<?php

if (!function_exists('convert_empty_strings_to_null')) {
  /**
   * Recursively convert empty strings to null in arrays or objects
   * 
   * @param mixed $data The data to process (array, object, or scalar)
   * @return mixed The processed data with empty strings converted to null
   */
  function convert_empty_strings_to_null($data) {
    if (is_array($data)) {
      foreach ($data as $key => $value) {
        if (is_array($value)) {
          $data[$key] = convert_empty_strings_to_null($value);
        } elseif (is_object($value)) {
          $data[$key] = convert_empty_strings_to_null($value);
        } elseif ($value === '') {
          $data[$key] = null;
        }
      }
    } elseif (is_object($data)) {
      foreach ($data as $key => $value) {
        if (is_array($value)) {
          $data->$key = convert_empty_strings_to_null($value);
        } elseif (is_object($value)) {
          $data->$key = convert_empty_strings_to_null($value);
        } elseif ($value === '') {
          $data->$key = null;
        }
      }
    }
    return $data;
  }
}

if (!function_exists('prepare_json_response')) {
  /**
   * Prepare data for JSON response by converting empty strings to null
   * This is a convenience wrapper around convert_empty_strings_to_null
   * 
   * @param mixed $data The data to prepare for JSON response
   * @return mixed The processed data ready for JSON encoding
   */
  function prepare_json_response($data) {
    return convert_empty_strings_to_null($data);
  }
}