///////////////////////////////////////////////////////////////////
//                                                               //
//  Win32utils.cpp - useful helper functions for Win32 API       //
//  ver 1.0                                                      //
//                                                               //
//  Language:        Visual C, ver 6.0                           //
//  Platform:        Micron Dual Pentium Pro 200, Win NT 4.0     //
//  Application:     CSE691 Project #1                           //
//  Author:          Jim Fawcett, Instructor, CSE691, Fall '99   //
//                   CST 2-187, Syracuse Univ, (315) 443-3948    //
//                   fawcett@ecs.syr.edu                         //
//                                                               //
///////////////////////////////////////////////////////////////////

#include <iostream>
#include <strstream>
#include "Win32utils.h"
using namespace std;

//----< display messagebox with system error string >--------------
//
//  errCode input is usually the result of a call to GetLastError()
//  pMsg is a pointer to any C string and becomes the title of the box
//
void showSysError(const char *pMsg, DWORD errCode) {

  LPVOID lpMsgBuf;
  DWORD dwRet = FormatMessage(
    FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
    NULL,
    errCode,
    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
    reinterpret_cast<LPTSTR>(&lpMsgBuf),
    0,NULL
  );
  MessageBox(NULL,reinterpret_cast<LPTSTR>(lpMsgBuf),pMsg,MB_OK);
  LocalFree(lpMsgBuf);
}

//----< show current thread ID >-----------------------------------

void showCurrentThreadID(HWND hwnd, const char *Msg) {

  DWORD cid = GetCurrentThreadId();

  MessageBox(
    hwnd,
    makeString("thread ID = ",cid).c_str(),
    Msg,
    MB_OK
  );
}

//

//----< test stub >------------------------------------------------

#ifdef TEST_WIN32UTILS

void main() {

  cout << "\n  Testing Win32 Utility Functions "
       << "\n =================================\n";

  showCurrentThreadID(NULL, "testing showCurrentThreadID(...)");

  int x, y = 0;
  try { 
    x = 1/y; 
  } catch(...) {
    cout << "\n  caught exception thrown by system on divide by zero\n";
  };
  showSysError("testing showSysError(...)",GetLastError());

  HANDLE h = 0;         // invalid handle to file
  char lpBuff[1];       // read buffer
  DWORD got;            // bytes read
  ReadFile(h,lpBuff,1,&got,NULL);
  showSysError("testing showSysError",GetLastError());

  cout << "\n\n  testing makeString(char*,_int64)\n  "
       << makeString("  error code = ",GetLastError());

  cout << "\n\n  testing makeString(char*,double)\n  "
       << makeString("  small double precision number = ",3.45);

  cout << "\n\n  testing makeString(double,char*)\n  "
       << makeString("  large double precision number = ",3.456789e+15);

  cout << "\n\n";
}

#endif