///////////////////////////////////////////////////////////////
//  Win32Files.cpp - demonstrate reading and writing with    //
//                   Win32 File API                          //
//  ver 1.0                                                  //
//                                                           //
//  Jim Fawcett, CSE 691/791 - SWM&A, Fall 2001              //
///////////////////////////////////////////////////////////////

#include <windows.h>
#include <cstring>
#include <iostream>
#include "sysUtils.h"
using namespace std;

int main(int argc, char *argv[]) {

  cout << "\n  Demonstrating Win32 File API "
       << "\n ==============================\n\n";

  if(argc == 1) {
    cout << "\n  please enter name of file to open on command line\n\n";
    return 1;
  }
  char *fileName = argv[1];
  
  // attempt to open file named in first argument of the command line

  HANDLE fileHandle = 
    CreateFile(
      fileName,
      GENERIC_READ,
      FILE_SHARE_READ,
      NULL,
      OPEN_EXISTING,
      FILE_FLAG_SEQUENTIAL_SCAN,
      NULL
    );

  sysError err;
  if(fileHandle == INVALID_HANDLE_VALUE) {
    cout << "\n  " << err.getLastMsg() << endl;
    return 1;
  }
  
  // read file in 20 byte blocks and write to stdout

  unsigned long int numRead, numWritten;
  HANDLE StdOut = GetStdHandle(STD_OUTPUT_HANDLE);
  const int bufferSize = 20;
  char buffer[bufferSize];
  BOOL readOK = TRUE;
  while(1) {
    readOK = ReadFile(fileHandle,buffer,bufferSize,&numRead,NULL);
    if(readOK && numRead > 0) {
      WriteFile(StdOut,buffer,numRead,&numWritten,NULL);
    }
    else
      break;
  }
  CloseHandle(fileHandle);

  cout << "\n\n";
  return 0;
}