/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** 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.org code.
 *
 * The Initial Developer of the Original Code is 
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2001
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Darin Fisher <darin@netscape.com> (original author)
 *
 * 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 "nsStreamObserverProxy.h"
#include "nsIGenericFactory.h"
#include "nsIServiceManager.h"
#include "nsIEventQueueService.h"
#include "nsString.h"

#if defined(PR_LOGGING)
PRLogModuleInfo *gStreamProxyLog;
#endif
#define LOG(args) PR_LOG(gStreamProxyLog, PR_LOG_DEBUG, args)

static NS_DEFINE_CID(kEventQueueService, NS_EVENTQUEUESERVICE_CID);

//
//----------------------------------------------------------------------------
// nsStreamObserverEvent implementation...
//----------------------------------------------------------------------------
//
nsStreamObserverEvent::nsStreamObserverEvent(nsStreamProxyBase *aProxy,
                                             nsIRequest *aRequest,
                                             nsISupports *aContext)
    : mProxy(aProxy)
    , mRequest(aRequest)
    , mContext(aContext)
{
    NS_IF_ADDREF(mProxy);
} 

nsStreamObserverEvent::~nsStreamObserverEvent()
{
    NS_IF_RELEASE(mProxy);
}

nsresult
nsStreamObserverEvent::FireEvent(nsIEventQueue *aEventQ)
{
    NS_PRECONDITION(aEventQ, "null event queue");

    PL_InitEvent(&mEvent, nsnull,
        (PLHandleEventProc) nsStreamObserverEvent::HandlePLEvent,
        (PLDestroyEventProc) nsStreamObserverEvent::DestroyPLEvent);

    PRStatus status = aEventQ->PostEvent(&mEvent);
    return status == PR_SUCCESS ? NS_OK : NS_ERROR_FAILURE;
}

void PR_CALLBACK
nsStreamObserverEvent::HandlePLEvent(PLEvent *aEvent)
{
    nsStreamObserverEvent *ev = GET_STREAM_OBSERVER_EVENT(aEvent);
    NS_ASSERTION(ev, "null event");

    // Pass control the real event handler
    if (ev)
        ev->HandleEvent();
}

void PR_CALLBACK
nsStreamObserverEvent::DestroyPLEvent(PLEvent *aEvent)
{
    nsStreamObserverEvent *ev = GET_STREAM_OBSERVER_EVENT(aEvent);
    NS_ASSERTION(ev, "null event");
    delete ev;
}

//
//----------------------------------------------------------------------------
// nsOnStartRequestEvent internal class...
//----------------------------------------------------------------------------
//
class nsOnStartRequestEvent : public nsStreamObserverEvent
{
public:
    nsOnStartRequestEvent(nsStreamProxyBase *aProxy,
                          nsIRequest *aRequest,
                          nsISupports *aContext)
        : nsStreamObserverEvent(aProxy, aRequest, aContext)
    {
        MOZ_COUNT_CTOR(nsOnStartRequestEvent);
    }

   ~nsOnStartRequestEvent()
    {
        MOZ_COUNT_DTOR(nsOnStartRequestEvent);
    }

    NS_IMETHOD HandleEvent();
};

NS_IMETHODIMP
nsOnStartRequestEvent::HandleEvent()
{
    LOG(("nsOnStartRequestEvent: HandleEvent [event=%x req=%x]\n",
        this, mRequest.get()));

    nsCOMPtr<nsIStreamObserver> observer = mProxy->GetReceiver();
    if (!observer) {
        LOG(("nsOnStartRequestEvent: Already called OnStopRequest (observer is NULL)\n"));
        return NS_ERROR_FAILURE;
    }

    nsresult rv = observer->OnStartRequest(mRequest, mContext);
    if (NS_FAILED(rv)) {
        LOG(("OnStartRequest failed [rv=%x] canceling request!\n", rv));
        mRequest->Cancel(rv);
    }
    return rv;
}

//
//----------------------------------------------------------------------------
// nsOnStopRequestEvent internal class...
//----------------------------------------------------------------------------
//
class nsOnStopRequestEvent : public nsStreamObserverEvent
{
public:
    nsOnStopRequestEvent(nsStreamProxyBase *aProxy,
                         nsIRequest *aRequest, nsISupports *aContext,
                         nsresult aStatus, const PRUnichar *aStatusText)
        : nsStreamObserverEvent(aProxy, aRequest, aContext)
        , mStatus(aStatus)
        , mStatusText(aStatusText)
    {
        MOZ_COUNT_CTOR(nsOnStopRequestEvent);
    }

