// 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_utils.h"

#include "src/webp/encode.h"

#include "src/webp/mux.h"

namespace {

const VP8CPUInfo default_VP8GetCPUInfo = VP8GetCPUInfo;

int AddFrame(WebPAnimEncoder** const enc,

             const WebPAnimEncoderOptions& anim_config, int* const width,

             int* const height, int timestamp_ms, const uint8_t data[],

             size_t size, uint32_t* const bit_pos) {

  if (enc == nullptr || width == nullptr || height == nullptr) {

    fprintf(stderr, "NULL parameters.\n");

    if (enc != nullptr) WebPAnimEncoderDelete(*enc);

    abort();

  }

  // Init the source picture.

  WebPPicture pic;

  if (!WebPPictureInit(&pic)) {

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

    WebPAnimEncoderDelete(*enc);

    abort();

  }

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

  // Read the source picture.

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

    const WebPEncodingError error_code = pic.error_code;

    WebPAnimEncoderDelete(*enc);

    WebPPictureFree(&pic);

    if (error_code == VP8_ENC_ERROR_OUT_OF_MEMORY) return 0;

    fprintf(stderr, "Can't read input image. Error code: %d\n", error_code);

    abort();

  }

  // Crop and scale.

  if (*enc == nullptr) {  // First frame will set canvas width and height.

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

      const WebPEncodingError error_code = pic.error_code;

      WebPPictureFree(&pic);

      if (error_code == VP8_ENC_ERROR_OUT_OF_MEMORY) return 0;

      fprintf(stderr, "ExtractAndCropOrScale failed. Error code: %d\n",

              error_code);

      abort();

    }

  } else {  // Other frames will be resized to the first frame's dimensions.

    if (!WebPPictureRescale(&pic, *width, *height)) {

      const WebPEncodingError error_code = pic.error_code;

      WebPAnimEncoderDelete(*enc);

      WebPPictureFree(&pic);

      if (error_code == VP8_ENC_ERROR_OUT_OF_MEMORY) return 0;

      fprintf(stderr,

              "WebPPictureRescale failed. Size: %d,%d. Error code: %d\n",

              *width, *height, error_code);

      abort();

    }

  }

  // Create encoder if it doesn't exist.

  if (*enc == nullptr) {

    *width = pic.width;

    *height = pic.height;

    *enc = WebPAnimEncoderNew(*width, *height, &anim_config);

    if (*enc == nullptr) {

      WebPPictureFree(&pic);

      return 0;

    }

  }

  // Create frame encoding config.

  WebPConfig config;

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

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

    WebPAnimEncoderDelete(*enc);

    WebPPictureFree(&pic);

    abort();

  }

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

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

    config.method = (config.method > 4) ? 4 : config.method;

    config.quality = (config.quality > 99.0f) ? 99.0f : config.quality;

    config.alpha_quality =

        (config.alpha_quality > 99) ? 99 : config.alpha_quality;

  }

  // Encode.

  if (!WebPAnimEncoderAdd(*enc, &pic, timestamp_ms, &config)) {

    const WebPEncodingError error_code = pic.error_code;

    WebPAnimEncoderDelete(*enc);

    WebPPictureFree(&pic);

    // Tolerate failures when running under the nallocfuzz engine as

    // WebPAnimEncoderAdd() may fail due to memory allocation errors outside of

    // the encoder; in muxer functions that return booleans for instance.

    if (error_code == VP8_ENC_ERROR_OUT_OF_MEMORY ||

        error_code == VP8_ENC_ERROR_BAD_WRITE ||

        getenv("NALLOC_FUZZ_VERSION") != nullptr) {

      return 0;

    }

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

    abort();

  }

  WebPPictureFree(&pic);

  return 1;

}

}  // namespace

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

  WebPAnimEncoder* enc = nullptr;

  int width = 0, height = 0, timestamp_ms = 0;

  uint32_t bit_pos = 0;

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

  // Extract a configuration from the packed bits.

  WebPAnimEncoderOptions anim_config;

  if (!WebPAnimEncoderOptionsInit(&anim_config)) {

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

    abort();

  }

  anim_config.minimize_size = Extract(1, data, size, &bit_pos);

  anim_config.kmax = Extract(15, data, size, &bit_pos);

  const int min_kmin = (anim_config.kmax > 1) ? (anim_config.kmax / 2) : 0;

  const int max_kmin = (anim_config.kmax > 1) ? (anim_config.kmax - 1) : 0;

  anim_config.kmin =

      min_kmin + Extract((uint32_t)(max_kmin - min_kmin), data, size, &bit_pos);

  anim_config.allow_mixed = Extract(1, data, size, &bit_pos);

  anim_config.verbose = 0;

  const int nb_frames = 1 + Extract(15, data, size, &bit_pos);

  // For each frame.

  for (int i = 0; i < nb_frames; ++i) {

    if (!AddFrame(&enc, anim_config, &width, &height, timestamp_ms, data, size,

                  &bit_pos)) {

      return 0;

    }

    timestamp_ms += (1 << (2 + Extract(15, data, size, &bit_pos))) +

                    Extract(1, data, size, &bit_pos);  // [1..131073], arbitrary

  }

  // Assemble.

  if (!WebPAnimEncoderAdd(enc, nullptr, timestamp_ms, nullptr)) {

    fprintf(stderr, "Last WebPAnimEncoderAdd failed: %s.\n",

            WebPAnimEncoderGetError(enc));

    WebPAnimEncoderDelete(enc);

    abort();

  }

  WebPData webp_data;

  WebPDataInit(&webp_data);

  // Tolerate failures when running under the nallocfuzz engine as allocations

  // during assembly may fail.

  if (!WebPAnimEncoderAssemble(enc, &webp_data) &&

      getenv("NALLOC_FUZZ_VERSION") == nullptr) {

    fprintf(stderr, "WebPAnimEncoderAssemble failed: %s.\n",

            WebPAnimEncoderGetError(enc));

    WebPAnimEncoderDelete(enc);

    WebPDataClear(&webp_data);

    abort();

  }

  WebPAnimEncoderDelete(enc);

  WebPDataClear(&webp_data);

  return 0;

}