Merge Subscriptions

functions.php

<?php

/**
 * Remove woocommerce and woo-subscriptions delete actions.
 * @return [type] [description]
 */
function mts_remove_delete_actions() {
	remove_action( 'delete_user', 'WC_Subscriptions_Manager::trash_users_subscriptions' );
	remove_action( 'deleted_user', 'wc_reset_order_customer_id_on_deleted_user' );
}
add_action( 'init', 'mts_remove_delete_actions', 0 );

/**
 * Re-assign order and subscriptions to new user.
 * @param [type] $user_id  [description]
 * @param [type] $reassign [description]
 */
function mts_reset_customer_id_on_delete_user( $user_id, $reassign ) {
	global $wpdb;

	$reassign = is_null( $reassign ) ? 0 : $reassign;
	// $wpdb->update( $wpdb->postmeta, array( 'meta_value' => $reassign ), array( 'meta_key' => '_customer_user', 'meta_value' => $user_id ) );

	// Get User Objects
	$user          = get_userdata( $user_id );
	$reassign_user = get_userdata( $reassign );

	// Re-Associate Orders
	$user_orders = get_posts(
		array(
			'post_type'   => array_merge( wc_get_order_types(), array( 'shop_subscription' ) ),
			'post_status' => 'any',
			'numberposts' => -1,
			'meta_key'    => '_customer_user',
			'meta_value'  => $user_id,
		)
	);
	if ( ! empty( $user_orders ) ) {
		foreach ( $user_orders as $order ) {
			// Get Order Meta
			$order_meta = get_post_meta( $order->ID );

			// Associate New User
			update_post_meta( $order->ID, '_customer_user', $reassign, $user_id );

			// Update WC Information
			update_post_meta( $order->ID, '_billing_first_name', $reassign_user->first_name, $user->first_name );
			update_post_meta( $order->ID, '_billing_last_name', $reassign_user->last_name, $user->last_name );
			update_post_meta( $order->ID, '_billing_email', $reassign_user->user_email, $user->user_email );
			update_post_meta( $order->ID, '_shipping_first_name', $reassign_user->first_name, $user->first_name );
			update_post_meta( $order->ID, '_shipping_last_name', $reassign_user->last_name, $user->last_name );
		}
	}

	// Re-Associate Product Downloadable Permissions
	$user_downloads = wc_get_customer_available_downloads( $user_id );
	if ( ! empty( $user_downloads ) ) {
		foreach ( $user_downloads as $download ) {
			$download_order = new WC_Order( $download['order_id'] );
			wc_downloadable_file_permission( $download['download_id'], $download['product_id'], $download_order );
		}
	}
}
add_action( 'deleted_user', 'mts_reset_customer_id_on_delete_user', 15, 2 );

/**
 * Re-assign user form on deleteion screen.
 * @param  [type] $current_user [description]
 * @param  [type] $userids      [description]
 * @return [type]               [description]
 */
function mts_delete_user_form( $current_user, $userids ) {
	wp_enqueue_style( 'woocommerce_admin_styles' );
	wp_enqueue_style( 'select-2' );
	wp_enqueue_script( 'wc-enhanced-select' );
	?>
	<fieldset id="mts-reassign-user-fieldset">
		<p><legend><?php _e( 'What should be done with content owned by this user?' ); ?></legend></p>
		<ul style="list-style:none;">
			<li><label><input type="radio" id="delete_option0" name="delete_option" value="delete" />
			<?php _e('Delete all content.'); ?></label></li>
			<li><input type="radio" id="delete_option1" name="delete_option" value="reassign" />
			<?php echo '<label for="delete_option1">' . __( 'Attribute all content to:' ) . '</label> '; ?>
			<select class="wc-customer-search" id="customer_user" name="reassign_user" data-placeholder="<?php esc_attr_e( 'Guest', 'woocommerce' ); ?>" data-allow_clear="true" style="width:50%;">
				<option value="" selected="selected"></option>
			</select>
			</li>
		</ul>
	</fieldset>
	<script>
		jQuery(document).ready( function($) {
			$('#mts-reassign-user-fieldset').prev().remove();
		});
	</script>
	<?php
}
add_action( 'delete_user_form', 'mts_delete_user_form', 10, 2 );