Refactor unified.rs to support sending to BIP 21 URIs as well as BIP 353 HRNs

Author: chuksys

bindings/ldk_node.udl

@@ -238,8 +238,8 @@ interface FeeRate {
 interface UnifiedPayment {
 	[Throws=NodeError]
 	string receive(u64 amount_sats, [ByRef]string message, u32 expiry_sec);
-	[Throws=NodeError]
-	PaymentResult send([ByRef]string uri_str);
+	[Throws=NodeError, Async]
+	PaymentResult send([ByRef]string uri_str, u64? amount_msat);
 };
 
 interface LSPS1Liquidity {

src/payment/unified.rs

@@ -26,7 +26,7 @@ use lightning_invoice::{Bolt11Invoice, Bolt11InvoiceDescription, Description};
 
 use bip21::de::ParamKind;
 use bip21::{DeserializationError, DeserializeParams, Param, SerializeParams};
-use bitcoin::address::{NetworkChecked, NetworkUnchecked};
+use bitcoin::address::NetworkChecked;
 use bitcoin::{Amount, Txid};
 
 use std::sync::Arc;
@@ -143,54 +143,104 @@ impl UnifiedPayment {
 		Ok(format_uri(uri))
 	}
 
-	/// Sends a payment given a [BIP 21] URI.
+	/// Sends a payment given a [BIP 21] URI or [BIP 353] HRN.
 	///
 	/// This method parses the provided URI string and attempts to send the payment. If the URI
 	/// has an offer and or invoice, it will try to pay the offer first followed by the invoice.
 	/// If they both fail, the on-chain payment will be paid.
 	///
-	/// Returns a `QrPaymentResult` indicating the outcome of the payment. If an error
+	/// Returns a `PaymentResult` indicating the outcome of the payment. If an error
 	/// occurs, an `Error` is returned detailing the issue encountered.
 	///
 	/// [BIP 21]: https://github.com/bitcoin/bips/blob/master/bip-0021.mediawiki
-	pub fn send(&self, uri_str: &str) -> Result<QrPaymentResult, Error> {
-		let uri: bip21::Uri<NetworkUnchecked, Extras> =
-			uri_str.parse().map_err(|_| Error::InvalidUri)?;
-
-		let uri_network_checked =
-			uri.clone().require_network(self.config.network).map_err(|_| Error::InvalidNetwork)?;
-
-		if let Some(offer) = uri_network_checked.extras.bolt12_offer {
-			let offer = maybe_wrap(offer);
-			match self.bolt12_payment.send(&offer, None, None) {
-				Ok(payment_id) => return Ok(QrPaymentResult::Bolt12 { payment_id }),
-				Err(e) => log_error!(self.logger, "Failed to send BOLT12 offer: {:?}. This is part of a unified QR code payment. Falling back to the BOLT11 invoice.", e),
+	/// [BIP 353]: https://github.com/bitcoin/bips/blob/master/bip-0353.mediawiki
+	pub async fn send(
+		&self, uri_str: &str, amount_msat: Option<u64>,
+	) -> Result<PaymentResult, Error> {
+		let instructions = match PaymentInstructions::parse(
+			uri_str,
+			self.config.network,
+			self.hrn_resolver.as_ref(),
+			true,
+		)
+		.await
+		{
+			Ok(instr) => instr,
+			Err(e) => {
+				log_error!(self.logger, "Failed to parse payment instructions: {:?}", e);
+				return Err(Error::UriParameterParsingFailed);
+			},
+		};
+
+		let resolved = match instructions {
+			PaymentInstructions::ConfigurableAmount(ref instr) => {
+				if let Some(amount) = amount_msat {
+					let amt = match BPIAmount::from_sats(amount) {
+						Ok(amt) => amt,
+						Err(e) => {
+							log_error!(self.logger, "Error while coverting amount : {:?}", e);
+							return Err(Error::InvalidAmount);
+						},
+					};
+					match instr.clone().set_amount(amt, self.hrn_resolver.as_ref()).await {
+						Ok(resolved) => resolved,
+						Err(e) => {
+							log_error!(self.logger, "Failed to set amount: {:?}", e);
+							return Err(Error::InvalidAmount);
+						},
+					}
+				} else {
+					log_error!(self.logger, "No amount specified. Aborting the payment.");
+					return Err(Error::InvalidAmount);
+				}
+			},
+			PaymentInstructions::FixedAmount(ref instr) => instr.clone(),
+		};
+
+		if let Some(PaymentMethod::LightningBolt12(offer)) =
+			resolved.methods().iter().find(|m| matches!(m, PaymentMethod::LightningBolt12(_)))
+		{
+			let offer = maybe_wrap(offer.clone());
+			if let Some(amount_msat) = amount_msat {
+				match self.bolt12_payment.send_using_amount(&offer, amount_msat, None, None) {
+					Ok(payment_id) => return Ok(PaymentResult::Bolt12 { payment_id }),
+					Err(e) => log_error!(self.logger, "Failed to send BOLT12 offer: {:?}. This is part of a unified payment. Falling back to the BOLT11 invoice.", e),
+				}
+			} else {
+				match self.bolt12_payment.send(&offer, None, None) {
+					Ok(payment_id) => return Ok(PaymentResult::Bolt12 { payment_id }),
+					Err(e) => log_error!(self.logger, "Failed to send BOLT12 offer: {:?}. This is part of a unified payment. Falling back to the BOLT11 invoice.", e),
+				}
 			}
 		}
 
