/*

 * Copyright (C) 2006, 2007, 2008 Apple 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:

 * 1. Redistributions of source code must retain the above copyright

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

 * 2. 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.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * 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 "ImageDocument.h"

#include "CSSStyleDeclaration.h"

#include "CachedImage.h"

#include "DocumentLoader.h"

#include "Element.h"

#include "EventListener.h"

#include "EventNames.h"

#include "Frame.h"

#include "FrameLoader.h"

#include "FrameView.h"

#include "HTMLImageElement.h"

#include "HTMLNames.h"

#include "LocalizedStrings.h"

#include "MouseEvent.h"

#include "NotImplemented.h"

#include "Page.h"

#include "SegmentedString.h"

#include "Settings.h"

#include "Text.h"

#include "XMLTokenizer.h"

using std::min;

namespace WebCore {

using namespace HTMLNames;

class ImageEventListener : public EventListener {

public:

    static PassRefPtr<ImageEventListener> create(ImageDocument* document) { return adoptRef(new ImageEventListener(document)); }

    static const ImageEventListener* cast(const EventListener* listener)

    {

        return listener->type() == ImageEventListenerType

            ? static_cast<const ImageEventListener*>(listener)

            : 0;

    }

    virtual bool operator==(const EventListener& other);

private:

    ImageEventListener(ImageDocument* document)

        : EventListener(ImageEventListenerType)

        , m_doc(document)

    {

    }

    virtual void handleEvent(ScriptExecutionContext*, Event*);

    ImageDocument* m_doc;

};

class ImageTokenizer : public Tokenizer {

public:

    ImageTokenizer(ImageDocument* doc) : m_doc(doc) {}

    virtual void write(const SegmentedString&, bool appendData);

    virtual void finish();

    virtual bool isWaitingForScripts() const;

    virtual bool wantsRawData() const { return true; }

    virtual bool writeRawData(const char* data, int len);

private:

    ImageDocument* m_doc;

};

class ImageDocumentElement : public HTMLImageElement {

public:

    ImageDocumentElement(ImageDocument* doc)

        : HTMLImageElement(imgTag, doc)

        , m_imageDocument(doc)

    {

    }

    virtual ~ImageDocumentElement();

    virtual void willMoveToNewOwnerDocument();

private:

    ImageDocument* m_imageDocument;

};

// --------

void ImageTokenizer::write(const SegmentedString&, bool)

{

    // <https://bugs.webkit.org/show_bug.cgi?id=25397>: JS code can always call document.write, we need to handle it.

    notImplemented();

}

bool ImageTokenizer::writeRawData(const char*, int)

{

    CachedImage* cachedImage = m_doc->cachedImage();

    cachedImage->data(m_doc->frame()->loader()->documentLoader()->mainResourceData(), false);

    m_doc->imageChanged();

    return false;

}

void ImageTokenizer::finish()

{

    if (!m_parserStopped && m_doc->imageElement()) {

        CachedImage* cachedImage = m_doc->cachedImage();

        RefPtr<SharedBuffer> data = m_doc->frame()->loader()->documentLoader()->mainResourceData();

        // If this is a multipart image, make a copy of the current part, since the resource data

        // will be overwritten by the next part.

        if (m_doc->frame()->loader()->documentLoader()->isLoadingMultipartContent())

            data = data->copy();

        cachedImage->data(data.release(), true);

        cachedImage->finish();

        cachedImage->setResponse(m_doc->frame()->loader()->documentLoader()->response());

        IntSize size = cachedImage->imageSize(m_doc->frame()->pageZoomFactor());

        if (size.width()) {

            // Compute the title, we use the decoded filename of the resource, falling

            // back on the (decoded) hostname if there is no path.

            String fileName = decodeURLEscapeSequences(m_doc->url().lastPathComponent());

            if (fileName.isEmpty())

                fileName = m_doc->url().host();

            m_doc->setTitle(imageTitle(fileName, size));

        }

        m_doc->imageChanged();

    }

    m_doc->finishedParsing();

}

bool ImageTokenizer::isWaitingForScripts() const

{

    // An image document is never waiting for scripts

    return false;

}

// --------

ImageDocument::ImageDocument(Frame* frame)

    : HTMLDocument(frame)

    , m_imageElement(0)

    , m_imageSizeIsKnown(false)

    , m_didShrinkImage(false)

    , m_shouldShrinkImage(shouldShrinkToFit())

{

    setParseMode(Compat);

}

Tokenizer* ImageDocument::createTokenizer()

{

    return new ImageTokenizer(this);

}

void ImageDocument::createDocumentStructure()

{

    ExceptionCode ec;

    RefPtr<Element> rootElement = Document::createElement(htmlTag, false);

    appendChild(rootElement, ec);

    RefPtr<Element> body = Document::createElement(bodyTag, false);

    body->setAttribute(styleAttr, "margin: 0px;");

    rootElement->appendChild(body, ec);

    RefPtr<ImageDocumentElement> imageElement = new ImageDocumentElement(this);

    imageElement->setAttribute(styleAttr, "-webkit-user-select: none");        

    imageElement->setLoadManually(true);

    imageElement->setSrc(url().string());

    body->appendChild(imageElement, ec);

    if (shouldShrinkToFit()) {

        // Add event listeners

        RefPtr<EventListener> listener = ImageEventListener::create(this);

        if (DOMWindow* domWindow = this->domWindow())

            domWindow->addEventListener("resize", listener, false);

        imageElement->addEventListener("click", listener.release(), false);

