/*

 * Copyright 2020 Google, LLC

 *

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

 * found in the LICENSE file.

 */

#include "include/core/SkCanvas.h"

#include "include/core/SkPaint.h"

#include "include/core/SkSurface.h"

#include "include/gpu/GrDirectContext.h"

#include "include/gpu/ganesh/SkSurfaceGanesh.h"

#include "include/private/chromium/GrDeferredDisplayList.h"

#include "include/private/chromium/GrDeferredDisplayListRecorder.h"

#include "include/private/chromium/GrSurfaceCharacterization.h"

#include "include/private/gpu/ganesh/GrTypesPriv.h"

#include "src/gpu/ganesh/GrShaderCaps.h"

#include "tools/gpu/GrContextFactory.h"

#include "fuzz/Fuzz.h"

#include <tuple>

/**

 * The fuzzer aims to fuzz the use of GrDeferredDisplayList. It mainly consists of

 * three parts.

 * 1. In create_surface_characterization, (make_characterization) Create GrSurfaceCharacterization

 * by using GrDirectContext of ContextType::kGL as it can be applied on all platform, and

 * (make_surface) create a GPU backend surface of the same GrDirectContext

 * 2. (make_ddl) Create GrDeferredDisplayListRecorder from the GrSurfaceCharacterization, and test

 * the recoder's corresponding canvas.

 * 3. (make_ddl, draw_ddl) Create GrDeferredDisplayList from the SkDeferredDisplayRecorder and draw

 * the ddl on a GPU backend surface.

 */

static constexpr int kMaxWidth = 64;

static constexpr int kMaxHeight = 64;

static constexpr int kSampleCount = 1;

static SkSurfaceProps gen_fuzzed_surface_props(Fuzz* fuzz) {

    SkPixelGeometry pixel;

    fuzz->nextEnum(&pixel, kBGR_V_SkPixelGeometry);

    return SkSurfaceProps(0x0, pixel);

}

static SkPaint gen_fuzzed_skpaint(Fuzz* fuzz) {

    float R, G, B, Alpha;

    fuzz->nextRange(&R, -1, 2);

    fuzz->nextRange(&G, -1, 2);

    fuzz->nextRange(&B, -1, 2);

    fuzz->nextRange(&Alpha, 0, 1);

    SkColor4f color = {R, G, B, Alpha};

    return SkPaint(color);

}

static SkImageInfo gen_fuzzed_imageinfo(Fuzz* fuzz, SkColorType surfaceType) {

    int width, height;

    fuzz->nextRange(&width, 1, kMaxWidth);

    fuzz->nextRange(&height, 1, kMaxHeight);

    SkAlphaType alphaType;

    fuzz->nextEnum(&alphaType, SkAlphaType::kLastEnum_SkAlphaType);

    skcms_TransferFunction skcmsFn;

    uint8_t skcms;

    fuzz->nextRange(&skcms, 0, 5);

    switch (skcms) {

        case 0: {

            skcmsFn = SkNamedTransferFn::kSRGB;

            break;

        }

        case 1: {

            skcmsFn = SkNamedTransferFn::k2Dot2;

            break;

        }

        case 2: {

            skcmsFn = SkNamedTransferFn::kHLG;

            break;

        }

        case 3: {

            skcmsFn = SkNamedTransferFn::kLinear;

            break;

        }

        case 4: {

            skcmsFn = SkNamedTransferFn::kPQ;

            break;

        }

        case 5: {

            skcmsFn = SkNamedTransferFn::kRec2020;

            break;

        }

        default:

            SkASSERT(false);

            break;

    }

    skcms_Matrix3x3 skcmsMat;

    fuzz->nextRange(&skcms, 0, 4);

    switch (skcms) {

        case 0: {

            skcmsMat = SkNamedGamut::kAdobeRGB;

            break;

        }

        case 1: {

            skcmsMat = SkNamedGamut::kDisplayP3;

            break;

        }

        case 2: {

            skcmsMat = SkNamedGamut::kRec2020;

            break;

        }

        case 3: {

            skcmsMat = SkNamedGamut::kSRGB;

            break;

        }

        case 4: {

            skcmsMat = SkNamedGamut::kXYZ;

            break;

        }

        default:

            SkASSERT(false);

            break;

    }

    return SkImageInfo::Make(width, height, surfaceType, alphaType,

                             SkColorSpace::MakeRGB(skcmsFn, skcmsMat));

}

static GrSurfaceCharacterization make_characterization(Fuzz* fuzz, GrDirectContext* dContext,