   ~nsOnStopRequestEvent()
    {
        MOZ_COUNT_DTOR(nsOnStopRequestEvent);
    }
    
    NS_IMETHOD HandleEvent();

protected:
    nsresult mStatus;
    nsString mStatusText;
};

NS_IMETHODIMP
nsOnStopRequestEvent::HandleEvent()
{
    LOG(("nsOnStopRequestEvent: HandleEvent [event=%x req=%x]\n",
        this, mRequest.get()));

    nsCOMPtr<nsIStreamObserver> observer = mProxy->GetReceiver();
    if (!observer) {
        LOG(("nsOnStopRequestEvent: Already called OnStopRequest (observer is NULL)\n"));
        return NS_ERROR_FAILURE;
    }

    //
    // Do not allow any more events to be handled after OnStopRequest
    //
    mProxy->SetReceiver(nsnull);

    return observer->OnStopRequest(mRequest,
                                   mContext,
                                   mStatus,
                                   mStatusText.get());
}

//
//----------------------------------------------------------------------------
// nsStreamProxyBase: nsISupports implementation...
//----------------------------------------------------------------------------
//
NS_IMPL_THREADSAFE_ISUPPORTS1(nsStreamProxyBase,
                              nsIStreamObserver)

//
//----------------------------------------------------------------------------
// nsStreamProxyBase: nsIStreamObserver implementation...
//----------------------------------------------------------------------------
//
NS_IMETHODIMP 
nsStreamProxyBase::OnStartRequest(nsIRequest *aRequest,
                                  nsISupports *aContext)
{
    LOG(("nsStreamProxyBase: OnStartRequest [this=%x req=%x]\n", this, aRequest));
    nsOnStartRequestEvent *ev = 
        new nsOnStartRequestEvent(this, aRequest, aContext);
    if (!ev)
        return NS_ERROR_OUT_OF_MEMORY;

    nsresult rv = ev->FireEvent(GetEventQueue());
    if (NS_FAILED(rv))
        delete ev;
    return rv;
}

NS_IMETHODIMP 
nsStreamProxyBase::OnStopRequest(nsIRequest *aRequest,
                                 nsISupports *aContext,
                                 nsresult aStatus,
                                 const PRUnichar *aStatusText)
{
    LOG(("nsStreamProxyBase: OnStopRequest [this=%x req=%x status=%x]\n",
        this, aRequest, aStatus));
    nsOnStopRequestEvent *ev = 
        new nsOnStopRequestEvent(this, aRequest, aContext, aStatus, aStatusText);
    if (!ev)
        return NS_ERROR_OUT_OF_MEMORY;

    nsresult rv = ev->FireEvent(GetEventQueue());
    if (NS_FAILED(rv))
        delete ev;
    return rv;
}

//
//----------------------------------------------------------------------------
// nsStreamProxyBase: implementation...
//----------------------------------------------------------------------------
//
nsresult
nsStreamProxyBase::SetEventQueue(nsIEventQueue *aEventQ)
{
#if defined(PR_LOGGING)
    if (!gStreamProxyLog)
        gStreamProxyLog = PR_NewLogModule("nsStreamProxy");
#endif
    nsresult rv = NS_OK;
    if ((aEventQ == NS_CURRENT_EVENTQ) || (aEventQ == NS_UI_THREAD_EVENTQ)) {
        nsCOMPtr<nsIEventQueueService> serv =
                do_GetService(kEventQueueService, &rv);
        if (NS_FAILED(rv)) 
            return rv;
        rv = serv->GetSpecialEventQueue((PRInt32) aEventQ,
                getter_AddRefs(mEventQ));
    } else
        mEventQ = aEventQ;
    return rv;
}

//
//----------------------------------------------------------------------------
// nsStreamObserverProxy: nsISupports implementation...
//----------------------------------------------------------------------------
//
NS_IMPL_ISUPPORTS_INHERITED1(nsStreamObserverProxy,
                             nsStreamProxyBase,
                             nsIStreamObserverProxy)

//
//----------------------------------------------------------------------------
// nsStreamObserverProxy: nsIStreamObserverProxy implementation...
//----------------------------------------------------------------------------
//
NS_IMETHODIMP
nsStreamObserverProxy::Init(nsIStreamObserver *aObserver,
                            nsIEventQueue *aEventQ)
{
    NS_PRECONDITION(aObserver, "null observer");
    SetReceiver(aObserver);
    return SetEventQueue(aEventQ);
}