bitcoind_async_client/

client.rs

use std::{
    env::var,
    fmt,
    sync::{
        Arc,
        atomic::{AtomicUsize, Ordering},
    },
    time::Duration,
};

use base64::{Engine, engine::general_purpose};
use bitcoin::{
    Address, Block, BlockHash, Network, Transaction, Txid,
    bip32::Xpriv,
    block::Header,
    consensus::{self, encode::serialize_hex},
};
use reqwest::{
    Client as ReqwestClient,
    header::{AUTHORIZATION, CONTENT_TYPE, HeaderMap},
};
use serde::{Deserialize, Serialize, de};
use serde_json::{
    json,
    value::{RawValue, Value},
};
use tokio::time::sleep;
use tracing::*;

use super::types::GetBlockHeaderVerbosityZero;
use crate::{
    error::{BitcoinRpcError, ClientError},
    traits::{Broadcaster, Reader, Signer, Wallet},
    types::{
        CreateRawTransaction, CreateWallet, GetBlockVerbosityOne, GetBlockVerbosityZero,
        GetBlockchainInfo, GetNewAddress, GetRawTransactionVerbosityOne,
        GetRawTransactionVerbosityZero, GetTransaction, GetTxOut, ImportDescriptor,
        ImportDescriptorResult, ListDescriptors, ListTransactions, ListUnspent,
        PreviousTransactionOutput, SignRawTransactionWithWallet, SubmitPackage, TestMempoolAccept,
    },
};

/// This is an alias for the result type returned by the [`Client`].
pub type ClientResult<T> = Result<T, ClientError>;

/// The maximum number of retries for a request.
const DEFAULT_MAX_RETRIES: u8 = 3;

/// The maximum number of retries for a request.
const DEFAULT_RETRY_INTERVAL_MS: u64 = 1_000;

/// Custom implementation to convert a value to a `Value` type.
pub fn to_value<T>(value: T) -> ClientResult<Value>
where
    T: Serialize,
{
    serde_json::to_value(value)
        .map_err(|e| ClientError::Param(format!("Error creating value: {e}")))
}

/// An `async` client for interacting with a `bitcoind` instance.
#[derive(Debug, Clone)]
pub struct Client {
    /// The URL of the `bitcoind` instance.
    url: String,

    /// The underlying `async` HTTP client.
    client: ReqwestClient,

    /// The ID of the current request.
    ///
    /// # Implementation Details
    ///
    /// Using an [`Arc`] so that [`Client`] is [`Clone`].
    id: Arc<AtomicUsize>,

    /// The maximum number of retries for a request.
    max_retries: u8,

    /// Interval between retries for a request in ms.
    retry_interval: u64,
}

/// Response returned by the `bitcoind` RPC server.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
struct Response<R> {
    pub result: Option<R>,
    pub error: Option<BitcoinRpcError>,
    pub id: u64,
}

impl Client {
    /// Creates a new [`Client`] with the given URL, username, and password.
    pub fn new(
        url: String,
        username: String,
        password: String,
        max_retries: Option<u8>,
        retry_interval: Option<u64>,
    ) -> ClientResult<Self> {
        if username.is_empty() || password.is_empty() {
            return Err(ClientError::MissingUserPassword);
        }

        let user_pw = general_purpose::STANDARD.encode(format!("{username}:{password}"));
        let authorization = format!("Basic {user_pw}")
            .parse()
            .map_err(|_| ClientError::Other("Error parsing header".to_string()))?;

        let content_type = "application/json"
            .parse()
            .map_err(|_| ClientError::Other("Error parsing header".to_string()))?;
        let headers =
            HeaderMap::from_iter([(AUTHORIZATION, authorization), (CONTENT_TYPE, content_type)]);

        trace!(headers = ?headers);

        let client = ReqwestClient::builder()
            .default_headers(headers)
            .build()
            .map_err(|e| ClientError::Other(format!("Could not create client: {e}")))?;

        let id = Arc::new(AtomicUsize::new(0));

        let max_retries = max_retries.unwrap_or(DEFAULT_MAX_RETRIES);
        let retry_interval = retry_interval.unwrap_or(DEFAULT_RETRY_INTERVAL_MS);

        trace!(url = %url, "Created bitcoin client");

