WooCommerce: Add Order notes to admin emails

wc-add-order-notes-to-admin-emails

add_action( 'woocommerce_email_order_meta', 'woo_add_order_notes_to_email', 10, 3 );
function woo_add_order_notes_to_email( $order, $sent_to_admin = true, $plain_text = false ) {

	// You want to send those only to the Admin
	if ( ! $sent_to_admin ) {
		return;
	}

	// You can also check which email you are sending, by checking the order status
	// Optional, comment it out, if not needed
	if ( 'completed' != $order->get_status() ) {
		// Will end execution, with everything other than the completed order email.
		return;
	}

	$notes = array();

	$args = array(
		'post_id' => $order->id,
		'approve' => 'approve',
		'type' => '' // You don't need type as orders get only order notes as comments.
	);

	// Remove the filter excluding the comments from queries
	remove_filter( 'comments_clauses', array( 'WC_Comments', 'exclude_order_comments' ) );

	// You get all notes for the order /public and private/
	$notes = get_comments( $args );

	// Add the filter again.
	add_filter( 'comments_clauses', array( 'WC_Comments', 'exclude_order_comments' ) );

	echo '<h4 style="font-family:Arial,sans-serif;font-size:120%;line-height:110%;color:red;">Order Notes</h4>';
	echo '<ul class="order_notes">';
	if ( $notes ) {
		foreach( $notes as $note ) {
			$note_classes = get_comment_meta( $note->comment_ID, 'is_customer_note', true ) ? array( 'customer-note', 'note' ) : array( 'note' );
			?>
			<li rel="<?php echo absint($note->comment_ID); ?>" class="<?php echo implode(' ', $note_classes); ?>">
				<div class="note_content">
					<?php echo wpautop( wptexturize( wp_kses_post( $note->comment_content ) ) ); ?>
				</div>
			</li>
		<?php
		}
	} else {
		echo '<li class="no-order-comment">There are no order notes</li>';
	}
	echo '</ul>';
}

Great stuff - Can you help me, I get how to make it only work on failed orders - but how would I get it to only add notes with certain text...

for example

I only want notes with the text "Error processing payment" in them to be added to the email such as this example:

Error processing payment. Reason: Processor Declined – Possible Stolen Card

how do I make add only those notes which contain the text "Error processing payment" in them and not send all comments?

Great stuff - Can you help me, I get how to make it only work on failed orders - but how would I get it to only add notes with certain text...

for example

I only want notes with the text "Error processing payment" in them to be added to the email such as this example:

Error processing payment. Reason: Processor Declined – Possible Stolen Card

how do I make add only those notes which contain the text "Error processing payment" in them and not send all comments?

you should change only 11 line like this if ( 'failed' != $order->get_status() )