/*
 * inetcpl.c - Indirect calls to inetcpl.cpl.
 */


/* Headers
 **********/

#if WINNT
#include "project.h"
#else
#include "project.hpp"
#endif
#pragma hdrstop

#include "inetcpl.h"


/* Types
 ********/

/* Internet CPL vtable */

typedef struct internetcplvtbl
{
   HRESULT (WINAPI *AddInternetPropertySheets)(LPFNADDPROPSHEETPAGE pfnAddPage, LPARAM lparam, PUINT pucRefCount, LPFNPSPCALLBACK pfnCallback);
}
INTERNETCPLVTBL;
DECLARE_STANDARD_TYPES(INTERNETCPLVTBL);


/* Module Constants
 *******************/

#pragma data_seg(DATA_SEG_READ_ONLY)

PRIVATE_DATA CCHAR s_cszInternetCPL[]               = "inetcpl.cpl";
PRIVATE_DATA CCHAR s_cszAddInternetPropertySheets[] = "AddInternetPropertySheets";

#pragma data_seg()


/* Module Variables
 *******************/

/* Internet CPL reference count */

PRIVATE_DATA ULONG s_ulcInternetCPLRef       = 0;

/* Internet CPL instance handle */

PRIVATE_DATA HINSTANCE s_hinstInternetCPL    = NULL;

/* Internet CPL vtable */

PRIVATE_DATA PINTERNETCPLVTBL s_pinetcplvtbl = NULL;


/***************************** Private Functions *****************************/


#ifdef DEBUG

PRIVATE_CODE BOOL IsValidPCINTERNETCPLVTBL(PCINTERNETCPLVTBL pcinetcplctbl)
{
   return(IS_VALID_READ_PTR(pcinetcplctbl, CINTERNETCPLVTBL) &&
          IS_VALID_CODE_PTR(pcinetcplctbl->AddInternetPropertySheets, AddInternetPropertySheets));
}


PRIVATE_CODE BOOL InternetCPLNotLoadedStateOK(void)
{
   return(! s_hinstInternetCPL &&
          ! s_pinetcplvtbl);
}


PRIVATE_CODE BOOL InternetCPLLoadedStateOK(void)
{
   return(IS_VALID_HANDLE(s_hinstInternetCPL, INSTANCE) &&
          IS_VALID_STRUCT_PTR(s_pinetcplvtbl, CINTERNETCPLVTBL));
}


PRIVATE_CODE BOOL InternetCPLStateOK(void)
{
   return(InternetCPLNotLoadedStateOK() ||
          InternetCPLLoadedStateOK());
}

#endif   /* DEBUG */


PRIVATE_CODE BOOL IsInternetCPLLoaded(void)
{
   ASSERT(InternetCPLStateOK());

   return(s_hinstInternetCPL != NULL);
}


PRIVATE_CODE BOOL GetInternetCPLProc(PCSTR pcszProc, FARPROC *pfp)
{
   ASSERT(IS_VALID_STRING_PTR(pcszProc, CSTR));
   ASSERT(IS_VALID_WRITE_PTR(pfp, FARPROC));

   ASSERT(IS_VALID_HANDLE(s_hinstInternetCPL, INSTANCE));

   *pfp = GetProcAddress(s_hinstInternetCPL, pcszProc);

   if (*pfp)
      TRACE_OUT(("GetInternetCPLProc(): Got address of %s!%s.",
                 s_cszInternetCPL,
                 pcszProc));
   else
      WARNING_OUT(("GetOLEProc(): Failed to get address of %s!%s.",
                   s_cszInternetCPL,
                   pcszProc));

   ASSERT(! *pfp ||
          IS_VALID_CODE_PTR(*pfp, FARPROC));

   return(*pfp != NULL);
}


PRIVATE_CODE BOOL FillInternetCPLVTable(void)
{
   BOOL bResult;

   ASSERT(IS_VALID_HANDLE(s_hinstInternetCPL, INSTANCE));

   if (AllocateMemory(sizeof(*s_pinetcplvtbl), &s_pinetcplvtbl))
   {
      bResult = GetInternetCPLProc(s_cszAddInternetPropertySheets,
                                   &(FARPROC)(s_pinetcplvtbl->AddInternetPropertySheets));

      if (bResult)
         TRACE_OUT(("FillInternetCPLVTable(): Internet CPL vtable filled successfully."));
      else
      {
         FreeMemory(s_pinetcplvtbl);
         s_pinetcplvtbl = NULL;
      }
   }
   else
      bResult = FALSE;

