#include <allheaders.h>

#include <tesseract/baseapi.h>

#include <libgen.h> // for dirname

#include <cstdio>   // for printf

#include <cstdlib>  // for std::getenv, std::setenv

#include <string>   // for std::string

#ifndef TESSERACT_FUZZER_WIDTH

#  define TESSERACT_FUZZER_WIDTH 100

#endif

#ifndef TESSERACT_FUZZER_HEIGHT

#  define TESSERACT_FUZZER_HEIGHT 100

#endif

class BitReader {

private:

  uint8_t const *data;

  size_t size;

  size_t shift;

public:

  BitReader(const uint8_t *data, size_t size) : data(data), size(size), shift(0) {}

  int Read(void) {

    if (size == 0) {

      return 0;

    }

    const int ret = ((*data) >> shift) & 1;

    shift++;

    if (shift >= 8) {

      shift = 0;

      data++;

      size--;

    }

    return ret;

  }

};

static tesseract::TessBaseAPI *api = nullptr;

extern "C" int LLVMFuzzerInitialize(int * /*pArgc*/, char ***pArgv) {

  if (std::getenv("TESSDATA_PREFIX") == nullptr) {

    std::string binary_path = *pArgv[0];

    const std::string filepath = dirname(&binary_path[0]);

    const std::string tessdata_path = filepath + "/" + "tessdata";

    if (setenv("TESSDATA_PREFIX", tessdata_path.c_str(), 1) != 0) {

      printf("Setenv failed\n");

      std::abort();

    }

  }

  api = new tesseract::TessBaseAPI();

  if (api->Init(nullptr, "eng") != 0) {

    printf("Cannot initialize API\n");

    abort();

  }

  /* Silence output */

  api->SetVariable("debug_file", "/dev/null");

  return 0;

}

static PIX *createPix(BitReader &BR, const size_t width, const size_t height) {

  Pix *pix = pixCreate(width, height, 1);

  if (pix == nullptr) {

    printf("pix creation failed\n");

    abort();

  }

  for (size_t i = 0; i < width; i++) {

    for (size_t j = 0; j < height; j++) {

      pixSetPixel(pix, i, j, BR.Read());

    }

  }

  return pix;

}

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

  BitReader BR(data, size);

  auto pix = createPix(BR, TESSERACT_FUZZER_WIDTH, TESSERACT_FUZZER_HEIGHT);

  api->SetImage(pix);

  char *outText = api->GetUTF8Text();

  pixDestroy(&pix);

  delete[] outText;

  return 0;

}