/*

 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)

 * Copyright (C) 2000 Frederik Holljen (frederik.holljen@hig.no)

 * Copyright (C) 2001 Peter Kelly (pmk@post.com)

 * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)

 * Copyright (C) 2004, 2008 Apple Inc. All rights reserved.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public License

 * along with this library; see the file COPYING.LIB.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 *

 */

#include "config.h"

#include "TreeWalker.h"

#include "ExceptionCode.h"

#include "ContainerNode.h"

#include "NodeFilter.h"

#include "ScriptState.h"

#include <wtf/PassRefPtr.h>

namespace WebCore {

TreeWalker::TreeWalker(PassRefPtr<Node> rootNode, unsigned whatToShow, PassRefPtr<NodeFilter> filter, bool expandEntityReferences)

    : Traversal(rootNode, whatToShow, filter, expandEntityReferences)

    , m_current(root())

{

}

void TreeWalker::setCurrentNode(PassRefPtr<Node> node, ExceptionCode& ec)

{

    if (!node) {

        ec = NOT_SUPPORTED_ERR;

        return;

    }

    m_current = node;

}

inline Node* TreeWalker::setCurrent(PassRefPtr<Node> node)

{

    m_current = node;

    return m_current.get();

}

Node* TreeWalker::parentNode(ScriptState* state)

{

    RefPtr<Node> node = m_current;

    while (node != root()) {

        node = node->parentNode();

        if (!node)

            return 0;

        short acceptNodeResult = acceptNode(state, node.get());

        if (state && state->hadException())

            return 0;

        if (acceptNodeResult == NodeFilter::FILTER_ACCEPT)

            return setCurrent(node.release());

    }

    return 0;

}

Node* TreeWalker::firstChild(ScriptState* state)

{

    for (RefPtr<Node> node = m_current->firstChild(); node; ) {

        short acceptNodeResult = acceptNode(state, node.get());

        if (state && state->hadException())

            return 0;

        switch (acceptNodeResult) {

            case NodeFilter::FILTER_ACCEPT:

                m_current = node.release();

                return m_current.get();

            case NodeFilter::FILTER_SKIP:

                if (node->firstChild()) {

                    node = node->firstChild();

                    continue;

                }

                break;

            case NodeFilter::FILTER_REJECT:

                break;

        }

        do {

            if (node->nextSibling()) {

                node = node->nextSibling();

                break;

            }

            Node* parent = node->parentNode();

            if (!parent || parent == root() || parent == m_current)

                return 0;

            node = parent;

        } while (node);

    }

    return 0;

}

Node* TreeWalker::lastChild(ScriptState* state)

{

    for (RefPtr<Node> node = m_current->lastChild(); node; ) {

        short acceptNodeResult = acceptNode(state, node.get());

        if (state && state->hadException())

            return 0;

        switch (acceptNodeResult) {

            case NodeFilter::FILTER_ACCEPT:

                m_current = node.release();

                return m_current.get();

            case NodeFilter::FILTER_SKIP:

                if (node->lastChild()) {

                    node = node->lastChild();

                    continue;

                }

                break;

            case NodeFilter::FILTER_REJECT:

                break;

        }

        do {

            if (node->previousSibling()) {

                node = node->previousSibling();

                break;

            }

            Node* parent = node->parentNode();

            if (!parent || parent == root() || parent == m_current)

                return 0;

            node = parent;

        } while (node);

    }

    return 0;

}

Node* TreeWalker::previousSibling(ScriptState* state)

{

    RefPtr<Node> node = m_current;

    if (node == root())

        return 0;

    while (1) {

        for (RefPtr<Node> sibling = node->previousSibling(); sibling; ) {

            short acceptNodeResult = acceptNode(state, sibling.get());

            if (state && state->hadException())

                return 0;

            switch (acceptNodeResult) {

                case NodeFilter::FILTER_ACCEPT:

                    m_current = sibling.release();

                    return m_current.get();

                case NodeFilter::FILTER_SKIP:

                    if (sibling->lastChild()) {

                        sibling = sibling->lastChild();

