Liquid/Lightning drain

cli/src/commands.rs

@@ -34,8 +34,12 @@ pub(crate) enum Command {
         #[arg(short, long)]
         amount_sat: Option<u64>,
 
-        /// Delay for the send, in seconds
+        /// Whether or not this is a drain operation. If true, all available funds will be used.
         #[arg(short, long)]
+        drain: Option<bool>,
+
+        /// Delay for the send, in seconds
+        #[arg(long)]
         delay: Option<u64>,
     },
     /// Fetch the current limits for Send and Receive payments
@@ -310,6 +314,7 @@ pub(crate) async fn handle_command(
             invoice,
             address,
             amount_sat,
+            drain,
             delay,
         } => {
             let destination = match (invoice, address) {
@@ -326,11 +331,16 @@ pub(crate) async fn handle_command(
                     ))
                 }
             };
+            let amount = match (amount_sat, drain.unwrap_or(false)) {
+                (Some(amount_sat), _) => Some(PayAmount::Receiver { amount_sat }),
+                (_, true) => Some(PayAmount::Drain),
+                (_, _) => None,
+            };
 
             let prepare_response = sdk
                 .prepare_send_payment(&PrepareSendRequest {
                     destination,
-                    amount_sat,
+                    amount,
                 })
                 .await?;
 
@@ -366,8 +376,8 @@ pub(crate) async fn handle_command(
             fee_rate_sat_per_vbyte,
         } => {
             let amount = match drain.unwrap_or(false) {
-                true => PayOnchainAmount::Drain,
-                false => PayOnchainAmount::Receiver {
+                true => PayAmount::Drain,
+                false => PayAmount::Receiver {
                     amount_sat: receiver_amount_sat.ok_or(anyhow::anyhow!(
                         "Must specify `receiver_amount_sat` if not draining"
                     ))?,

lib/bindings/langs/flutter/breez_sdk_liquid/include/breez_sdk_liquid.h

@@ -279,21 +279,21 @@ typedef struct wire_cst_prepare_ln_url_pay_request {
   bool *validate_success_action_url;
 } wire_cst_prepare_ln_url_pay_request;
 
-typedef struct wire_cst_PayOnchainAmount_Receiver {
+typedef struct wire_cst_PayAmount_Receiver {
   uint64_t amount_sat;
-} wire_cst_PayOnchainAmount_Receiver;
+} wire_cst_PayAmount_Receiver;
 
-typedef union PayOnchainAmountKind {
-  struct wire_cst_PayOnchainAmount_Receiver Receiver;
-} PayOnchainAmountKind;
+typedef union PayAmountKind {
+  struct wire_cst_PayAmount_Receiver Receiver;
+} PayAmountKind;
 
-typedef struct wire_cst_pay_onchain_amount {
+typedef struct wire_cst_pay_amount {
   int32_t tag;
-  union PayOnchainAmountKind kind;
-} wire_cst_pay_onchain_amount;
+  union PayAmountKind kind;
+} wire_cst_pay_amount;
 
 typedef struct wire_cst_prepare_pay_onchain_request {
-  struct wire_cst_pay_onchain_amount amount;
+  struct wire_cst_pay_amount amount;
   uint32_t *fee_rate_sat_per_vbyte;
 } wire_cst_prepare_pay_onchain_request;
 
@@ -310,7 +310,7 @@ typedef struct wire_cst_prepare_refund_request {
 
 typedef struct wire_cst_prepare_send_request {
   struct wire_cst_list_prim_u_8_strict *destination;
-  uint64_t *amount_sat;
+  struct wire_cst_pay_amount *amount;
 } wire_cst_prepare_send_request;
 
 typedef struct wire_cst_prepare_receive_response {
@@ -1166,6 +1166,8 @@ struct wire_cst_ln_url_withdraw_success_data *frbgen_breez_liquid_cst_new_box_au
 
 struct wire_cst_message_success_action_data *frbgen_breez_liquid_cst_new_box_autoadd_message_success_action_data(void);
 
+struct wire_cst_pay_amount *frbgen_breez_liquid_cst_new_box_autoadd_pay_amount(void);
+
 struct wire_cst_pay_onchain_request *frbgen_breez_liquid_cst_new_box_autoadd_pay_onchain_request(void);
 
 struct wire_cst_payment *frbgen_breez_liquid_cst_new_box_autoadd_payment(void);
@@ -1253,6 +1255,7 @@ static int64_t dummy_method_to_enforce_bundling(void) {
     dummy_var ^= ((int64_t) (void*) frbgen_breez_liquid_cst_new_box_autoadd_ln_url_withdraw_request_data);
     dummy_var ^= ((int64_t) (void*) frbgen_breez_liquid_cst_new_box_autoadd_ln_url_withdraw_success_data);
     dummy_var ^= ((int64_t) (void*) frbgen_breez_liquid_cst_new_box_autoadd_message_success_action_data);
+    dummy_var ^= ((int64_t) (void*) frbgen_breez_liquid_cst_new_box_autoadd_pay_amount);
     dummy_var ^= ((int64_t) (void*) frbgen_breez_liquid_cst_new_box_autoadd_pay_onchain_request);
     dummy_var ^= ((int64_t) (void*) frbgen_breez_liquid_cst_new_box_autoadd_payment);
     dummy_var ^= ((int64_t) (void*) frbgen_breez_liquid_cst_new_box_autoadd_prepare_buy_bitcoin_request);

lib/bindings/src/breez_sdk_liquid.udl

@@ -373,7 +373,7 @@ dictionary LnUrlPayRequest {
 
 dictionary PrepareSendRequest {
     string destination;
-    u64? amount_sat = null;
+    PayAmount? amount = null;
 };
 
 [Enum]
@@ -439,13 +439,13 @@ dictionary OnchainPaymentLimitsResponse {
 };
 
 [Enum]
-interface PayOnchainAmount {
+interface PayAmount {
     Receiver(u64 amount_sat);
     Drain();
 };
 
 dictionary PreparePayOnchainRequest {
-    PayOnchainAmount amount;
+    PayAmount amount;
     u32? fee_rate_sat_per_vbyte = null;
 };
 

lib/core/src/chain_swap.rs

@@ -612,30 +612,14 @@ impl ChainSwapHandler {
             lockup_details.amount, lockup_details.lockup_address
         );
 
-        let lockup_tx = match self
+        let lockup_tx = self
             .onchain_wallet
-            .build_tx(
-                self.config
-                    .lowball_fee_rate_msat_per_vbyte()
-                    .map(|v| v as f32),
+            .build_tx_or_drain_tx(
+                self.config.lowball_fee_rate_msat_per_vbyte(),
                 &lockup_details.lockup_address,
                 lockup_details.amount,
             )
-            .await
-        {
-            Err(PaymentError::InsufficientFunds) => {
-                warn!("Cannot build normal lockup tx due to insufficient funds, attempting to build drain tx");
-                self.onchain_wallet
-                    .build_drain_tx(
-                        None,
-                        &lockup_details.lockup_address,
-                        Some(lockup_details.amount),
-                    )
-                    .await
-            }
-            Err(e) => Err(e),
-            Ok(lockup_tx) => Ok(lockup_tx),
-        }?;
+            .await?;
 
         let lockup_tx_id = self
             .liquid_chain_service