/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is the Mozilla browser.
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications, Inc.  Portions created by Netscape are
 * Copyright (C) 1999, Mozilla.  All Rights Reserved.
 * 
 * Contributor(s):
 *   Radha Kulkarni <radha@netscape.com>
 */

#ifndef nsSHistory_h
#define nsSHistory_h

// Helper Classes
#include "nsCOMPtr.h"

//Interfaces Needed
#include "nsISHistory.h"
#include "nsISHistoryInternal.h"
#include "nsISHTransaction.h"
#include "nsIWebNavigation.h"
#include "nsIWeakReference.h"
#include "nsISimpleEnumerator.h"
#include "nsISHistoryListener.h"
#include "nsIHistoryEntry.h"

class nsIDocShell;
class nsSHEnumerator;
class nsSHistory: public nsISHistory,
                  public nsISHistoryInternal,
                  public nsIWebNavigation
{
public:
	nsSHistory();

  NS_DECL_ISUPPORTS
  NS_DECL_NSISHISTORY
  NS_DECL_NSISHISTORYINTERNAL
  NS_DECL_NSIWEBNAVIGATION

  NS_IMETHOD Init();

protected:
  virtual ~nsSHistory();
  friend class nsSHEnumerator;

   // Could become part of nsIWebNavigation
   NS_IMETHOD GetEntryAtIndex(PRInt32 aIndex, PRBool aModifyIndex, nsISHEntry** aResult);
   NS_IMETHOD GetTransactionAtIndex(PRInt32 aIndex, nsISHTransaction ** aResult);
   nsresult CompareFrames(nsISHEntry * prevEntry, nsISHEntry * nextEntry, nsIDocShell * rootDocShell, long aLoadType, PRBool * aIsFrameFound);
   nsresult InitiateLoad(nsISHEntry * aFrameEntry, nsIDocShell * aFrameDS, long aLoadType);

   NS_IMETHOD LoadEntry(PRInt32 aIndex, long aLoadType, PRUint32 histCmd);
	
#ifdef DEBUG
   nsresult PrintHistory();
#endif

protected:
  nsCOMPtr<nsISHTransaction> mListRoot;
  PRInt32 mIndex;
  PRInt32 mLength;
  PRInt32 mRequestedIndex;
  // Session History listener
  nsWeakPtr mListener;
  // Weak reference. Do not refcount this.
  nsIDocShell *  mRootDocShell;
};
//*****************************************************************************
//***    nsSHEnumerator: Object Management
//*****************************************************************************
class nsSHEnumerator : public nsISimpleEnumerator
{
public:

  NS_DECL_ISUPPORTS
  NS_DECL_NSISIMPLEENUMERATOR

  nsSHEnumerator(nsSHistory *  aHistory);
  
protected:
  friend class nsSHistory;
  virtual ~nsSHEnumerator();
private:
  PRInt32     mIndex;
  nsSHistory *  mSHistory;  
};



#endif   /* nsSHistory */