        Ok(Self {
            url,
            client,
            id,
            max_retries,
            retry_interval,
        })
    }

    fn next_id(&self) -> usize {
        self.id.fetch_add(1, Ordering::AcqRel)
    }

    async fn call<T: de::DeserializeOwned + fmt::Debug>(
        &self,
        method: &str,
        params: &[Value],
    ) -> ClientResult<T> {
        let mut retries = 0;
        loop {
            trace!(%method, ?params, %retries, "Calling bitcoin client");

            let id = self.next_id();

            let response = self
                .client
                .post(&self.url)
                .json(&json!({
                    "jsonrpc": "1.0",
                    "id": id,
                    "method": method,
                    "params": params
                }))
                .send()
                .await;
            trace!(?response, "Response received");
            match response {
                Ok(resp) => {
                    let raw_response = resp
                        .text()
                        .await
                        .map_err(|e| ClientError::Parse(e.to_string()))?;
                    trace!(%raw_response, "Raw response received");
                    let data: Response<T> = serde_json::from_str(&raw_response)
                        .map_err(|e| ClientError::Parse(e.to_string()))?;
                    if let Some(err) = data.error {
                        return Err(ClientError::Server(err.code, err.message));
                    }
                    return data
                        .result
                        .ok_or_else(|| ClientError::Other("Empty data received".to_string()));
                }
                Err(err) => {
                    warn!(err = %err, "Error calling bitcoin client");

                    if err.is_body() {
                        // Body error is unrecoverable
                        return Err(ClientError::Body(err.to_string()));
                    } else if err.is_status() {
                        // Status error is unrecoverable
                        let e = match err.status() {
                            Some(code) => ClientError::Status(code.to_string(), err.to_string()),
                            _ => ClientError::Other(err.to_string()),
                        };
                        return Err(e);
                    } else if err.is_decode() {
                        // Error decoding response, might be recoverable
                        let e = ClientError::MalformedResponse(err.to_string());
                        warn!(%e, "decoding error, retrying...");
                    } else if err.is_connect() {
                        // Connection error, might be recoverable
                        let e = ClientError::Connection(err.to_string());
                        warn!(%e, "connection error, retrying...");
                    } else if err.is_timeout() {
                        // Timeout error, might be recoverable
                        let e = ClientError::Timeout;
                        warn!(%e, "timeout error, retrying...");
                    } else if err.is_request() {
                        // General request error, might be recoverable
                        let e = ClientError::Request(err.to_string());
                        warn!(%e, "request error, retrying...");
                    } else if err.is_builder() {
                        // Request builder error is unrecoverable
                        return Err(ClientError::ReqBuilder(err.to_string()));
                    } else if err.is_redirect() {
                        // Redirect error is unrecoverable
                        return Err(ClientError::HttpRedirect(err.to_string()));
                    } else {
                        // Unknown error is unrecoverable
                        return Err(ClientError::Other("Unknown error".to_string()));
                    }
                }
            }
            retries += 1;
            if retries >= self.max_retries {
                return Err(ClientError::MaxRetriesExceeded(self.max_retries));
            }
            sleep(Duration::from_millis(self.retry_interval)).await;
        }
    }
}

impl Reader for Client {
    async fn estimate_smart_fee(&self, conf_target: u16) -> ClientResult<u64> {
        let result = self
            .call::<Box<RawValue>>("estimatesmartfee", &[to_value(conf_target)?])
            .await?
            .to_string();

        let result_map: Value = result.parse::<Value>()?;

        let btc_vkb = result_map
            .get("feerate")
            .unwrap_or(&"0.00001".parse::<Value>().unwrap())
            .as_f64()
            .unwrap();