    }

    m_imageElement = imageElement.get();

}

float ImageDocument::scale() const

{

    if (!m_imageElement)

        return 1.0f;

    IntSize imageSize = m_imageElement->cachedImage()->imageSize(frame()->pageZoomFactor());

    IntSize windowSize = IntSize(frame()->view()->width(), frame()->view()->height());

    float widthScale = (float)windowSize.width() / imageSize.width();

    float heightScale = (float)windowSize.height() / imageSize.height();

    return min(widthScale, heightScale);

}

void ImageDocument::resizeImageToFit()

{

    if (!m_imageElement)

        return;

    IntSize imageSize = m_imageElement->cachedImage()->imageSize(frame()->pageZoomFactor());

    float scale = this->scale();

    m_imageElement->setWidth(static_cast<int>(imageSize.width() * scale));

    m_imageElement->setHeight(static_cast<int>(imageSize.height() * scale));

    ExceptionCode ec;

    m_imageElement->style()->setProperty("cursor", "-webkit-zoom-in", ec);

}

void ImageDocument::imageClicked(int x, int y)

{

    if (!m_imageSizeIsKnown || imageFitsInWindow())

        return;

    m_shouldShrinkImage = !m_shouldShrinkImage;

    if (m_shouldShrinkImage)

        windowSizeChanged();

    else {

        restoreImageSize();

        updateLayout();

        float scale = this->scale();

        int scrollX = static_cast<int>(x / scale - (float)frame()->view()->width() / 2);

        int scrollY = static_cast<int>(y / scale - (float)frame()->view()->height() / 2);

        frame()->view()->setScrollPosition(IntPoint(scrollX, scrollY));

    }

}

void ImageDocument::imageChanged()

{

    ASSERT(m_imageElement);

    if (m_imageSizeIsKnown)

        return;

    if (m_imageElement->cachedImage()->imageSize(frame()->pageZoomFactor()).isEmpty())

        return;

    m_imageSizeIsKnown = true;

    if (shouldShrinkToFit()) {

        // Force resizing of the image

        windowSizeChanged();

    }

}

void ImageDocument::restoreImageSize()

{

    if (!m_imageElement || !m_imageSizeIsKnown)

        return;

    m_imageElement->setWidth(m_imageElement->cachedImage()->imageSize(frame()->pageZoomFactor()).width());

    m_imageElement->setHeight(m_imageElement->cachedImage()->imageSize(frame()->pageZoomFactor()).height());

    ExceptionCode ec;

    if (imageFitsInWindow())

        m_imageElement->style()->removeProperty("cursor", ec);

    else

        m_imageElement->style()->setProperty("cursor", "-webkit-zoom-out", ec);

    m_didShrinkImage = false;

}

bool ImageDocument::imageFitsInWindow() const

{

    if (!m_imageElement)

        return true;

    IntSize imageSize = m_imageElement->cachedImage()->imageSize(frame()->pageZoomFactor());

    IntSize windowSize = IntSize(frame()->view()->width(), frame()->view()->height());

    return imageSize.width() <= windowSize.width() && imageSize.height() <= windowSize.height();    

}

void ImageDocument::windowSizeChanged()

{

    if (!m_imageElement || !m_imageSizeIsKnown)

        return;

    bool fitsInWindow = imageFitsInWindow();

    // If the image has been explicitly zoomed in, restore the cursor if the image fits

    // and set it to a zoom out cursor if the image doesn't fit

    if (!m_shouldShrinkImage) {

        ExceptionCode ec;

        if (fitsInWindow)

            m_imageElement->style()->removeProperty("cursor", ec);

        else

            m_imageElement->style()->setProperty("cursor", "-webkit-zoom-out", ec);

        return;

    }

    if (m_didShrinkImage) {

        // If the window has been resized so that the image fits, restore the image size

        // otherwise update the restored image size.

        if (fitsInWindow)

            restoreImageSize();

        else

            resizeImageToFit();

    } else {

        // If the image isn't resized but needs to be, then resize it.

        if (!fitsInWindow) {

            resizeImageToFit();

            m_didShrinkImage = true;

        }

    }

}

CachedImage* ImageDocument::cachedImage()

{ 

    if (!m_imageElement)

        createDocumentStructure();

    return m_imageElement->cachedImage();

}

bool ImageDocument::shouldShrinkToFit() const

{

    return frame()->page()->settings()->shrinksStandaloneImagesToFit() &&

        frame()->page()->mainFrame() == frame();

}

// --------

void ImageEventListener::handleEvent(ScriptExecutionContext*, Event* event)

{

    if (event->type() == eventNames().resizeEvent)

        m_doc->windowSizeChanged();

    else if (event->type() == eventNames().clickEvent) {

        MouseEvent* mouseEvent = static_cast<MouseEvent*>(event);

        m_doc->imageClicked(mouseEvent->x(), mouseEvent->y());

    }

}

bool ImageEventListener::operator==(const EventListener& listener)

{

    if (const ImageEventListener* imageEventListener = ImageEventListener::cast(&listener))

        return m_doc == imageEventListener->m_doc;

    return false;

}

// --------

ImageDocumentElement::~ImageDocumentElement()

{

    if (m_imageDocument)

        m_imageDocument->disconnectImageElement();

}

void ImageDocumentElement::willMoveToNewOwnerDocument()

{

    if (m_imageDocument) {

        m_imageDocument->disconnectImageElement();

        m_imageDocument = 0;

    }

    HTMLImageElement::willMoveToNewOwnerDocument();

}

}