/*
 * Copyright (C) 2023 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. ``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
 * 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 "CSSNumericValue.h"
#include "ScrollTimeline.h"
#include "ViewTimelineOptions.h"
#include <wtf/Ref.h>
#include <wtf/WeakPtr.h>

namespace WebCore {

namespace Style {
class BuilderState;
}

class CSSViewValue;
class Element;

struct ViewTimelineInsets {
    std::optional<Length> start;
    std::optional<Length> end;
    bool operator==(const ViewTimelineInsets&) const = default;
};

class ViewTimeline final : public ScrollTimeline {
public:
    static Ref<ViewTimeline> create(ViewTimelineOptions&& = { });
    static Ref<ViewTimeline> create(const AtomString&, ScrollAxis, ViewTimelineInsets&&);
    static Ref<ViewTimeline> createFromCSSValue(Style::BuilderState&, const CSSViewValue&);

    Element* subject() const { return m_subject.get(); }
    const CSSNumericValue& startOffset() const;
    const CSSNumericValue& endOffset() const;
    const ViewTimelineInsets& insets() const { return m_insets; }
    AnimationTimeline::ShouldUpdateAnimationsAndSendEvents documentWillUpdateAnimationsAndSendEvents() override;
    AnimationTimelinesController* controller() const override;

    RenderBox* sourceRenderer() const;
    Element* source() const override;

private:
    struct Data {
        float currentScrollOffset { 0 };
        float coverRangeStart { 0 };
        float coverRangeEnd { 0 };
    };
    Data computeViewTimelineData() const;

    explicit ViewTimeline(ViewTimelineOptions&& = { });
    explicit ViewTimeline(const AtomString&, ScrollAxis, ViewTimelineInsets&&);

    void dump(TextStream&) const final;
    Ref<CSSValue> toCSSValue(const RenderStyle&) const final;
    bool isViewTimeline() const final { return true; }

    WeakPtr<Element, WeakPtrImplWithEventTargetData> m_subject;
    ViewTimelineInsets m_insets;
};

} // namespace WebCore

SPECIALIZE_TYPE_TRAITS_ANIMATION_TIMELINE(ViewTimeline, isViewTimeline())
