/*

 * Copyright 2019 Google Inc.

 *

 * Use of this source code is governed by a BSD-style license that can be

 * found in the LICENSE file.

 */

#include "include/core/SkColor.h"

#include "include/core/SkPoint.h"

#include "include/core/SkRefCnt.h"

#include "include/core/SkScalar.h"

#include "include/private/base/SkTPin.h"

#include "include/private/base/SkTo.h"

#include "modules/skottie/src/SkottiePriv.h"

#include "modules/skottie/src/SkottieValue.h"

#include "modules/skottie/src/animator/Animator.h"

#include "modules/skottie/src/effects/Effects.h"

#include "modules/sksg/include/SkSGRenderEffect.h"

#include "modules/sksg/include/SkSGRenderNode.h"

#include <cstddef>

#include <utility>

namespace skjson {

class ArrayValue;

}

namespace skottie {

namespace internal {

namespace  {

class DropShadowAdapter final : public AnimatablePropertyContainer {

public:

    static sk_sp<DropShadowAdapter> Make(const skjson::ArrayValue& jprops,

                                         sk_sp<sksg::RenderNode> layer,

                                         const AnimationBuilder& abuilder) {

        enum : size_t {

            kShadowColor_Index = 0,

                kOpacity_Index = 1,

              kDirection_Index = 2,

               kDistance_Index = 3,

               kSoftness_Index = 4,

             kShadowOnly_Index = 5,

        };

        sk_sp<DropShadowAdapter> adapter(new DropShadowAdapter(std::move(layer)));

        EffectBinder(jprops, abuilder, adapter.get())

                .bind(kShadowColor_Index, adapter->fColor    )

                .bind(    kOpacity_Index, adapter->fOpacity  )

                .bind(  kDirection_Index, adapter->fDirection)

                .bind(   kDistance_Index, adapter->fDistance )

                .bind(   kSoftness_Index, adapter->fSoftness )

                .bind( kShadowOnly_Index, adapter->fShdwOnly );

        return adapter;

    }

    const sk_sp<sksg::RenderNode>& node() const { return fImageFilterEffect; }

private:

    explicit DropShadowAdapter(sk_sp<sksg::RenderNode> layer)

        : fDropShadow(sksg::DropShadowImageFilter::Make())

        , fImageFilterEffect(sksg::ImageFilterEffect::Make(std::move(layer), fDropShadow)) {}

    void onSync() override {

        // fColor -> RGB, fOpacity -> A

        const SkColor color = fColor;

        fDropShadow->setColor(SkColorSetA(color, SkTPin(SkScalarRoundToInt(fOpacity), 0, 255)));

        // The offset is specified in terms of a bearing + distance.

        const auto rad = SkDegreesToRadians(90 - fDirection);

        fDropShadow->setOffset(SkVector::Make( fDistance * SkScalarCos(rad),

                                              -fDistance * SkScalarSin(rad)));

        const auto sigma = fSoftness * kBlurSizeToSigma;

        fDropShadow->setSigma(SkVector::Make(sigma, sigma));

        fDropShadow->setMode(SkToBool(fShdwOnly)

                                ? sksg::DropShadowImageFilter::Mode::kShadowOnly

                                : sksg::DropShadowImageFilter::Mode::kShadowAndForeground);

    }

    const sk_sp<sksg::DropShadowImageFilter> fDropShadow;

    const sk_sp<sksg::RenderNode>            fImageFilterEffect;

    ColorValue  fColor     = { 0, 0, 0, 1 };

    ScalarValue fOpacity   = 255,

                fDirection = 0,

                fDistance  = 0,

                fSoftness  = 0,

                fShdwOnly  = 0;

};

}  // namespace

sk_sp<sksg::RenderNode> EffectBuilder::attachDropShadowEffect(const skjson::ArrayValue& jprops,

                                                              sk_sp<sksg::RenderNode> layer) const {

    return fBuilder->attachDiscardableAdapter<DropShadowAdapter>(jprops,

                                                                 std::move(layer),

                                                                 *fBuilder);

}

} // namespace internal

} // namespace skottie