/*
 * Copyright 2022 Google LLC
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef skgpu_graphite_PrecompileInternal_DEFINED
#define skgpu_graphite_PrecompileInternal_DEFINED

#include "include/core/SkBlendMode.h"
#include "include/core/SkRefCnt.h"
#include "include/gpu/graphite/precompile/PaintOptions.h"
#include "include/gpu/graphite/precompile/PrecompileBase.h"
#include "include/private/base/SkTArray.h"
#include "include/private/base/SkTemplates.h"
#include "src/gpu/graphite/precompile/PaintOptionsPriv.h"

#include <functional>
#include <optional>
#include <vector>

class SkRuntimeEffect;

namespace skgpu::graphite {

enum class Coverage;
class Context;


class UniquePaintParamsID;

// Create the Pipelines specified by 'options' by combining the shading portion w/ the specified
// 'drawTypes' and a stock set of RenderPass descriptors (e.g., kDepth+msaa, kDepthStencil+msaa)
void PrecompileCombinations(Context* context,
                            const PaintOptions& options,
                            const KeyContext& keyContext,
                            DrawTypeFlags drawTypes,
                            bool withPrimitiveBlender,
                            Coverage coverage);

//--------------------------------------------------------------------------------------------------

class PrecompileColorFilter : public PrecompileBase {
public:
    PrecompileColorFilter() : PrecompileBase(Type::kColorFilter) {}

    sk_sp<PrecompileColorFilter> makeComposed(sk_sp<PrecompileColorFilter> inner) const;
};

//--------------------------------------------------------------------------------------------------
class PrecompileImageFilter : public PrecompileBase {
public:
    virtual sk_sp<PrecompileColorFilter> isColorFilterNode() const { return nullptr; }

    int countInputs() const { return fInputs.count(); }

    const PrecompileImageFilter* getInput(int index) const {
        SkASSERT(index < this->countInputs());
        return fInputs[index].get();
    }

protected:
    PrecompileImageFilter(SkSpan<sk_sp<PrecompileImageFilter>> inputs)
            : PrecompileBase(Type::kImageFilter) {
        fInputs.reset(inputs.size());
        for (int i = 0; i < (int) inputs.size(); ++i) {
            fInputs[i] = inputs[i];
        }
    }

private:
    friend class PaintOptions;  // for createPipelines() access

    // The PrecompileImageFilter classes do not use the PrecompileBase::addToKey virtual since
    // they, in general, do not themselves contribute to a given SkPaint/Pipeline but, rather,
    // create separate SkPaints/Pipelines from whole cloth (in onCreatePipelines).
    void addToKey(const KeyContext& keyContext,
                  PaintParamsKeyBuilder* builder,
                  PipelineDataGatherer* gatherer,
                  int desiredCombination) const final {
        SkASSERT(false);
    }

    sk_sp<PrecompileColorFilter> asAColorFilter() const {
        sk_sp<PrecompileColorFilter> tmp = this->isColorFilterNode();
        if (!tmp) {
            return nullptr;
        }
        SkASSERT(this->countInputs() == 1);
        if (this->getInput(0)) {
            return nullptr;
        }
        // TODO: as in SkImageFilter::asAColorFilter, handle the special case of
        // affectsTransparentBlack. This is tricky for precompilation since we don't,
        // necessarily, have all the parameters of the ColorFilter in order to evaluate
        // filterColor4f(SkColors::kTransparent) - the normal API's implementation.
        return tmp;
    }

    virtual void onCreatePipelines(const KeyContext&,
                                   PipelineDataGatherer*,
                                   const PaintOptionsPriv::ProcessCombination&) const = 0;

    void createPipelines(const KeyContext& keyContext,
                         PipelineDataGatherer* gatherer,
                         const PaintOptionsPriv::ProcessCombination& processCombination) {
        // TODO: we will want to mark already visited nodes to prevent loops and track
        // already created Pipelines so we don't over-generate too much (e.g., if a DAG
        // has multiple blurs we don't want to keep trying to create all the blur pipelines).
        this->onCreatePipelines(keyContext, gatherer, processCombination);

        for (const sk_sp<PrecompileImageFilter>& input : fInputs) {
            if (input) {
                input->createPipelines(keyContext, gatherer, processCombination);
            }
        }
    }

    skia_private::AutoSTArray<2, sk_sp<PrecompileImageFilter>> fInputs;
};

class PrecompileMaskFilter : public PrecompileBase {
public:
    PrecompileMaskFilter() : PrecompileBase(Type::kMaskFilter) {}

private:
    friend class PaintOptions;  // for createPipelines() access

    // The PrecompileMaskFilter classes do not use the PrecompileBase::addToKey virtual since
    // they, in general, do not themselves contribute to a given SkPaint/Pipeline but, rather,
    // create separate SkPaints/Pipelines from whole cloth (in createPipelines).
    void addToKey(const KeyContext& keyContext,
                  PaintParamsKeyBuilder* builder,
                  PipelineDataGatherer* gatherer,
                  int desiredCombination) const final {
        SkASSERT(false);
    }

    virtual void createPipelines(const KeyContext&,
                                 PipelineDataGatherer*,
                                 const PaintOptionsPriv::ProcessCombination&) const = 0;
};

} // namespace skgpu::graphite

#endif // skgpu_graphite_PrecompileInternal_DEFINED