// Copyright 2024 Google Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//      http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

//

////////////////////////////////////////////////////////////////////////////////

// Fuzzing of libwebp's image readers

#include <cstddef>

#include <cstdint>

#include <cstdlib>

#include <iostream>

#include <string_view>

#include "imageio/image_dec.h"

#include "imageio/metadata.h"

#include "src/webp/encode.h"

#include "tests/fuzzer/fuzz_utils.h"

namespace {

void TestReader(const uint8_t *data, size_t size, WebPImageReader reader,

                bool keep_alpha, bool use_argb) {

  WebPPicture pic;

  if (!WebPPictureInit(&pic)) {

    std::cerr << "WebPPictureInit failed" << std::endl;

    std::abort();

  }

  Metadata metadata;

  MetadataInit(&metadata);

  pic.use_argb = use_argb ? 1 : 0;

  if (!fuzz_utils::IsImageTooBig(data, size)) {

    (void)(*reader)(data, size, &pic, keep_alpha ? 1 : 0, &metadata);

  }

  WebPPictureFree(&pic);

  MetadataFree(&metadata);

}

constexpr WebPInputFileFormat kUnknown = WEBP_UNSUPPORTED_FORMAT;

void Decode(std::string_view arbitrary_bytes, WebPInputFileFormat format,

            bool keep_alpha, bool use_argb) {

  const uint8_t *data =

      reinterpret_cast<const uint8_t *>(arbitrary_bytes.data());

  const size_t size = arbitrary_bytes.size();

  if (format == kUnknown) {

    (void)WebPGuessImageType(data, size);  // shouldn't fail

    TestReader(data, size, WebPGuessImageReader(data, size), keep_alpha,

               use_argb);

  } else {

    TestReader(data, size, WebPGetImageReader(format), keep_alpha, use_argb);

  }

}

FUZZ_TEST(ImageIOSuite, Decode)

    .WithDomains(

        fuzztest::String()

            .WithMaxSize(fuzz_utils::kMaxWebPFileSize + 1),

        fuzztest::ElementOf<WebPInputFileFormat>(

            {WEBP_PNG_FORMAT, WEBP_JPEG_FORMAT, WEBP_TIFF_FORMAT,

             WEBP_WEBP_FORMAT, WEBP_PNM_FORMAT, kUnknown}),

        /*keep_alpha=*/fuzztest::Arbitrary<bool>(),

        /*use_argb=*/fuzztest::Arbitrary<bool>());

}  // namespace