/*

 * Copyright (C) 2008, 2009 Google 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:

 *

 *     * Redistributions of source code must retain the above copyright

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

 *     * 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.

 *     * Neither the name of Google Inc. nor the names of its

 * contributors may be used to endorse or promote products derived from

 * this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "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 THE COPYRIGHT

 * OWNER 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 "V8Utilities.h"

#include <v8.h>

#include "Document.h"

#include "Frame.h"

#include "ScriptExecutionContext.h"

#include "ScriptState.h"

#include "V8Binding.h"

#include "V8Proxy.h"

#include "WorkerContext.h"

#include "WorkerContextExecutionProxy.h"

#include <wtf/Assertions.h>

#include "Frame.h"

namespace WebCore {

// Use an array to hold dependents. It works like a ref-counted scheme.

// A value can be added more than once to the DOM object.

void createHiddenDependency(v8::Handle<v8::Object> object, v8::Local<v8::Value> value, int cacheIndex)

{

    v8::Local<v8::Value> cache = object->GetInternalField(cacheIndex);

    if (cache->IsNull() || cache->IsUndefined()) {

        cache = v8::Array::New();

        object->SetInternalField(cacheIndex, cache);

    }

    v8::Local<v8::Array> cacheArray = v8::Local<v8::Array>::Cast(cache);

    cacheArray->Set(v8::Integer::New(cacheArray->Length()), value);

}

void removeHiddenDependency(v8::Handle<v8::Object> object, v8::Local<v8::Value> value, int cacheIndex)

{

    v8::Local<v8::Value> cache = object->GetInternalField(cacheIndex);

    if (!cache->IsArray())

        return;

    v8::Local<v8::Array> cacheArray = v8::Local<v8::Array>::Cast(cache);

    for (int i = cacheArray->Length() - 1; i >= 0; --i) {

        v8::Local<v8::Value> cached = cacheArray->Get(v8::Integer::New(i));

        if (cached->StrictEquals(value)) {

            cacheArray->Delete(i);

            return;

        }

    }

}

void transferHiddenDependency(v8::Handle<v8::Object> object,

                              EventListener* oldValue, 

                              v8::Local<v8::Value> newValue, 

                              int cacheIndex)

{

    if (oldValue) {

        V8AbstractEventListener* oldListener = V8AbstractEventListener::cast(oldValue);

        if (oldListener) {

            v8::Local<v8::Object> oldListenerObject = oldListener->getExistingListenerObject();

            if (!oldListenerObject.IsEmpty())

                removeHiddenDependency(object, oldListenerObject, cacheIndex);

        }

    }

    if (!newValue->IsNull() && !newValue->IsUndefined())

        createHiddenDependency(object, newValue, cacheIndex);

}

bool processingUserGesture()

{

    Frame* frame = V8Proxy::retrieveFrameForEnteredContext();

    return frame && frame->script()->processingUserGesture();

}

Frame* callingOrEnteredFrame()

{

    Frame* frame = V8Proxy::retrieveFrameForCallingContext();

    if (!frame) {

        // Unfortunately, when processing script from a plug-in, we might not

        // have a calling context.  In those cases, we fall back to the

        // entered context for security checks.

        // FIXME: We need a better API for retrieving frames that abstracts

        //        away this concern.

        frame = V8Proxy::retrieveFrameForEnteredContext();

    }

    return frame;

}

bool shouldAllowNavigation(Frame* frame)

{

    Frame* callingOrEntered = callingOrEnteredFrame();

    return callingOrEntered && callingOrEntered->loader()->shouldAllowNavigation(frame);

}

KURL completeURL(const String& relativeURL)

{

    // For histoical reasons, we need to complete the URL using the dynamic frame.

    Frame* frame = V8Proxy::retrieveFrameForEnteredContext();

    if (!frame)

        return KURL();

    return frame->loader()->completeURL(relativeURL);

}

void navigateIfAllowed(Frame* frame, const KURL& url, bool lockHistory, bool lockBackForwardList)

{

    Frame* callingOrEntered = callingOrEnteredFrame();

    if (!callingOrEntered)

        return;

    if (!protocolIsJavaScript(url) || ScriptController::isSafeScript(frame))

        frame->redirectScheduler()->scheduleLocationChange(url.string(), callingOrEntered->loader()->outgoingReferrer(), lockHistory, lockBackForwardList, processingUserGesture());

}

ScriptExecutionContext* getScriptExecutionContext()

{

#if ENABLE(WORKERS)

    if (WorkerScriptController* controller = WorkerScriptController::controllerForContext())

        return controller->workerContext();

#endif

    if (Frame* frame = V8Proxy::retrieveFrameForCurrentContext())

        return frame->document()->scriptExecutionContext();

    return 0;

}

} // namespace WebCore