/*
 * Copyright (C) 2006, 2008, 2011 Apple Inc. All rights reserved.
 * Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies)
 *
 * 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 "HitTestResult.h"

#include "CachedImage.h"
#include "DocumentMarkerController.h"
#include "Editor.h"
#include "Frame.h"
#include "FrameSelection.h"
#include "FrameTree.h"
#include "HTMLAnchorElement.h"
#include "HTMLAreaElement.h"
#include "HTMLAudioElement.h"
#include "HTMLImageElement.h"
#include "HTMLInputElement.h"
#include "HTMLMediaElement.h"
#include "HTMLNames.h"
#include "HTMLParserIdioms.h"
#include "HTMLPlugInImageElement.h"
#include "HTMLTextAreaElement.h"
#include "HTMLVideoElement.h"
#include "HitTestLocation.h"
#include "RenderBlock.h"
#include "RenderImage.h"
#include "RenderInline.h"
#include "Scrollbar.h"
#include "UserGestureIndicator.h"

#if ENABLE(SVG)
#include "SVGImageElement.h"
#include "SVGNames.h"
#include "XLinkNames.h"
#endif

namespace WebCore {

using namespace HTMLNames;

HitTestResult::HitTestResult()
    : m_isOverWidget(false)
{
}

HitTestResult::HitTestResult(const LayoutPoint& point)
    : m_hitTestLocation(point)
    , m_pointInInnerNodeFrame(point)
    , m_isOverWidget(false)
{
}

HitTestResult::HitTestResult(const LayoutPoint& centerPoint, unsigned topPadding, unsigned rightPadding, unsigned bottomPadding, unsigned leftPadding)
    : m_hitTestLocation(centerPoint, topPadding, rightPadding, bottomPadding, leftPadding)
    , m_pointInInnerNodeFrame(centerPoint)
    , m_isOverWidget(false)
{
}

HitTestResult::HitTestResult(const HitTestLocation& other)
    : m_hitTestLocation(other)
    , m_pointInInnerNodeFrame(m_hitTestLocation.point())
    , m_isOverWidget(false)
{
}

HitTestResult::HitTestResult(const HitTestResult& other)
    : m_hitTestLocation(other.m_hitTestLocation)
    , m_innerNode(other.innerNode())
    , m_innerNonSharedNode(other.innerNonSharedNode())
    , m_pointInInnerNodeFrame(other.m_pointInInnerNodeFrame)
    , m_localPoint(other.localPoint())
    , m_innerURLElement(other.URLElement())
    , m_scrollbar(other.scrollbar())
    , m_isOverWidget(other.isOverWidget())
{
    // Only copy the NodeSet in case of rect hit test.
    m_rectBasedTestResult = adoptPtr(other.m_rectBasedTestResult ? new NodeSet(*other.m_rectBasedTestResult) : 0);
}

HitTestResult::~HitTestResult()
{
}

HitTestResult& HitTestResult::operator=(const HitTestResult& other)
{
    m_hitTestLocation = other.m_hitTestLocation;
    m_innerNode = other.innerNode();
    m_innerNonSharedNode = other.innerNonSharedNode();
    m_pointInInnerNodeFrame = other.m_pointInInnerNodeFrame;
    m_localPoint = other.localPoint();
    m_innerURLElement = other.URLElement();
    m_scrollbar = other.scrollbar();
    m_isOverWidget = other.isOverWidget();

    // Only copy the NodeSet in case of rect hit test.
    m_rectBasedTestResult = adoptPtr(other.m_rectBasedTestResult ? new NodeSet(*other.m_rectBasedTestResult) : 0);

    return *this;
}

void HitTestResult::setToNonShadowAncestor()
{
    Node* node = innerNode();
    if (node)
        node = node->document()->ancestorInThisScope(node);
    setInnerNode(node);
    node = innerNonSharedNode();
    if (node)
        node = node->document()->ancestorInThisScope(node);
    setInnerNonSharedNode(node);
}

void HitTestResult::setInnerNode(Node* n)
{
    if (n && n->isPseudoElement())
        n = n->parentOrShadowHostNode();
    m_innerNode = n;
}
    
void HitTestResult::setInnerNonSharedNode(Node* n)
{
    if (n && n->isPseudoElement())
        n = n->parentOrShadowHostNode();
    m_innerNonSharedNode = n;
}

void HitTestResult::setURLElement(Element* n) 
{ 
    m_innerURLElement = n; 
}

void HitTestResult::setScrollbar(Scrollbar* s)
{
    m_scrollbar = s;
}

Frame* HitTestResult::innerNodeFrame() const
{
    if (m_innerNonSharedNode)
        return m_innerNonSharedNode->document()->frame();
    if (m_innerNode)
        return m_innerNode->document()->frame();
    return 0;
}

