/*
 * Help Access Library 
 * A Library to access the contents of Windows Help files.
 *
 * Copyright (C) 1995-2004 Bernd Herd, http://www.herdsoft.com
 *                                                                  
 * This program is free software; you can redistribute it and/or    
 * modify it under the terms of the GNU General Public License as   
 * published by the Free Software Foundation; either version 2 of   
 * the License.              
 *                                                                  
 * This program is distributed in the hope that it will be useful,  
 * but WITHOUT ANY WARRANTY; without even the implied warranty of   
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    
 * GNU General Public License for more details.                     
 *                                                                  
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software      
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.        
 */
/* gettopiccount.c ------------------------------------
 * @doc
 * @module gettopiccount.c |
 * Gets number of topics in a help file.
 *
 * Help Access Library Project.
 *
 *-----------------------------------------------------*/

#include <windows.h>
#include <windowsx.h>
#include <time.h>
#include <stdio.h>
#include <string.h>
#include "hlpacces.h"


static int nGetBtreeCount(NPIFSFILE ifsfile);


/**
 * Get the number of topics stored in a helpfile.
 * This is required to aid for "next" button handling
 *
 * @param     ifs     Handle for Integrated Help filesystem opened by IFSOpen
 *
 * @return Number of topics, -1 on error.
 */
int WINAPI HlpGetTopicCount(HIFS ifs)   
{ 
  int result=-1;
  NPIFSFILE ifsfile = IFSOpenFile(ifs, "|TTLBTREE");

  if (ifsfile)
  {
    result = nGetBtreeCount(ifsfile);

    IFSCloseFile(ifsfile);
  }
  return result;
}


/**
 * Get the number of keywords stored in a helpfile.
 *
 * @param     ifs     Handle for Integrated Help filesystem opened by IFSOpen
 *
 * @return Number of Keywords, 0 on error.
 */
int WINAPI HlpGetKeywordCount(HIFS ifs)   
{ 
  int result=0;
  NPIFSFILE ifsfile = IFSOpenFile(ifs, "|KWBTREE");

  if (ifsfile)
  {
    result = nGetBtreeCount(ifsfile);

    IFSCloseFile(ifsfile);
  }
  return result;
}


/**
 * Get the number of entries in a btree
 */
static
int
nGetBtreeCount(NPIFSFILE ifsfile)
{ 
  BTREEHEADER     BTreeHdr;

  //--------- Read Title B-Tree header ------------------
  IFSReadFile(ifsfile, &BTreeHdr, sizeof(BTreeHdr));

  return ledword(BTreeHdr.TotalBtreeEntries);
}