/*
 * Copyright (C) 2011 Google 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google Inc. 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 THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
 * OWNER OR 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.
 *
 */

#ifndef LinkLoader_h
#define LinkLoader_h

#include "CachedResource.h"
#include "CachedResourceClient.h"
#include "CachedResourceHandle.h"
#include "LinkLoaderClient.h"
#include "Timer.h"
#include <wtf/Optional.h>
#include <wtf/RefPtr.h>

namespace WebCore {

struct LinkRelAttribute;
#if ENABLE(LINK_PRERENDER)
class PrerenderHandle;
#endif

// The LinkLoader can load link rel types icon, dns-prefetch, subresource, prefetch and prerender.
class LinkLoader : public CachedResourceClient {
public:
    explicit LinkLoader(LinkLoaderClient*);
    virtual ~LinkLoader();

    // from CachedResourceClient
    virtual void notifyFinished(CachedResource*);
    
    void released();
    bool loadLink(const LinkRelAttribute&, const String& type, const String& sizes, const KURL&, const String& as, const String& crossOrigin, Document*);
    static Optional<CachedResource::Type> resourceTypeFromAsAttribute(const String& as);

private:
    void linkLoadTimerFired(Timer<LinkLoader>*);
    void linkLoadingErrorTimerFired(Timer<LinkLoader>*);

    LinkLoaderClient* m_client;

    CachedResourceHandle<CachedResource> m_cachedLinkResource;
    Timer<LinkLoader> m_linkLoadTimer;
    Timer<LinkLoader> m_linkLoadingErrorTimer;

#if ENABLE(LINK_PRERENDER)
    RefPtr<PrerenderHandle> m_prerenderHandle;
#endif
};
    
}

#endif
