/*

 * Copyright (C) 2006, 2007 Apple Inc.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#include "config.h"

#include "WebKitDLL.h"

#include "WebNotificationCenter.h"

#include "WebNotification.h"

#pragma warning( push, 0 )

#include <WebCore/StringImpl.h>

#include <wtf/HashMap.h>

#include <wtf/HashTraits.h>

#pragma warning(pop)

#include <tchar.h>

using namespace WebCore;

// ----------------------------------------------------------------------------

struct ObserverHash;

class ObserverKey

{

    friend ObserverHash;

public:

    ObserverKey(BSTR n = 0, IUnknown* o = 0);

    ObserverKey(const ObserverKey& key);

    ~ObserverKey();

    bool operator==(const ObserverKey &) const;

    ObserverKey& operator=(const ObserverKey &);

private:

    BSTR m_notificationName;

    IUnknown* m_anObject;

};

ObserverKey::ObserverKey(BSTR n, IUnknown* o)

: m_notificationName(0)

, m_anObject(o)

{

    if (n == (BSTR)-1)

        m_notificationName = n;

    else if (n)

        m_notificationName = SysAllocString(n);

    if (o)

       o->AddRef();

}

ObserverKey::ObserverKey(const ObserverKey& other)

: m_notificationName(0)

, m_anObject(0)

{

    *this = other;

}

ObserverKey::~ObserverKey()

{

    if (m_notificationName && m_notificationName != (BSTR)-1)

        SysFreeString(m_notificationName);

    if (m_anObject)

        m_anObject->Release();

}

bool ObserverKey::operator==(const ObserverKey &other) const

{

    if (m_anObject && other.m_anObject && m_anObject != other.m_anObject)

        return false; // only fail to match anObject if both are non-null (treat null as a wildcard)

    if (m_notificationName == other.m_notificationName)

        return true;

    if (!m_notificationName || m_notificationName == (BSTR)-1 || !other.m_notificationName || other.m_notificationName == (BSTR)-1)

        return false;

    return !_tcscmp(m_notificationName, other.m_notificationName);

}

ObserverKey& ObserverKey::operator=(const ObserverKey& other)

{

    if (m_notificationName && m_notificationName != (BSTR)-1)

        SysFreeString(m_notificationName);

    m_notificationName = other.m_notificationName;

    if (m_notificationName && m_notificationName != (BSTR)-1)

        m_notificationName = SysAllocString(m_notificationName);

    if (m_anObject != other.m_anObject) {

        if (m_anObject)

            m_anObject->Release();

        m_anObject = other.m_anObject;

        if (m_anObject)

            m_anObject->AddRef();

    }

    return *this;

}

struct ObserverKeyTraits : WTF::GenericHashTraits<ObserverKey> {

    static const bool emptyValueIsZero = true;

    static const bool needsDestruction = true;

    static ObserverKey deletedValue() { return ObserverKey((BSTR)-1, 0); }

};

struct ObserverHash {

    static unsigned hash(const ObserverKey&);

    static bool equal(const ObserverKey& a, const ObserverKey& b) { return a == b; }

};

unsigned ObserverHash::hash(const ObserverKey& key)

{

    unsigned h = 0;

    if (key.m_notificationName) {

        if (key.m_notificationName == (BSTR)-1)

            h = (unsigned)-1;

        else

            h = StringImpl::computeHash(key.m_notificationName, SysStringLen(key.m_notificationName));

    }

    // DO NOT take m_anObject into account for the hash.  We need to match based on m_notificationName only.

    // We ensure a match in operator== if both of the values are non-null.  This matches semantics of

    // NSNotificationCenter.

    return h;

}

typedef HashMap<ObserverKey, Vector<IWebNotificationObserver*>, ObserverHash, ObserverKeyTraits> MappedObservers;

struct WebNotificationCenterPrivate

{

    MappedObservers m_mappedObservers;

};

// WebNotificationCenter ----------------------------------------------------------------

IWebNotificationCenter* WebNotificationCenter::m_defaultCenter = 0;

WebNotificationCenter::WebNotificationCenter()

: m_refCount(0)

, d(new WebNotificationCenterPrivate)

{

    gClassCount++;

}

WebNotificationCenter::~WebNotificationCenter()

{

    delete d;

    gClassCount--;

}

WebNotificationCenter* WebNotificationCenter::createInstance()

{

    WebNotificationCenter* instance = new WebNotificationCenter();

    instance->AddRef();

    return instance;

