/*
 * Copyright (C) 2012 Adobe Systems Incorporated. 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 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 HOLDER 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.
 */

#include "core/layout/shapes/Shape.h"

#include "core/css/BasicShapeFunctions.h"
#include "core/dom/DOMArrayBuffer.h"
#include "core/dom/DOMTypedArray.h"
#include "core/layout/shapes/BoxShape.h"
#include "core/layout/shapes/PolygonShape.h"
#include "core/layout/shapes/RasterShape.h"
#include "core/layout/shapes/RectangleShape.h"
#include "core/style/ComputedStyle.h"
#include "core/svg/graphics/SVGImage.h"
#include "platform/LengthFunctions.h"
#include "platform/geometry/FloatRoundedRect.h"
#include "platform/geometry/FloatSize.h"
#include "platform/graphics/GraphicsTypes.h"
#include "platform/graphics/ImageBuffer.h"
#include "wtf/MathExtras.h"
#include "wtf/PtrUtil.h"
#include "wtf/typed_arrays/ArrayBufferContents.h"
#include <memory>

namespace blink {

static std::unique_ptr<Shape> createInsetShape(const FloatRoundedRect& bounds) {
  ASSERT(bounds.rect().width() >= 0 && bounds.rect().height() >= 0);
  return WTF::makeUnique<BoxShape>(bounds);
}

static std::unique_ptr<Shape> createCircleShape(const FloatPoint& center,
                                                float radius) {
  ASSERT(radius >= 0);
  return WTF::wrapUnique(
      new RectangleShape(FloatRect(center.x() - radius, center.y() - radius,
                                   radius * 2, radius * 2),
                         FloatSize(radius, radius)));
}

static std::unique_ptr<Shape> createEllipseShape(const FloatPoint& center,
                                                 const FloatSize& radii) {
  ASSERT(radii.width() >= 0 && radii.height() >= 0);
  return WTF::wrapUnique(new RectangleShape(
      FloatRect(center.x() - radii.width(), center.y() - radii.height(),
                radii.width() * 2, radii.height() * 2),
      radii));
}

static std::unique_ptr<Shape> createPolygonShape(
    std::unique_ptr<Vector<FloatPoint>> vertices,
    WindRule fillRule) {
  return WTF::wrapUnique(new PolygonShape(std::move(vertices), fillRule));
}

static inline FloatRect physicalRectToLogical(const FloatRect& rect,
                                              float logicalBoxHeight,
                                              WritingMode writingMode) {
  if (isHorizontalWritingMode(writingMode))
    return rect;
  if (isFlippedBlocksWritingMode(writingMode))
    return FloatRect(rect.y(), logicalBoxHeight - rect.maxX(), rect.height(),
                     rect.width());
  return rect.transposedRect();
}

static inline FloatPoint physicalPointToLogical(const FloatPoint& point,
                                                float logicalBoxHeight,
                                                WritingMode writingMode) {
  if (isHorizontalWritingMode(writingMode))
    return point;
  if (isFlippedBlocksWritingMode(writingMode))
    return FloatPoint(point.y(), logicalBoxHeight - point.x());
  return point.transposedPoint();
}

static inline FloatSize physicalSizeToLogical(const FloatSize& size,
                                              WritingMode writingMode) {
  if (isHorizontalWritingMode(writingMode))
    return size;
  return size.transposedSize();
}

std::unique_ptr<Shape> Shape::createShape(const BasicShape* basicShape,
                                          const LayoutSize& logicalBoxSize,
                                          WritingMode writingMode,
                                          float margin) {
  ASSERT(basicShape);

  bool horizontalWritingMode = isHorizontalWritingMode(writingMode);
  float boxWidth = horizontalWritingMode ? logicalBoxSize.width().toFloat()
                                         : logicalBoxSize.height().toFloat();
  float boxHeight = horizontalWritingMode ? logicalBoxSize.height().toFloat()
                                          : logicalBoxSize.width().toFloat();
  std::unique_ptr<Shape> shape;

