Refactor bolt11 send methods to use default sending params

Refactored the send methods in Bolt11Payment to combine user-set
SendingParameters with default values from Config. If the user
sets any parameter to None, the related default value is used.

src/payment/bolt11.rs

@@ -93,13 +93,38 @@ impl Bolt11Payment {
 			}
 		}
 
-		if let Some(payment_params) = sending_parameters {
-			payment_params
-				.max_total_routing_fee_msat
-				.map(|fee| route_params.max_total_routing_fee_msat = Some(fee));
-			payment_params
-				.max_total_cltv_expiry_delta
-				.map(|delta| route_params.payment_params.max_total_cltv_expiry_delta = delta);
+		if let Some(user_set_params) = sending_parameters {
+			if let Some(mut default_params) =
+				self.config.sending_parameters_config.as_ref().cloned()
+			{
+				default_params.max_total_routing_fee_msat = user_set_params
+					.max_total_routing_fee_msat
+					.or(default_params.max_total_routing_fee_msat);
+				default_params.max_total_cltv_expiry_delta = user_set_params
+					.max_total_cltv_expiry_delta
+					.or(default_params.max_total_cltv_expiry_delta);
+				default_params.max_path_count =
+					user_set_params.max_path_count.or(default_params.max_path_count);
+				default_params.max_channel_saturation_power_of_half = user_set_params
+					.max_channel_saturation_power_of_half
+					.or(default_params.max_channel_saturation_power_of_half);
+
+				route_params.max_total_routing_fee_msat = default_params.max_total_routing_fee_msat;
+				route_params.payment_params.max_total_cltv_expiry_delta =
+					default_params.max_total_cltv_expiry_delta.unwrap_or_default();
+				route_params.payment_params.max_path_count =
+					default_params.max_path_count.unwrap_or_default();
+				route_params.payment_params.max_channel_saturation_power_of_half =
+					default_params.max_channel_saturation_power_of_half.unwrap_or_default();
+			}
+		} else if let Some(default_params) = &self.config.sending_parameters_config {
+			route_params.max_total_routing_fee_msat = default_params.max_total_routing_fee_msat;
+			route_params.payment_params.max_total_cltv_expiry_delta =
+				default_params.max_total_cltv_expiry_delta.unwrap_or_default();
+			route_params.payment_params.max_path_count =
+				default_params.max_path_count.unwrap_or_default();
+			route_params.payment_params.max_channel_saturation_power_of_half =
+				default_params.max_channel_saturation_power_of_half.unwrap_or_default();
 		}
 
 		let payment_secret = Some(*invoice.payment_secret());
@@ -212,13 +237,38 @@ impl Bolt11Payment {
 		let mut route_params =
 			RouteParameters::from_payment_params_and_value(payment_params, amount_msat);
 
-		if let Some(payment_params) = sending_parameters {
-			payment_params
-				.max_total_routing_fee_msat
-				.map(|fee| route_params.max_total_routing_fee_msat = Some(fee));
-			payment_params
-				.max_total_cltv_expiry_delta
-				.map(|delta| route_params.payment_params.max_total_cltv_expiry_delta = delta);
+		if let Some(user_set_params) = sending_parameters {
+			if let Some(mut default_params) =
+				self.config.sending_parameters_config.as_ref().cloned()
+			{
+				default_params.max_total_routing_fee_msat = user_set_params
+					.max_total_routing_fee_msat
+					.or(default_params.max_total_routing_fee_msat);
+				default_params.max_total_cltv_expiry_delta = user_set_params
+					.max_total_cltv_expiry_delta
+					.or(default_params.max_total_cltv_expiry_delta);
+				default_params.max_path_count =
+					user_set_params.max_path_count.or(default_params.max_path_count);
+				default_params.max_channel_saturation_power_of_half = user_set_params
+					.max_channel_saturation_power_of_half
+					.or(default_params.max_channel_saturation_power_of_half);
+
+				route_params.max_total_routing_fee_msat = default_params.max_total_routing_fee_msat;
+				route_params.payment_params.max_total_cltv_expiry_delta =
+					default_params.max_total_cltv_expiry_delta.unwrap_or_default();
+				route_params.payment_params.max_path_count =
+					default_params.max_path_count.unwrap_or_default();
+				route_params.payment_params.max_channel_saturation_power_of_half =
+					default_params.max_channel_saturation_power_of_half.unwrap_or_default();
+			}
+		} else if let Some(default_params) = &self.config.sending_parameters_config {
+			route_params.max_total_routing_fee_msat = default_params.max_total_routing_fee_msat;
+			route_params.payment_params.max_total_cltv_expiry_delta =
+				default_params.max_total_cltv_expiry_delta.unwrap_or_default();
+			route_params.payment_params.max_path_count =
+				default_params.max_path_count.unwrap_or_default();
+			route_params.payment_params.max_channel_saturation_power_of_half =
+				default_params.max_channel_saturation_power_of_half.unwrap_or_default();
 		}
 
 		let retry_strategy = Retry::Timeout(LDK_PAYMENT_RETRY_TIMEOUT);

tests/integration_tests_rust.rs

@@ -159,6 +159,8 @@ fn multi_hop_sending() {
 	let payment_params = SendingParameters {
 		max_total_routing_fee_msat: Some(75_000),
 		max_total_cltv_expiry_delta: Some(1000),
+		max_path_count: Some(10),
+		max_channel_saturation_power_of_half: Some(2),
 	};
 
 	let invoice = nodes[4].bolt11_payment().receive(2_500_000, &"asdf", 9217).unwrap();