/*

 * Copyright (C) 2010. Adam Barth. 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. 

 * 3.  Neither the name of Apple Computer, Inc. ("Apple") 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 APPLE AND ITS 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 APPLE OR ITS 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 "DocumentWriter.h"

#include "DOMImplementation.h"

#include "DOMWindow.h"

#include "Frame.h"

#include "FrameLoader.h"

#include "FrameLoaderClient.h"

#include "FrameLoaderStateMachine.h"

#include "FrameView.h"

#include "PlaceholderDocument.h"

#include "PluginDocument.h"

#include "RawDataDocumentParser.h"

#include "ScriptableDocumentParser.h"

#include "SecurityOrigin.h"

#include "SegmentedString.h"

#include "Settings.h"

#include "SinkDocument.h"

#include "TextResourceDecoder.h"

namespace WebCore {

static inline bool canReferToParentFrameEncoding(const Frame* frame, const Frame* parentFrame) 

{

    return parentFrame && parentFrame->document()->securityOrigin()->canAccess(frame->document()->securityOrigin());

}

DocumentWriter::DocumentWriter(Frame* frame)

    : m_frame(frame)

    , m_receivedData(false)

    , m_encodingWasChosenByUser(false)

{

}

// This is only called by ScriptController::executeIfJavaScriptURL

// and always contains the result of evaluating a javascript: url.

// This is the <iframe src="javascript:'html'"> case.

void DocumentWriter::replaceDocument(const String& source)

{

    m_frame->loader()->stopAllLoaders();

    begin(m_frame->loader()->url(), true, m_frame->document()->securityOrigin());

    if (!source.isNull()) {

        if (!m_receivedData) {

            m_receivedData = true;

            m_frame->document()->setParseMode(Document::Strict);

        }

        // FIXME: This should call DocumentParser::appendBytes instead of append

        // to support RawDataDocumentParsers.

        if (DocumentParser* parser = m_frame->document()->parser())

            parser->append(source);

    }

    end();

}

void DocumentWriter::clear()

{

    m_decoder = 0;

    m_receivedData = false;

    if (!m_encodingWasChosenByUser)

        m_encoding = String();

}

void DocumentWriter::begin()

{

    begin(KURL());

}

PassRefPtr<Document> DocumentWriter::createDocument(const KURL& url)

{

    if (!m_frame->loader()->stateMachine()->isDisplayingInitialEmptyDocument() && m_frame->loader()->client()->shouldUsePluginDocument(m_mimeType))

        return PluginDocument::create(m_frame, url);

    if (!m_frame->loader()->client()->hasHTMLView())

        return PlaceholderDocument::create(m_frame, url);

    return DOMImplementation::createDocument(m_mimeType, m_frame, url, m_frame->inViewSourceMode());

}

void DocumentWriter::begin(const KURL& url, bool dispatch, SecurityOrigin* origin)

{

    // We need to take a reference to the security origin because |clear|

    // might destroy the document that owns it.

    RefPtr<SecurityOrigin> forcedSecurityOrigin = origin;

    // Create a new document before clearing the frame, because it may need to

    // inherit an aliased security context.

    RefPtr<Document> document = createDocument(url);

    // If the new document is for a Plugin but we're supposed to be sandboxed from Plugins,

    // then replace the document with one whose parser will ignore the incoming data (bug 39323)

    if (document->isPluginDocument() && m_frame->loader()->isSandboxed(SandboxPlugins))

        document = SinkDocument::create(m_frame, url);

    bool resetScripting = !(m_frame->loader()->stateMachine()->isDisplayingInitialEmptyDocument() && m_frame->document()->securityOrigin()->isSecureTransitionTo(url));

    m_frame->loader()->clear(resetScripting, resetScripting);

    if (resetScripting)

        m_frame->script()->updatePlatformScriptObjects();

    m_frame->loader()->setURL(url);

    m_frame->setDocument(document);

    if (m_decoder)

        document->setDecoder(m_decoder.get());

    if (forcedSecurityOrigin)

        document->setSecurityOrigin(forcedSecurityOrigin.get());

    m_frame->domWindow()->setURL(document->url());

    m_frame->domWindow()->setSecurityOrigin(document->securityOrigin());

    m_frame->loader()->didBeginDocument(dispatch);

    document->implicitOpen();

    if (m_frame->view() && m_frame->loader()->client()->hasHTMLView())

        m_frame->view()->setContentsSize(IntSize());

