#include <stddef.h>

#include <unistd.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <stdbool.h>

#include <string.h>

#include "mpg123.h"

static char* fuzzer_get_tmpfile(const uint8_t* data, size_t size) {

  char* filename_buffer = strdup("/tmp/generate_temporary_file.XXXXXX");

  if (!filename_buffer) {

    perror("Failed to allocate file name buffer.");

    abort();

  }

  const int file_descriptor = mkstemp(filename_buffer);

  if (file_descriptor < 0) {

    perror("Failed to make temporary file.");

    abort();

  }

  FILE* file = fdopen(file_descriptor, "wb");

  if (!file) {

    perror("Failed to open file descriptor.");

    close(file_descriptor);

    abort();

  }

  const size_t bytes_written = fwrite(data, sizeof(uint8_t), size, file);

  if (bytes_written < size) {

    close(file_descriptor);

    fprintf(stderr, "Failed to write all bytes to file (%zu out of %zu)",

            bytes_written, size);

    abort();

  }

  fclose(file);

  return filename_buffer;

}

static void fuzzer_release_tmpfile(char* filename) {

  if (unlink(filename) != 0) {

    perror("WARNING: Failed to delete temporary file.");

  }

  free(filename);

}

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

  static bool initialized = false;

  if (!initialized) {

    mpg123_init();

    initialized = true;

  }

  char* filename = fuzzer_get_tmpfile(data, size);

  if (filename == NULL) {

    return 0;

  }

  size_t outmemorysize = size * 2;  // Guess based on the size of data.

  unsigned char* outmemory = (unsigned char*)malloc(outmemorysize);

  if (outmemory == NULL) {

    fuzzer_release_tmpfile(filename);

    return 0;

  }

  int error;

  mpg123_handle* handle = mpg123_new(NULL, &error);

  if (handle == NULL || mpg123_param(handle,

      MPG123_ADD_FLAGS, MPG123_QUIET, 0.) != MPG123_OK) {

    free(outmemory);

    fuzzer_release_tmpfile(filename);

    return 0;

  }

  if (mpg123_open(handle, filename) == MPG123_OK) {

    int read_error;

    do {

      size_t decoded_size;

      read_error = mpg123_read(handle, outmemory, outmemorysize, &decoded_size);

    } while (read_error == MPG123_OK && mpg123_tellframe(handle) <= 10000

          && mpg123_tell_stream(handle) <= 1<<20);

  }

  mpg123_close(handle);

  mpg123_delete(handle);

  free(outmemory);

  fuzzer_release_tmpfile(filename);

  return 0;

}