// Copyright 2018 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.

//

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

#include <stdio.h>

#include <stdlib.h>

#include "fuzz.h"

#include "webp/encode.h"

#include "webp/decode.h"

namespace {

const VP8CPUInfo default_VP8GetCPUInfo = VP8GetCPUInfo;

}  // namespace

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

  uint32_t bit_pos = 0;

  ExtractAndDisableOptimizations(default_VP8GetCPUInfo, data, size, &bit_pos);

  // Init the source picture.

  WebPPicture pic;

  if (!WebPPictureInit(&pic)) {

    fprintf(stderr, "WebPPictureInit failed.\n");

    abort();

  }

  pic.use_argb = Extract(1, data, size, &bit_pos);

  // Read the source picture.

  if (!ExtractSourcePicture(&pic, data, size, &bit_pos)) {

    fprintf(stderr, "Can't read input image.\n");

    WebPPictureFree(&pic);

    abort();

  }

  // Crop and scale.

  if (!ExtractAndCropOrScale(&pic, data, size, &bit_pos)) {

    fprintf(stderr, "ExtractAndCropOrScale failed.");

    WebPPictureFree(&pic);

    abort();

  }

  // Extract a configuration from the packed bits.

  WebPConfig config;

  if (!ExtractWebPConfig(&config, data, size, &bit_pos)) {

    fprintf(stderr, "ExtractWebPConfig failed.\n");

    abort();

  }

  // Skip slow settings on big images, it's likely to timeout.

  if (pic.width * pic.height > 32 * 32) {

    if (config.lossless) {

      if (config.quality > 99.0f && config.method >= 5) {

        config.quality = 99.0f;

        config.method = 5;

      }

    } else {

      if (config.quality > 99.0f && config.method == 6) {

        config.quality = 99.0f;

      }

    }

    if (config.alpha_quality == 100 && config.method == 6) {

      config.alpha_quality = 99;

    }

  }

  // Encode.

  WebPMemoryWriter memory_writer;

  WebPMemoryWriterInit(&memory_writer);

  pic.writer = WebPMemoryWrite;

  pic.custom_ptr = &memory_writer;

  if (!WebPEncode(&config, &pic)) {

    fprintf(stderr, "WebPEncode failed. Error code: %d\n", pic.error_code);

    WebPMemoryWriterClear(&memory_writer);

    WebPPictureFree(&pic);

    abort();

  }

  // Try decoding the result.

  int w, h;

  const uint8_t* const out_data = memory_writer.mem;

  const size_t out_size = memory_writer.size;

  uint8_t* const rgba = WebPDecodeBGRA(out_data, out_size, &w, &h);

  if (rgba == nullptr || w != pic.width || h != pic.height) {

    fprintf(stderr, "WebPDecodeBGRA failed.\n");

    WebPFree(rgba);

    WebPMemoryWriterClear(&memory_writer);

    WebPPictureFree(&pic);

    abort();

  }

  // Compare the results if exact encoding.

  if (pic.use_argb && config.lossless && config.near_lossless == 100) {

    const uint32_t* src1 = (const uint32_t*)rgba;

    const uint32_t* src2 = pic.argb;

    for (int y = 0; y < h; ++y, src1 += w, src2 += pic.argb_stride) {

      for (int x = 0; x < w; ++x) {

        uint32_t v1 = src1[x], v2 = src2[x];

        if (!config.exact) {

          if ((v1 & 0xff000000u) == 0 || (v2 & 0xff000000u) == 0) {

            // Only keep alpha for comparison of fully transparent area.

            v1 &= 0xff000000u;

            v2 &= 0xff000000u;

          }

        }

        if (v1 != v2) {

          fprintf(stderr, "Lossless compression failed pixel-exactness.\n");

          WebPFree(rgba);

          WebPMemoryWriterClear(&memory_writer);

          WebPPictureFree(&pic);

          abort();

        }

      }

    }

  }

  WebPFree(rgba);

  WebPMemoryWriterClear(&memory_writer);

  WebPPictureFree(&pic);

  return 0;

}