/*
 * Copyright (C) 2012 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.
 *     * 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.
 */

#ifndef ElementShadow_h
#define ElementShadow_h

#include "ContentDistributor.h"
#include "ExceptionCode.h"
#include "SelectRuleFeatureSet.h"
#include "ShadowRoot.h"
#include <wtf/DoublyLinkedList.h>
#include <wtf/Noncopyable.h>
#include <wtf/OwnPtr.h>
#include <wtf/PassRefPtr.h>
#include <wtf/Vector.h>

namespace WebCore {

class Node;
class Element;
class TreeScope;

class ElementShadow {
   WTF_MAKE_NONCOPYABLE(ElementShadow); WTF_MAKE_FAST_ALLOCATED;
public:
    ElementShadow();
    ~ElementShadow();

    Element* host() const;
    ShadowRoot* youngestShadowRoot() const;
    ShadowRoot* oldestShadowRoot() const;

    void removeAllShadowRoots();
    void addShadowRoot(Element* shadowHost, PassRefPtr<ShadowRoot>, ShadowRoot::ShadowRootType, ExceptionCode&);

    void attach();
    void detach();

    bool childNeedsStyleRecalc();
    bool needsStyleRecalc();
    void recalcStyle(Node::StyleChange);

    void setValidityUndetermined();
    void invalidateDistribution();
    void ensureDistribution();
    void ensureDistributionFromDocument();

    ContentDistributor& distributor();
    const ContentDistributor& distributor() const;

    bool shouldCollectSelectFeatureSet() const { return m_shouldCollectSelectFeatureSet; }
    void setShouldCollectSelectFeatureSet();
    void ensureSelectFeatureSetCollected();

    const SelectRuleFeatureSet& selectRuleFeatureSet() const;

    void reportMemoryUsage(MemoryObjectInfo*) const;

private:
    void invalidateDistribution(Element* host);

    void collectSelectFeatureSetFrom(ShadowRoot*);

    DoublyLinkedList<ShadowRoot> m_shadowRoots;
    ContentDistributor m_distributor;
    SelectRuleFeatureSet m_selectFeatures;
    bool m_shouldCollectSelectFeatureSet : 1;
};

void invalidateParentDistributionIfNecessary(Element*, SelectRuleFeatureSet::SelectRuleFeatureMask updatedFeatures);

inline ShadowRoot* ElementShadow::youngestShadowRoot() const
{
    return m_shadowRoots.head();
}

inline ShadowRoot* ElementShadow::oldestShadowRoot() const
{
    return m_shadowRoots.tail();
}

inline ContentDistributor& ElementShadow::distributor()
{
    return m_distributor;
}

inline const ContentDistributor& ElementShadow::distributor() const
{
    return m_distributor;
}

inline Element* ElementShadow::host() const
{
    ASSERT(!m_shadowRoots.isEmpty());
    return youngestShadowRoot()->host();
}

inline const SelectRuleFeatureSet& ElementShadow::selectRuleFeatureSet() const
{
    ASSERT(!m_shouldCollectSelectFeatureSet);
    return m_selectFeatures;
}

inline ShadowRoot* Node::youngestShadowRoot() const
{
    if (!this->isElementNode())
        return 0;
    if (ElementShadow* shadow = toElement(this)->shadow())
        return shadow->youngestShadowRoot();
    return 0;
}

class ShadowRootVector : public Vector<RefPtr<ShadowRoot> > {
public:
    explicit ShadowRootVector(ElementShadow* tree)
    {
        for (ShadowRoot* root = tree->youngestShadowRoot(); root; root = root->olderShadowRoot())
            append(root);
    }
};

} // namespace

#endif