fixup: LSPS5 events - Improve type safety and documentation

- Replaces raw error code/message pairs with a structured LSPS5Error type
- Changes String timestamp fields to use the proper LSPSDateTime type
- Improves documentation with references to MAX_APP_NAME_LENGTH constant

Author: martinsaposnic

lightning-liquidity/src/lsps5/event.rs

@@ -9,15 +9,16 @@
 
 //! Events generated by the LSPS5 service and client
 
+use crate::lsps0::ser::LSPSDateTime;
 use crate::lsps0::ser::LSPSRequestId;
 use alloc::string::String;
 use alloc::vec::Vec;
 use bitcoin::secp256k1::PublicKey;
 
 use super::msgs::LSPS5AppName;
+use super::msgs::LSPS5Error;
 use super::msgs::LSPS5WebhookUrl;
 use super::msgs::WebhookNotification;
-
 /// An event which an bLIP-55 / LSPS5 server should take some action in response to.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum LSPS5ServiceEvent {
@@ -28,9 +29,22 @@ pub enum LSPS5ServiceEvent {
 	WebhookRegistered {
 		/// Client node ID that registered the webhook
 		counterparty_node_id: PublicKey,
-		/// App name provided by the client (up to 64 bytes in UTF-8 format)
+		/// App name provided by the client.
+		///
+		/// This app name is used to identify the webhook registration.
+		///
+		/// **Note**: Ensure the app name is valid and its length does not exceed [`MAX_APP_NAME_LENGTH`].
+		///
+		/// [`MAX_APP_NAME_LENGTH`]: super::msgs::MAX_APP_NAME_LENGTH
 		app_name: LSPS5AppName,
-		/// Webhook URL (HTTPS) that should be contacted to notify the client (up to 1024 ASCII characters)
+		/// Webhook URL (HTTPS) to be contacted for notifying the client.
+		///
+		/// This URL is used by the LSP to send notifications.
+		///
+		/// **Note**: Ensure the URL is valid and its length does not exceed [`MAX_APP_NAME_LENGTH`].
+		/// Also ensure that the URL points to a public host.
+		///
+		/// [`MAX_APP_NAME_LENGTH`]: super::msgs::MAX_APP_NAME_LENGTH
 		url: LSPS5WebhookUrl,
 		/// The identifier of the issued bLIP-55 / LSPS5 webhook registration request
 		///
@@ -91,7 +105,7 @@ pub enum LSPS5ServiceEvent {
 		/// Notification method with its parameters
 		notification: WebhookNotification,
 		/// ISO8601 timestamp of the notification (YYYY-MM-DDThh:mm:ss.uuuZ format)
-		timestamp: String,
+		timestamp: LSPSDateTime,
 		/// Signature of the notification using the LSP's node ID
 		signature: String,
 		/// Headers to be included in the HTTP POST request
@@ -116,9 +130,9 @@ pub enum LSPS5ClientEvent {
 		/// Whether this was an unchanged registration (same app_name and URL)
 		/// If true, the LSP didn't send a webhook notification for this registration
 		no_change: bool,
-		/// The app name that was registered (up to 64 bytes in UTF-8 format)
+		/// The app name that was registered
 		app_name: LSPS5AppName,
-		/// The webhook URL that was registered (HTTPS protocol)
+		/// The webhook URL that was registered
 		url: LSPS5WebhookUrl,
 		/// The identifier of the issued bLIP-55 / LSPS5 webhook registration request
 		///
@@ -134,11 +148,8 @@ pub enum LSPS5ClientEvent {
 	WebhookRegistrationFailed {
 		/// The node id of the LSP that rejected the registration
 		counterparty_node_id: PublicKey,
-		/// Error code from the LSP (500: too_long, 501: url_parse_error,
-		/// 502: unsupported_protocol, 503: too_many_webhooks)
-		error_code: i32,
-		/// Error message from the LSP
-		error_message: String,
+		/// Error from the LSP
+		error: LSPS5Error,
 		/// The app name that was attempted
 		app_name: LSPS5AppName,
 		/// The webhook URL that was attempted
@@ -171,10 +182,8 @@ pub enum LSPS5ClientEvent {
 	WebhooksListFailed {
 		/// The node id of the LSP that rejected the request
 		counterparty_node_id: PublicKey,
-		/// Error code from the LSP
-		error_code: i32,
-		/// Error message from the LSP
-		error_message: String,
+		/// Error from the LSP
+		error: LSPS5Error,
 		/// The identifier of the issued bLIP-55 / LSPS5 list webhooks request
 		///
 		/// This can be used to track which request this event corresponds to.
@@ -203,10 +212,8 @@ pub enum LSPS5ClientEvent {
 	WebhookRemovalFailed {
 		/// The node id of the LSP that rejected the removal
 		counterparty_node_id: PublicKey,
-		/// Error code from the LSP (1010: app_name_not_found)
-		error_code: i32,
-		/// Error message from the LSP
-		error_message: String,
+		/// Error from the LSP
+		error: LSPS5Error,
 		/// The app name that was attempted to be removed
 		app_name: LSPS5AppName,
 		/// The identifier of the issued bLIP-55 / LSPS5 remove webhook request
@@ -226,7 +233,7 @@ pub enum LSPS5ClientEvent {
 		/// The notification with its method and parameters
 		notification: WebhookNotification,
 		/// Timestamp of the notification in ISO8601 format (YYYY-MM-DDThh:mm:ss.uuuZ)
-		timestamp: String,
+		timestamp: LSPSDateTime,
 		/// Whether the LSP's signature was successfully verified
 		signature_valid: bool,
 	},