        // convert to sat/vB and round up
        Ok((btc_vkb * 100_000_000.0 / 1000.0) as u64)
    }

    async fn get_block_header(&self, hash: &BlockHash) -> ClientResult<Header> {
        let get_block_header = self
            .call::<GetBlockHeaderVerbosityZero>(
                "getblockheader",
                &[to_value(hash.to_string())?, to_value(false)?],
            )
            .await?;
        let header = get_block_header
            .header()
            .map_err(|err| ClientError::Other(format!("header decode: {err}")))?;
        Ok(header)
    }

    async fn get_block(&self, hash: &BlockHash) -> ClientResult<Block> {
        let get_block = self
            .call::<GetBlockVerbosityZero>("getblock", &[to_value(hash.to_string())?, to_value(0)?])
            .await?;
        let block = get_block
            .block()
            .map_err(|err| ClientError::Other(format!("block decode: {err}")))?;
        Ok(block)
    }

    async fn get_block_height(&self, hash: &BlockHash) -> ClientResult<u64> {
        let block_verobose = self
            .call::<GetBlockVerbosityOne>("getblock", &[to_value(hash.to_string())?])
            .await?;

        let block_height = block_verobose.height as u64;
        Ok(block_height)
    }

    async fn get_block_header_at(&self, height: u64) -> ClientResult<Header> {
        let hash = self.get_block_hash(height).await?;
        self.get_block_header(&hash).await
    }

    async fn get_block_at(&self, height: u64) -> ClientResult<Block> {
        let hash = self.get_block_hash(height).await?;
        self.get_block(&hash).await
    }

    async fn get_block_count(&self) -> ClientResult<u64> {
        self.call::<u64>("getblockcount", &[]).await
    }

    async fn get_block_hash(&self, height: u64) -> ClientResult<BlockHash> {
        self.call::<BlockHash>("getblockhash", &[to_value(height)?])
            .await
    }

    async fn get_blockchain_info(&self) -> ClientResult<GetBlockchainInfo> {
        self.call::<GetBlockchainInfo>("getblockchaininfo", &[])
            .await
    }

    async fn get_current_timestamp(&self) -> ClientResult<u32> {
        let best_block_hash = self.call::<BlockHash>("getbestblockhash", &[]).await?;
        let block = self.get_block(&best_block_hash).await?;
        Ok(block.header.time)
    }

    async fn get_raw_mempool(&self) -> ClientResult<Vec<Txid>> {
        self.call::<Vec<Txid>>("getrawmempool", &[]).await
    }

    async fn get_raw_transaction_verbosity_zero(
        &self,
        txid: &Txid,
    ) -> ClientResult<GetRawTransactionVerbosityZero> {
        self.call::<GetRawTransactionVerbosityZero>(
            "getrawtransaction",
            &[to_value(txid.to_string())?, to_value(0)?],
        )
        .await
    }

    async fn get_raw_transaction_verbosity_one(
        &self,
        txid: &Txid,
    ) -> ClientResult<GetRawTransactionVerbosityOne> {
        self.call::<GetRawTransactionVerbosityOne>(
            "getrawtransaction",
            &[to_value(txid.to_string())?, to_value(1)?],
        )
        .await
    }

    async fn get_tx_out(
        &self,
        txid: &Txid,
        vout: u32,
        include_mempool: bool,
    ) -> ClientResult<GetTxOut> {
        self.call::<GetTxOut>(
            "gettxout",
            &[
                to_value(txid.to_string())?,
                to_value(vout)?,
                to_value(include_mempool)?,
            ],
        )
        .await
    }

    async fn network(&self) -> ClientResult<Network> {
        self.call::<GetBlockchainInfo>("getblockchaininfo", &[])
            .await?
            .chain
            .parse::<Network>()
            .map_err(|e| ClientError::Parse(e.to_string()))
    }
}

impl Broadcaster for Client {
    async fn send_raw_transaction(&self, tx: &Transaction) -> ClientResult<Txid> {
        let txstr = serialize_hex(tx);
        trace!(txstr = %txstr, "Sending raw transaction");
        match self
            .call::<Txid>("sendrawtransaction", &[to_value(txstr)?])
            .await
        {
            Ok(txid) => {
                trace!(?txid, "Transaction sent");
                Ok(txid)
            }
            Err(ClientError::Server(i, s)) => match i {
                // Dealing with known and common errors
                -27 => Ok(tx.compute_txid()), // Tx already in chain
                _ => Err(ClientError::Server(i, s)),
            },
            Err(e) => Err(ClientError::Other(e.to_string())),
        }
    }

