From e3fc005aa7c8393b0be26bb57dfde1bc71dc3e0e Mon Sep 17 00:00:00 2001
From: Rob N <rob.netzke@gmail.com>
Date: Tue, 10 Dec 2024 09:54:23 -1000
Subject: [PATCH] feat: add `broadcast_minimum` to `Client`

---
 examples/wallet.rs |  4 ++++
 src/lib.rs         | 19 +++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/examples/wallet.rs b/examples/wallet.rs
index 2f298a6..2dcc7ca 100644
--- a/examples/wallet.rs
+++ b/examples/wallet.rs
@@ -66,6 +66,10 @@ async fn main() -> anyhow::Result<()> {
             tracing::info!("Local chain tip: {}", wallet.local_chain().tip().height());
             let next = wallet.peek_address(KeychainKind::External, last_revealed + 1);
             tracing::info!("Next receiving address: {next}");
+            tracing::info!(
+                "Broadcast minimum fee rate: {}",
+                receiver.broadcast_minimum()
+            );
         }
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index 4aef450..d580357 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -168,6 +168,7 @@ use bdk_chain::{
 };
 use bdk_chain::{ConfirmationBlockTime, TxUpdate};
 
+pub use bdk_chain::bitcoin::FeeRate;
 pub use bdk_chain::local_chain::MissingGenesisError;
 
 pub extern crate kyoto;
@@ -197,6 +198,8 @@ pub struct EventReceiver<K> {
     chain: local_chain::LocalChain,
     // receive graph
     graph: IndexedTxGraph<ConfirmationBlockTime, KeychainTxOutIndex<K>>,
+    // the network minimum to broadcast a transaction
+    min_broadcast_fee: FeeRate,
 }
 
 impl<K> EventReceiver<K>
@@ -213,6 +216,7 @@ where
             receiver,
             chain: LocalChain::from_tip(cp)?,
             graph: IndexedTxGraph::new(index.clone()),
+            min_broadcast_fee: FeeRate::BROADCAST_MIN,
         })
     }
 
@@ -256,6 +260,11 @@ where
                     });
                     break;
                 }
+                NodeMessage::FeeFilter(fee_filter) => {
+                    if self.min_broadcast_fee < fee_filter {
+                        self.min_broadcast_fee = fee_filter;
+                    }
+                }
                 _ => (),
             }
         }
@@ -379,11 +388,21 @@ where
                 NodeMessage::TxBroadcastFailure(failure_payload) => {
                     return Some(Event::TxFailed(failure_payload));
                 }
+                NodeMessage::FeeFilter(fee_filter) => {
+                    if self.min_broadcast_fee < fee_filter {
+                        self.min_broadcast_fee = fee_filter;
+                    }
+                }
                 _ => continue,
             }
         }
         None
     }
+
+    /// The minimum fee required for a transaction to propagate to the connected peers.
+    pub fn broadcast_minimum(&self) -> FeeRate {
+        self.min_broadcast_fee
+    }
 }
 
 /// Handle dialog and state changes from a node with some arbitrary behavior.