/*

 * Copyright 2022 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/SkData.h"

#include "include/core/SkFont.h"

#include "include/core/SkFontMgr.h"

#include "include/core/SkStream.h"

#include "include/core/SkSurface.h"

#include "include/core/SkTypeface.h"

#include "tools/fonts/FontToolUtils.h"

#include <algorithm>

void FuzzCOLRv1(const uint8_t* data, size_t size) {

    // We do not want the portable fontmgr here, as it does not allow creation of fonts from bytes.

    sk_sp<SkFontMgr> mgr = ToolUtils::TestFontMgr();

    std::unique_ptr<SkStreamAsset> stream = SkMemoryStream::MakeDirect(data, size);

    sk_sp<SkTypeface> typeface = mgr->makeFromStream(std::move(stream), 0);

    if (!typeface) {

        return;

    }

    auto s = SkSurfaces::Raster(SkImageInfo::MakeN32Premul(128, 128));

    if (!s) {

        return;

    }

    // Place at a baseline in the lower part of the canvas square, but canvas size and baseline

    // placement are chosen arbitrarily and we just need to cover colrv1 rendering in this

    // fuzz test.

    SkFont colrv1Font = SkFont(typeface, 120);

    SkCanvas* canvas = s->getCanvas();

    SkPaint paint;

    int numGlyphs = typeface->countGlyphs();

    for (int i = 0; i < std::min(numGlyphs, 10); ++i) {

        SkPoint origin = SkPoint::Make(10, 108);

        SkPoint position = SkPoint::Make(0, 0);

        SkGlyphID glyphId = i;

        canvas->drawGlyphs(1, &glyphId, &position, origin, colrv1Font, paint);

    }

}

#if defined(SK_BUILD_FOR_LIBFUZZER)

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

    // COLRv1 corpus file sizes range from 8k for a small test glyph file to about 80k covering

    // most of the complex Noto Emoji glyphs, compare:

    // See https://github.com/googlefonts/color-fonts/blob/main/rebuild_fuzzer_corpus.py

    if (size > 80 * 1024) {

        return 0;

    }

    FuzzCOLRv1(data, size);

    return 0;

}

#endif