Frame* HitTestResult::targetFrame() const
{
    if (!m_innerURLElement)
        return 0;

    Frame* frame = m_innerURLElement->document()->frame();
    if (!frame)
        return 0;

    return frame->tree()->find(m_innerURLElement->target());
}

bool HitTestResult::isSelected() const
{
    if (!m_innerNonSharedNode)
        return false;

    Frame* frame = m_innerNonSharedNode->document()->frame();
    if (!frame)
        return false;

    return frame->selection()->contains(m_hitTestLocation.point());
}

String HitTestResult::spellingToolTip(TextDirection& dir) const
{
    dir = LTR;
    // Return the tool tip string associated with this point, if any. Only markers associated with bad grammar
    // currently supply strings, but maybe someday markers associated with misspelled words will also.
    if (!m_innerNonSharedNode)
        return String();
    
    DocumentMarker* marker = m_innerNonSharedNode->document()->markers()->markerContainingPoint(m_hitTestLocation.point(), DocumentMarker::Grammar);
    if (!marker)
        return String();

    if (RenderObject* renderer = m_innerNonSharedNode->renderer())
        dir = renderer->style()->direction();
    return marker->description();
}

String HitTestResult::replacedString() const
{
    // Return the replaced string associated with this point, if any. This marker is created when a string is autocorrected, 
    // and is used for generating a contextual menu item that allows it to easily be changed back if desired.
    if (!m_innerNonSharedNode)
        return String();
    
    DocumentMarker* marker = m_innerNonSharedNode->document()->markers()->markerContainingPoint(m_hitTestLocation.point(), DocumentMarker::Replacement);
    if (!marker)
        return String();
    
    return marker->description();
}    
    
String HitTestResult::title(TextDirection& dir) const
{
    dir = LTR;
    // Find the title in the nearest enclosing DOM node.
    // For <area> tags in image maps, walk the tree for the <area>, not the <img> using it.
    for (Node* titleNode = m_innerNode.get(); titleNode; titleNode = titleNode->parentNode()) {
        if (titleNode->isElementNode()) {
            String title = toElement(titleNode)->title();
            if (!title.isEmpty()) {
                if (RenderObject* renderer = titleNode->renderer())
                    dir = renderer->style()->direction();
                return title;
            }
        }
    }
    return String();
}

String HitTestResult::innerTextIfTruncated(TextDirection& dir) const
{
    for (Node* truncatedNode = m_innerNode.get(); truncatedNode; truncatedNode = truncatedNode->parentNode()) {
        if (!truncatedNode->isElementNode())
            continue;

        if (RenderObject* renderer = truncatedNode->renderer()) {
            if (renderer->isRenderBlock()) {
                RenderBlock* block = toRenderBlock(renderer);
                if (block->style()->textOverflow()) {
                    for (RootInlineBox* line = block->firstRootBox(); line; line = line->nextRootBox()) {
                        if (line->hasEllipsisBox()) {
                            dir = block->style()->direction();
                            return toElement(truncatedNode)->innerText();
                        }
                    }
                }
                break;
            }
        }
    }

    dir = LTR;
    return String();
}

String displayString(const String& string, const Node* node)
{
    if (!node)
        return string;
    return node->document()->displayStringModifiedByEncoding(string);
}

