Update fee threshold snippet to avoid rust-only fn

Author: ok300

snippets/rust/src/communicating_fees.rs

@@ -6,21 +6,25 @@ use log::info;
 
 async fn get_fee_info_before_receiving_payment(sdk: Arc<BreezServices>) -> Result<()> {
     // ANCHOR: get-fee-info-before-receiving-payment
-    // Unless chosen otherwise by the app or the user, the SDK defaults to the cheapest fees
-    let opening_fees = sdk
-        .lsp_info()
-        .await?
-        .opening_fee_params_list
-        .get_cheapest_opening_fee_params()?;
-
-    let fee_percentage = opening_fees.proportional * 100_f64 / 1_000_000_f64;
-    let min_fee_sat = opening_fees.min_msat / 1_000;
-    let inbound_liquidity_sat = sdk.node_info()?.inbound_liquidity_msats / 1000;
-
-    if inbound_liquidity_sat == 0 {
-        info!("A setup fee of {fee_percentage}% with a minimum of {min_fee_sat} sats will be applied.");
-    } else {
-        info!("A setup fee of {fee_percentage}% with a minimum of {min_fee_sat} sats will be applied for receiving more than {inbound_liquidity_sat} sats.");
+    let inbound_liquidity_msat = sdk.node_info()?.inbound_liquidity_msats;
+    let inbound_liquidity_sat = inbound_liquidity_msat / 1000;
+
+    let opening_fee_response = sdk
+        .open_channel_fee(OpenChannelFeeRequest {
+            amount_msat: inbound_liquidity_msat + 1,
+            expiry: None,
+        })
+        .await?;
+
+    if let Some(opening_fees) = opening_fee_response.used_fee_params {
+        let fee_percentage = opening_fees.proportional * 100_f64 / 1_000_000_f64;
+        let min_fee_sat = opening_fees.min_msat / 1_000;
+
+        if inbound_liquidity_sat == 0 {
+            info!("A setup fee of {fee_percentage}% with a minimum of {min_fee_sat} sats will be applied.");
+        } else {
+            info!("A setup fee of {fee_percentage}% with a minimum of {min_fee_sat} sats will be applied for receiving more than {inbound_liquidity_sat} sats.");
+        }
     }
     // ANCHOR_END: get-fee-info-before-receiving-payment