  switch (basicShape->type()) {
    case BasicShape::BasicShapeCircleType: {
      const BasicShapeCircle* circle = toBasicShapeCircle(basicShape);
      FloatPoint center = floatPointForCenterCoordinate(
          circle->centerX(), circle->centerY(), FloatSize(boxWidth, boxHeight));
      float radius =
          circle->floatValueForRadiusInBox(FloatSize(boxWidth, boxHeight));
      FloatPoint logicalCenter = physicalPointToLogical(
          center, logicalBoxSize.height().toFloat(), writingMode);

      shape = createCircleShape(logicalCenter, radius);
      break;
    }

    case BasicShape::BasicShapeEllipseType: {
      const BasicShapeEllipse* ellipse = toBasicShapeEllipse(basicShape);
      FloatPoint center =
          floatPointForCenterCoordinate(ellipse->centerX(), ellipse->centerY(),
                                        FloatSize(boxWidth, boxHeight));
      float radiusX = ellipse->floatValueForRadiusInBox(ellipse->radiusX(),
                                                        center.x(), boxWidth);
      float radiusY = ellipse->floatValueForRadiusInBox(ellipse->radiusY(),
                                                        center.y(), boxHeight);
      FloatPoint logicalCenter = physicalPointToLogical(
          center, logicalBoxSize.height().toFloat(), writingMode);

      shape = createEllipseShape(logicalCenter, FloatSize(radiusX, radiusY));
      break;
    }

    case BasicShape::BasicShapePolygonType: {
      const BasicShapePolygon* polygon = toBasicShapePolygon(basicShape);
      const Vector<Length>& values = polygon->values();
      size_t valuesSize = values.size();
      ASSERT(!(valuesSize % 2));
      std::unique_ptr<Vector<FloatPoint>> vertices =
          WTF::wrapUnique(new Vector<FloatPoint>(valuesSize / 2));
      for (unsigned i = 0; i < valuesSize; i += 2) {
        FloatPoint vertex(floatValueForLength(values.at(i), boxWidth),
                          floatValueForLength(values.at(i + 1), boxHeight));
        (*vertices)[i / 2] = physicalPointToLogical(
            vertex, logicalBoxSize.height().toFloat(), writingMode);
      }
      shape = createPolygonShape(std::move(vertices), polygon->getWindRule());
      break;
    }

    case BasicShape::BasicShapeInsetType: {
      const BasicShapeInset& inset = *toBasicShapeInset(basicShape);
      float left = floatValueForLength(inset.left(), boxWidth);
      float top = floatValueForLength(inset.top(), boxHeight);
      float right = floatValueForLength(inset.right(), boxWidth);
      float bottom = floatValueForLength(inset.bottom(), boxHeight);
      FloatRect rect(left, top, std::max<float>(boxWidth - left - right, 0),
                     std::max<float>(boxHeight - top - bottom, 0));
      FloatRect logicalRect = physicalRectToLogical(
          rect, logicalBoxSize.height().toFloat(), writingMode);

      FloatSize boxSize(boxWidth, boxHeight);
      FloatSize topLeftRadius = physicalSizeToLogical(
          floatSizeForLengthSize(inset.topLeftRadius(), boxSize), writingMode);
      FloatSize topRightRadius = physicalSizeToLogical(
          floatSizeForLengthSize(inset.topRightRadius(), boxSize), writingMode);
      FloatSize bottomLeftRadius = physicalSizeToLogical(
          floatSizeForLengthSize(inset.bottomLeftRadius(), boxSize),
          writingMode);
      FloatSize bottomRightRadius = physicalSizeToLogical(
          floatSizeForLengthSize(inset.bottomRightRadius(), boxSize),
          writingMode);
      FloatRoundedRect::Radii cornerRadii(topLeftRadius, topRightRadius,
                                          bottomLeftRadius, bottomRightRadius);