String HitTestResult::altDisplayString() const
{
    if (!m_innerNonSharedNode)
        return String();
    
    if (isHTMLImageElement(m_innerNonSharedNode.get())) {
        HTMLImageElement* image = toHTMLImageElement(m_innerNonSharedNode.get());
        return displayString(image->getAttribute(altAttr), m_innerNonSharedNode.get());
    }
    
    if (isHTMLInputElement(m_innerNonSharedNode.get())) {
        HTMLInputElement* input = toHTMLInputElement(m_innerNonSharedNode.get());
        return displayString(input->alt(), m_innerNonSharedNode.get());
    }

    return String();
}

Image* HitTestResult::image() const
{
    if (!m_innerNonSharedNode)
        return 0;
    
    RenderObject* renderer = m_innerNonSharedNode->renderer();
    if (renderer && renderer->isImage()) {
        RenderImage* image = static_cast<WebCore::RenderImage*>(renderer);
        if (image->cachedImage() && !image->cachedImage()->errorOccurred())
            return image->cachedImage()->imageForRenderer(image);
    }

    return 0;
}

IntRect HitTestResult::imageRect() const
{
    if (!image())
        return IntRect();
    return m_innerNonSharedNode->renderBox()->absoluteContentQuad().enclosingBoundingBox();
}

KURL HitTestResult::absoluteImageURL() const
{
    if (!(m_innerNonSharedNode && m_innerNonSharedNode->document()))
        return KURL();

    if (!(m_innerNonSharedNode->renderer() && m_innerNonSharedNode->renderer()->isImage()))
        return KURL();

    AtomicString urlString;
    if (m_innerNonSharedNode->hasTagName(embedTag)
        || isHTMLImageElement(m_innerNonSharedNode.get())
        || isHTMLInputElement(m_innerNonSharedNode.get())
        || m_innerNonSharedNode->hasTagName(objectTag)
#if ENABLE(SVG)
        || isSVGImageElement(m_innerNonSharedNode.get())
#endif
       ) {
        Element* element = toElement(m_innerNonSharedNode.get());
        urlString = element->imageSourceURL();
    } else
        return KURL();

    return m_innerNonSharedNode->document()->completeURL(stripLeadingAndTrailingHTMLSpaces(urlString));
}

KURL HitTestResult::absolutePDFURL() const
{
    if (!(m_innerNonSharedNode && m_innerNonSharedNode->document()))
        return KURL();

    if (!m_innerNonSharedNode->hasTagName(embedTag) && !m_innerNonSharedNode->hasTagName(objectTag))
        return KURL();

    HTMLPlugInImageElement* element = toHTMLPlugInImageElement(m_innerNonSharedNode.get());
    KURL url = m_innerNonSharedNode->document()->completeURL(stripLeadingAndTrailingHTMLSpaces(element->url()));
    if (!url.isValid())
        return KURL();

    if (element->serviceType() == "application/pdf" || (element->serviceType().isEmpty() && url.path().lower().endsWith(".pdf")))
        return url;
    return KURL();
}

KURL HitTestResult::absoluteMediaURL() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElt = mediaElement())
        return mediaElt->currentSrc();
    return KURL();
#else
    return KURL();
#endif
}

bool HitTestResult::mediaSupportsFullscreen() const
{
#if ENABLE(VIDEO)
    HTMLMediaElement* mediaElt(mediaElement());
    return (mediaElt && mediaElt->hasTagName(HTMLNames::videoTag) && mediaElt->supportsFullscreen());
#else
    return false;
#endif
}

#if ENABLE(VIDEO)
HTMLMediaElement* HitTestResult::mediaElement() const
{
    if (!(m_innerNonSharedNode && m_innerNonSharedNode->document()))
        return 0;

    if (!(m_innerNonSharedNode->renderer() && m_innerNonSharedNode->renderer()->isMedia()))
        return 0;

    if (m_innerNonSharedNode->hasTagName(HTMLNames::videoTag) || isHTMLAudioElement(m_innerNonSharedNode.get()))
        return toHTMLMediaElement(m_innerNonSharedNode.get());
    return 0;
}
#endif

void HitTestResult::toggleMediaControlsDisplay() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElt = mediaElement())
        mediaElt->setControls(!mediaElt->controls());
#endif
}

void HitTestResult::toggleMediaLoopPlayback() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElt = mediaElement())
        mediaElt->setLoop(!mediaElt->loop());
#endif
}

