plugins: lsps: implement ClnSender for bolt8 transport

Implement the MessageSender trait for Bolt8 transport via core-lightning

Signed-off-by: Peter Neuroth <pet.v.ne@gmail.com>

plugins/lsps-plugin/src/cln_adapters/mod.rs

@@ -1,2 +1,3 @@
+pub mod sender;
 pub mod service;
 pub mod transport;

plugins/lsps-plugin/src/cln_adapters/sender.rs

@@ -0,0 +1,40 @@
+use crate::{
+    cln_adapters::utils::encode_lsps0_frame_hex,
+    core::transport::{Error as TransportError, MessageSender},
+};
+use async_trait::async_trait;
+use bitcoin::secp256k1::PublicKey;
+use cln_rpc::{model::requests::SendcustommsgRequest, ClnRpc};
+use std::path::PathBuf;
+
+#[derive(Clone)]
+pub struct ClnSender {
+    rpc_path: PathBuf,
+}
+
+impl ClnSender {
+    pub fn new(rpc_path: PathBuf) -> Self {
+        Self { rpc_path }
+    }
+}
+
+#[async_trait]
+impl MessageSender for ClnSender {
+    async fn send(&self, peer_id: &PublicKey, payload: &[u8]) -> Result<(), TransportError> {
+        let mut rpc = ClnRpc::new(&self.rpc_path)
+            .await
+            .map_err(|e| TransportError::Internal(e.to_string()))?;
+
+        // Encode frame for LSPS0 Bolt8 transport.
+        let msg = encode_lsps0_frame_hex(payload);
+
+        rpc.call_typed(&SendcustommsgRequest {
+            msg,
+            node_id: peer_id.to_owned(),
+        })
+        .await
+        .map_err(|e| TransportError::Internal(e.to_string()))?;
+
+        Ok(())
+    }
+}