/*
 * Copyright (C) 2011 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 COMPUTER, 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 COMPUTER, 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.
 */

#ifndef FilterOperation_h
#define FilterOperation_h

#include "core/CoreExport.h"
#include "platform/Length.h"
#include "platform/graphics/BoxReflection.h"
#include "platform/graphics/Color.h"
#include "platform/graphics/filters/Filter.h"
#include "platform/heap/Handle.h"
#include "wtf/Noncopyable.h"
#include "wtf/text/WTFString.h"

namespace blink {

// CSS Filters

class CORE_EXPORT FilterOperation
    : public GarbageCollectedFinalized<FilterOperation> {
  WTF_MAKE_NONCOPYABLE(FilterOperation);

 public:
  enum OperationType {
    REFERENCE,  // url(#somefilter)
    GRAYSCALE,
    SEPIA,
    SATURATE,
    HUE_ROTATE,
    INVERT,
    OPACITY,
    BRIGHTNESS,
    CONTRAST,
    BLUR,
    DROP_SHADOW,
    BOX_REFLECT,
    NONE
  };

  static bool canInterpolate(FilterOperation::OperationType type) {
    switch (type) {
      case GRAYSCALE:
      case SEPIA:
      case SATURATE:
      case HUE_ROTATE:
      case INVERT:
      case OPACITY:
      case BRIGHTNESS:
      case CONTRAST:
      case BLUR:
      case DROP_SHADOW:
        return true;
      case REFERENCE:
      case BOX_REFLECT:
        return false;
      case NONE:
        break;
    }
    NOTREACHED();
    return false;
  }

  virtual ~FilterOperation() {}
  DEFINE_INLINE_VIRTUAL_TRACE() {}

  static FilterOperation* blend(const FilterOperation* from,
                                const FilterOperation* to,
                                double progress);
  virtual bool operator==(const FilterOperation&) const = 0;
  bool operator!=(const FilterOperation& o) const { return !(*this == o); }

  OperationType type() const { return m_type; }
  virtual bool isSameType(const FilterOperation& o) const {
    return o.type() == m_type;
  }

  // True if the alpha channel of any pixel can change under this operation.
  virtual bool affectsOpacity() const { return false; }
  // True if the the value of one pixel can affect the value of another pixel
  // under this operation, such as blur.
  virtual bool movesPixels() const { return false; }

  // Maps "forward" to determine which pixels in a destination rect are
  // affected by pixels in the source rect.
  // See also FilterEffect::mapRect.
  virtual FloatRect mapRect(const FloatRect& rect) const { return rect; }

 protected:
  FilterOperation(OperationType type) : m_type(type) {}

  OperationType m_type;

 private:
  virtual FilterOperation* blend(const FilterOperation* from,
                                 double progress) const = 0;
};

#define DEFINE_FILTER_OPERATION_TYPE_CASTS(thisType, operationType) \
  DEFINE_TYPE_CASTS(thisType, FilterOperation, op,                  \
                    op->type() == FilterOperation::operationType,   \
                    op.type() == FilterOperation::operationType);

class CORE_EXPORT ReferenceFilterOperation : public FilterOperation {
 public:
  static ReferenceFilterOperation* create(const String& url,
                                          const AtomicString& fragment) {
    return new ReferenceFilterOperation(url, fragment);
  }

  bool affectsOpacity() const override { return true; }
  bool movesPixels() const override { return true; }
  FloatRect mapRect(const FloatRect&) const override;

  const String& url() const { return m_url; }
  const AtomicString& fragment() const { return m_fragment; }

  Filter* getFilter() const { return m_filter.get(); }
  void setFilter(Filter* filter) { m_filter = filter; }

  DECLARE_VIRTUAL_TRACE();

 private:
  FilterOperation* blend(const FilterOperation* from,
                         double progress) const override {
    NOTREACHED();
    return nullptr;
  }

  bool operator==(const FilterOperation& o) const override {
    if (!isSameType(o))
      return false;
    const ReferenceFilterOperation* other =
        static_cast<const ReferenceFilterOperation*>(&o);
    return m_url == other->m_url;
  }

  ReferenceFilterOperation(const String& url, const AtomicString& fragment)
      : FilterOperation(REFERENCE), m_url(url), m_fragment(fragment) {}

  String m_url;
  AtomicString m_fragment;
  Member<Filter> m_filter;
};

DEFINE_FILTER_OPERATION_TYPE_CASTS(ReferenceFilterOperation, REFERENCE);

// GRAYSCALE, SEPIA, SATURATE and HUE_ROTATE are variations on a basic color
// matrix effect.  For HUE_ROTATE, the angle of rotation is stored in m_amount.
class CORE_EXPORT BasicColorMatrixFilterOperation : public FilterOperation {
 public:
  static BasicColorMatrixFilterOperation* create(double amount,
                                                 OperationType type) {
    return new BasicColorMatrixFilterOperation(amount, type);
  }

  double amount() const { return m_amount; }

 private:
  FilterOperation* blend(const FilterOperation* from,
                         double progress) const override;
  bool operator==(const FilterOperation& o) const override {
    if (!isSameType(o))
      return false;
    const BasicColorMatrixFilterOperation* other =
        static_cast<const BasicColorMatrixFilterOperation*>(&o);
    return m_amount == other->m_amount;
  }

  BasicColorMatrixFilterOperation(double amount, OperationType type)
      : FilterOperation(type), m_amount(amount) {}

  double m_amount;
};

inline bool isBasicColorMatrixFilterOperation(
    const FilterOperation& operation) {
  FilterOperation::OperationType type = operation.type();
  return type == FilterOperation::GRAYSCALE || type == FilterOperation::SEPIA ||
         type == FilterOperation::SATURATE ||
         type == FilterOperation::HUE_ROTATE;
}

