<?php
/**
 * This Singleton class has the code for defining which category to
 * use according to the shortcode.
 * @author fernando@picandocodigo.net
 */
class LcpCategory{
  // Singleton implementation
  private static $instance = null;

  public static function get_instance(){
    if( !isset( self::$instance ) ){
      self::$instance = new self;
    }
    return self::$instance;
  }

  /*
   * When the category is set using the `name` parameter.
   */
  public function with_name($name){
    $lcp_category_id = null;
    // AND relationship
    if ( preg_match('/\+/', $name) ){
      $categories = array();
      $cat_array = explode("+", $name);

      foreach ($cat_array as $category){
        $categories[] = $this->get_category_id_by_name($category);
      }
      $lcp_category_id = $categories;
      // OR relationship
    } elseif (preg_match('/,/', $name )){
      $categories = '';
      $cat_array = explode(",", $name);

      foreach ($cat_array as $category){
        $id = $this->get_category_id_by_name($category);
        $categories .= $id . ",";
      }

      $lcp_category_id = $categories;
    } else {
      $lcp_category_id = $this->get_category_id_by_name($name);
    }
    return $lcp_category_id;
  }

  public function with_id($id){
    if (preg_match('/\+/', $id)){
      if ( preg_match('/(-[0-9]+)+/', $id, $matches) ){
        $this->exclude = implode(',', explode("-", ltrim($matches[0], '-') ));
      }
      $lcp_category_id = array_map( 'intval', explode( "+", $id ) );
    } else {
      $lcp_category_id = $id;
    }
    return $lcp_category_id;
  }

  public function current_category(){
    $category = get_category( get_query_var( 'cat' ) );
    if( isset( $category->errors ) && $category->errors["invalid_term"][0] == __("Empty Term.") ){
      global $post;
      $categories = get_the_category($post->ID);
      if ( !empty($categories) ){
        return $categories[0]->cat_ID;
      } else {
        return;
      }
    }
    return $category->cat_ID;
  }

  /**
   * Get the category id from its name
   * by Eric Celeste / http://eric.clst.org
   */
  private function get_category_id_by_name($cat_name){
    //TODO: Support multiple names (this used to work, but not anymore)
    //We check if the name gets the category id, if not, we check the slug.
    $term = get_term_by('slug', $cat_name, 'category');
    if (!$term){
      $term = get_term_by('name', $cat_name, 'category');
    }
    return ($term) ? $term->term_id : 0;
  }

}