Add command to withdraw BTC

If no amount is given the wallet will be drained.

swap/src/asb/command.rs

@@ -1,6 +1,6 @@
 use crate::bitcoin::Amount;
 use bitcoin::util::amount::ParseAmountError;
-use bitcoin::Denomination;
+use bitcoin::{Address, Denomination};
 use std::path::PathBuf;
 
 #[derive(structopt::StructOpt, Debug)]
@@ -29,6 +29,15 @@ pub enum Command {
         max_buy: Amount,
     },
     History,
+    WithdrawBtc {
+        #[structopt(
+            long = "amount",
+            help = "Optionally specify the amount of Bitcoin to be withdrawn. If not specified the wallet will be drained."
+        )]
+        amount: Option<Amount>,
+        #[structopt(long = "address", help = "The address to receive the Bitcoin.")]
+        address: Address,
+    },
 }
 
 fn parse_btc(s: &str) -> Result<Amount, ParseAmountError> {

swap/src/bin/asb.rs

@@ -127,6 +127,23 @@ async fn main() -> Result<()> {
             // Print the table to stdout
             table.printstd();
         }
+        Command::WithdrawBtc { amount, address } => {
+            let bitcoin_wallet = init_bitcoin_wallet(&config, &seed, env_config).await?;
+
+            let amount = match amount {
+                Some(amount) => amount,
+                None => {
+                    bitcoin_wallet
+                        .max_giveable(address.script_pubkey().len())
+                        .await?
+                }
+            };
+
+            let psbt = bitcoin_wallet.send_to_address(address, amount).await?;
+            let signed_tx = bitcoin_wallet.sign_and_finalize(psbt).await?;
+
+            bitcoin_wallet.broadcast(signed_tx, "withdraw").await?;
+        }
     };
 
     Ok(())