                        continue;

                    }

                    break;

                case NodeFilter::FILTER_REJECT:

                    break;

            }

            sibling = sibling->previousSibling();

        }

        node = node->parentNode();

        if (!node || node == root())

            return 0;

        short acceptNodeResult = acceptNode(state, node.get());

        if (state && state->hadException())

            return 0;

        if (acceptNodeResult == NodeFilter::FILTER_ACCEPT)

            return 0;

    }

}

Node* TreeWalker::nextSibling(ScriptState* state)

{

    RefPtr<Node> node = m_current;

    if (node == root())

        return 0;

    while (1) {

        for (RefPtr<Node> sibling = node->nextSibling(); sibling; ) {

            short acceptNodeResult = acceptNode(state, sibling.get());

            if (state && state->hadException())

                return 0;

            switch (acceptNodeResult) {

                case NodeFilter::FILTER_ACCEPT:

                    m_current = sibling.release();

                    return m_current.get();

                case NodeFilter::FILTER_SKIP:

                    if (sibling->firstChild()) {

                        sibling = sibling->firstChild();

                        continue;

                    }

                    break;

                case NodeFilter::FILTER_REJECT:

                    break;

            }

            sibling = sibling->nextSibling();

        }

        node = node->parentNode();

        if (!node || node == root())

            return 0;

        short acceptNodeResult = acceptNode(state, node.get());

        if (state && state->hadException())

            return 0;

        if (acceptNodeResult == NodeFilter::FILTER_ACCEPT)

            return 0;

    }

}

Node* TreeWalker::previousNode(ScriptState* state)

{

    RefPtr<Node> node = m_current;

    while (node != root()) {

        while (Node* previousSibling = node->previousSibling()) {

            node = previousSibling;

            short acceptNodeResult = acceptNode(state, node.get());

            if (state && state->hadException())

                return 0;

            if (acceptNodeResult == NodeFilter::FILTER_REJECT)

                continue;

            while (Node* lastChild = node->lastChild()) {

                node = lastChild;

                acceptNodeResult = acceptNode(state, node.get());

                if (state && state->hadException())

                    return 0;

                if (acceptNodeResult == NodeFilter::FILTER_REJECT)

                    break;

            }

            if (acceptNodeResult == NodeFilter::FILTER_ACCEPT) {

                m_current = node.release();

                return m_current.get();

            }

        }

        if (node == root())

            return 0;

        Node* parent = node->parentNode();

        if (!parent)

            return 0;

        node = parent;

        short acceptNodeResult = acceptNode(state, node.get());

        if (state && state->hadException())

            return 0;

        if (acceptNodeResult == NodeFilter::FILTER_ACCEPT)

            return setCurrent(node.release());

    }

    return 0;

}

Node* TreeWalker::nextNode(ScriptState* state)

{

    RefPtr<Node> node = m_current;

Children:

    while (Node* firstChild = node->firstChild()) {

        node = firstChild;

        short acceptNodeResult = acceptNode(state, node.get());

        if (state && state->hadException())

            return 0;

        if (acceptNodeResult == NodeFilter::FILTER_ACCEPT)

            return setCurrent(node.release());

        if (acceptNodeResult == NodeFilter::FILTER_REJECT)

            break;

    }

    while (Node* nextSibling = node->traverseNextSibling(root())) {

        node = nextSibling;

        short acceptNodeResult = acceptNode(state, node.get());

        if (state && state->hadException())

            return 0;

        if (acceptNodeResult == NodeFilter::FILTER_ACCEPT)

            return setCurrent(node.release());

        if (acceptNodeResult == NodeFilter::FILTER_SKIP)

            goto Children;

    }

    return 0;

}

} // namespace WebCore