Override product image when loading a preset

override-product-image-with-preset-image.php

<?php

add_filter( 'wp_get_attachment_image', function( $html, $attachment_id, $size, $icon, $attr ) {
	global $product;
	static $doing_filter = false;
	if ( $doing_filter ) return $html;
	if ( ! isset( $_REQUEST[ 'load-preset' ] ) ) return $html;
	$doing_filter = true;
	
	$post = get_post( (int) $_REQUEST[ 'load-preset' ] );
	if ( ! $post || 'preset' !== $post->post_status || ! class_exists( 'Mkl_PC_Preset_Configuration' ) ) return $html;

	$preset = new Mkl_PC_Preset_Configuration( (int) $_REQUEST[ 'load-preset' ] );

	if ( is_a( $product, 'WC_Product' ) && (int)$product->get_image_id() === (int)$attachment_id ) {

		$preset_post = $preset->get_the_post();
		if ( $preset_post->post_parent != $product->get_id() ) {
			$doing_filter = false;
			return $html;
		}

		if ( isset( $attr['srcset'] ) ) unset( $attr['srcset'] );
		if ( $image = $preset->get_image( 'woocommerce_single', $attr, false ) ) {			
			$doing_filter = false;
			return $image;
		}
	}
	$doing_filter = false;
	return $html;
}, 2000, 5 );