// Copyright (c) Google LLC 2019

//

// Use of this source code is governed by an MIT-style

// license that can be found in the LICENSE file or at

// https://opensource.org/licenses/MIT.

#include <cstddef>

#include <cstdint>

#include <vector>

// #include "gtest/gtest.h"

// #include "testing/fuzzing/fuzztest.h"

#include <brunsli/jpeg_data.h>

#include "../common/platform.h"

#include <brunsli/status.h>

#include <brunsli/brunsli_decode.h>

#include <brunsli/jpeg_data_writer.h>

#include "../dec/state.h"

#include "./test_utils.h"

size_t DiscardOutputFunction(void* data, const uint8_t* buf, size_t count) {

  BRUNSLI_UNUSED(data);

  BRUNSLI_UNUSED(buf);

  return count;

}

int DoTestOneInput(const uint8_t* data, size_t size) {

  brunsli::JPEGOutput out(DiscardOutputFunction, nullptr);

  brunsli::JPEGData jpg;

  brunsli::internal::dec::State state;

  brunsli::BrunsliStatus status;

  size_t start = 0;

  for (size_t end = 0; end <= size; ++end) {

    state.data = data + start;

    state.pos = 0;

    state.len = end - start;

    status = brunsli::internal::dec::ProcessJpeg(&state, &jpg);

    brunsli::BrunsliStatus expected_status =

        end < size ? brunsli::BRUNSLI_NOT_ENOUGH_DATA : brunsli::BRUNSLI_OK;

    if (status != expected_status) return 0;

    start += state.pos;

  }

  // TODO(eustas): check that streaming and non-streaming decoders produce the

  //               same output

  brunsli::WriteJpeg(jpg, out);

  return 0;

}

// Entry point for LibFuzzer.

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

  return DoTestOneInput(data, size);

}

void TestOneInput(const std::vector<uint8_t>& data) {

  DoTestOneInput(data.data(), data.size());

}

std::vector<std::tuple<std::vector<uint8_t>>> ReadSeeds() {

  const std::vector<uint8_t> data = brunsli::ReadTestData("fuzz-decode.mar");

  return brunsli::ParseMar(data.data(), data.size());

}

FUZZ_TEST(BrunsliDecodeStreamingFuzz, TestOneInput).WithSeeds(&ReadSeeds);

// TODO(eustas): Add existing cases.

TEST(BrunsliDecodeStreamingFuzz, Empty) {

  DoTestOneInput(nullptr, 0);

}