Price range filter for Woocommerce with facetwp

facetwp-price-range-filter.php

/*
 * 1. Create the filter by price Facet:  
 *      - Set "Facet type" to "Checkboxes"
 *      - Set "Data source" to "Price"
 *      - Set "Sort by" to "Raw Value"
 * 2. Set $price_facet_name to the name of the crewated facet
 */

function index_custom_price_range( $params, $class ) {

  $price_facet_name = 'price';
  if ( $price_facet_name == $params['facet_name'] ) {
    $price = (double) $params['facet_value'];
    
    if( $price > 0 ){
      $symbol = get_woocommerce_currency_symbol();
      if ( $price < 25 ) {
          $params['facet_value'] = 1;
          $params['facet_display_value'] = sprintf ( __('Under %s', 'woocommerce'), $symbol.'25' );
      }
      elseif ( $price < 50 ) {
          $params['facet_value'] = 2;
          $params['facet_display_value'] = $symbol.'25-'.$symbol.'50';
      }
      elseif ( $price < 100 ) {
          $params['facet_value'] = 3;
          $params['facet_display_value'] = $symbol.'50-'.$symbol.'100';
      }
      elseif ( $price < 200 ) {
          $params['facet_value'] = 4;
          $params['facet_display_value'] = $symbol.'100-'.$symbol.'200';
      }
      else {
          $params['facet_value'] = 5;
          $params['facet_display_value'] = sprintf ( __('Above %s', 'woocommerce'), $symbol.'200' );
      }
    }
  }
  return $params;
}