                                                       SkImageInfo& ii, SkColorType surfaceType,

                                                       GrSurfaceOrigin origin) {

    if (!dContext->colorTypeSupportedAsSurface(surfaceType)) {

        SkDebugf("Couldn't create backend texture in the backend %s",

                 GrBackendApiToStr(dContext->backend()));

        return {};

    }

    GrBackendFormat backendFormat = dContext->defaultBackendFormat(surfaceType,

                                                                   GrRenderable::kYes);

    if (!backendFormat.isValid()) {

        SkDebugf("Color Type is not supported in the backend %s",

                 GrBackendApiToStr(dContext->backend()));

        return {};

    }

    GrProtected protect = GrProtected::kNo;

#ifdef SK_VULKAN

    fuzz->nextEnum(&protect, GrProtected::kYes);

#endif

    GrSurfaceCharacterization c;

    size_t maxResourceBytes = dContext->getResourceCacheLimit();

    c = dContext->threadSafeProxy()->createCharacterization(maxResourceBytes,

                                                            ii,

                                                            backendFormat,

                                                            kSampleCount,

                                                            origin,

                                                            gen_fuzzed_surface_props(fuzz),

                                                            skgpu::Mipmapped::kYes,

                                                            false,

                                                            true,

                                                            protect);

    if (!c.isValid()) {

        SkDebugf("Could not create Characterization in the backend %s",

                 GrBackendApiToStr(dContext->backend()));

        return {};

    }

    return c;

}

static sk_sp<GrDeferredDisplayList> make_ddl(Fuzz* fuzz, GrDirectContext* dContext,

                                             const GrSurfaceCharacterization& c) {

    GrDeferredDisplayListRecorder r(c);

    SkCanvas* canvas = r.getCanvas();

    if (!canvas) {

        SkDebugf("Could not create canvas for backend %s", GrBackendApiToStr(dContext->backend()));

        return nullptr;

    }

    // For now we only draw a rect into the DDL. This will be scaled up to draw more varied content.

    SkRect tile;

    fuzz->next(&tile);

    canvas->drawRect(tile, gen_fuzzed_skpaint(fuzz));

    return r.detach();

}

static sk_sp<SkSurface> make_surface(Fuzz* fuzz, GrDirectContext* dContext, const SkImageInfo& ii,

                                     GrSurfaceOrigin origin) {

    skgpu::Budgeted budgeted;

    fuzz->nextEnum(&budgeted, skgpu::Budgeted::kYes);

    SkSurfaceProps surfaceProps = gen_fuzzed_surface_props(fuzz);

    auto surface =

            SkSurfaces::RenderTarget(dContext, budgeted, ii, kSampleCount, origin, &surfaceProps);

    return surface;

}

static bool draw_ddl(sk_sp<SkSurface> surface, sk_sp<const GrDeferredDisplayList> ddl) {

    return skgpu::ganesh::DrawDDL(std::move(surface), std::move(ddl));

}

using SurfaceAndChar = std::tuple<sk_sp<SkSurface>, GrSurfaceCharacterization>;

static SurfaceAndChar create_surface_and_characterization(Fuzz* fuzz, GrDirectContext* dContext,

                                                          SkColorType surfaceType,

                                                          GrSurfaceOrigin origin) {

    SkImageInfo ii = gen_fuzzed_imageinfo(fuzz, surfaceType);

    GrSurfaceCharacterization c = make_characterization(fuzz, dContext, ii, surfaceType, origin);

    if (!c.isValid()) {

       return {};

    }

    auto surface = make_surface(fuzz, dContext, ii, origin);

    if (!surface) {

        return {};

    }

    return {surface, c};

}

DEF_FUZZ(CreateDDL, fuzz) {

    SkColorType surfaceType;

    GrSurfaceOrigin origin;

    fuzz->nextEnum(&surfaceType, SkColorType::kLastEnum_SkColorType);

    fuzz->nextEnum(&origin, GrSurfaceOrigin::kTopLeft_GrSurfaceOrigin);

    sk_gpu_test::GrContextFactory factory;

    auto ctxInfo = factory.getContextInfo(skgpu::ContextType::kGL);

    GrDirectContext* dContext = ctxInfo.directContext();

    if (!dContext) {

        SkDebugf("Context creation failed");

        return;

    }

    auto[surface, c] = create_surface_and_characterization(fuzz, dContext, surfaceType, origin);

    if (!surface || !c.isValid()) {

        return;

    }

    sk_sp<GrDeferredDisplayList> ddl = make_ddl(fuzz, dContext, c);

    if (!ddl) {

        SkDebugf("Could not create ddl %s", GrBackendApiToStr(dContext->backend()));

        return;

    }

    if (!draw_ddl(std::move(surface), std::move(ddl))) {

        SkDebugf("Could not draw ddl in the backend");

    }

    return;

}