}

TextResourceDecoder* DocumentWriter::createDecoderIfNeeded()

{

    if (!m_decoder) {

        if (Settings* settings = m_frame->settings()) {

            m_decoder = TextResourceDecoder::create(m_mimeType,

                settings->defaultTextEncodingName(),

                settings->usesEncodingDetector());

            Frame* parentFrame = m_frame->tree()->parent();

            // Set the hint encoding to the parent frame encoding only if

            // the parent and the current frames share the security origin.

            // We impose this condition because somebody can make a child frame 

            // containing a carefully crafted html/javascript in one encoding

            // that can be mistaken for hintEncoding (or related encoding) by

            // an auto detector. When interpreted in the latter, it could be

            // an attack vector.

            // FIXME: This might be too cautious for non-7bit-encodings and

            // we may consider relaxing this later after testing.

            if (canReferToParentFrameEncoding(m_frame, parentFrame))

                m_decoder->setHintEncoding(parentFrame->document()->decoder());

        } else

            m_decoder = TextResourceDecoder::create(m_mimeType, String());

        Frame* parentFrame = m_frame->tree()->parent();

        if (m_encoding.isEmpty()) {

            if (canReferToParentFrameEncoding(m_frame, parentFrame))

                m_decoder->setEncoding(parentFrame->document()->inputEncoding(), TextResourceDecoder::EncodingFromParentFrame);

        } else {

            m_decoder->setEncoding(m_encoding,

                m_encodingWasChosenByUser ? TextResourceDecoder::UserChosenEncoding : TextResourceDecoder::EncodingFromHTTPHeader);

        }

        m_frame->document()->setDecoder(m_decoder.get());

    }

    return m_decoder.get();

}

void DocumentWriter::reportDataRecieved()

{

    ASSERT(m_decoder);

    if (!m_receivedData) {

        m_receivedData = true;

        if (m_decoder->encoding().usesVisualOrdering())

            m_frame->document()->setVisuallyOrdered();

        m_frame->document()->recalcStyle(Node::Force);

    }

}

void DocumentWriter::addData(const char* str, int len, bool flush)

{

    if (len == -1)

        len = strlen(str);

    DocumentParser* parser = m_frame->document()->parser();

    if (parser)

        parser->appendBytes(this, str, len, flush);

}

void DocumentWriter::end()

{

    m_frame->loader()->didEndDocument();

    endIfNotLoadingMainResource();

}

void DocumentWriter::endIfNotLoadingMainResource()

{

    if (m_frame->loader()->isLoadingMainResource() || !m_frame->page() || !m_frame->document())

        return;

    // http://bugs.webkit.org/show_bug.cgi?id=10854

    // The frame's last ref may be removed and it can be deleted by checkCompleted(), 

    // so we'll add a protective refcount

    RefPtr<Frame> protector(m_frame);

    // make sure nothing's left in there

    addData(0, 0, true);

    m_frame->document()->finishParsing();

}

String DocumentWriter::encoding() const

{

    if (m_encodingWasChosenByUser && !m_encoding.isEmpty())

        return m_encoding;

    if (m_decoder && m_decoder->encoding().isValid())

        return m_decoder->encoding().name();

    Settings* settings = m_frame->settings();

    return settings ? settings->defaultTextEncodingName() : String();

}

void DocumentWriter::setEncoding(const String& name, bool userChosen)

{

    m_frame->loader()->willSetEncoding();

    m_encoding = name;

    m_encodingWasChosenByUser = userChosen;

}

void DocumentWriter::setDecoder(TextResourceDecoder* decoder)

{

    m_decoder = decoder;

}

String DocumentWriter::deprecatedFrameEncoding() const

{

    return m_frame->loader()->url().isEmpty() ? m_encoding : encoding();

}

} // namespace WebCore