// component.cpp
#include <iostream.h>  // For cout
#include "Component\component.h" // Generated by MIDL

// {10000002-0000-0000-0000-000000000001}
const CLSID CLSID_InsideCOM = 
    {0x10000002,0x0000,0x0000,
    {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01}};

long g_cLocks = 0;

class CInsideCOM : public ISum
{
public:
	// IUnknown
	ULONG __stdcall AddRef();
	ULONG __stdcall Release();
	HRESULT __stdcall QueryInterface(REFIID riid, void** ppv);

	// ISum
	HRESULT __stdcall Sum(int x, int y, int* retval);

	CInsideCOM() : m_cRef(1) { g_cLocks++; }
	~CInsideCOM()
		{
		cout << "Component: CInsideCOM::~CInsideCOM()" << endl;
		g_cLocks--;
		}

private:
	ULONG m_cRef;
};

ULONG CInsideCOM::AddRef()
{
	cout << "Component: CInsideCOM::AddRef() m_cRef = " << m_cRef + 1 << endl;
	return ++m_cRef;
}

ULONG CInsideCOM::Release()
{
	cout << "Component: CInsideCOM::Release() m_cRef = " << m_cRef - 1 << endl;
	if(--m_cRef != 0)
		return m_cRef;
	delete this;
	return 0;
}

HRESULT CInsideCOM::QueryInterface(REFIID riid, void** ppv)
{
	if(riid == IID_IUnknown)
	{
		cout << "Component: CInsideCOM::QueryInterface() for IUnknown returning " << this << endl;
		*ppv = (IUnknown*)this;
	}
	else if(riid == IID_ISum)
	{
		cout << "Component: CInsideCOM::QueryInterface() for ISum returning " << this << endl;
		*ppv = (ISum*)this;
	}
	else 
	{
		*ppv = NULL;
		return E_NOINTERFACE;
	}
	AddRef();
	return S_OK;
}

HRESULT CInsideCOM::Sum(int x, int y, int* retval)
{
	cout << "Component: CInsideCOM::Sum() " << x << " + " << y << " = " << x + y << endl;
	*retval = x + y;
	return S_OK;
}

class CFactory : public IClassFactory
{
public:
	// IUnknown
	ULONG __stdcall AddRef();
	ULONG __stdcall Release();
	HRESULT __stdcall QueryInterface(REFIID riid, void** ppv);

	// IClassFactory
	HRESULT __stdcall CreateInstance(IUnknown *pUnknownOuter, 
            REFIID riid, void** ppv);
	HRESULT __stdcall LockServer(BOOL bLock);

	CFactory() : m_cRef(1) { g_cLocks++; }
	~CFactory() { g_cLocks--; }

private:
	ULONG m_cRef;
};

ULONG CFactory::AddRef()
{
	cout << "Component: CFactory::AddRef() m_cRef = " << m_cRef + 1 << endl;
	return ++m_cRef;
}

ULONG CFactory::Release()
{
	cout << "Component: CFactory::Release() m_cRef = " << m_cRef - 1 << endl;
	if(--m_cRef != 0)
		return m_cRef;
	delete this;
	return 0;
}

HRESULT CFactory::QueryInterface(REFIID riid, void** ppv)
{
	if(riid == IID_IUnknown)
	{
		cout << "Component: CFactory::QueryInterface() for IUnknown returning " << this << endl;
		*ppv = (IUnknown*)this;
	}
	else if(riid == IID_IClassFactory)
	{
		cout << "Component: CFactory::QueryInteface() for IClassFactory " << this << endl;
		*ppv = (IClassFactory*)this;
	}
	else
	{
		*ppv = NULL;
		return E_NOINTERFACE;
	}
	AddRef();
	return S_OK;
}

HRESULT CFactory::CreateInstance(IUnknown *pUnknownOuter, 
    REFIID riid, void** ppv)
{
	if(pUnknownOuter != NULL)
		return CLASS_E_NOAGGREGATION;

	CInsideCOM *pInsideCOM = new CInsideCOM;
	cout << "Component: CFactory::CreateInstance() " << pInsideCOM << endl;

	if(pInsideCOM == NULL)
		return E_OUTOFMEMORY;

	HRESULT hr = pInsideCOM->QueryInterface(riid, ppv);
	pInsideCOM->Release();
	return hr;
}

HRESULT CFactory::LockServer(BOOL bLock)
{
	if(bLock)
		g_cLocks++;
	else
		g_cLocks--;
	return S_OK;
}

HRESULT __stdcall DllCanUnloadNow()
{
	cout << "Component: DllCanUnloadNow() " << (g_cLocks == 0 ? "Yes" : "No") << endl;
	if(g_cLocks == 0)
		return S_OK;
	else
		return S_FALSE;
}

HRESULT __stdcall DllGetClassObject(REFCLSID clsid, REFIID riid, 
    void** ppv)
{
	cout << "Component: DllGetClassObject" << endl;
	
	if(clsid != CLSID_InsideCOM)
		return CLASS_E_CLASSNOTAVAILABLE;

	CFactory* pFactory = new CFactory;
	if(pFactory == NULL)
		return E_OUTOFMEMORY;

	// riid is probably IID_IClassFactory.
	HRESULT hr = pFactory->QueryInterface(riid, ppv);
	pFactory->Release();
	return hr;
}