add LSPS5 event enums for webhook operations

- Introduce LSPS5ServiceEvent for LSPS-side webhook events including registration, listing, removal, and notification.
- Define LSPS5ClientEvent for handling webhook outcomes on the client (Lightning node) side.
- Outline WebhookNotificationParams enum to support notification-specific parameters.

Author: martinsaposnic

lightning-liquidity/src/lsps5/event.rs

@@ -0,0 +1,172 @@
+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
+//! Events generated by the LSPS5 service and client
+
+use crate::lsps0::ser::LSPSRequestId;
+use crate::lsps5::msgs::WebhookNotificationMethod;
+use crate::prelude::String;
+use crate::prelude::Vec;
+use bitcoin::secp256k1::PublicKey;
+
+/// Events emitted by the LSPS5 webhook service (LSP side)
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum LSPS5ServiceEvent {
+	/// A webhook was registered by a client
+	WebhookRegistered {
+		/// Client node ID
+		client: PublicKey,
+		/// App name
+		app_name: String,
+		/// Webhook URL
+		url: String,
+		/// Request ID for tracking
+		request_id: LSPSRequestId,
+		/// Whether this was a new registration or an update to existing one
+		no_change: bool,
+	},
+
+	/// Webhooks were listed for a client
+	WebhooksListed {
+		/// Client node ID
+		client: PublicKey,
+		/// App names with registered webhooks
+		app_names: Vec<String>,
+		/// Maximum number of webhooks allowed
+		max_webhooks: u32,
+		/// Request ID for tracking
+		request_id: LSPSRequestId,
+	},
+
+	/// A webhook was removed
+	WebhookRemoved {
+		/// Client node ID
+		client: PublicKey,
+		/// App name
+		app_name: String,
+		/// Request ID for tracking
+		request_id: LSPSRequestId,
+	},
+
+	/// A notification was sent to a webhook
+	WebhookNotificationSent {
+		/// Client node ID
+		client: PublicKey,
+		/// App name
+		app_name: String,
+		/// Webhook URL
+		url: String,
+		/// Notification method
+		method: WebhookNotificationMethod,
+		/// Timestamp of the notification
+		timestamp: String,
+		/// Signature of the notification
+		signature: String,
+	},
+}
+
+/// Events emitted by the LSPS5 webhook client (Lightning node side)
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum LSPS5ClientEvent {
+	/// A webhook was successfully registered with the LSP
+	WebhookRegistered {
+		/// LSP node ID
+		lsp: PublicKey,
+		/// App name
+		app_name: String,
+		/// Webhook URL
+		url: String,
+		/// Number of webhooks now registered
+		num_webhooks: u32,
+		/// Maximum number of webhooks allowed
+		max_webhooks: u32,
+		/// Whether this was a new registration or an update to existing one
+		no_change: bool,
+	},
+
+	/// Failed to register a webhook with the LSP
+	WebhookRegistrationFailed {
+		/// LSP node ID
+		lsp: PublicKey,
+		/// App name
+		app_name: String,
+		/// Webhook URL
+		url: String,
+		/// Error code
+		error_code: i32,
+		/// Error message
+		error_message: String,
+	},
+
+	/// Received list of registered webhooks from the LSP
+	WebhooksListed {
+		/// LSP node ID
+		lsp: PublicKey,
+		/// App names with registered webhooks
+		app_names: Vec<String>,
+		/// Maximum number of webhooks allowed
+		max_webhooks: u32,
+	},
+
+	/// Failed to list webhooks
+	WebhooksListFailed {
+		/// LSP node ID
+		lsp: PublicKey,
+		/// Error code
+		error_code: i32,
+		/// Error message
+		error_message: String,
+	},
+
+	/// A webhook was successfully removed
+	WebhookRemoved {
+		/// LSP node ID
+		lsp: PublicKey,
+		/// App name
+		app_name: String,
+	},
+
+	/// Failed to remove a webhook
+	WebhookRemovalFailed {
+		/// LSP node ID
+		lsp: PublicKey,
+		/// App name
+		app_name: String,
+		/// Error code
+		error_code: i32,
+		/// Error message
+		error_message: String,
+	},
+
+	/// A webhook notification was received from the LSP
+	WebhookNotificationReceived {
+		/// LSP node ID
+		lsp: PublicKey,
+		/// The notification method that was received
+		method: WebhookNotificationMethod,
+		/// Timestamp of the notification
+		timestamp: String,
+		/// Whether the signature verification succeeded
+		signature_valid: bool,
+		/// The notification parameters (might be empty depending on method)
+		parameters: Option<WebhookNotificationParams>,
+	},
+}
+
+/// Parameters for different webhook notification methods
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum WebhookNotificationParams {
+	/// Parameters for lsps5.expiry_soon notification
+	ExpirySoon {
+		/// Block height when timeout occurs
+		timeout: u32,
+	},
+	/// For future extensions of other notification types that might have parameters
+	Other,
+}