bool HitTestResult::mediaIsInFullscreen() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElement = this->mediaElement())
        return mediaElement->isVideo() && mediaElement->isFullscreen();
#endif
    return false;
}

void HitTestResult::toggleMediaFullscreenState() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElement = this->mediaElement()) {
        if (mediaElement->isVideo() && mediaElement->supportsFullscreen()) {
            UserGestureIndicator indicator(DefinitelyProcessingUserGesture);
            mediaElement->toggleFullscreenState();
        }
    }
#endif
}

void HitTestResult::enterFullscreenForVideo() const
{
#if ENABLE(VIDEO)
    HTMLMediaElement* mediaElt(mediaElement());
    if (mediaElt && mediaElt->hasTagName(HTMLNames::videoTag)) {
        HTMLVideoElement* videoElt = toHTMLVideoElement(mediaElt);
        if (!videoElt->isFullscreen() && mediaElt->supportsFullscreen()) {
            UserGestureIndicator indicator(DefinitelyProcessingUserGesture);
            videoElt->enterFullscreen();
        }
    }
#endif
}

bool HitTestResult::mediaControlsEnabled() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElt = mediaElement())
        return mediaElt->controls();
#endif
    return false;
}

bool HitTestResult::mediaLoopEnabled() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElt = mediaElement())
        return mediaElt->loop();
#endif
    return false;
}

bool HitTestResult::mediaPlaying() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElt = mediaElement())
        return !mediaElt->paused();
#endif
    return false;
}

void HitTestResult::toggleMediaPlayState() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElt = mediaElement())
        mediaElt->togglePlayState();
#endif
}

bool HitTestResult::mediaHasAudio() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElt = mediaElement())
        return mediaElt->hasAudio();
#endif
    return false;
}

bool HitTestResult::mediaIsVideo() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElt = mediaElement())
        return mediaElt->hasTagName(HTMLNames::videoTag);
#endif
    return false;
}

bool HitTestResult::mediaMuted() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElt = mediaElement())
        return mediaElt->muted();
#endif
    return false;
}

void HitTestResult::toggleMediaMuteState() const
{
#if ENABLE(VIDEO)
    if (HTMLMediaElement* mediaElt = mediaElement())
        mediaElt->setMuted(!mediaElt->muted());
#endif
}

KURL HitTestResult::absoluteLinkURL() const
{
    if (!(m_innerURLElement && m_innerURLElement->document()))
        return KURL();

    AtomicString urlString;
    if (isHTMLAnchorElement(m_innerURLElement.get()) || isHTMLAreaElement(m_innerURLElement.get()) || m_innerURLElement->hasTagName(linkTag))
        urlString = m_innerURLElement->getAttribute(hrefAttr);
#if ENABLE(SVG)
    else if (m_innerURLElement->hasTagName(SVGNames::aTag))
        urlString = m_innerURLElement->getAttribute(XLinkNames::hrefAttr);
#endif
    else
        return KURL();

    return m_innerURLElement->document()->completeURL(stripLeadingAndTrailingHTMLSpaces(urlString));
}

bool HitTestResult::isLiveLink() const
{
    if (!(m_innerURLElement && m_innerURLElement->document()))
        return false;

    if (isHTMLAnchorElement(m_innerURLElement.get()))
        return toHTMLAnchorElement(m_innerURLElement.get())->isLiveLink();
#if ENABLE(SVG)
    if (m_innerURLElement->hasTagName(SVGNames::aTag))
        return m_innerURLElement->isLink();
#endif

    return false;
}

bool HitTestResult::isOverLink() const
{
    return m_innerURLElement && m_innerURLElement->isLink();
}

String HitTestResult::titleDisplayString() const
{
    if (!m_innerURLElement)
        return String();
    
    return displayString(m_innerURLElement->title(), m_innerURLElement.get());
}

String HitTestResult::textContent() const
{
    if (!m_innerURLElement)
        return String();
    return m_innerURLElement->textContent();
}