    async fn test_mempool_accept(&self, tx: &Transaction) -> ClientResult<Vec<TestMempoolAccept>> {
        let txstr = serialize_hex(tx);
        trace!(%txstr, "Testing mempool accept");
        self.call::<Vec<TestMempoolAccept>>("testmempoolaccept", &[to_value([txstr])?])
            .await
    }

    async fn submit_package(&self, txs: &[Transaction]) -> ClientResult<SubmitPackage> {
        let txstrs: Vec<String> = txs.iter().map(serialize_hex).collect();
        self.call::<SubmitPackage>("submitpackage", &[to_value(txstrs)?])
            .await
    }
}

impl Wallet for Client {
    async fn get_new_address(&self) -> ClientResult<Address> {
        let address_unchecked = self
            .call::<GetNewAddress>("getnewaddress", &[])
            .await?
            .0
            .parse::<Address<_>>()
            .map_err(|e| ClientError::Parse(e.to_string()))?
            .assume_checked();
        Ok(address_unchecked)
    }
    async fn get_transaction(&self, txid: &Txid) -> ClientResult<GetTransaction> {
        self.call::<GetTransaction>("gettransaction", &[to_value(txid.to_string())?])
            .await
    }

    async fn get_utxos(&self) -> ClientResult<Vec<ListUnspent>> {
        let resp = self.call::<Vec<ListUnspent>>("listunspent", &[]).await?;
        trace!(?resp, "Got UTXOs");
        Ok(resp)
    }

    async fn list_transactions(&self, count: Option<usize>) -> ClientResult<Vec<ListTransactions>> {
        self.call::<Vec<ListTransactions>>("listtransactions", &[to_value(count)?])
            .await
    }

    async fn list_wallets(&self) -> ClientResult<Vec<String>> {
        self.call::<Vec<String>>("listwallets", &[]).await
    }

    async fn create_raw_transaction(
        &self,
        raw_tx: CreateRawTransaction,
    ) -> ClientResult<Transaction> {
        let raw_tx = self
            .call::<String>(
                "createrawtransaction",
                &[to_value(raw_tx.inputs)?, to_value(raw_tx.outputs)?],
            )
            .await?;
        trace!(%raw_tx, "Created raw transaction");
        consensus::encode::deserialize_hex(&raw_tx)
            .map_err(|e| ClientError::Other(format!("Failed to deserialize raw transaction: {e}")))
    }
}

impl Signer for Client {
    async fn sign_raw_transaction_with_wallet(
        &self,
        tx: &Transaction,
        prev_outputs: Option<Vec<PreviousTransactionOutput>>,
    ) -> ClientResult<SignRawTransactionWithWallet> {
        let tx_hex = serialize_hex(tx);
        trace!(tx_hex = %tx_hex, "Signing transaction");
        trace!(?prev_outputs, "Signing transaction with previous outputs");
        self.call::<SignRawTransactionWithWallet>(
            "signrawtransactionwithwallet",
            &[to_value(tx_hex)?, to_value(prev_outputs)?],
        )
        .await
    }

    async fn get_xpriv(&self) -> ClientResult<Option<Xpriv>> {
        // If the ENV variable `BITCOIN_XPRIV_RETRIEVABLE` is not set, we return `None`
        if var("BITCOIN_XPRIV_RETRIEVABLE").is_err() {
            return Ok(None);
        }

        let descriptors = self
            .call::<ListDescriptors>("listdescriptors", &[to_value(true)?]) // true is the xpriv, false is the xpub
            .await?
            .descriptors;
        if descriptors.is_empty() {
            return Err(ClientError::Other("No descriptors found".to_string()));
        }

        // We are only interested in the one that contains `tr(`
        let descriptor = descriptors
            .iter()
            .find(|d| d.desc.contains("tr("))
            .map(|d| d.desc.clone())
            .ok_or(ClientError::Xpriv)?;

