/*

    Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)

    Copyright (C) 2001 Dirk Mueller (mueller@kde.org)

    Copyright (C) 2002 Waldo Bastian (bastian@kde.org)

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

    Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.

    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.

    This class provides all functionality needed for loading images, style sheets and html

    pages from the web. It has a memory cache for these objects.

*/

#include "config.h"

#include "CachedCSSStyleSheet.h"

#include "CachedResourceClient.h"

#include "CachedResourceClientWalker.h"

#include "HTTPParsers.h"

#include "TextResourceDecoder.h"

#include "loader.h"

#include <wtf/Vector.h>

namespace WebCore {

CachedCSSStyleSheet::CachedCSSStyleSheet(const String& url, const String& charset)

    : CachedResource(url, CSSStyleSheet)

    , m_decoder(TextResourceDecoder::create("text/css", charset))

{

    // Prefer text/css but accept any type (dell.com serves a stylesheet

    // as text/html; see <http://bugs.webkit.org/show_bug.cgi?id=11451>).

    setAccept("text/css,*/*;q=0.1");

}

CachedCSSStyleSheet::~CachedCSSStyleSheet()

{

}

void CachedCSSStyleSheet::didAddClient(CachedResourceClient *c)

{

    if (!m_loading)

        c->setCSSStyleSheet(m_url, m_decoder->encoding().name(), this);

}

void CachedCSSStyleSheet::allClientsRemoved()

{

    if (isSafeToMakePurgeable())

        makePurgeable(true);

}

void CachedCSSStyleSheet::setEncoding(const String& chs)

{

    m_decoder->setEncoding(chs, TextResourceDecoder::EncodingFromHTTPHeader);

}

String CachedCSSStyleSheet::encoding() const

{

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

}

const String CachedCSSStyleSheet::sheetText(bool enforceMIMEType) const 

{ 

    ASSERT(!isPurgeable());

    if (!m_data || m_data->isEmpty() || !canUseSheet(enforceMIMEType))

        return String();

    if (!m_decodedSheetText.isNull())

        return m_decodedSheetText;

    // Don't cache the decoded text, regenerating is cheap and it can use quite a bit of memory

    String sheetText = m_decoder->decode(m_data->data(), m_data->size());

    sheetText += m_decoder->flush();

    return sheetText;

}

void CachedCSSStyleSheet::data(PassRefPtr<SharedBuffer> data, bool allDataReceived)

{

    if (!allDataReceived)

        return;

    m_data = data;

    setEncodedSize(m_data.get() ? m_data->size() : 0);

    // Decode the data to find out the encoding and keep the sheet text around during checkNotify()

    if (m_data) {

        m_decodedSheetText = m_decoder->decode(m_data->data(), m_data->size());

        m_decodedSheetText += m_decoder->flush();

    }

    m_loading = false;

    checkNotify();

    // Clear the decoded text as it is unlikely to be needed immediately again and is cheap to regenerate.

    m_decodedSheetText = String();

}

void CachedCSSStyleSheet::checkNotify()

{

    if (m_loading)

        return;

    CachedResourceClientWalker w(m_clients);

    while (CachedResourceClient *c = w.next())

        c->setCSSStyleSheet(m_response.url().string(), m_decoder->encoding().name(), this);

}

void CachedCSSStyleSheet::error()

{

    m_loading = false;

    m_errorOccurred = true;

    checkNotify();

}

bool CachedCSSStyleSheet::canUseSheet(bool enforceMIMEType) const

{

    if (errorOccurred())

        return false;

    if (!enforceMIMEType)

        return true;

    // This check exactly matches Firefox.  Note that we grab the Content-Type

    // header directly because we want to see what the value is BEFORE content

    // sniffing.  Firefox does this by setting a "type hint" on the channel.

    // This implementation should be observationally equivalent.

    //

    // This code defaults to allowing the stylesheet for non-HTTP protocols so

    // folks can use standards mode for local HTML documents.

    String mimeType = extractMIMETypeFromMediaType(response().httpHeaderField("Content-Type"));

    return mimeType.isEmpty() || equalIgnoringCase(mimeType, "text/css") || equalIgnoringCase(mimeType, "application/x-unknown-content-type");

}

}