Generate 301 Redirects for and remove Taxonomy Terms

functions.php

<?php

function redirect_builder(){

// CLEAN UP TAGS
	// GATHER TAGS
	$product_tag = 'product_tag';

	$tags = get_terms( array(
	    'taxonomy' => $product_tag,
	    'hide_empty' => false,
	) );

	// RORDER TAGS BY COUNT THEN NAME
	$count  = array_column( $tags, 'count' );
	$name  = array_column( $tags, 'name' );
	array_multisort($count, SORT_ASC, $name, SORT_ASC, $tags);

	// FOREACH
	foreach($tags as $tag):

		// If the term has 1 or fewer items
		if( $tag->count <= 1 ):

			/* output redirect rule */
			// echo 'Redirect 301 /YOURPATH/'.$tag->slug.' / <br/>';

			/* remove term */
			// wp_delete_term( $tag->term_id, $product_tag );

		endif;
	endforeach;


// CLEAN UP CATS
	// GATHER TAGS
	$product_cat = 'product_cat';

	$cats = get_terms( array(
	    'taxonomy' => $product_cat,
	    'hide_empty' => false,
	) );

	// RORDER TAGS BY COUNT THEN NAME
	$count  = array_column( $cats, 'count' );
	$name  = array_column( $cats, 'name' );
	array_multisort($count, SORT_ASC, $name, SORT_ASC, $cats);

	// FOREACH
	foreach($cats as $cat):

		// If the term has 1 or fewer items
		if( $cat->count <= 1 ):

			/* output redirect rule */
			// echo 'Redirect 301 /YOURPATH/'.$cat->slug.' / <br/>';

			/* remove term */
			// wp_delete_term( $cat->term_id, $product_cat );

		endif;
	endforeach;

}
// add_action('wp_header', 'redirect_builder');