Merge pull request #823 from MutinyWallet/dynamic-fee

Dynamic fee

Author: AnthonyRonning

mutiny-core/src/lspclient.rs

@@ -45,6 +45,7 @@ pub struct ProposalRequest {
     pub host: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub port: Option<u16>,
+    pub fee_id: String,
 }
 
 #[derive(Serialize, Deserialize)]
@@ -60,6 +61,7 @@ pub struct FeeRequest {
 
 #[derive(Serialize, Deserialize)]
 pub struct FeeResponse {
+    pub id: String,
     pub fee_amount_msat: u64,
 }
 
@@ -120,11 +122,16 @@ impl LspClient {
         })
     }
 
-    pub(crate) async fn get_lsp_invoice(&self, bolt11: String) -> Result<String, MutinyError> {
+    pub(crate) async fn get_lsp_invoice(
+        &self,
+        bolt11: String,
+        fee_id: String,
+    ) -> Result<String, MutinyError> {
         let payload = ProposalRequest {
             bolt11,
             host: None,
             port: None,
+            fee_id,
         };
 
         let request = self
@@ -170,7 +177,7 @@ impl LspClient {
     pub(crate) async fn get_lsp_fee_msat(
         &self,
         fee_request: FeeRequest,
-    ) -> Result<u64, MutinyError> {
+    ) -> Result<FeeResponse, MutinyError> {
         let request = self
             .http_client
             .post(format!("{}{}", &self.url, FEE_PATH))
@@ -185,6 +192,6 @@ impl LspClient {
             .await
             .map_err(|_| MutinyError::LspGenericError)?;
 
-        Ok(fee_response.fee_amount_msat)
+        Ok(fee_response)
     }
 }

mutiny-core/src/node.rs

@@ -793,7 +793,7 @@ impl<S: MutinyStorage> Node<S> {
         route_hints: Option<Vec<PhantomRouteHints>>,
     ) -> Result<Bolt11Invoice, MutinyError> {
         // the amount to create for the invoice whether or not there is an lsp
-        let (amount_sat, lsp_fee_msat) = if let Some(lsp) = self.lsp_client.as_ref() {
+        let (amount_sat, lsp_fee) = if let Some(lsp) = self.lsp_client.as_ref() {
             // LSP requires an amount:
             let amount_sat = amount_sat.ok_or(MutinyError::BadAmountError)?;
 
@@ -815,15 +815,15 @@ impl<S: MutinyStorage> Node<S> {
             }
 
             // check the fee from the LSP
-            let lsp_fee_msat = lsp
+            let lsp_fee = lsp
                 .get_lsp_fee_msat(FeeRequest {
                     pubkey: self.pubkey.to_hex(),
                     amount_msat: amount_sat * 1000,
                 })
                 .await?;
 
             // Convert the fee from msat to sat for comparison and subtraction
-            let lsp_fee_sat = lsp_fee_msat / 1000;
+            let lsp_fee_sat = lsp_fee.fee_amount_msat / 1000;
 
             // Ensure that the fee is less than the amount being requested.
             // If it isn't, we don't subtract it.
@@ -837,19 +837,27 @@ impl<S: MutinyStorage> Node<S> {
                 amount_sat
             };
 
-            (Some(amount_minus_fee), Some(lsp_fee_msat))
+            (Some(amount_minus_fee), Some(lsp_fee))
         } else {
             (amount_sat, None)
         };
 
+        let lsp_fee_msat = lsp_fee.as_ref().map(|l| l.fee_amount_msat);
+
         let invoice = self
             .create_internal_invoice(amount_sat, lsp_fee_msat, labels, route_hints)
             .await?;
 
         if let Some(lsp) = self.lsp_client.as_ref() {
             self.connect_peer(PubkeyConnectionInfo::new(&lsp.connection_string)?, None)
                 .await?;
-            let lsp_invoice = match lsp.get_lsp_invoice(invoice.to_string()).await {
+            let lsp_invoice = match lsp
+                .get_lsp_invoice(
+                    invoice.to_string(),
+                    lsp_fee.expect("should have gotten a fee id").id,
+                )
+                .await
+            {
                 Ok(lsp_invoice_str) => Bolt11Invoice::from_str(&lsp_invoice_str)?,
                 Err(e) => {
                     log_error!(self.logger, "Failed to get invoice from LSP: {e}");