      FloatRoundedRect finalRect(logicalRect, cornerRadii);
      finalRect.constrainRadii();

      shape = createInsetShape(finalRect);
      break;
    }

    default:
      ASSERT_NOT_REACHED();
  }

  shape->m_writingMode = writingMode;
  shape->m_margin = margin;

  return shape;
}

std::unique_ptr<Shape> Shape::createEmptyRasterShape(WritingMode writingMode,
                                                     float margin) {
  std::unique_ptr<RasterShapeIntervals> intervals =
      WTF::makeUnique<RasterShapeIntervals>(0, 0);
  std::unique_ptr<RasterShape> rasterShape =
      WTF::wrapUnique(new RasterShape(std::move(intervals), IntSize()));
  rasterShape->m_writingMode = writingMode;
  rasterShape->m_margin = margin;
  return std::move(rasterShape);
}

std::unique_ptr<Shape> Shape::createRasterShape(Image* image,
                                                float threshold,
                                                const LayoutRect& imageR,
                                                const LayoutRect& marginR,
                                                WritingMode writingMode,
                                                float margin) {
  IntRect imageRect = pixelSnappedIntRect(imageR);
  IntRect marginRect = pixelSnappedIntRect(marginR);

  std::unique_ptr<RasterShapeIntervals> intervals = WTF::wrapUnique(
      new RasterShapeIntervals(marginRect.height(), -marginRect.y()));
  std::unique_ptr<ImageBuffer> imageBuffer =
      ImageBuffer::create(imageRect.size());

  if (image && imageBuffer) {
    // FIXME: This is not totally correct but it is needed to prevent shapes
    // that loads SVG Images during paint invalidations to mark layoutObjects
    // for layout, which is not allowed. See https://crbug.com/429346
    ImageObserverDisabler disabler(image);
    SkPaint paint;
    IntRect imageSourceRect(IntPoint(), image->size());
    IntRect imageDestRect(IntPoint(), imageRect.size());
    // TODO(ccameron): No color conversion is required here.
    image->draw(imageBuffer->canvas(), paint, imageDestRect, imageSourceRect,
                DoNotRespectImageOrientation,
                Image::DoNotClampImageToSourceRect,
                ColorBehavior::transformToGlobalTarget());

    WTF::ArrayBufferContents contents;
    imageBuffer->getImageData(Unmultiplied,
                              IntRect(IntPoint(), imageRect.size()), contents);
    DOMArrayBuffer* arrayBuffer = DOMArrayBuffer::create(contents);
    DOMUint8ClampedArray* pixelArray =
        DOMUint8ClampedArray::create(arrayBuffer, 0, arrayBuffer->byteLength());
    unsigned pixelArrayOffset = 3;  // Each pixel is four bytes: RGBA.
    uint8_t alphaPixelThreshold = threshold * 255;

    ASSERT(static_cast<unsigned>(imageRect.width() * imageRect.height() * 4) ==
           pixelArray->length());

    int minBufferY = std::max(0, marginRect.y() - imageRect.y());
    int maxBufferY =
        std::min(imageRect.height(), marginRect.maxY() - imageRect.y());

    for (int y = minBufferY; y < maxBufferY; ++y) {
      int startX = -1;
      for (int x = 0; x < imageRect.width(); ++x, pixelArrayOffset += 4) {
        uint8_t alpha = pixelArray->item(pixelArrayOffset);
        bool alphaAboveThreshold = alpha > alphaPixelThreshold;
        if (startX == -1 && alphaAboveThreshold) {
          startX = x;
        } else if (startX != -1 &&
                   (!alphaAboveThreshold || x == imageRect.width() - 1)) {
          int endX = alphaAboveThreshold ? x + 1 : x;
          intervals->intervalAt(y + imageRect.y())
              .unite(IntShapeInterval(startX + imageRect.x(),
                                      endX + imageRect.x()));
          startX = -1;
        }
      }
    }
  }

  std::unique_ptr<RasterShape> rasterShape =
      WTF::wrapUnique(new RasterShape(std::move(intervals), marginRect.size()));
  rasterShape->m_writingMode = writingMode;
  rasterShape->m_margin = margin;
  return std::move(rasterShape);
}

std::unique_ptr<Shape> Shape::createLayoutBoxShape(
    const FloatRoundedRect& roundedRect,
    WritingMode writingMode,
    float margin) {
  FloatRect rect(0, 0, roundedRect.rect().width(), roundedRect.rect().height());
  FloatRoundedRect bounds(rect, roundedRect.getRadii());
  std::unique_ptr<Shape> shape = createInsetShape(bounds);
  shape->m_writingMode = writingMode;
  shape->m_margin = margin;

  return shape;
}

}  // namespace blink