// Copyright 2020 Google LLC
//
// 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 <glog/logging.h>

#include <iostream>

#include "../lodepng/lodepng.h"
#include "helpers.h"
#include "sandboxed_api/sandbox2/util/fileops.h"

void EncodeDecodeOneStep(const std::string &images_path) {
  // Generate the values.
  std::vector<uint8_t> image(GenerateValues());

  // Encode the image.
  const std::string filename = images_path + "/out_generated1.png";
  unsigned int result =
      lodepng_encode32_file(filename.c_str(), image.data(), kWidth, kHeight);

  CHECK(!result);

  // After the image has been encoded, decode it to check that the
  // pixel values are the same.
  unsigned int width2, height2;
  uint8_t *image2 = 0;

  result = lodepng_decode32_file(&image2, &width2, &height2, filename.c_str());

  CHECK(!result);

  CHECK(width2 == kWidth);
  CHECK(height2 == kHeight);

  // Now, we can compare the values.
  CHECK(absl::equal(image.begin(), image.end(), image2, image2 + kImgLen));

  free(image2);
}

void EncodeDecodeTwoSteps(const std::string &images_path) {
  // Generate the values.
  std::vector<uint8_t> image(GenerateValues());

  // Encode the image into memory first.
  const std::string filename = images_path + "/out_generated2.png";
  uint8_t *png;
  size_t pngsize;

  unsigned int result =
      lodepng_encode32(&png, &pngsize, image.data(), kWidth, kHeight);

  CHECK(!result);

  // Write the image into the file (from memory).
  result = lodepng_save_file(png, pngsize, filename.c_str());

  CHECK(!result);

  // Now, decode the image using the 2 steps in order to compare the values.
  unsigned int width2, height2;
  uint8_t *png2;
  size_t pngsize2;

  // Load the file in memory.
  result = lodepng_load_file(&png2, &pngsize2, filename.c_str());

  CHECK(!result);
  CHECK(pngsize == pngsize2);

  uint8_t *image2;
  result = lodepng_decode32(&image2, &width2, &height2, png2, pngsize2);

  CHECK(!result);
  CHECK(width2 == kWidth);
  CHECK(height2 == kHeight);

  // Compare the values.
  CHECK(absl::equal(image.begin(), image.end(), image2, image2 + kImgLen));

  free(png);
  free(png2);
  free(image2);
}

int main(int argc, char *argv[]) {
  google::InitGoogleLogging(argv[0]);

  const std::string images_path = CreateTempDirAtCWD();

  EncodeDecodeOneStep(images_path);
  EncodeDecodeTwoSteps(images_path);

  CHECK(sandbox2::file_util::fileops::DeleteRecursively(images_path));

  return EXIT_SUCCESS;
}