feat: implement RPC wallet example

Author: vladimirfomene

example-crates/wallet_rpc/Cargo.toml

@@ -6,3 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+bdk = { path = "../../crates/bdk" }
+bdk_bitcoind_rpc = { path = "../../crates/bitcoind_rpc" }
+bdk_file_store = { path = "../../crates/file_store" }
+anyhow = "1"

example-crates/wallet_rpc/src/main.rs

@@ -1,3 +1,127 @@
-fn main() {
-    println!("Hello, world!");
+use bdk::{
+    bitcoin::{ Network, Address },
+    chain::{indexed_tx_graph, local_chain, Append},
+    wallet::{AddressIndex, WalletChangeSet},
+    Wallet,
+    SignOptions,
+};
+use bdk_bitcoind_rpc::{
+    bitcoincore_rpc::{Auth, Client, RpcApi},
+    EmittedUpdate, Emitter,
+};
+use bdk_file_store::Store;
+use std::sync::mpsc::sync_channel;
+use std::str::FromStr;
+
+const DB_MAGIC: &str = "bdk-rpc-example";
+const FALLBACK_HEIGHT: u32 = 0;
+const CHANNEL_BOUND: usize = 100;
+const SEND_AMOUNT: u64 = 5000;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let db_path = std::env::temp_dir().join("bdk-rpc-example");
+    let db = Store::<bdk::wallet::ChangeSet>::new_from_path(DB_MAGIC.as_bytes(), db_path)?;
+    let external_descriptor = "wpkh(tprv8ZgxMBicQKsPdy6LMhUtFHAgpocR8GC6QmwMSFpZs7h6Eziw3SpThFfczTDh5rW2krkqffa11UpX3XkeTTB2FvzZKWXqPY54Y6Rq4AQ5R8L/84'/1'/0'/0/*)";
+    let internal_descriptor = "wpkh(tprv8ZgxMBicQKsPdy6LMhUtFHAgpocR8GC6QmwMSFpZs7h6Eziw3SpThFfczTDh5rW2krkqffa11UpX3XkeTTB2FvzZKWXqPY54Y6Rq4AQ5R8L/84'/1'/0'/1/*)";
+
+    let mut wallet = Wallet::new(
+        external_descriptor,
+        Some(internal_descriptor),
+        db,
+        Network::Testnet,
+    )?;
+
+    let address = wallet.get_address(AddressIndex::New);
+    println!("Generated Address: {}", address);
+
+    let balance = wallet.get_balance();
+    println!("Wallet balance before syncing: {} sats", balance.total());
+
+    // create a sync function that returns a WalletUpdate
+    print!("Syncing...");
+    // implement an internal function that returns a wallet update.
+    let client = Client::new(
+        "127.0.0.1:8332",
+        Auth::UserPass("bitcoin".to_string(), "password".to_string()),
+    )?;
+
+    let (chan, recv) = sync_channel::<(EmittedUpdate, u32)>(CHANNEL_BOUND);
+    let prev_cp = wallet.latest_checkpoint();
+
+    let join_handle = std::thread::spawn(move || -> anyhow::Result<()> {
+        let mut tip_height = Option::<u32>::None;
+
+        let mut emitter = Emitter::new(&client, FALLBACK_HEIGHT, prev_cp);
+        loop {
+            let item = emitter.emit_update()?;
+            let is_mempool = item.is_mempool();
+
+            if tip_height.is_none() || is_mempool {
+                tip_height = Some(client.get_block_count()? as u32);
+            }
+            chan.send((item, tip_height.expect("must have tip height")))?;
+
+            if !is_mempool {
+                continue;
+            } else {
+                break;
+            }
+        }
+
+        Ok(())
+    });
+
+    for (item, _) in recv {
+        let chain_update = item.chain_update();
+
+        let mut indexed_changeset = indexed_tx_graph::ChangeSet::default();
+
+        let graph_update = item.indexed_tx_graph_update(bdk_bitcoind_rpc::confirmation_time_anchor);
+        indexed_changeset.append(wallet.mut_indexed_tx_graph().insert_relevant_txs(graph_update));
+
+        let chain_changeset = match chain_update {
+            Some(update) => wallet.mut_local_chain().apply_update(update)?,
+            None => local_chain::ChangeSet::default(),
+        };
+
+        let mut wallet_changeset = WalletChangeSet::from(chain_changeset);
+        wallet_changeset.append(WalletChangeSet::from(indexed_changeset));
+        wallet.stage(wallet_changeset);
+        wallet.commit()?;
+    }
+
+    let _ = join_handle.join().expect("failed to join chain source thread");
+
+    let balance = wallet.get_balance();
+    println!("Wallet balance before 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::Testnet)?;
+
+    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();
+    let client = Client::new(
+        "127.0.0.1:8332",
+        Auth::UserPass("bitcoin".to_string(), "password".to_string()),
+    )?;
+    client.send_raw_transaction(&tx)?;
+    println!("Tx broadcasted! Txid: {}", tx.txid());
+
+    Ok(())
 }