WooCommerce get primary category for product

get-product-primary-category.php

<?php
/**
 * Get a product's primary category using Yoast when available.
 */
function get_product_primary_category() {
	global $product;
	// if Yoast is being used, utilize it to get the primary category.
	if ( function_exists( 'yoast_get_primary_term_id' ) ) {
		$primary_category_id = yoast_get_primary_term_id( 'product_cat' );
		$category            = get_term( $primary_category_id );
	}
	if ( ! function_exists( 'yoast_get_primary_term_id' ) || is_wp_error( $category ) ) {
		$categories = get_the_terms( $product->get_id(), 'product_cat' );
		$category   = ! empty( $categories ) ? $categories[0] : false;
	}
	if ( ! empty( $category ) && ! is_wp_error( $category ) ) {
		return (object) array(
			'name'      => $category->name,
			'slug'      => $category->slug,
			'permalink' => get_term_link( $category->slug, 'product_cat' ),
		);
	}
	return false;
}