        // Now we extract the xpriv from the `tr()` up to the first `/`
        let xpriv_str = descriptor
            .split("tr(")
            .nth(1)
            .ok_or(ClientError::Xpriv)?
            .split("/")
            .next()
            .ok_or(ClientError::Xpriv)?;

        let xpriv = xpriv_str.parse::<Xpriv>().map_err(|_| ClientError::Xpriv)?;
        Ok(Some(xpriv))
    }

    async fn import_descriptors(
        &self,
        descriptors: Vec<ImportDescriptor>,
        wallet_name: String,
    ) -> ClientResult<Vec<ImportDescriptorResult>> {
        let wallet_args = CreateWallet {
            wallet_name,
            load_on_startup: Some(true),
        };

        // TODO: this should check for -35 error code which is good,
        //       means that is already created
        let _wallet_create = self
            .call::<Value>("createwallet", &[to_value(wallet_args.clone())?])
            .await;
        // TODO: this should check for -35 error code which is good, -18 is bad.
        let _wallet_load = self
            .call::<Value>("loadwallet", &[to_value(wallet_args)?])
            .await;

        let result = self
            .call::<Vec<ImportDescriptorResult>>("importdescriptors", &[to_value(descriptors)?])
            .await?;
        Ok(result)
    }
}

#[cfg(test)]
mod test {

    use std::sync::Once;

    use bitcoin::{
        Amount, NetworkKind,
        consensus::{self, encode::deserialize_hex},
        hashes::Hash,
        transaction,
    };
    use tracing_subscriber::{EnvFilter, fmt, layer::SubscriberExt, util::SubscriberInitExt};

    use super::*;
    use crate::{
        test_utils::corepc_node_helpers::{get_bitcoind_and_client, mine_blocks},
        types::{CreateRawTransactionInput, CreateRawTransactionOutput},
    };

    /// 50 BTC in [`Network::Regtest`].
    const COINBASE_AMOUNT: Amount = Amount::from_sat(50 * 100_000_000);

    /// Only attempts to start tracing once.
    fn init_tracing() {
        static INIT: Once = Once::new();

        INIT.call_once(|| {
            tracing_subscriber::registry()
                .with(fmt::layer())
                .with(EnvFilter::from_default_env())
                .try_init()
                .ok();
        });
    }

    #[tokio::test()]
    async fn client_works() {
        init_tracing();

        let (bitcoind, client) = get_bitcoind_and_client();

        // network
        let got = client.network().await.unwrap();
        let expected = Network::Regtest;

        assert_eq!(expected, got);
        // get_blockchain_info
        let get_blockchain_info = client.get_blockchain_info().await.unwrap();
        assert_eq!(get_blockchain_info.blocks, 0);

        // get_current_timestamp
        let _ = client
            .get_current_timestamp()
            .await
            .expect("must be able to get current timestamp");

        let blocks = mine_blocks(&bitcoind, 101, None).unwrap();

        // get_block
        let expected = blocks.last().unwrap();
        let got = client.get_block(expected).await.unwrap().block_hash();
        assert_eq!(*expected, got);

        // get_block_at
        let target_height = blocks.len() as u64;
        let expected = blocks.last().unwrap();
        let got = client
            .get_block_at(target_height)
            .await
            .unwrap()
            .block_hash();
        assert_eq!(*expected, got);

        // get_block_count
        let expected = blocks.len() as u64;
        let got = client.get_block_count().await.unwrap();
        assert_eq!(expected, got);

        // get_block_hash
        let target_height = blocks.len() as u64;
        let expected = blocks.last().unwrap();
        let got = client.get_block_hash(target_height).await.unwrap();
        assert_eq!(*expected, got);

        // get_new_address
        let address = client.get_new_address().await.unwrap();
        let txid = client
            .call::<String>(
                "sendtoaddress",
                &[to_value(address.to_string()).unwrap(), to_value(1).unwrap()],
            )
            .await
            .unwrap()
            .parse::<Txid>()
            .unwrap();

