/*
 * Copyright (C) 2011 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.
 */

#include "config.h"
#include "ShadowRoot.h"
#include "Element.h"

#include "Document.h"
#include "NodeRareData.h"
#include "ShadowContentElement.h"
#include "ShadowInclusionSelector.h"
#include "Text.h"

namespace WebCore {

ShadowRoot::ShadowRoot(Document* document)
    : TreeScope(document, CreateShadowRoot)
    , m_applyAuthorSheets(false)
{
    ASSERT(document);
    
    // Assume document as parent scope.
    setParentTreeScope(document);
    // Shadow tree scopes have the scope pointer point to themselves.
    // This way, direct children will receive the correct scope pointer.
    ensureRareData()->setTreeScope(this);
}

ShadowRoot::~ShadowRoot()
{
}

String ShadowRoot::nodeName() const
{
    return "#shadow-root";
}

Node::NodeType ShadowRoot::nodeType() const
{
    return SHADOW_ROOT_NODE;
}

PassRefPtr<Node> ShadowRoot::cloneNode(bool)
{
    // ShadowRoot should not be arbitrarily cloned.
    return 0;
}

bool ShadowRoot::childTypeAllowed(NodeType type) const
{
    switch (type) {
    case ELEMENT_NODE:
    case PROCESSING_INSTRUCTION_NODE:
    case COMMENT_NODE:
    case TEXT_NODE:
    case CDATA_SECTION_NODE:
    case ENTITY_REFERENCE_NODE:
        return true;
    default:
        return false;
    }
}

void ShadowRoot::recalcShadowTreeStyle(StyleChange change)
{
    if (hasContentElement())
        reattach();
    else {
        for (Node* n = firstChild(); n; n = n->nextSibling()) {
            if (n->isElementNode())
                static_cast<Element*>(n)->recalcStyle(change);
            else if (n->isTextNode())
                static_cast<Text*>(n)->recalcTextStyle(change);
        }
    }

    clearNeedsStyleRecalc();
    clearChildNeedsStyleRecalc();
}

ShadowContentElement* ShadowRoot::includerFor(Node* node) const
{
    if (!m_inclusions)
        return 0;
    ShadowInclusion* found = m_inclusions->findFor(node);
    if (!found)
        return 0;
    return found->includer();
}

void ShadowRoot::hostChildrenChanged()
{
    if (!hasContentElement())
        return;
    // This results in forced detaching/attaching of the shadow render tree. See ShadowRoot::recalcStyle().
    setNeedsStyleRecalc();
}

bool ShadowRoot::isInclusionSelectorActive() const
{
    return m_inclusions && m_inclusions->hasCandidates();
}

bool ShadowRoot::hasContentElement() const
{
    for (Node* n = firstChild(); n; n = n->traverseNextNode(this)) {
        if (n->isContentElement())
            return true;
    }

    return false;
}

bool ShadowRoot::applyAuthorSheets() const
{
    return m_applyAuthorSheets;
}

void ShadowRoot::setApplyAuthorSheets(bool value)
{
    m_applyAuthorSheets = value;
}

void ShadowRoot::attach()
{
    // Children of m_inclusions is populated lazily in
    // ensureInclusions(), and here we just ensure that
    // it is in clean state.
    ASSERT(!m_inclusions || !m_inclusions->hasCandidates());
    TreeScope::attach();
    if (m_inclusions)
        m_inclusions->didSelect();
}

ShadowInclusionSelector* ShadowRoot::inclusions() const
{
    return m_inclusions.get();
}

ShadowInclusionSelector* ShadowRoot::ensureInclusions()
{
    if (!m_inclusions)
        m_inclusions = adoptPtr(new ShadowInclusionSelector());
    m_inclusions->willSelectOver(this);
    return m_inclusions.get();
}


}