-		if let Some(invoice) = uri_network_checked.extras.bolt11_invoice {
-			let invoice = maybe_wrap(invoice);
+		if let Some(PaymentMethod::LightningBolt11(invoice)) =
+			resolved.methods().iter().find(|m| matches!(m, PaymentMethod::LightningBolt11(_)))
+		{
+			let invoice = maybe_wrap(invoice.clone());
 			match self.bolt11_invoice.send(&invoice, None) {
-				Ok(payment_id) => return Ok(QrPaymentResult::Bolt11 { payment_id }),
-				Err(e) => log_error!(self.logger, "Failed to send BOLT11 invoice: {:?}. This is part of a unified QR code payment. Falling back to the on-chain transaction.", e),
+				Ok(payment_id) => return Ok(PaymentResult::Bolt11 { payment_id }),
+				Err(e) => log_error!(self.logger, "Failed to send BOLT11 invoice: {:?}. This is part of a unified payment. Falling back to the on-chain transaction.", e),
 			}
 		}
 
-		let amount = match uri_network_checked.amount {
-			Some(amount) => amount,
-			None => {
-				log_error!(self.logger, "No amount specified in the URI. Aborting the payment.");
-				return Err(Error::InvalidAmount);
-			},
-		};
-
-		let txid = self.onchain_payment.send_to_address(
-			&uri_network_checked.address,
-			amount.to_sat(),
-			None,
-		)?;
+		if let Some(PaymentMethod::OnChain(address)) =
+			resolved.methods().iter().find(|m| matches!(m, PaymentMethod::OnChain(_)))
+		{
+			let amount = match resolved.onchain_payment_amount() {
+				Some(amount) => amount,
+				None => {
+					log_error!(self.logger, "No amount specified. Aborting the payment.");
+					return Err(Error::InvalidAmount);
+				},
+			};
 
-		Ok(QrPaymentResult::Onchain { txid })
+			let txid =
+				self.onchain_payment.send_to_address(&address, amount.sats().unwrap(), None)?;
+			return Ok(PaymentResult::Onchain { txid });
+		}
+		log_error!(self.logger, "Payable methods not found in URI");
+		Err(Error::PaymentSendingFailed)
 	}
 }
 
@@ -319,7 +369,7 @@ impl DeserializationError for Extras {
 mod tests {
 	use super::*;
 	use crate::payment::unified::Extras;
-	use bitcoin::{Address, Network};
+	use bitcoin::{address::NetworkUnchecked, Address, Network};
 	use std::str::FromStr;
 
 	#[test]