Bit of cleanup after all the excitement

side-node/src/clients/btc_esplora_client.rs

@@ -0,0 +1,115 @@
+use std::{collections::BTreeSet, io::Write, str::FromStr};
+
+use bdk_esplora::{esplora_client, EsploraAsyncExt};
+use bdk_wallet::{
+    bitcoin::{Address, Amount, Network, Script},
+    KeychainKind, SignOptions, Wallet,
+};
+
+use bdk_sqlite::{rusqlite::Connection, Store};
+
+const SEND_AMOUNT: Amount = Amount::from_sat(5000);
+const STOP_GAP: usize = 50;
+const PARALLEL_REQUESTS: usize = 5;
+
+/// Demonstrates the use of bdk with the Esplora client.
+pub async fn run() -> Result<(), anyhow::Error> {
+    let db_path = "/tmp/bdk-esplora-async-example.sqlite";
+    let conn = Connection::open(db_path)?;
+    let mut db = Store::new(conn)?;
+    let external_descriptor = "wpkh(tprv8ZgxMBicQKsPdy6LMhUtFHAgpocR8GC6QmwMSFpZs7h6Eziw3SpThFfczTDh5rW2krkqffa11UpX3XkeTTB2FvzZKWXqPY54Y6Rq4AQ5R8L/84'/1'/0'/0/*)";
+    let internal_descriptor = "wpkh(tprv8ZgxMBicQKsPdy6LMhUtFHAgpocR8GC6QmwMSFpZs7h6Eziw3SpThFfczTDh5rW2krkqffa11UpX3XkeTTB2FvzZKWXqPY54Y6Rq4AQ5R8L/84'/1'/0'/1/*)";
+    let changeset = db.read()?;
+
+    let mut wallet = Wallet::new_or_load(
+        external_descriptor,
+        internal_descriptor,
+        changeset,
+        Network::Signet,
+    )?;
+
+    let address = wallet.next_unused_address(KeychainKind::External);
+    if let Some(changeset) = wallet.take_staged() {
+        db.write(&changeset)?;
+    }
+    println!("Generated Address: {}", address);
+
+    let balance = wallet.balance();
+    println!("Wallet balance before syncing: {} sats", balance.total());
+
+    print!("Syncing...");
+    let client = esplora_client::Builder::new("http://signet.bitcoindevkit.net").build_async()?;
+
+    fn generate_inspect(kind: KeychainKind) -> impl FnMut(u32, &Script) + Send + Sync + 'static {
+        let mut once = Some(());
+        let mut stdout = std::io::stdout();
+        move |spk_i, _| {
+            match once.take() {
+                Some(_) => print!("\nScanning keychain [{:?}]", kind),
+                None => print!(" {:<3}", spk_i),
+            };
+            stdout.flush().expect("must flush");
+        }
+    }
+    let request = wallet
+        .start_full_scan()
+        .inspect_spks_for_all_keychains({
+            let mut once = BTreeSet::<KeychainKind>::new();
+            move |keychain, spk_i, _| {
+                match once.insert(keychain) {
+                    true => print!("\nScanning keychain [{:?}]", keychain),
+                    false => print!(" {:<3}", spk_i),
+                }
+                std::io::stdout().flush().expect("must flush")
+            }
+        })
+        .inspect_spks_for_keychain(
+            KeychainKind::External,
+            generate_inspect(KeychainKind::External),
+        )
+        .inspect_spks_for_keychain(
+            KeychainKind::Internal,
+            generate_inspect(KeychainKind::Internal),
+        );
+
+    let mut update = client
+        .full_scan(request, STOP_GAP, PARALLEL_REQUESTS)
+        .await?;
+    let now = std::time::UNIX_EPOCH.elapsed().unwrap().as_secs();
+    let _ = update.graph_update.update_last_seen_unconfirmed(now);
+
+    wallet.apply_update(update)?;
+    if let Some(changeset) = wallet.take_staged() {
+        db.write(&changeset)?;
+    }
+    println!();
+
+    let balance = wallet.balance();
+    println!("Wallet balance after syncing: {} sats", balance.total());
+
+    if balance.total() < SEND_AMOUNT {
+        println!(
+            "Please send at least {} sats to the receiving address",
+            SEND_AMOUNT
+        );
+        std::process::exit(0);
+    }
+
+    let faucet_address = Address::from_str("mkHS9ne12qx9pS9VojpwU5xtRd4T7X7ZUt")?
+        .require_network(Network::Signet)?;
+
+    let mut tx_builder = wallet.build_tx();
+    tx_builder
+        .add_recipient(faucet_address.script_pubkey(), SEND_AMOUNT)
+        .enable_rbf();
+
+    let mut psbt = tx_builder.finish()?;
+    let finalized = wallet.sign(&mut psbt, SignOptions::default())?;
+    assert!(finalized);
+
+    let tx = psbt.extract_tx()?;
+    client.broadcast(&tx).await?;
+    println!("Tx broadcasted! Txid: {}", tx.compute_txid());
+
+    Ok(())
+}