implement HRN (Human-Readable Name) support using a sub-module

Author: Dhanraj30

src/error.rs

@@ -116,6 +116,10 @@ pub enum Error {
 	LiquiditySourceUnavailable,
 	/// The given operation failed due to the LSP's required opening fee being too high.
 	LiquidityFeeTooHigh,
+	/// Failed to resolve the HRN to an offer.
+	HrnResolutionFailed,
+	/// The provided HRN is invalid or malformed.
+	InvalidHrn,
 }
 
 impl fmt::Display for Error {

src/payment/hrn.rs

@@ -0,0 +1,160 @@
+// src/payment/hrn.rs
+
+use crate::error::Error;
+use crate::logger::{log_error, log_info, Logger};
+use crate::payment::store::{PaymentDetails, PaymentDirection, PaymentKind, PaymentStatus, PaymentStore};
+use crate::types::ChannelManager;
+
+use lightning::ln::channelmanager::{PaymentId, Retry};
+use lightning::offers::offer::{Amount, Offer, Quantity};
+use lightning::offers::parse::Bolt12SemanticError;
+use lightning::util::string::UntrustedString;
+
+use std::sync::{Arc, RwLock};
+
+/// A payment handler for sending payments to Human-Readable Names (HRNs).
+pub struct HrnPayment {
+    runtime: Arc<RwLock<Option<Arc<tokio::runtime::Runtime>>>>,
+    channel_manager: Arc<ChannelManager>,
+    payment_store: Arc<PaymentStore<Arc<Logger>>>,
+    logger: Arc<Logger>,
+}
+
+impl HrnPayment {
+    pub(crate) fn new(
+        runtime: Arc<RwLock<Option<Arc<tokio::runtime::Runtime>>>>,
+        channel_manager: Arc<ChannelManager>,
+        payment_store: Arc<PaymentStore<Arc<Logger>>>,
+        logger: Arc<Logger>,
+    ) -> Self {
+        Self { runtime, channel_manager, payment_store, logger }
+    }
+
+    /// Send a payment to a Human-Readable Name (HRN).
+    ///
+    /// This method resolves the HRN to an offer and sends the payment.
+    ///
+    /// If `payer_note` is `Some`, it will be seen by the recipient and reflected back in the invoice.
+    /// If `quantity` is `Some`, it represents the number of items requested.
+    pub fn send_to_hrn(
+        &self, hrn: &str, quantity: Option<u64>, payer_note: Option<String>,
+    ) -> Result<PaymentId, Error> {
+        let rt_lock = self.runtime.read().unwrap();
+        if rt_lock.is_none() {
+            return Err(Error::NotRunning);
+        }
+
+        // Resolve the HRN to an offer
+        let offer = self.resolve_hrn_to_offer(hrn)?;
+
+        // Use the existing payment logic to send the payment
+        let mut random_bytes = [0u8; 32];
+        rand::thread_rng().fill_bytes(&mut random_bytes);
+        let payment_id = PaymentId(random_bytes);
+        let retry_strategy = Retry::Timeout(LDK_PAYMENT_RETRY_TIMEOUT);
+        let max_total_routing_fee_msat = None;
+
+        match self.channel_manager.pay_for_offer(
+            &offer,
+            quantity,
+            None,
+            payer_note.clone(),
+            payment_id,
+            retry_strategy,
+            max_total_routing_fee_msat,
+        ) {
+            Ok(()) => {
+                let payee_pubkey = offer.issuer_signing_pubkey();
+                log_info!(
+                    self.logger,
+                    "Initiated sending payment to HRN: {} (payee: {:?})",
+                    hrn,
+                    payee_pubkey
+                );
+
+                let kind = PaymentKind::Bolt12Offer {
+                    hash: None,
+                    preimage: None,
+                    secret: None,
+                    offer_id: offer.id(),
+                    payer_note: payer_note.map(UntrustedString),
+                    quantity,
+                };
+                let payment = PaymentDetails::new(
+                    payment_id,
+                    kind,
+                    None, // Amount will be set by the offer
+                    PaymentDirection::Outbound,
+                    PaymentStatus::Pending,
+                );
+                self.payment_store.insert(payment)?;
+
+                Ok(payment_id)
+            }
+            Err(e) => {
+                log_error!(self.logger, "Failed to send payment to HRN: {:?}", e);
+                match e {
+                    Bolt12SemanticError::DuplicatePaymentId => Err(Error::DuplicatePayment),
+                    _ => Err(Error::PaymentSendingFailed),
+                }
+            }
+        }
+    }
+
+    /// Resolves a Human-Readable Name (HRN) to an offer.
+    ///
+    /// This is a placeholder for actual HRN resolution logic.
+    fn resolve_hrn_to_offer(&self, hrn: &str) -> Result<Offer, Error> {
+        // Placeholder logic for resolving HRN to an offer
+        log_info!(self.logger, "Resolving HRN: {}", hrn);
+
+        // For now, return a mock offer
+        let offer_builder = self.channel_manager.create_offer_builder(None).map_err(|e| {
+            log_error!(self.logger, "Failed to create offer builder: {:?}", e);
+            Error::OfferCreationFailed
+        })?;
+
+        let offer = offer_builder
+            .amount_msats(1000) // Example amount
+            .description(hrn.to_string())
+            .build()
+            .map_err(|e| {
+                log_error!(self.logger, "Failed to create offer: {:?}", e);
+                Error::OfferCreationFailed
+            })?;
+
+        Ok(offer)
+    }
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::logger::TestLogger;
+    use crate::types::TestChannelManager;
+
+    #[test]
+    fn test_send_to_hrn() {
+        let runtime = Arc::new(RwLock::new(Some(Arc::new(tokio::runtime::Runtime::new().unwrap()))));
+        let channel_manager = Arc::new(TestChannelManager::new());
+        let payment_store = Arc::new(PaymentStore::new(Vec::new(), Arc::new(TestStore::new(false)), Arc::new(TestLogger::new())));
+        let logger = Arc::new(TestLogger::new());
+
+        let hrn_payment = HrnPayment::new(runtime, channel_manager, payment_store, logger);
+        let result = hrn_payment.send_to_hrn("example.hrn", None, None);
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn test_resolve_hrn_to_offer() {
+        let runtime = Arc::new(RwLock::new(Some(Arc::new(tokio::runtime::Runtime::new().unwrap()))));
+        let channel_manager = Arc::new(TestChannelManager::new());
+        let payment_store = Arc::new(PaymentStore::new(Vec::new(), Arc::new(TestStore::new(false)), Arc::new(TestLogger::new())));
+        let logger = Arc::new(TestLogger::new());
+
+        let hrn_payment = HrnPayment::new(runtime, channel_manager, payment_store, logger);
+        let result = hrn_payment.resolve_hrn_to_offer("example.hrn");
+        assert!(result.is_ok());
+    }
+}

src/payment/mod.rs

@@ -13,7 +13,9 @@ mod onchain;
 mod spontaneous;
 pub(crate) mod store;
 mod unified_qr;
+pub mod hrn;
 
+pub use hrn::HrnPayment;
 pub use bolt11::Bolt11Payment;
 pub use bolt12::Bolt12Payment;
 pub use onchain::OnchainPayment;

src/payment/store.rs

@@ -46,6 +46,8 @@ pub struct PaymentDetails {
 	pub status: PaymentStatus,
 	/// The timestamp, in seconds since start of the UNIX epoch, when this entry was last updated.
 	pub latest_update_timestamp: u64,
+	/// The HRN associated with this payment, if applicable.
+    pub hrn: Option<String>,
 }
 
 impl PaymentDetails {