Add note on first order creation (https://github.com/woocommerce/woocommerce-admin/pull/4531)

* Add note on first order creation

* Add note when first order is created manually

plugins/woocommerce-admin/src/FeaturePlugin.php

@@ -17,6 +17,7 @@ use \Automattic\WooCommerce\Admin\Notes\WC_Admin_Notes_Tracking_Opt_In;
 use \Automattic\WooCommerce\Admin\Notes\WC_Admin_Notes_WooCommerce_Payments;
 use \Automattic\WooCommerce\Admin\Notes\WC_Admin_Notes_Install_JP_And_WCS_Plugins;
 use \Automattic\WooCommerce\Admin\Notes\WC_Admin_Notes_Draw_Attention;
+use \Automattic\WooCommerce\Admin\Notes\WC_Admin_Notes_First_Order;
 use \Automattic\WooCommerce\Admin\RemoteInboxNotifications\RemoteInboxNotificationsEngine;
 use \Automattic\WooCommerce\Admin\Notes\WC_Admin_Notes_Home_Screen_Feedback;
 
@@ -190,6 +191,7 @@ class FeaturePlugin {
 		new WC_Admin_Notes_WooCommerce_Payments();
 		new WC_Admin_Notes_Install_JP_And_WCS_Plugins();
 		new WC_Admin_Notes_Draw_Attention();
+		new WC_Admin_Notes_First_Order();
 		new WC_Admin_Notes_Home_Screen_Feedback();
 
 		// Initialize RemoteInboxNotificationsEngine.

plugins/woocommerce-admin/src/Notes/WC_Admin_Notes_First_Order.php

@@ -0,0 +1,77 @@
+<?php
+/**
+ * WooCommerce Admin First Order Note.
+ *
+ * Adds a note on first order creation.
+ *
+ * @package WooCommerce Admin
+ */
+
+namespace Automattic\WooCommerce\Admin\Notes;
+
+defined( 'ABSPATH' ) || exit;
+
+/**
+ * WC_Admin_Notes_First_Order
+ */
+class WC_Admin_Notes_First_Order {
+	/**
+	 * Note traits.
+	 */
+	use NoteTraits;
+
+	/**
+	 * Name of the note for use in the database.
+	 */
+	const NOTE_NAME = 'wc-admin-first-order';
+
+	/**
+	 * Attach hooks.
+	 */
+	public function __construct() {
+		add_action( 'wp_insert_post', array( __CLASS__, 'add_on_first_order' ), 10, 2 );
+	}
+
+	/**
+	 * Check to see if this is the first order being created.
+	 *
+	 * @param integer $post_id Post ID.
+	 * @param WP_Post $post Post object.
+	 */
+	public static function add_on_first_order( $post_id, $post ) {
+		if ( 'shop_order' !== $post->post_type ) {
+			return;
+		}
+
+		// Only add this note if no previous orders exist.
+		$query  = new \WC_Order_Query(
+			array(
+				'limit' => 2,
+			)
+		);
+		$orders = $query->get_orders();
+
+		if ( count( $orders ) !== 1 ) {
+			return;
+		}
+
+		self::possibly_add_note();
+	}
+
+	/**
+	 * Get the note.
+	 */
+	public static function get_note() {
+		$content = __( "Congratulations on getting your first order! Now it's a great time to learn how to manage your orders.", 'woocommerce-admin' );
+
+		$note = new WC_Admin_Note();
+		$note->set_title( __( 'First order received', 'woocommerce-admin' ) );
+		$note->set_content( $content );
+		$note->set_content_data( (object) array() );
+		$note->set_type( WC_Admin_Note::E_WC_ADMIN_NOTE_INFORMATIONAL );
+		$note->set_name( self::NOTE_NAME );
+		$note->set_source( 'woocommerce-admin' );
+		$note->add_action( 'learn-more', __( 'Learn more', 'woocommerce-admin' ), 'https://docs.woocommerce.com/document/managing-orders/?utm_source=inbox' );
+		return $note;
+	}
+}