/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * 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 the Initial Developer are Copyright (C) 1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Adam Lock <adamlock@netscape.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsCommandHandler.h"
#include "nsWebBrowser.h"
#include "nsDocShellTreeOwner.h"

#include "nsIAllocator.h"
#include "nsIScriptGlobalObject.h"

nsCommandHandler::nsCommandHandler() :
    mWindow(nsnull)
{
}

nsCommandHandler::~nsCommandHandler()
{
}

nsresult nsCommandHandler::GetCommandHandler(nsICommandHandler **aCommandHandler)
{
    NS_ENSURE_ARG_POINTER(aCommandHandler);

    *aCommandHandler = nsnull;
    if (mWindow == nsnull)
    {
        return NS_ERROR_FAILURE;
    }

    nsCOMPtr<nsIScriptGlobalObject> globalObj( do_QueryInterface(mWindow) );
    if (!globalObj)
    {
        return NS_ERROR_FAILURE;
    }

    // Get the document tree owner

    nsCOMPtr<nsIDocShellTreeItem> docShellAsTreeItem =
      do_QueryInterface(globalObj->GetDocShell());
    nsIDocShellTreeOwner *treeOwner = nsnull;
    docShellAsTreeItem->GetTreeOwner(&treeOwner);

    // Make sure the tree owner is an an nsDocShellTreeOwner object
    // by QI'ing for a hidden interface. If it doesn't have the interface
    // then it's not safe to do the casting.

    nsCOMPtr<nsICDocShellTreeOwner> realTreeOwner(do_QueryInterface(treeOwner));
    if (realTreeOwner)
    {
        nsDocShellTreeOwner *tree = NS_STATIC_CAST(nsDocShellTreeOwner *, treeOwner);
        if (tree->mTreeOwner)
        {
            nsresult rv;
            rv = tree->mTreeOwner->QueryInterface(NS_GET_IID(nsICommandHandler), (void **)aCommandHandler);
            NS_RELEASE(treeOwner);
            return rv;
        }
     
        NS_RELEASE(treeOwner);
     }

    *aCommandHandler = nsnull;

    return NS_OK;
}


NS_IMPL_ADDREF(nsCommandHandler)
NS_IMPL_RELEASE(nsCommandHandler)

NS_INTERFACE_MAP_BEGIN(nsCommandHandler)
    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsICommandHandler)
    NS_INTERFACE_MAP_ENTRY(nsICommandHandlerInit)
    NS_INTERFACE_MAP_ENTRY(nsICommandHandler)
NS_INTERFACE_MAP_END

///////////////////////////////////////////////////////////////////////////////
// nsICommandHandlerInit implementation

/* attribute nsIDocShell docShell; */
NS_IMETHODIMP nsCommandHandler::GetWindow(nsIDOMWindow * *aWindow)
{
    *aWindow = nsnull;
    return NS_OK;
}

NS_IMETHODIMP nsCommandHandler::SetWindow(nsIDOMWindow * aWindow)
{
    if (aWindow == nsnull)
    {
       return NS_ERROR_FAILURE;
    }
    mWindow = aWindow;
    return NS_OK;
}

///////////////////////////////////////////////////////////////////////////////
// nsICommandHandler implementation

/* string exec (in string aCommand, in string aStatus); */
NS_IMETHODIMP nsCommandHandler::Exec(const char *aCommand, const char *aStatus, char **aResult)
{
    NS_ENSURE_ARG_POINTER(aCommand);
    NS_ENSURE_ARG_POINTER(aResult);

    nsCOMPtr<nsICommandHandler> commandHandler;
    GetCommandHandler(getter_AddRefs(commandHandler));

    // Call the client's command handler to deal with this command
    if (commandHandler)
    {
        *aResult = nsnull;
        return commandHandler->Exec(aCommand, aStatus, aResult);
    }

    // Return an empty string
    const char szEmpty[] = "";
    *aResult = (char *) nsAllocator::Clone(szEmpty, sizeof(szEmpty));

    return NS_OK;
}

/* string query (in string aCommand, in string aStatus); */
NS_IMETHODIMP nsCommandHandler::Query(const char *aCommand, const char *aStatus, char **aResult)
{
    NS_ENSURE_ARG_POINTER(aCommand);
    NS_ENSURE_ARG_POINTER(aResult);

    nsCOMPtr<nsICommandHandler> commandHandler;
    GetCommandHandler(getter_AddRefs(commandHandler));

    // Call the client's command handler to deal with this command
    if (commandHandler)
    {
        *aResult = nsnull;
        return commandHandler->Query(aCommand, aStatus, aResult);
    }

    // Return an empty string
    const char szEmpty[] = "";
    *aResult = (char *) nsAllocator::Clone(szEmpty, sizeof(szEmpty));

    return NS_OK;
}