Implement Payer and Router for lightning crate

Implements Payer for ChannelManager and Rotuer for find_route, which can
be used to parameterize InvoicePayer when needing payment retries.

diff --git a/lightning-invoice/src/utils.rs b/lightning-invoice/src/utils.rs
index 02bb31dfaf441814973943b9a91b998be65f6e60..ef885f20381fb626fa3ca34e1a61d3dacdbf1198 100644 (file)
--- a/lightning-invoice/src/utils.rs
+++ b/lightning-invoice/src/utils.rs
@@ -1,14 +1,21 @@
 //! Convenient utilities to create an invoice.
+
 use {Currency, DEFAULT_EXPIRY_TIME, Invoice, InvoiceBuilder, SignOrCreationError, RawInvoice};
+use payment::{Payer, Router};
+
 use bech32::ToBase32;
 use bitcoin_hashes::Hash;
 use lightning::chain;
 use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use lightning::chain::keysinterface::{Sign, KeysInterface};
-use lightning::ln::channelmanager::{ChannelManager, MIN_FINAL_CLTV_EXPIRY};
-use lightning::routing::network_graph::RoutingFees;
-use lightning::routing::router::{RouteHint, RouteHintHop};
+use lightning::ln::{PaymentHash, PaymentSecret};
+use lightning::ln::channelmanager::{ChannelDetails, ChannelManager, PaymentId, PaymentSendFailure, MIN_FINAL_CLTV_EXPIRY};
+use lightning::ln::msgs::LightningError;
+use lightning::routing::network_graph::{NetworkGraph, RoutingFees};
+use lightning::routing::router::{Route, RouteHint, RouteHintHop, RouteParameters, find_route};
+use lightning::routing::scorer::Scorer;
 use lightning::util::logger::Logger;
+use secp256k1::key::PublicKey;
 use std::convert::TryInto;
 use std::ops::Deref;
 
@@ -89,6 +96,58 @@ where
        }
 }
 
+/// A [`Router`] implemented using [`find_route`].
+pub struct DefaultRouter<G, L: Deref> where G: Deref<Target = NetworkGraph>, L::Target: Logger {
+       network_graph: G,
+       logger: L,
+}
+
+impl<G, L: Deref> DefaultRouter<G, L> where G: Deref<Target = NetworkGraph>, L::Target: Logger {
+       /// Creates a new router using the given [`NetworkGraph`] and  [`Logger`].
+       pub fn new(network_graph: G, logger: L) -> Self {
+               Self { network_graph, logger }
+       }
+}
+
+impl<G, L: Deref> Router for DefaultRouter<G, L>
+where G: Deref<Target = NetworkGraph>, L::Target: Logger {
+       fn find_route(
+               &self, payer: &PublicKey, params: &RouteParameters, first_hops: Option<&[&ChannelDetails]>,
+       ) -> Result<Route, LightningError> {
+               let scorer = Scorer::default();
+               find_route(payer, params, &*self.network_graph, first_hops, &*self.logger, &scorer)
+       }
+}
+
+impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Payer for ChannelManager<Signer, M, T, K, F, L>
+where
+       M::Target: chain::Watch<Signer>,
+       T::Target: BroadcasterInterface,
+       K::Target: KeysInterface<Signer = Signer>,
+       F::Target: FeeEstimator,
+       L::Target: Logger,
+{
+       fn node_id(&self) -> PublicKey {
+               self.get_our_node_id()
+       }
+
+       fn first_hops(&self) -> Vec<ChannelDetails> {
+               self.list_usable_channels()
+       }
+
+       fn send_payment(
+               &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>
+       ) -> Result<PaymentId, PaymentSendFailure> {
+               self.send_payment(route, payment_hash, payment_secret)
+       }
+
+       fn retry_payment(
+               &self, route: &Route, payment_id: PaymentId
+       ) -> Result<(), PaymentSendFailure> {
+               self.retry_payment(route, payment_id)
+       }
+}
+
 #[cfg(test)]
 mod test {
        use {Currency, Description, InvoiceDescription};