Add utils for creating blinded PaymentParameters

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index 8d903441ca8e944be75d8336c1ed77b69754cc06..c8468798eecb4ba955fea2256b66d470f16170cf 100644 (file)
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -18,7 +18,7 @@ use crate::ln::PaymentHash;
 use crate::ln::channelmanager::{ChannelDetails, PaymentId};
 use crate::ln::features::{Bolt12InvoiceFeatures, ChannelFeatures, InvoiceFeatures, NodeFeatures};
 use crate::ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
-use crate::offers::invoice::BlindedPayInfo;
+use crate::offers::invoice::{BlindedPayInfo, Invoice as Bolt12Invoice};
 use crate::routing::gossip::{DirectedChannelInfo, EffectiveCapacity, ReadOnlyNetworkGraph, NetworkGraph, NodeId, RoutingFees};
 use crate::routing::scoring::{ChannelUsage, LockableScore, Score};
 use crate::util::ser::{Writeable, Readable, ReadableArgs, Writer};
@@ -634,8 +634,40 @@ 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 from the provided invoice. Sets
+       /// [`Payee::Blinded::route_hints`], [`Payee::Blinded::features`], and
+       /// [`PaymentParameters::expiry_time`].
+       pub fn from_bolt12_invoice(invoice: &Bolt12Invoice) -> Self {
+               Self::blinded(invoice.payment_paths().to_vec())
+                       .with_bolt12_features(invoice.features().clone()).unwrap()
+                       .with_expiry_time(invoice.created_at().as_secs().saturating_add(invoice.relative_expiry().as_secs()))
+       }
+
+       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::from_bolt12_invoice`].
+       ///
+       /// 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::from_bolt12_invoice`].
        ///
        /// 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 +683,7 @@ impl PaymentParameters {
        }
 
        /// Includes hints for routing to the payee. Errors if the parameters were initialized with
-       /// blinded payment paths.
+       /// [`PaymentParameters::from_bolt12_invoice`].
        ///
        /// 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, ()> {