/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 *           (C) 2000 Simon Hausmann <hausmann@kde.org>
 * Copyright (C) 2007-2016 Apple Inc. All rights reserved.
 *
 * 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.
 *
 */

#pragma once

#include "HTMLElement.h"
#include "HTMLNames.h"
#include "LinkHash.h"
#include "URLDecomposition.h"
#include <wtf/OptionSet.h>

namespace WebCore {

class DOMTokenList;

// Link relation bitmask values.
enum class Relation {
    NoReferrer = 1 << 0,
    NoOpener = 1 << 1,
    Opener = 1 << 2,
};

class HTMLAnchorElement : public HTMLElement, public URLDecomposition {
public:
    static Ref<HTMLAnchorElement> create(Document*);
    static Ref<HTMLAnchorElement> create(const QualifiedName&, Document*);

    virtual ~HTMLAnchorElement();

    KURL href() const;
    void setHref(const AtomicString&);

    const AtomicString& name() const;

    String origin() const;

    WEBCORE_EXPORT void setProtocol(StringView value);

    String text();
    void setText(const String&);

    bool isLiveLink() const;

    virtual bool willRespondToMouseClickEvents() OVERRIDE;

    bool hasRel(Relation) const;
    
    LinkHash visitedLinkHash() const;

    DOMTokenList& relList();

    void setReferrerPolicyForBindings(const AtomString&);
    String referrerPolicyForBindings() const;
    ReferrerPolicy referrerPolicy() const;

protected:
    HTMLAnchorElement(const QualifiedName&, Document*);

    virtual void attributeChanged(const QualifiedName&, const AtomString& oldValue, const AtomString& newValue, AttributeModificationReason) override;

private:
    virtual bool supportsFocus() const OVERRIDE;
    virtual bool isMouseFocusable() const OVERRIDE;
    virtual bool isKeyboardFocusable(KeyboardEvent*) const OVERRIDE;
    virtual void defaultEventHandler(Event*) OVERRIDE;
    virtual void setActive(bool active, bool pause) FINAL;
    virtual bool isURLAttribute(const Attribute&) const OVERRIDE;
    virtual bool canStartSelection() const FINAL;
    virtual String target() const OVERRIDE;
    virtual int defaultTabIndex() const FINAL;
    virtual bool draggable() const FINAL;
    virtual bool isInteractiveContent() const final;

    String effectiveTarget() const;

    void sendPings(const KURL& destinationURL);

    void handleClick(Event*);

    enum EventType {
        MouseEventWithoutShiftKey,
        MouseEventWithShiftKey,
        NonMouseEvent,
    };
    static EventType eventType(Event*);
    bool treatLinkAsLiveForEventType(EventType) const;

#if ENABLE(MICRODATA)
    virtual String itemValueText() const OVERRIDE;
    virtual void setItemValueText(const String&, ExceptionCode&) OVERRIDE;
#endif

    Element* rootEditableElementForSelectionOnMouseDown() const;
    void setRootEditableElementForSelectionOnMouseDown(Element*);
    void clearRootEditableElementForSelectionOnMouseDown();

    virtual KURL fullURL() const final { return href(); }
    virtual void setFullURL(const KURL& fullURL) final { setHref(fullURL.string()); }

    bool m_hasRootEditableElementForSelectionOnMouseDown { false };
    bool m_wasShiftKeyDownOnMouseDown { false };
    OptionSet<Relation> m_linkRelations;

    // This is computed only once and must not be affected by subsequent URL changes.
    mutable Optional<SharedStringHash> m_storedVisitedLinkHash;

    OwnPtr<DOMTokenList> m_relList;
};

inline const AtomicString& HTMLAnchorElement::name() const
{
    return getNameAttribute();
}

inline LinkHash HTMLAnchorElement::visitedLinkHash() const
{
    ASSERT(isLink());
    if (!m_storedVisitedLinkHash)
        m_storedVisitedLinkHash = computeVisitedLinkHash(document().baseURL(), attributeWithoutSynchronization(HTMLNames::hrefAttr));
    return *m_storedVisitedLinkHash;
}

inline bool isHTMLAnchorElement(const Node& node)
{
    return node.hasTagName(HTMLNames::aTag);
}

inline bool isHTMLAnchorElement(const Element& element)
{
    return element.hasTagName(HTMLNames::aTag);
}

inline bool isHTMLAnchorElement(const HTMLElement& element)
{
    return element.hasTagName(HTMLNames::aTag);
}

NODE_TYPE_CASTS(HTMLAnchorElement)

template <typename ArgType>
struct ElementTypeCastTraits<const HTMLAnchorElement, ArgType> {
    static bool is(ArgType& node) { return isHTMLAnchorElement(node); }
};

// Functions shared with the other anchor elements (i.e., SVG).

bool isEnterKeyKeydownEvent(Event*);
bool shouldProhibitLinks(const Element&);

} // namespace WebCore
