// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_ANIMATION_CSS_INTERPOLATION_ENVIRONMENT_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_ANIMATION_CSS_INTERPOLATION_ENVIRONMENT_H_

#include "third_party/blink/renderer/core/animation/interpolation_environment.h"
#include "third_party/blink/renderer/core/css/resolver/style_resolver_state.h"

namespace blink {

class CascadeResolver;
class ComputedStyle;
class StyleCascade;

class CSSInterpolationEnvironment : public InterpolationEnvironment {
 public:
  explicit CSSInterpolationEnvironment(const InterpolationTypesMap& map,
                                       StyleResolverState& state,
                                       StyleCascade* cascade,
                                       CascadeResolver* cascade_resolver)
      : InterpolationEnvironment(map),
        state_(&state),
        style_(state.Style()),
        cascade_(cascade),
        cascade_resolver_(cascade_resolver) {}

  explicit CSSInterpolationEnvironment(const InterpolationTypesMap& map,
                                       const ComputedStyle& style)
      : InterpolationEnvironment(map), style_(&style) {}

  bool IsCSS() const final { return true; }

  StyleResolverState& GetState() {
    DCHECK(state_);
    return *state_;
  }
  const StyleResolverState& GetState() const {
    DCHECK(state_);
    return *state_;
  }

  const ComputedStyle& Style() const {
    DCHECK(style_);
    return *style_;
  }

  // TODO(crbug.com/985023): This effective violates const.
  const CSSValue* Resolve(const PropertyHandle&, const CSSValue*) const;

 private:
  StyleResolverState* state_ = nullptr;
  const ComputedStyle* style_ = nullptr;
  StyleCascade* cascade_ = nullptr;
  CascadeResolver* cascade_resolver_ = nullptr;
};

template <>
struct DowncastTraits<CSSInterpolationEnvironment> {
  static bool AllowFrom(const InterpolationEnvironment& value) {
    return value.IsCSS();
  }
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_ANIMATION_CSS_INTERPOLATION_ENVIRONMENT_H_