/*

 * Copyright 2019 Google, LLC

 *

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

 * found in the LICENSE file.

 */

#include "src/gpu/GrShaderCaps.h"

#include "src/sksl/SkSLCompiler.h"

#include "src/sksl/codegen/SkSLPipelineStageCodeGenerator.h"

#include "src/sksl/ir/SkSLVarDeclarations.h"

#include "src/sksl/ir/SkSLVariable.h"

#include "fuzz/Fuzz.h"

bool FuzzSKSL2Pipeline(sk_sp<SkData> bytes) {

    sk_sp<GrShaderCaps> caps = SkSL::ShaderCapsFactory::Default();

    SkSL::Compiler compiler(caps.get());

    SkSL::Program::Settings settings;

    std::unique_ptr<SkSL::Program> program = compiler.convertProgram(

                                                    SkSL::ProgramKind::kRuntimeShader,

                                                    SkSL::String((const char*) bytes->data(),

                                                                 bytes->size()),

                                                    settings);

    if (!program) {

        return false;

    }

    class Callbacks : public SkSL::PipelineStage::Callbacks {

        using String = SkSL::String;

        String declareUniform(const SkSL::VarDeclaration* decl) override {

            return String(decl->var().name());

        }

        void defineFunction(const char* /*decl*/, const char* /*body*/, bool /*isMain*/) override {}

        void defineStruct(const char* /*definition*/) override {}

        void declareGlobal(const char* /*declaration*/) override {}

        String sampleShader(int index, String coords) override {

            return "sample(" + SkSL::to_string(index) + ", " + coords + ")";

        }

        String sampleColorFilter(int index, String color) override {

            String result = "sample(" + SkSL::to_string(index);

            if (!color.empty()) {

                result += ", " + color;

            }

            result += ")";

            return result;

        }

        String sampleBlender(int index, String src, String dst) override {

            return "sample(" + SkSL::to_string(index) + ", " + src + ", " + dst + ")";

        }

    };

    Callbacks callbacks;

    SkSL::PipelineStage::ConvertProgram(*program, "coords", "inColor", "half4(1)", &callbacks);

    return true;

}

#if defined(SK_BUILD_FOR_LIBFUZZER)

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {

    if (size > 3000) {

        return 0;

    }

    auto bytes = SkData::MakeWithoutCopy(data, size);

    FuzzSKSL2Pipeline(bytes);

    return 0;

}

#endif