/*
 * Copyright (C) 2024 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
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "RenderViewTransitionCapture.h"

#include "ImageOverlayController.h"
#include "ImageQualityController.h"
#include "PaintInfo.h"
#include "RenderBoxModelObjectInlines.h"
#include "RenderLayer.h"
#include "RenderObjectInlines.h"
#include "StyleContain.h"
#include "StyleObjectViewBox.h"
#include <wtf/TZoneMallocInlines.h>

namespace WebCore {

WTF_MAKE_TZONE_ALLOCATED_IMPL(RenderViewTransitionCapture);

RenderViewTransitionCapture::RenderViewTransitionCapture(Type type, Document& document, Style::ComputedStyle&& style, bool isRootElement)
    : RenderReplaced(type, document, WTF::move(style), { }, ReplacedFlag::IsViewTransitionCapture)
    , m_isRootElementCapture(isRootElement)
{
}

RenderViewTransitionCapture::~RenderViewTransitionCapture() = default;

bool RenderViewTransitionCapture::canUseExistingLayers() const
{
    return !hasNonVisibleOverflow() && style().objectViewBox().isNone();
}

RefPtr<ImageBuffer> RenderViewTransitionCapture::image()
{
    if (!style().objectViewBox().isNone())
        return nullptr;
    return m_oldImage;
}

void RenderViewTransitionCapture::setImage(RefPtr<ImageBuffer> oldImage)
{
    m_oldImage = oldImage;
    if (hasLayer())
        layer()->contentChanged(ContentChangeType::Image);
    if (parent())
        repaint();
}

bool RenderViewTransitionCapture::setCapturedSize(const LayoutSize& size, const LayoutRect& overflowRect, const LayoutPoint& layerToLayoutOffset)
{
    if (m_overflowRect == overflowRect && intrinsicSize() == size && m_layerToLayoutOffset == layerToLayoutOffset)
        return false;
    m_imageIntrinsicSize = size;
    setIntrinsicSize(size);
    m_overflowRect = overflowRect;
    m_layerToLayoutOffset = layerToLayoutOffset;
    return true;
}

void RenderViewTransitionCapture::intrinsicSizeChanged()
{
    if (intrinsicSize() == m_imageIntrinsicSize)
        return;
    setIntrinsicSize(m_imageIntrinsicSize);
    invalidateContentLogicalWidths();
    setNeedsLayout();
}

void RenderViewTransitionCapture::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    auto& context = paintInfo.context();
    if (context.detectingContentfulPaint())
        return;

    RefPtr oldImage = m_oldImage;
    if (!oldImage)
        return;

    LayoutRect replacedContentRect = this->replacedContentRect();
    replacedContentRect.moveBy(paintOffset);

    auto viewBox = resolvedObjectViewBox(FloatSize(intrinsicSize()));

    // dstRect: where to draw on screen.
    // srcRect: which portion of the snapshot to draw (defaults to the full image).
    FloatRect dstRect = m_localOverflowRect;
    FloatRect srcRect = FloatRect { { }, FloatSize(oldImage->logicalSize()) };

    if (viewBox) {
        if (hasNonVisibleOverflow()) {
            // Clipped (e.g. contain: paint): map only the view-box region onto replacedContentRect.
            dstRect = FloatRect(replacedContentRect);
            srcRect = FloatRect(*viewBox);
        } else {
            // Overflow-visible: scale the full image so the view-box region maps onto replacedContentRect.
            dstRect = snapRectToDevicePixels(computePaintRectForObjectViewBox(replacedContentRect), document().deviceScaleFactor());
        }
    }

    InterpolationQualityMaintainer interpolationMaintainer(context, ImageQualityController::interpolationQualityFromStyle(style()));
    context.drawImageBuffer(*oldImage, dstRect, srcRect, { context.compositeOperation() });
}

void RenderViewTransitionCapture::layout()
{
    RenderReplaced::layout();
    // Move the overflow rect of the captured renderer into layout coords, and then scale/position so that the intrinsic size subset covers
    // our replaced content rect.
    m_localOverflowRect = m_overflowRect;
    m_localOverflowRect.moveBy(-m_layerToLayoutOffset);
    m_scale = { replacedContentRect().width().toFloat() / intrinsicSize().width().toFloat() , replacedContentRect().height().toFloat() / intrinsicSize().height().toFloat()  };
    m_localOverflowRect.scale(m_scale.width(), m_scale.height());
    m_localOverflowRect.moveBy(replacedContentRect().location());

    auto viewBox = resolvedObjectViewBox(FloatSize(intrinsicSize()));

    // For the clipped view-box case, don't expand visual overflow: the element clips to its
    // own border, and expanding would expose stale CA contents outside the painted area.
    if (viewBox && hasNonVisibleOverflow())
        return;

    LayoutRect overflowRect = m_localOverflowRect;
    if (viewBox)
        overflowRect.unite(computePaintRectForObjectViewBox(replacedContentRect()));
    addVisualOverflow(overflowRect);
}

void RenderViewTransitionCapture::updateFromStyle()
{
    RenderReplaced::updateFromStyle();

    // The ::view-transition-new(root) capture should hold exactly the snapshot containing
    // block without overflow, but can host layers that extend outside this area. Force overflow
    // clipping.
    // effectiveOverflowX/Y checks paintContainmentApplies(), which requires element() != null and
    // therefore always returns false for pseudo-elements. Check usedContain() directly so that
    // contain: paint on ::view-transition-old/new correctly triggers overflow clipping.
    if (effectiveOverflowX() != Overflow::Visible || effectiveOverflowY() != Overflow::Visible
        || style().usedContain().contains(Style::ContainValue::Paint)
        || (m_isRootElementCapture && style().pseudoElementType() == PseudoElementType::ViewTransitionNew))
        setHasNonVisibleOverflow();
}

void RenderViewTransitionCapture::styleDidChange(Style::Difference diff, const Style::ComputedStyle* oldStyle)
{
    RenderReplaced::styleDidChange(diff, oldStyle);

    if (oldStyle && oldStyle->usedVisibility() != style().usedVisibility() && hasLayer())
        layer()->setNeedsCompositingLayerConnection();
}

LayoutPoint RenderViewTransitionCapture::captureContentInset() const
{
    LayoutPoint location = m_localOverflowRect.location();
    location.moveBy(-visualOverflowRect().location());
    return location;
}

Node* RenderViewTransitionCapture::nodeForHitTest() const
{
    // The view transition pseudo-elements should hit-test to their originating element (the document element).
    return document().documentElement();
}

bool RenderViewTransitionCapture::paintsContent() const
{
    if (style().pseudoElementType() == PseudoElementType::ViewTransitionOld)
        return true;
    return !canUseExistingLayers();
}

String RenderViewTransitionCapture::debugDescription() const
{
    StringBuilder builder;

    builder.append(renderName(), " 0x"_s, hex(reinterpret_cast<uintptr_t>(this), Lowercase));

    builder.append(" ::view-transition-"_s, style().pseudoElementType() == PseudoElementType::ViewTransitionNew ? "new("_s : "old("_s);
    builder.append(style().pseudoElementNameArgument(), ')');
    return builder.toString();
}

} // namespace WebCore