}

// IUnknown -------------------------------------------------------------------

HRESULT STDMETHODCALLTYPE WebNotificationCenter::QueryInterface(REFIID riid, void** ppvObject)

{

    *ppvObject = 0;

    if (IsEqualGUID(riid, IID_IUnknown))

        *ppvObject = static_cast<IWebNotificationCenter*>(this);

    else if (IsEqualGUID(riid, IID_IWebNotificationCenter))

        *ppvObject = static_cast<IWebNotificationCenter*>(this);

    else

        return E_NOINTERFACE;

    AddRef();

    return S_OK;

}

ULONG STDMETHODCALLTYPE WebNotificationCenter::AddRef(void)

{

    return ++m_refCount;

}

ULONG STDMETHODCALLTYPE WebNotificationCenter::Release(void)

{

    ULONG newRef = --m_refCount;

    if (!newRef)

        delete(this);

    return newRef;

}

IWebNotificationCenter* WebNotificationCenter::defaultCenterInternal()

{

    if (!m_defaultCenter)

        m_defaultCenter = WebNotificationCenter::createInstance();

    return m_defaultCenter;

}

void WebNotificationCenter::postNotificationInternal(IWebNotification* notification, BSTR notificationName, IUnknown* anObject)

{

    ObserverKey key(notificationName, anObject);

    MappedObservers::iterator it = d->m_mappedObservers.find(key);

    if (it != d->m_mappedObservers.end()) {

        Vector<IWebNotificationObserver*> list = it->second;

        Vector<IWebNotificationObserver*>::iterator end = list.end();

        for (Vector<IWebNotificationObserver*>::iterator it2 = list.begin(); it2 != end; ++it2) {

            (*it2)->onNotify(notification);

        }

    }

}

// IWebNotificationCenter -----------------------------------------------------

HRESULT STDMETHODCALLTYPE WebNotificationCenter::defaultCenter( 

    /* [retval][out] */ IWebNotificationCenter** center)

{

    *center = defaultCenterInternal();

    (*center)->AddRef();

    return S_OK;

}

HRESULT STDMETHODCALLTYPE WebNotificationCenter::addObserver( 

    /* [in] */ IWebNotificationObserver* observer,

    /* [in] */ BSTR notificationName,

    /* [in] */ IUnknown* anObject)

{

    ObserverKey key(notificationName, anObject);

    MappedObservers::iterator it = d->m_mappedObservers.find(key);

    observer->AddRef();

    if (it != d->m_mappedObservers.end())

        it->second.append(observer);

    else {

        Vector<IWebNotificationObserver*> list;

        list.append(observer);

        d->m_mappedObservers.add(key, list);

    }

    return S_OK;

}

HRESULT STDMETHODCALLTYPE WebNotificationCenter::postNotification( 

    /* [in] */ IWebNotification* notification)

{

    BSTR name;

    HRESULT hr = notification->name(&name);

    if (SUCCEEDED(hr)) {

        IUnknown* obj;

        hr = notification->getObject(&obj);

        if (SUCCEEDED(hr)) {

            postNotificationInternal(notification, name, obj);

            if (obj)

                obj->Release();

        }

        SysFreeString(name);

    }

    return hr;

}

HRESULT STDMETHODCALLTYPE WebNotificationCenter::postNotificationName( 

    /* [in] */ BSTR notificationName,

    /* [in] */ IUnknown* anObject,

    /* [optional][in] */ IPropertyBag* userInfo)

{

    WebNotification* notification = WebNotification::createInstance(notificationName, anObject, userInfo);

    postNotificationInternal(notification, notificationName, anObject);

    notification->Release();

    return S_OK;

}

HRESULT STDMETHODCALLTYPE WebNotificationCenter::removeObserver( 

    /* [in] */ IWebNotificationObserver* anObserver,

    /* [in] */ BSTR notificationName,

    /* [optional][in] */ IUnknown* anObject)

{

    ObserverKey key(notificationName, anObject);

    MappedObservers::iterator it = d->m_mappedObservers.find(key);

    if (it == d->m_mappedObservers.end())

        return E_FAIL;

    Vector<IWebNotificationObserver*>& observerList = it->second;

    Vector<IWebNotificationObserver*>::iterator end = observerList.end();

    int i=0;

    for (Vector<IWebNotificationObserver*>::iterator it2 = observerList.begin(); it2 != end; ++it2, i++) {

        if (*it2 == anObserver) {

            (*it2)->Release();

            observerList.remove(i);

            break;

        }

    }

    if (observerList.isEmpty())

        d->m_mappedObservers.remove(key);

    return S_OK;

}