/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * 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 Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s): 
 *   Pierre Phaneuf <pp@ludusdesign.com>
 */

#include "MyService.h"
#include "nsIServiceManager.h"
#include <stdio.h>
#include "nsIFactory.h"

////////////////////////////////////////////////////////////////////////////////

class MyService : public IMyService {
public:

    NS_IMETHOD
    Doit(void);

    MyService(nsISupports* outer);
    virtual ~MyService(void);

    NS_DECL_ISUPPORTS

};

////////////////////////////////////////////////////////////////////////////////

class MyServiceFactory : public nsIFactory {
public:

    NS_DECL_ISUPPORTS

    // nsIFactory methods:

    NS_IMETHOD CreateInstance(nsISupports *aOuter,
                              REFNSIID aIID,
                              void **aResult);

    NS_IMETHOD LockFactory(PRBool aLock);

    // MyService methods:

    MyServiceFactory(void);
    virtual ~MyServiceFactory(void);

    PRBool CanUnload(void) { return mOutstandingInstances == 0; }

    friend class MyService;

protected:
    PRBool      mStarted;
    PRUint32    mOutstandingInstances;
};

MyServiceFactory* gFact = NULL;

////////////////////////////////////////////////////////////////////////////////
// MyService Implementation

NS_IMPL_ISUPPORTS(MyService, NS_GET_IID(IMyService));

MyService::MyService(nsISupports* outer)
{
    NS_INIT_REFCNT();
    // incrementing this will keep our factory from getting unloaded
    gFact->mOutstandingInstances++;
    printf("  creating my service\n");
}

MyService::~MyService(void)
{
    // decrementing this will allow our factory to get unloaded
    --gFact->mOutstandingInstances;
    printf("  destroying my service\n");
}

nsresult
MyService::Doit(void)
{
    printf("    invoking my service\n");
    return NS_OK;
}

////////////////////////////////////////////////////////////////////////////////
// MyServiceFactory Implementation

NS_IMPL_ISUPPORTS(MyServiceFactory, NS_GET_IID(nsIFactory));

MyServiceFactory::MyServiceFactory(void)
    : mStarted(PR_FALSE), mOutstandingInstances(0)
{
    NS_INIT_REFCNT();
    printf("initializing my service factory\n");
}

MyServiceFactory::~MyServiceFactory(void)
{
    NS_ASSERTION(mOutstandingInstances == 0, "unloading factory when there are still instances");
    printf("finalizing my service factory\n");
}

nsresult
MyServiceFactory::CreateInstance(nsISupports *aOuter, REFNSIID aIID, void **aResult)
{
    MyService* serv = new MyService(aOuter);
    if (serv == NULL)
        return NS_ERROR_OUT_OF_MEMORY;
    return serv->QueryInterface(aIID, aResult);
}

nsresult
MyServiceFactory::LockFactory(PRBool aLock)
{
    mOutstandingInstances += aLock ? 1 : -1;
    return NS_OK;
}

////////////////////////////////////////////////////////////////////////////////
// DLL Entry Points:

static NS_DEFINE_CID(kIMyServiceCID, NS_IMYSERVICE_CID);

extern "C" NS_EXPORT nsresult
NSGetFactory(nsISupports* serviceMgr,
             const nsCID &aClass,
             const char *aClassName,
             const char *aProgID,
             nsIFactory **aFactory)
{
    if (!aClass.Equals(kIMyServiceCID))
        return NS_ERROR_FACTORY_NOT_REGISTERED;
    if (gFact == NULL) {
        printf("loading my service factory\n");
        gFact = new MyServiceFactory();
        if (gFact == NULL)
            return NS_ERROR_OUT_OF_MEMORY;
        gFact->AddRef();    // one for our global
    }
    gFact->AddRef();        // one for the client
    *aFactory = gFact;
    return NS_OK;
}

extern "C" NS_EXPORT PRBool
NSCanUnload(nsISupports* serviceMgr)
{
    if (gFact && gFact->CanUnload()) {
        nsrefcnt cnt = gFact->Release();
        NS_ASSERTION(cnt == 0, "can't release service factory");
        gFact = NULL;
        printf("unloading my service factory\n");
        return PR_TRUE;
    }
    return PR_FALSE;
}

////////////////////////////////////////////////////////////////////////////////