PHP скрипт для генерации текста из шаблона

<?php
/**
 * @file
 * Text generation from template.
 * Template example: {My|Your} {name|surname} is {Semen {Angarsky|Aleksandrov}|Alex|Dima}.
 *
 * @author http://www.angarsky.ru/
 */
 
class TextTemplateGenerator {
 
  // Text template provided by user.
  private $template = '';
  // Text template prepared for generation.
  private $generator = '';
  // Array of replacements for text generator.
  private $replacements = array();
  // Symbol that used as replacement in generator text template.
  private $replace_symbol = 'RPLC';
 
  /**
   * Constructor.
   *
   * @param string $template
   *   Template for text generation.
   */
  function __construct($template = '') {
    $this->set_template($template);
  }
 
  /**
   * Sets text template for further generation.
   *
   * @param $template
   *   Template for text generation.
   */
  public function set_template($template) {
    $this->template = $template;
    $this->prepare($template);
  }
 
  /**
   * Starts text generation from template.
   *
   * @param $count
   *   Number of lines to generate.
   * @return string
   *   Generated text.
   */
  public function generate($count) {
    $result = array();
    for ($i = 0; $i < $count; $i++) {
      $result[] = $this->generate_line();
    }
    return $result;
  }
 
  /**
   * Prepares text template for generation.
   *
   * Converts text template to line with replacements.
   *
   * @param $template
   * @return string
   */
  private function prepare($template) {
 
    // Number of iteration for while loop.
    $i = 0;
    // ID of replacement in array.
    $rid = 0;
    $replacements = array();
 
    // Find all sets of {a|b|c}.
    while (preg_match_all("/{([^{}]+)}/", $template, $matches)) {
 
      foreach ($matches[1] as $match) {
        $rid++;
        $replace = "{" . $match . "}";
        $template = str_replace($replace, '_' . $this->replace_symbol . $rid . '_', $template);
 
        // Explode match to array.
        $elements = explode('|', $match);
        foreach ($elements as $element) {
          $replacements[$rid][] = $element;
        }
      }
 
      // Prevents infinite loop.
      if ($i++ > 100) {
        $template = 'INFINITE LOOP!';
        break;
      }
    }
 
    $this->generator = $template;
    $this->replacements = $replacements;
  }
 
  /**
   * Generates single line of text from template array.
   *
   * @return string
   */
  private function generate_line() {
    $result = $this->process_replacements($this->generator);
    return $result;
  }
 
  /**
   * Recursively generates text.
   *
   * Replaces all replacement symbols in generator text template.
   *
   * @param $text - text with replacements to generate.
   */
  private function process_replacements($text) {
    preg_match_all('/_' . $this->replace_symbol . '([0-9]+)_/', $text, $matches);
    if (!empty($matches[1])) {
      foreach ($matches[1] as $id) {
        if (isset($this->replacements[$id])) {
          $rand = mt_rand(0, count($this->replacements[$id]) - 1);
          $case = $this->replacements[$id][$rand];
          $replace = $this->process_replacements($case);
          $text = str_replace('_' . $this->replace_symbol . $id . '_', $replace, $text);
        }
      }
    }
 
    return $text;
  }
}

module_load_include('php', 'my_module', 'includes/TextTemplateGenerator.class');

$text = "{Добрый день|Доброе утро}! Какая {на улице|за {окном|бортом}} {прекрасная|очаровательная|великолепная} погода!";
$generator = new TextTemplateGenerator($text);
// Генерируем 5 различных вариантов текста. Результат в виде массива будет.
$result = $generator->generate(5);
 
// Устанавливаем новый шаблон и генерируем 1 вариант текста.
$new_text = "{Semen|Andrew|Alex}";
$result = $generator->set_template($new_text);
$result = $generator->generate(1);
$output = array_shift($result);