolicyConfig.h
// Undocumented COM-interface IPolicyConfig.
// Use for set default audio render endpoint
// @author EreTIk
// ----------------------------------------------------------------------------
 
#pragma once
 
interface DECLSPEC_UUID("f8679f50-850a-41cf-9c72-430f290290c8")
IPolicyConfig;
class DECLSPEC_UUID("870af99c-171d-4f9e-af0d-e63df40c2bc9")
CPolicyConfigClient;
// ----------------------------------------------------------------------------
// class CPolicyConfigClient
// {870af99c-171d-4f9e-af0d-e63df40c2bc9}
//
// interface IPolicyConfig
// {f8679f50-850a-41cf-9c72-430f290290c8}
//
// Query interface:
// CComPtr[IPolicyConfig] PolicyConfig;
// PolicyConfig.CoCreateInstance(__uuidof(CPolicyConfigClient));
//
// @compatible: Windows 7 and Later
// ----------------------------------------------------------------------------
interface IPolicyConfig : public IUnknown
{
public:
 
    virtual HRESULT GetMixFormat(
        PCWSTR,
        WAVEFORMATEX **
    );
 
    virtual HRESULT STDMETHODCALLTYPE GetDeviceFormat(
        PCWSTR,
        INT,
        WAVEFORMATEX **
    );
 
    virtual HRESULT STDMETHODCALLTYPE ResetDeviceFormat(
        PCWSTR
    );
 
    virtual HRESULT STDMETHODCALLTYPE SetDeviceFormat(
        PCWSTR,
        WAVEFORMATEX *,
        WAVEFORMATEX *
    );
 
    virtual HRESULT STDMETHODCALLTYPE GetProcessingPeriod(
        PCWSTR,
        INT,
        PINT64,
        PINT64
    );
 
    virtual HRESULT STDMETHODCALLTYPE SetProcessingPeriod(
        PCWSTR,
        PINT64
    );
 
    virtual HRESULT STDMETHODCALLTYPE GetShareMode(
        PCWSTR,
        struct DeviceShareMode *
    );
 
    virtual HRESULT STDMETHODCALLTYPE SetShareMode(
        PCWSTR,
        struct DeviceShareMode *
    );
 
    virtual HRESULT STDMETHODCALLTYPE GetPropertyValue(
        PCWSTR,
        const PROPERTYKEY &,
        PROPVARIANT *
    );
 
    virtual HRESULT STDMETHODCALLTYPE SetPropertyValue(
        PCWSTR,
        const PROPERTYKEY &,
        PROPVARIANT *
    );
 
    virtual HRESULT STDMETHODCALLTYPE SetDefaultEndpoint(
        __in PCWSTR wszDeviceId,
        __in ERole eRole
    );
 
    virtual HRESULT STDMETHODCALLTYPE SetEndpointVisibility(
        PCWSTR,
        INT
    );
};
 
interface DECLSPEC_UUID("568b9108-44bf-40b4-9006-86afe5b5a620")
IPolicyConfigVista;
class DECLSPEC_UUID("294935CE-F637-4E7C-A41B-AB255460B862")
CPolicyConfigVistaClient;
// ----------------------------------------------------------------------------
// class CPolicyConfigVistaClient
// {294935CE-F637-4E7C-A41B-AB255460B862}
//
// interface IPolicyConfigVista
// {568b9108-44bf-40b4-9006-86afe5b5a620}
//
// Query interface:
// CComPtr[IPolicyConfigVista] PolicyConfig;
// PolicyConfig.CoCreateInstance(__uuidof(CPolicyConfigVistaClient));
//
// @compatible: Windows Vista and Later
// ----------------------------------------------------------------------------
interface IPolicyConfigVista : public IUnknown
{
public:
 
    virtual HRESULT GetMixFormat(
        PCWSTR,
        WAVEFORMATEX **
    );  // not available on Windows 7, use method from IPolicyConfig
 
    virtual HRESULT STDMETHODCALLTYPE GetDeviceFormat(
        PCWSTR,
        INT,
        WAVEFORMATEX **
    );
 
    virtual HRESULT STDMETHODCALLTYPE SetDeviceFormat(
        PCWSTR,
        WAVEFORMATEX *,
        WAVEFORMATEX *
    );
 
    virtual HRESULT STDMETHODCALLTYPE GetProcessingPeriod(
        PCWSTR,
        INT,
        PINT64,
        PINT64
    );  // not available on Windows 7, use method from IPolicyConfig
 