   ASSERT(! bResult ||
          InternetCPLLoadedStateOK());

   return(bResult);
}


PRIVATE_CODE BOOL LoadInternetCPL(void)
{
   BOOL bResult;

   bResult = IsInternetCPLLoaded();

   if (! bResult)
   {
      s_hinstInternetCPL = LoadLibrary(s_cszInternetCPL);

      if (s_hinstInternetCPL)
      {
         bResult = FillInternetCPLVTable();

         if (bResult)
            TRACE_OUT(("LoadInternetCPL(): %s loaded.",
                       s_cszInternetCPL));
      }
      else
         WARNING_OUT(("LoadInternetCPL(): LoadLibrary(%s) failed.",
                      s_cszInternetCPL));

      if (! bResult)
         UnloadInternetCPL();
   }

   ASSERT(InternetCPLStateOK());

   return(bResult);
}


PRIVATE_CODE ULONG InternetCPLAddRef(void)
{
   ULONG ulcRef;

   ASSERT(s_ulcInternetCPLRef < ULONG_MAX);

   ulcRef = ++s_ulcInternetCPLRef;

   TRACE_OUT(("InternetCPLAddRef(): Internet CPL reference count is now %lu.",
              ulcRef));

   return(ulcRef);
}


PRIVATE_CODE ULONG InternetCPLRelease(void)
{
   ULONG ulcRef;

   if (EVAL(s_ulcInternetCPLRef > 0))
      s_ulcInternetCPLRef--;

   ulcRef = s_ulcInternetCPLRef;

   TRACE_OUT(("InternetCPLRelease(): Internet CPL reference count is now %lu.",
              ulcRef));

   return(ulcRef);
}


/****************************** Public Functions *****************************/


PUBLIC_CODE PULONG GetInternetCPLRefCountPtr(void)
{
   return(&s_ulcInternetCPLRef);
}


PUBLIC_CODE HRESULT InternetCPLCanUnloadNow(void)
{
   HRESULT hr;

   hr = (s_ulcInternetCPLRef > 0) ? S_FALSE : S_OK;

   TRACE_OUT(("InternetCPLCanUnloadNow(): Internet CPL reference count is %lu.",
              s_ulcInternetCPLRef));

   return(hr);
}


PUBLIC_CODE void UnloadInternetCPL(void)
{
   if (EVAL(! s_ulcInternetCPLRef))
   {
      if (s_pinetcplvtbl)
      {
         FreeMemory(s_pinetcplvtbl);
         s_pinetcplvtbl = NULL;

         TRACE_OUT(("UnloadInternetCPL(): Freed %s vtable.",
                    s_cszInternetCPL));
      }

      if (s_hinstInternetCPL)
      {
         FreeLibrary(s_hinstInternetCPL);
         s_hinstInternetCPL = NULL;

         TRACE_OUT(("UnloadInternetCPL(): Freed %s.",
                    s_cszInternetCPL));
      }

      ASSERT(InternetCPLNotLoadedStateOK());
   }

   return;
}


PUBLIC_CODE BOOL InitInternetCPLModule(void)
{
   return(TRUE);
}


/*
** ExitInternetCPLModule()
**
** Unloads the Internet cpl at DLL_PROCESS_DETACH if it has not already been
** unloaded.  N.b., the Internet cpl should have already been unloaded when the
** last Internet property sheet was destroyed.
**
** Arguments:
**
** Returns:
**
** Side Effects:  none
*/
PUBLIC_CODE void ExitInternetCPLModule(void)
{
   /* Force the Internet cpl reference count to 0 if it is not 0 already. */

   if (s_ulcInternetCPLRef > 0)
   {
      ERROR_OUT(("ExitInternetCPLModule(): %s reference count still %lu at process exit.  Forcing unload.",
                 s_cszInternetCPL,
                 s_ulcInternetCPLRef));

      s_ulcInternetCPLRef = 0;
   }

   UnloadInternetCPL();

   return;
}


PUBLIC_CODE HRESULT WINAPI AddInternetPropertySheets(
                                             LPFNADDPROPSHEETPAGE pfnAddPage,
                                             LPARAM lparam, PUINT pucRefCount,
                                             LPFNPSPCALLBACK pfnCallback)
{
   HRESULT hr;

   /*
    * Increment the Internet CPL's reference count around this call it so that
    * it is not unloaded during the call.
    */

   InternetCPLAddRef();
   {
      if (LoadInternetCPL())
         hr = s_pinetcplvtbl->AddInternetPropertySheets(pfnAddPage, lparam,
                                                        pucRefCount,
                                                        pfnCallback);
      else
         hr = E_FAIL;
   }
   InternetCPLRelease();

   return(hr);
}