/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: NPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Netscape 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/NPL/
 *
 * 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 Mozilla Communicator client code.
 *
 * The Initial Developer of the Original Code is 
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *  Simon Fraser <sfraser@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 NPL, 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 NPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsCOMPtr.h"
#include "nsError.h"
#include "nsIObserverService.h"
#include "nsIServiceManager.h"
#include "nsString.h"
#include "nsReadableUtils.h"
#include "nsAEUtils.h"
#include "nsAESpyglassSuiteHandler.h"

#include "nsDocLoadObserver.h"

nsDocLoadObserver::nsDocLoadObserver()
:	mRegistered(PR_FALSE)
{
}

nsDocLoadObserver::~nsDocLoadObserver()
{
}


NS_IMPL_ISUPPORTS1(nsDocLoadObserver, nsIObserver)

void nsDocLoadObserver::Register()
{
	if (!mRegistered)
	{
		nsresult rv;
		nsCOMPtr<nsIObserverService> anObserverService = do_GetService("@mozilla.org/observer-service;1", &rv);
		if (NS_SUCCEEDED(rv))
		{
			if (NS_SUCCEEDED(anObserverService->AddObserver(this, "EndDocumentLoad", PR_FALSE)))
			{
				mRegistered = PR_TRUE;
			}
		}
	}
}

void nsDocLoadObserver::Unregister()
{
	if (mRegistered)
	{
		nsresult rv;
		nsCOMPtr<nsIObserverService> anObserverService = do_GetService("@mozilla.org/observer-service;1", &rv);
		if (NS_SUCCEEDED(rv))
		{
			if (NS_SUCCEEDED(anObserverService->RemoveObserver(this, 
				"EndDocumentLoad")))
			{
				mRegistered = PR_FALSE;
			}
		}
	}
}

void nsDocLoadObserver::AddEchoRequester(OSType appSignature)
{
  // make sure an application is only in the list once
  mEchoRequesters.RemoveElement((void*)appSignature);
  
	mEchoRequesters.AppendElement((void*)appSignature);
	Register();     // ensure we are registered
}

void nsDocLoadObserver::RemoveEchoRequester(OSType appSignature)
{
	mEchoRequesters.RemoveElement((void*)appSignature);
	if (mEchoRequesters.Count() == 0)
	  Unregister();
}

NS_IMETHODIMP nsDocLoadObserver::Observe(nsISupports* /*aSubject*/,
		const char* /*aTopic*/, const PRUnichar* someData)
{
	// we need a URL to forward
	if (!someData)
		return NS_ERROR_NULL_POINTER;

	// are there any echo requesters to notify?
	if (mEchoRequesters.Count() == 0)
		return NS_OK;

	// create the descriptor for identifying this application
	StAEDesc from;
	const OSType mozz = 'MOZZ';
	if (noErr != ::AECreateDesc(typeType, &mozz, sizeof(mozz), &from))
		return NS_ERROR_UNEXPECTED;

	// create the descriptor for the URL
	nsString urlText(someData);
	char* urlString = ToNewCString(urlText);

	StAEDesc url;
	OSErr err = ::AECreateDesc(typeChar, urlString, urlText.Length(), &url);
	nsMemory::Free(urlString);
	if (err != noErr)
		return NS_ERROR_UNEXPECTED;

	// keep track of any invalid requesters and remove them when we're done
	nsVoidArray requestersToRemove;
	
	PRInt32		numRequesters = mEchoRequesters.Count();
	
	// now notify all the echo requesters
	for (PRInt32 i = 0; i < numRequesters; i ++)
	{
		// specify the address of the requester
		StAEDesc targetAddress;
		const OSType target = (OSType)mEchoRequesters.ElementAt(i);
		if (noErr != ::AECreateDesc(typeApplSignature, &target, sizeof(target), &targetAddress))
			return NS_ERROR_UNEXPECTED;

		// create the event
		AppleEvent sendEvent;
		err = ::AECreateAppleEvent(AESpyglassSuiteHandler::kSpyglassSendSignature,
				AESpyglassSuiteHandler::kSendURLEchoEvent, 
				&targetAddress, kAutoGenerateReturnID, kAnyTransactionID, &sendEvent);
		if (noErr != err)
		{	// this target is no longer available
			requestersToRemove.AppendElement((void *)target);
			continue;
		}

		// attach our signature - to let the requester know who we are
		err = ::AEPutParamDesc(&sendEvent, keyOriginalAddressAttr, &from);
		NS_ASSERTION(noErr == err, "AEPutParamDesc");

		// attach the new URL
		err = ::AEPutParamDesc(&sendEvent, keyDirectObject, &url);
		NS_ASSERTION(noErr == err, "AEPutParamDesc");
		
		// send it
		AppleEvent reply;
		err = ::AESend(&sendEvent, &reply, kAENoReply, kAENormalPriority, 180, NULL, NULL);
		NS_ASSERTION(noErr == err, "AESend");
		::AEDisposeDesc(&sendEvent);
	}

	// now remove unresponsive requestors
	for (PRInt32 i = 0; i < requestersToRemove.Count(); i ++)
	{
		OSType	thisRequester = (OSType)requestersToRemove.ElementAt(i);
		mEchoRequesters.RemoveElement((void *)thisRequester);
	}
	
	return NS_OK;
}