Remove product-category slug from Woocommerce

remove-woo-slug.php

<?php
/*
Plugin Name: Remove product-category slug
Plugin URI: https://timersys.com/
Description: Check if url slug matches a woocommerce product category and use it instead
Version: 0.1
Author: Timersys
License: GPLv2 or later
*/

add_filter('request', function( $vars ) {
	global $wpdb;
	if( ! empty( $vars['pagename'] ) || ! empty( $vars['category_name'] ) || ! empty( $vars['name'] ) || ! empty( $vars['attachment'] ) ) {
		$slug = ! empty( $vars['pagename'] ) ? $vars['pagename'] : ( ! empty( $vars['name'] ) ? $vars['name'] : ( !empty( $vars['category_name'] ) ? $vars['category_name'] : $vars['attachment'] ) );
		$exists = $wpdb->get_var( $wpdb->prepare( "SELECT t.term_id FROM $wpdb->terms t LEFT JOIN $wpdb->term_taxonomy tt ON tt.term_id = t.term_id WHERE tt.taxonomy = 'product_cat' AND t.slug = %s" ,array( $slug )));
		if( $exists ){
			$old_vars = $vars;
			$vars = array('product_cat' => $slug );
			if ( !empty( $old_vars['paged'] ) || !empty( $old_vars['page'] ) )
				$vars['paged'] = ! empty( $old_vars['paged'] ) ? $old_vars['paged'] : $old_vars['page'];
			if ( !empty( $old_vars['orderby'] ) )
	 	        	$vars['orderby'] = $old_vars['orderby'];
      			if ( !empty( $old_vars['order'] ) )
 			        $vars['order'] = $old_vars['order'];	
		}
	}
	return $vars;
});

Does anyone know how we can use Regex
url/product-category/product-slug to url/product-slug so as to add redirects?

@gerharddt were you able to make it work with Pagination? finally, it doesn't work for me or anyone else figured out how to make it work with pagination.

@gerharddt were you able to make it work with Pagination? finally, it doesn't work for me or anyone else figured out how to make it work with pagination.

I ended up just renaming it and the client was happy. Please see the function below:

// the neat way using WooCommerce filter - permalinks
function product_cat_setup($args){
$args['rewrite']['slug'] = 'shop';
return $args;
}
add_filter('woocommerce_taxonomy_args_product_cat', 'product_cat_setup');

@gerharddt ah, unfortunately, won't work for me as I need this product-category gone, but thanks.

For anyone having issues with pagination not working, use this plugin instead https://wordpress.org/plugins/woo-permalink-manager/

Using jet woo builder and/or nested categories?
Use this code:

add_filter('request', function( $vars ) {
	global $wpdb;
	if(isset($vars['jet-woo-builder']))
		return $vars;
	if(isset($vars['error'])){
		$lastVar = basename($_SERVER['REQUEST_URI']);
		$vars['attachment'] = $lastVar;
	}
	if( ! empty( $vars['pagename'] ) || ! empty( $vars['category_name'] ) || ! empty( $vars['name'] ) || !empty( $vars['attachment'] ) ) {
		$slug = ! empty( $vars['pagename'] ) ? $vars['pagename'] : ( ! empty( $vars['name'] ) ?
			$vars['name'] : ( !empty( $vars['category_name'] ) ? $vars['category_name'] : $vars['attachment'] ) );
		$_slug = explode('/',$slug);
		$slug = end($_slug);
		$exists = $wpdb->get_var( $wpdb->prepare( "SELECT t.term_id FROM $wpdb->terms t LEFT JOIN $wpdb->term_taxonomy tt ON tt.term_id = t.term_id WHERE tt.taxonomy = 'product_cat' AND t.slug = %s" ,array(
			$slug )));
		if( $exists ){
			$old_vars = $vars;
			$vars = array('product_cat' => $slug );
			if ( !empty( $old_vars['paged'] ) || !empty( $old_vars['page'] ) )
				$vars['paged'] = ! empty( $old_vars['paged'] ) ? $old_vars['paged'] : $old_vars['page'];
			if ( !empty( $old_vars['orderby'] ) )
				$vars['orderby'] = $old_vars['orderby'];
			if ( !empty( $old_vars['order'] ) )
				$vars['order'] = $old_vars['order'];
		}
	}
	return $vars;
});