/*
 * Copyright (C) 2019 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 INC. 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 INC. 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.
 */

#pragma once

#include "AffineTransform.h"
#include "IntRectHash.h"
#include "InteractionRegion.h"
#include "Node.h"
#include "Region.h"
#include "RenderStyleConstants.h"
#include "TouchAction.h"
#include <wtf/ArgumentCoder.h>
#include <wtf/OptionSet.h>
#include <wtf/Ref.h>
#include <wtf/Vector.h>

namespace WebCore {

class EventRegion;
class Path;
class RenderObject;
class RenderStyle;

enum class WindRule : bool;

class EventRegionContext {
public:
    explicit EventRegionContext(EventRegion&);

    void pushTransform(const AffineTransform&);
    void popTransform();

    void pushClip(const IntRect&);
    void pushClip(const Path&, WindRule);
    void popClip();

    void unite(const Region&, RenderObject&, const RenderStyle&, bool overrideUserModifyIsEditable = false);
    bool contains(const IntRect&) const;

#if ENABLE(INTERACTION_REGIONS_IN_EVENT_REGION)
    void uniteInteractionRegions(const Region&, RenderObject&);
    bool shouldConsolidateInteractionRegion(IntRect, RenderObject&);
    void copyInteractionRegionsToEventRegion();
#endif

private:
    EventRegion& m_eventRegion;
    Vector<AffineTransform> m_transformStack;
    Vector<IntRect> m_clipStack;

#if ENABLE(INTERACTION_REGIONS_IN_EVENT_REGION)
    Vector<InteractionRegion> m_interactionRegions;
    HashSet<IntRect> m_interactionRects;
    HashSet<IntRect> m_occlusionRects;
    HashMap<ElementIdentifier, IntRect> m_discoveredInteractionRectsByElement;
#endif
};

class EventRegionContextStateSaver {
public:
    EventRegionContextStateSaver(EventRegionContext* context)
        : m_context(context)
    {
    }
    
    ~EventRegionContextStateSaver()
    {
        if (!m_context)
            return;

        if (m_pushedClip)
            m_context->popClip();
    }
    
    void pushClip(const IntRect& clipRect)
    {
        ASSERT(!m_pushedClip);
        if (m_context)
            m_context->pushClip(clipRect);
        m_pushedClip = true;
    }

    void pushClip(const Path& path, WindRule windRule)
    {
        ASSERT(!m_pushedClip);
        if (m_context)
            m_context->pushClip(path, windRule);
        m_pushedClip = true;
    }

    EventRegionContext* context() const { return m_context; }

private:
    EventRegionContext* m_context;
    bool m_pushedClip { false };
};

class EventRegion {
public:
    WEBCORE_EXPORT EventRegion();
    WEBCORE_EXPORT EventRegion(Region&&
#if ENABLE(TOUCH_ACTION_REGIONS)
    , Vector<WebCore::Region> touchActionRegions
#endif
#if ENABLE(WHEEL_EVENT_REGIONS)
    , WebCore::Region wheelEventListenerRegion
    , WebCore::Region nonPassiveWheelEventListenerRegion
#endif
#if ENABLE(EDITABLE_REGION)
    , std::optional<WebCore::Region>
#endif
#if ENABLE(INTERACTION_REGIONS_IN_EVENT_REGION)
    , Vector<WebCore::InteractionRegion>
#endif
    );

    EventRegionContext makeContext() { return EventRegionContext(*this); }

    bool isEmpty() const { return m_region.isEmpty(); }

    WEBCORE_EXPORT bool operator==(const EventRegion&) const;

    void unite(const Region&, const RenderStyle&, bool overrideUserModifyIsEditable = false);
    void translate(const IntSize&);

    bool contains(const IntPoint& point) const { return m_region.contains(point); }
    bool contains(const IntRect& rect) const { return m_region.contains(rect); }
    bool intersects(const IntRect& rect) const { return m_region.intersects(rect); }

    const Region& region() const { return m_region; }

#if ENABLE(TOUCH_ACTION_REGIONS)
    bool hasTouchActions() const { return !m_touchActionRegions.isEmpty(); }
    WEBCORE_EXPORT OptionSet<TouchAction> touchActionsForPoint(const IntPoint&) const;
    const Region* regionForTouchAction(TouchAction) const;
#endif

#if ENABLE(WHEEL_EVENT_REGIONS)
    WEBCORE_EXPORT OptionSet<EventListenerRegionType> eventListenerRegionTypesForPoint(const IntPoint&) const;
    const Region& eventListenerRegionForType(EventListenerRegionType) const;
#endif

#if ENABLE(EDITABLE_REGION)
    void ensureEditableRegion();
    bool hasEditableRegion() const { return m_editableRegion.has_value(); }
    WEBCORE_EXPORT bool containsEditableElementsInRect(const IntRect&) const;
    Vector<IntRect, 1> rectsForEditableElements() const { return m_editableRegion ? m_editableRegion->rects() : Vector<IntRect, 1> { }; }
#endif

    void dump(TextStream&) const;

#if ENABLE(INTERACTION_REGIONS_IN_EVENT_REGION)
    const Vector<InteractionRegion>& interactionRegions() const { return m_interactionRegions; }
    void uniteInteractionRegions(const Vector<InteractionRegion>&);
#endif

private:
    friend struct IPC::ArgumentCoder<EventRegion, void>;
#if ENABLE(TOUCH_ACTION_REGIONS)
    void uniteTouchActions(const Region&, OptionSet<TouchAction>);
#endif
    void uniteEventListeners(const Region&, OptionSet<EventListenerRegionType>);

    Region m_region;
#if ENABLE(TOUCH_ACTION_REGIONS)
    Vector<Region> m_touchActionRegions;
#endif
#if ENABLE(WHEEL_EVENT_REGIONS)
    Region m_wheelEventListenerRegion;
    Region m_nonPassiveWheelEventListenerRegion;
#endif
#if ENABLE(EDITABLE_REGION)
    std::optional<Region> m_editableRegion;
#endif
#if ENABLE(INTERACTION_REGIONS_IN_EVENT_REGION)
    Vector<InteractionRegion> m_interactionRegions;
#endif
};

WEBCORE_EXPORT TextStream& operator<<(TextStream&, const EventRegion&);

#if ENABLE(EDITABLE_REGION)

inline void EventRegion::ensureEditableRegion()
{
    if (!m_editableRegion)
        m_editableRegion.emplace();
}

#endif

}
