Display WooCommerce featured images on archive-product.php

archive-product.php

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly
}

get_header( 'shop' ); ?>

	<?php
		/**
		 * woocommerce_before_main_content hook.
		 *
		 * @hooked woocommerce_output_content_wrapper - 10 (outputs opening divs for the content)
		 * @hooked woocommerce_breadcrumb - 20
		 */
		do_action( 'woocommerce_before_main_content' );
	?>

		<?php if ( apply_filters( 'woocommerce_show_page_title', true ) ) : ?>

		<div class="wc-archive-hero-wrapper full-width" <?php woocommerce_category_featured_image(); ?>>
			<h1 class="page-title"><?php woocommerce_page_title(); ?></h1>
				<?php
				/**
				* woocommerce_archive_description hook.
				*
				* @hooked woocommerce_taxonomy_archive_description - 10
				* @hooked woocommerce_product_archive_description - 10
				*/
				do_action( 'woocommerce_archive_description' );
				?>
		</div>
		<?php endif; ?>

		

		<?php if ( have_posts() ) : ?>

			<?php
				/**
				 * woocommerce_before_shop_loop hook.
				 *
				 * @hooked woocommerce_result_count - 20
				 * @hooked woocommerce_catalog_ordering - 30
				 */
				do_action( 'woocommerce_before_shop_loop' );
			?>

			<?php woocommerce_product_loop_start(); ?>

				<?php woocommerce_product_subcategories(); ?>

				<?php while ( have_posts() ) : the_post(); ?>

					<?php wc_get_template_part( 'content', 'product' ); ?>

				<?php endwhile; // end of the loop. ?>

			<?php woocommerce_product_loop_end(); ?>

			<?php
				/**
				 * woocommerce_after_shop_loop hook.
				 *
				 * @hooked woocommerce_pagination - 10
				 */
				do_action( 'woocommerce_after_shop_loop' );
			?>

		<?php elseif ( ! woocommerce_product_subcategories( array( 'before' => woocommerce_product_loop_start( false ), 'after' => woocommerce_product_loop_end( false ) ) ) ) : ?>

			<?php wc_get_template( 'loop/no-products-found.php' ); ?>

		<?php endif; ?>

	<?php
		/**
		 * woocommerce_after_main_content hook.
		 *
		 * @hooked woocommerce_output_content_wrapper_end - 10 (outputs closing divs for the content)
		 */
		do_action( 'woocommerce_after_main_content' );
	?>

	<?php
		/**
		 * woocommerce_sidebar hook.
		 *
		 * @hooked woocommerce_get_sidebar - 10
		 */
		do_action( 'woocommerce_sidebar' );
	?>

<?php get_footer( 'shop' ); ?>

woocommerce-category-featured-image.php

/**
 * woocommerce_category_featured_image function  
 *
 * Give me a category thumbnail image. Used in the archive page as the header 
 * https://docs.woocommerce.com/document/woocommerce-display-category-image-on-category-archive/
 * http://wordpress.stackexchange.com/questions/200170/woocommerce-get-category-image-full-size
 *
 * Compatible with WooCommerce 3.0.2
 * 
 * Out put a header image for the categories with a fallback to a featured image. 
 * Featured image seems to only be necessary for the /shop base page. 
 * 
 * @access public
 * @author gabelloyd
 * @since 1.0
 * @return void 
 */

// check for plugin using plugin name
function set_image_size() {

	/**
	 * Detect plugin. For use on Front End only.
	 */
	include_once( ABSPATH . 'wp-admin/includes/plugin.php' );

	if ( is_plugin_active( 'mobble/mobble.php' ) ) {

		if(is_mobile()){
			$size = 'large';
		} elseif (is_tablet()) {
			$size = 'fixed-height-gallery';
		} else {
			$size = 'full';
		}

		return $size;
	} else {
		$size = 'full';
	}
}

// This is output on the archive-product.php line 37
function woocommerce_category_featured_image() {


  
    if ( is_product_category() ){
	    global $wp_query;
	    
		// Category Image 
		$size = set_image_size();
	    // get the query object
		$cat = $wp_query->get_queried_object();
		// get the thumbnail id using the queried category term_id
		$thumbnail_id = get_woocommerce_term_meta( $cat->term_id, 'thumbnail_id', true ); 
		// Get the attachment image information. Set the thumbnail size you want here.
		$category_img = wp_get_attachment_image_src( $thumbnail_id, $size, false );

		if ( $category_img ) {
		    echo 'style="background-image: url(' . $category_img[0] . ');"';
		}
		wp_reset_postdata();

	} elseif (is_shop()) {
		// Help from https://gist.github.com/Bradley-D/7287723
		// Featured Image 
		// get the shop ID
		$post_id = get_option( 'woocommerce_shop_page_id' );
		// Get the size we want 
		$size = set_image_size();
		// Set the url 
    	$featured_image = get_the_post_thumbnail_url( $post_id, $size );;
		if ( $featured_image ) {
			echo 'style="background-image: url(' . $featured_image . ');"';
		}

	}
}

Hello,

I want it to be like :
if a category has subcategories then display subcategories else display products. Can you please, help me.

Regards,
Usha