xpay: add sendamount command

Changelog-Added: sendamount command, to make a payment specifying the desired amount to send instead of the amount to be received.

Signed-off-by: Lagrang3 <lagrang3@protonmail.com>

Author: Lagrang3

.msggen.json

@@ -3876,6 +3876,23 @@
             "sendpay_success.status": 12,
             "sendpay_success.updated_index": 5
         },
+        "SendamountRequest": {
+            "SendAmount.amount_msat": 2,
+            "SendAmount.invstring": 1,
+            "SendAmount.label": 8,
+            "SendAmount.layers[]": 4,
+            "SendAmount.maxdelay": 6,
+            "SendAmount.maxfee": 3,
+            "SendAmount.payer_note": 7,
+            "SendAmount.retry_for": 5
+        },
+        "SendamountResponse": {
+            "SendAmount.amount_msat": 4,
+            "SendAmount.amount_sent_msat": 5,
+            "SendAmount.failed_parts": 2,
+            "SendAmount.payment_preimage": 1,
+            "SendAmount.successful_parts": 3
+        },
         "SendcustommsgRequest": {
             "SendCustomMsg.msg": 2,
             "SendCustomMsg.node_id": 1
@@ -13315,6 +13332,58 @@
             "added": "pre-v0.10.1",
             "deprecated": null
         },
+        "SendAmount": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.amount_msat": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.amount_sent_msat": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.failed_parts": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.invstring": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.label": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.layers[]": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.maxdelay": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.maxfee": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.payer_note": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.payment_preimage": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.retry_for": {
+            "added": "v26.06",
+            "deprecated": null
+        },
+        "SendAmount.successful_parts": {
+            "added": "v26.06",
+            "deprecated": null
+        },
         "SendCustomMsg": {
             "added": "v0.10.1",
             "deprecated": null

cln-grpc/proto/node.proto

@@ -4850,6 +4850,38 @@ impl Node for Server
 
     }
 
+    async fn send_amount(
+        &self,
+        request: tonic::Request<pb::SendamountRequest>,
+    ) -> Result<tonic::Response<pb::SendamountResponse>, tonic::Status> {
+        let req = request.into_inner();
+        let req: requests::SendamountRequest = req.into();
+        debug!("Client asked for send_amount");
+        trace!("send_amount request: {:?}", req);
+        let mut rpc = ClnRpc::new(&self.rpc_path)
+            .await
+            .map_err(|e| Status::new(Code::Internal, e.to_string()))?;
+        let result = rpc.call(Request::SendAmount(req))
+            .await
+            .map_err(|e| Status::new(
+               Code::Unknown,
+               format!("Error calling method SendAmount: {:?}", e)))?;
+        match result {
+            Response::SendAmount(r) => {
+               trace!("send_amount response: {:?}", r);
+               Ok(tonic::Response::new(r.into()))
+            },
+            r => Err(Status::new(
+                Code::Internal,
+                format!(
+                    "Unexpected result {:?} to method call SendAmount",
+                    r
+                )
+            )),
+        }
+
+    }
+
 
 
     type SubscribeBalanceSnapshotStream = NotificationStream<pb::BalanceSnapshotNotification>;