#include <objbase.h>

// pure abstract base class
interface IX : IUnknown{  
  virtual void __stdcall Fx() = 0; // pure virtual function
};

// pure abstract base class
interface IY : IUnknown{
  virtual void __stdcall Fy() = 0; // pure virtual function
};

// pure abstract base class
interface IZ : IUnknown{
  virtual void __stdcall Fz() = 0; // pure virtual function
};

extern "C"{
  extern const IID IID_IX;
  extern const IID IID_IY;
  extern const IID IID_IZ;
}

//#include "../../std_lib_facilities.h"
#include <iostream>
#include "IFace.h"

// COM component
class CA :
  public IX,
  public IY,
  public IZ
{
public:
  CA();
  ~CA();
  virtual void __stdcall Fx(); // IX
  virtual void __stdcall Fy(); // IY
  virtual void __stdcall Fz(); // IZ
  // IUnknown
  virtual HRESULT __stdcall QueryInterface(const IID& iid, void** ppv);
  virtual ULONG __stdcall IX::AddRef(); // for IX instances
  virtual ULONG __stdcall IX::Release(); // for IX instances

  virtual ULONG __stdcall IY::AddRef(); // for IY instances
  virtual ULONG __stdcall IY::Release(); // for IY instances

  virtual ULONG __stdcall IZ::AddRef(); // for IZ instances
  virtual ULONG __stdcall IZ::Release(); // for IZ instances

private:
  // Each interface has own counter (for convenience of debugging)
  ULONG ix_counter;
  ULONG iy_counter;
  ULONG iz_counter;
};

CA::CA() :
ix_counter(0),
iy_counter(0),
iz_counter(0){
  std::cout << "CA:CA()" << std::endl;
}

CA::~CA(){
  std::cout << "CA:~CA()" << std::endl;
}


// TODO: this is wrong syntax (function signature)
ULONG __stdcall CA::IX::Release(){
  InterlockedDecrement(&ix_counter);
  ULONG count = ix_counter + iy_counter + iz_counter;
  if (0 == count) delete this;
  return count;
}

void __stdcall CA::Fx(){ std::cout << "\tFx()" << std::endl; }

void __stdcall CA::Fy(){ std::cout << "\tFy()" << std::endl; }

void __stdcall CA::Fz(){ std::cout << "\tFz()" << std::endl; }

// This is function is the same for each interface
HRESULT __stdcall CA::QueryInterface(const IID& iid, void** ppv){
  HRESULT h = S_OK;
  if (IID_IX == iid){
    *ppv = static_cast<IX*>(this);
    std::cout << "QueryInterface: IX interface returned." << std::endl;
  }
  else if (IID_IY == iid){
    *ppv = static_cast<IY*>(this);
    std::cout << "QueryInterface: IY interface returned." << std::endl;
  }
  else if (IID_IZ == iid){
    *ppv = static_cast<IZ*>(this);
    std::cout << "QueryInterface: IZ interface returned." << std::endl;
  }
  else{
    std::cout << "QueryInterface: Unexpected interface. NULL returned."
      << std::endl;
    h = E_NOINTERFACE;
    *ppv = NULL;
  }
  return h;
}

// TODO: this is wrong syntax (function signature)
ULONG __stdcall CA::IX::AddRef(){
  return InterlockedIncrement(&ix_counter);
}