DEFINE_TYPE_CASTS(BasicColorMatrixFilterOperation,
                  FilterOperation,
                  op,
                  isBasicColorMatrixFilterOperation(*op),
                  isBasicColorMatrixFilterOperation(op));

// INVERT, BRIGHTNESS, CONTRAST and OPACITY are variations on a basic component
// transfer effect.
class CORE_EXPORT BasicComponentTransferFilterOperation
    : public FilterOperation {
 public:
  static BasicComponentTransferFilterOperation* create(double amount,
                                                       OperationType type) {
    return new BasicComponentTransferFilterOperation(amount, type);
  }

  double amount() const { return m_amount; }

  bool affectsOpacity() const override { return m_type == OPACITY; }

 private:
  FilterOperation* blend(const FilterOperation* from,
                         double progress) const override;
  bool operator==(const FilterOperation& o) const override {
    if (!isSameType(o))
      return false;
    const BasicComponentTransferFilterOperation* other =
        static_cast<const BasicComponentTransferFilterOperation*>(&o);
    return m_amount == other->m_amount;
  }

  BasicComponentTransferFilterOperation(double amount, OperationType type)
      : FilterOperation(type), m_amount(amount) {}

  double m_amount;
};

inline bool isBasicComponentTransferFilterOperation(
    const FilterOperation& operation) {
  FilterOperation::OperationType type = operation.type();
  return type == FilterOperation::INVERT || type == FilterOperation::OPACITY ||
         type == FilterOperation::BRIGHTNESS ||
         type == FilterOperation::CONTRAST;
}

DEFINE_TYPE_CASTS(BasicComponentTransferFilterOperation,
                  FilterOperation,
                  op,
                  isBasicComponentTransferFilterOperation(*op),
                  isBasicComponentTransferFilterOperation(op));

class CORE_EXPORT BlurFilterOperation : public FilterOperation {
 public:
  static BlurFilterOperation* create(const Length& stdDeviation) {
    return new BlurFilterOperation(stdDeviation);
  }

  const Length& stdDeviation() const { return m_stdDeviation; }

  bool affectsOpacity() const override { return true; }
  bool movesPixels() const override { return true; }
  FloatRect mapRect(const FloatRect&) const override;

 private:
  FilterOperation* blend(const FilterOperation* from,
                         double progress) const override;
  bool operator==(const FilterOperation& o) const override {
    if (!isSameType(o))
      return false;
    const BlurFilterOperation* other =
        static_cast<const BlurFilterOperation*>(&o);
    return m_stdDeviation == other->m_stdDeviation;
  }

  BlurFilterOperation(const Length& stdDeviation)
      : FilterOperation(BLUR), m_stdDeviation(stdDeviation) {}

  Length m_stdDeviation;
};

DEFINE_FILTER_OPERATION_TYPE_CASTS(BlurFilterOperation, BLUR);

class CORE_EXPORT DropShadowFilterOperation : public FilterOperation {
 public:
  static DropShadowFilterOperation* create(const IntPoint& location,
                                           int stdDeviation,
                                           Color color) {
    return new DropShadowFilterOperation(location, stdDeviation, color);
  }

  int x() const { return m_location.x(); }
  int y() const { return m_location.y(); }
  IntPoint location() const { return m_location; }
  int stdDeviation() const { return m_stdDeviation; }
  Color getColor() const { return m_color; }

  bool affectsOpacity() const override { return true; }
  bool movesPixels() const override { return true; }
  FloatRect mapRect(const FloatRect&) const override;

 private:
  FilterOperation* blend(const FilterOperation* from,
                         double progress) const override;
  bool operator==(const FilterOperation& o) const override {
    if (!isSameType(o))
      return false;
    const DropShadowFilterOperation* other =
        static_cast<const DropShadowFilterOperation*>(&o);
    return m_location == other->m_location &&
           m_stdDeviation == other->m_stdDeviation && m_color == other->m_color;
  }

  DropShadowFilterOperation(const IntPoint& location,
                            int stdDeviation,
                            Color color)
      : FilterOperation(DROP_SHADOW),
        m_location(location),
        m_stdDeviation(stdDeviation),
        m_color(color) {}

  IntPoint m_location;  // FIXME: should location be in Lengths?
  int m_stdDeviation;
  Color m_color;
};

DEFINE_FILTER_OPERATION_TYPE_CASTS(DropShadowFilterOperation, DROP_SHADOW);

class CORE_EXPORT BoxReflectFilterOperation : public FilterOperation {
 public:
  static BoxReflectFilterOperation* create(const BoxReflection& reflection) {
    return new BoxReflectFilterOperation(reflection);
  }

  const BoxReflection& reflection() const { return m_reflection; }

  bool affectsOpacity() const override { return true; }
  bool movesPixels() const override { return true; }
  FloatRect mapRect(const FloatRect&) const override;

 private:
  FilterOperation* blend(const FilterOperation* from,
                         double progress) const override;
  bool operator==(const FilterOperation&) const override;

  BoxReflectFilterOperation(const BoxReflection& reflection)
      : FilterOperation(BOX_REFLECT), m_reflection(reflection) {}

  BoxReflection m_reflection;
};
DEFINE_FILTER_OPERATION_TYPE_CASTS(BoxReflectFilterOperation, BOX_REFLECT);

}  // namespace blink

#endif  // FilterOperation_h