    virtual HRESULT STDMETHODCALLTYPE SetProcessingPeriod(
        PCWSTR,
        PINT64
    );  // not available on Windows 7, use method from IPolicyConfig
 
    virtual HRESULT STDMETHODCALLTYPE GetShareMode(
        PCWSTR,
        struct DeviceShareMode *
    );  // not available on Windows 7, use method from IPolicyConfig
 
    virtual HRESULT STDMETHODCALLTYPE SetShareMode(
        PCWSTR,
        struct DeviceShareMode *
    );  // not available on Windows 7, use method from IPolicyConfig
 
    virtual HRESULT STDMETHODCALLTYPE GetPropertyValue(
        PCWSTR,
        const PROPERTYKEY &,
        PROPVARIANT *
    );
 
    virtual HRESULT STDMETHODCALLTYPE SetPropertyValue(
        PCWSTR,
        const PROPERTYKEY &,
        PROPVARIANT *
    );
 
    virtual HRESULT STDMETHODCALLTYPE SetDefaultEndpoint(
        __in PCWSTR wszDeviceId,
        __in ERole eRole
    );
 
    virtual HRESULT STDMETHODCALLTYPE SetEndpointVisibility(
        PCWSTR,
        INT
    );  // not available on Windows 7, use method from IPolicyConfig
};

#include "stdio.h"
#include "wchar.h"
#include "tchar.h"
#include "windows.h"
#include "Mmdeviceapi.h"
#include "PolicyConfig.h"
#include "Propidl.h"
#include "Functiondiscoverykeys_devpkey.h"
 
HRESULT SetDefaultAudioPlaybackDevice(LPCWSTR devID)
{
	IPolicyConfigVista *pPolicyConfig;
	ERole reserved = eConsole;
 
    HRESULT hr = CoCreateInstance(__uuidof(CPolicyConfigVistaClient),
		NULL, CLSCTX_ALL, __uuidof(IPolicyConfigVista), (LPVOID *)&pPolicyConfig);
	if (SUCCEEDED(hr))
	{
		hr = pPolicyConfig->SetDefaultEndpoint(devID, reserved);
		pPolicyConfig->Release();
	}
	return hr;
}
 
// EndPointController.exe [NewDefaultDeviceID]
int _tmain(int argc, _TCHAR* argv[])
{
	// read the command line option, -1 indicates list devices.
	int option = -1;
	if (argc == 2) option = atoi((char*)argv[1]);
 
	HRESULT hr = CoInitialize(NULL);
	if (SUCCEEDED(hr))
	{
		IMMDeviceEnumerator *pEnum = NULL;
		// Create a multimedia device enumerator.
		hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL,
			CLSCTX_ALL, __uuidof(IMMDeviceEnumerator), (void**)&pEnum);
		if (SUCCEEDED(hr))
		{
			IMMDeviceCollection *pDevices;
			// Enumerate the output devices.
			hr = pEnum->EnumAudioEndpoints(eRender, DEVICE_STATE_ACTIVE, &pDevices);
			if (SUCCEEDED(hr))
			{
				UINT count;
				pDevices->GetCount(&count);
				if (SUCCEEDED(hr))
				{
					for (int i = 0; i < count; i++)
					{
						IMMDevice *pDevice;
						hr = pDevices->Item(i, &pDevice);
						if (SUCCEEDED(hr))
						{
							LPWSTR wstrID = NULL;
							hr = pDevice->GetId(&wstrID);
							if (SUCCEEDED(hr))
							{
								IPropertyStore *pStore;
								hr = pDevice->OpenPropertyStore(STGM_READ, &pStore);
								if (SUCCEEDED(hr))
								{
									PROPVARIANT friendlyName;
									PropVariantInit(&friendlyName);
									hr = pStore->GetValue(PKEY_Device_FriendlyName, &friendlyName);
									if (SUCCEEDED(hr))
									{
										// if no options, print the device
										// otherwise, find the selected device and set it to be default
										if (option == -1) printf("Audio Device %d: %ws\n",i, friendlyName.pwszVal);
										if (i == option) SetDefaultAudioPlaybackDevice(wstrID);
										PropVariantClear(&friendlyName);
									}
									pStore->Release();
								}
							}
							pDevice->Release();
						}
					}
				}
				pDevices->Release();
			}
			pEnum->Release();
		}
	}
	return hr;
}