Add utils for creating blinded PaymentParameters

Author: valentinewallace

lightning/src/routing/router.rs

@@ -634,8 +634,32 @@ impl PaymentParameters {
 			.expect("PaymentParameters::from_node_id should always initialize the payee as unblinded")
 	}
 
-	/// Includes the payee's features. Errors if the parameters were initialized with blinded payment
-	/// paths.
+	/// Creates parameters for paying to a blinded payee.
+	pub fn blinded(blinded_route_hints: Vec<(BlindedPayInfo, BlindedPath)>) -> Self {
+		Self {
+			payee: Payee::Blinded { route_hints: blinded_route_hints, features: None },
+			expiry_time: None,
+			max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
+			max_path_count: DEFAULT_MAX_PATH_COUNT,
+			max_channel_saturation_power_of_half: 2,
+			previously_failed_channels: Vec::new(),
+		}
+	}
+
+	/// Includes the payee's features. Errors if the parameters were not initialized with
+	/// [`PaymentParameters::blinded`].
+	///
+	/// This is not exported to bindings users since bindings don't support move semantics
+	pub fn with_bolt12_features(self, features: Bolt12InvoiceFeatures) -> Result<Self, ()> {
+		match self.payee {
+			Payee::Clear { .. } => Err(()),
+			Payee::Blinded { route_hints, .. } =>
+				Ok(Self { payee: Payee::Blinded { route_hints, features: Some(features) }, ..self })
+		}
+	}
+
+	/// Includes the payee's features. Errors if the parameters were initialized with
+	/// [`PaymentParameters::blinded`].
 	///
 	/// This is not exported to bindings users since bindings don't support move semantics
 	pub fn with_bolt11_features(self, features: InvoiceFeatures) -> Result<Self, ()> {
@@ -651,7 +675,7 @@ impl PaymentParameters {
 	}
 
 	/// Includes hints for routing to the payee. Errors if the parameters were initialized with
-	/// blinded payment paths.
+	/// [`PaymentParameters::blinded`].
 	///
 	/// This is not exported to bindings users since bindings don't support move semantics
 	pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Result<Self, ()> {