// FIXME: This function needs a better name and may belong in a different class. It's not
// really isContentEditable(); it's more like needsEditingContextMenu(). In many ways, this
// function would make more sense in the ContextMenu class, except that WebElementDictionary 
// hooks into it. Anyway, we should architect this better. 
bool HitTestResult::isContentEditable() const
{
    if (!m_innerNonSharedNode)
        return false;

    if (isHTMLTextAreaElement(m_innerNonSharedNode.get()))
        return true;

    if (isHTMLInputElement(m_innerNonSharedNode.get()))
        return toHTMLInputElement(m_innerNonSharedNode.get())->isTextField();

    return m_innerNonSharedNode->rendererIsEditable();
}

bool HitTestResult::addNodeToRectBasedTestResult(Node* node, const HitTestRequest& request, const HitTestLocation& locationInContainer, const LayoutRect& rect)
{
    // If it is not a rect-based hit test, this method has to be no-op.
    // Return false, so the hit test stops.
    if (!isRectBasedTest())
        return false;

    // If node is null, return true so the hit test can continue.
    if (!node)
        return true;

    if (request.disallowsShadowContent())
        node = node->document()->ancestorInThisScope(node);

    mutableRectBasedTestResult().add(node);

    bool regionFilled = rect.contains(locationInContainer.boundingBox());
    return !regionFilled;
}

bool HitTestResult::addNodeToRectBasedTestResult(Node* node, const HitTestRequest& request, const HitTestLocation& locationInContainer, const FloatRect& rect)
{
    // If it is not a rect-based hit test, this method has to be no-op.
    // Return false, so the hit test stops.
    if (!isRectBasedTest())
        return false;

    // If node is null, return true so the hit test can continue.
    if (!node)
        return true;

    if (request.disallowsShadowContent())
        node = node->document()->ancestorInThisScope(node);

    mutableRectBasedTestResult().add(node);

    bool regionFilled = rect.contains(locationInContainer.boundingBox());
    return !regionFilled;
}

void HitTestResult::append(const HitTestResult& other)
{
    ASSERT(isRectBasedTest() && other.isRectBasedTest());

    if (!m_innerNode && other.innerNode()) {
        m_innerNode = other.innerNode();
        m_innerNonSharedNode = other.innerNonSharedNode();
        m_localPoint = other.localPoint();
        m_pointInInnerNodeFrame = other.m_pointInInnerNodeFrame;
        m_innerURLElement = other.URLElement();
        m_scrollbar = other.scrollbar();
        m_isOverWidget = other.isOverWidget();
    }

    if (other.m_rectBasedTestResult) {
        NodeSet& set = mutableRectBasedTestResult();
        for (NodeSet::const_iterator it = other.m_rectBasedTestResult->begin(), last = other.m_rectBasedTestResult->end(); it != last; ++it)
            set.add(it->get());
    }
}

const HitTestResult::NodeSet& HitTestResult::rectBasedTestResult() const
{
    if (!m_rectBasedTestResult)
        m_rectBasedTestResult = adoptPtr(new NodeSet);
    return *m_rectBasedTestResult;
}

HitTestResult::NodeSet& HitTestResult::mutableRectBasedTestResult()
{
    if (!m_rectBasedTestResult)
        m_rectBasedTestResult = adoptPtr(new NodeSet);
    return *m_rectBasedTestResult;
}

Vector<String> HitTestResult::dictationAlternatives() const
{
    // Return the dictation context handle if the text at this point has DictationAlternative marker, which means this text is
    if (!m_innerNonSharedNode)
        return Vector<String>();

    DocumentMarker* marker = m_innerNonSharedNode->document()->markers()->markerContainingPoint(pointInInnerNodeFrame(), DocumentMarker::DictationAlternatives);
    if (!marker)
        return Vector<String>();

    Frame* frame = innerNonSharedNode()->document()->frame();
    if (!frame)
        return Vector<String>();

    return frame->editor().dictationAlternativesForMarker(marker);
}

Node* HitTestResult::targetNode() const
{
    Node* node = innerNode();
    if (!node)
        return 0;
    if (node->inDocument())
        return node;

    Element* element = node->parentElement();
    if (element && element->inDocument())
        return element;

    return node;
}

Element* HitTestResult::innerElement() const
{
    for (Node* node = m_innerNode.get(); node; node = node->parentNode()) {
        if (node->isElementNode())
            return toElement(node);
    }

    return 0;
}

} // namespace WebCore