        // get_transaction
        let tx = client.get_transaction(&txid).await.unwrap().hex;
        let got = client.send_raw_transaction(&tx).await.unwrap();
        let expected = txid; // Don't touch this!
        assert_eq!(expected, got);

        // get_raw_transaction_verbosity_zero
        let got = client
            .get_raw_transaction_verbosity_zero(&txid)
            .await
            .unwrap()
            .0;
        let got = deserialize_hex::<Transaction>(&got).unwrap().compute_txid();
        assert_eq!(expected, got);

        // get_raw_transaction_verbosity_one
        let got = client
            .get_raw_transaction_verbosity_one(&txid)
            .await
            .unwrap()
            .transaction
            .compute_txid();
        assert_eq!(expected, got);

        // get_raw_mempool
        let got = client.get_raw_mempool().await.unwrap();
        let expected = vec![txid];
        assert_eq!(expected, got);

        // estimate_smart_fee
        let got = client.estimate_smart_fee(1).await.unwrap();
        let expected = 1; // 1 sat/vB
        assert_eq!(expected, got);

        // sign_raw_transaction_with_wallet
        let got = client
            .sign_raw_transaction_with_wallet(&tx, None)
            .await
            .unwrap();
        assert!(got.complete);
        assert!(consensus::encode::deserialize_hex::<Transaction>(&got.hex).is_ok());

        // test_mempool_accept
        let txids = client
            .test_mempool_accept(&tx)
            .await
            .expect("must be able to test mempool accept");
        let got = txids.first().expect("there must be at least one txid");
        assert_eq!(
            got.txid,
            tx.compute_txid(),
            "txids must match in the mempool"
        );

        // send_raw_transaction
        let got = client.send_raw_transaction(&tx).await.unwrap();
        assert!(got.as_byte_array().len() == 32);

        // list_transactions
        let got = client.list_transactions(None).await.unwrap();
        assert_eq!(got.len(), 10);

        // get_utxos
        // let's mine one more block
        mine_blocks(&bitcoind, 1, None).unwrap();
        let got = client.get_utxos().await.unwrap();
        assert_eq!(got.len(), 3);

        // listdescriptors
        let got = client.get_xpriv().await.unwrap().unwrap().network;
        let expected = NetworkKind::Test;
        assert_eq!(expected, got);

        // importdescriptors
        // taken from https://github.com/rust-bitcoin/rust-bitcoin/blob/bb38aeb786f408247d5bbc88b9fa13616c74c009/bitcoin/examples/taproot-psbt.rs#L18C38-L18C149
        let descriptor_string = "tr([e61b318f/20000'/20']tprv8ZgxMBicQKsPd4arFr7sKjSnKFDVMR2JHw9Y8L9nXN4kiok4u28LpHijEudH3mMYoL4pM5UL9Bgdz2M4Cy8EzfErmU9m86ZTw6hCzvFeTg7/101/*)#2plamwqs".to_owned();
        let timestamp = "now".to_owned();
        let list_descriptors = vec![ImportDescriptor {
            desc: descriptor_string,
            active: Some(true),
            timestamp,
        }];
        let got = client
            .import_descriptors(list_descriptors, "strata".to_owned())
            .await
            .unwrap();
        let expected = vec![ImportDescriptorResult { success: true }];
        assert_eq!(expected, got);
    }

    #[tokio::test()]
    async fn get_tx_out() {
        init_tracing();

        let (bitcoind, client) = get_bitcoind_and_client();

        // network sanity check
        let got = client.network().await.unwrap();
        let expected = Network::Regtest;
        assert_eq!(expected, got);

        let address = bitcoind.client.new_address().unwrap();
        let blocks = mine_blocks(&bitcoind, 101, Some(address)).unwrap();
        let last_block = client.get_block(blocks.first().unwrap()).await.unwrap();
        let coinbase_tx = last_block.coinbase().unwrap();

        // gettxout should work with a non-spent UTXO.
        let got = client
            .get_tx_out(&coinbase_tx.compute_txid(), 0, true)
            .await
            .unwrap();
        assert_eq!(got.value, COINBASE_AMOUNT.to_btc());

        // gettxout should fail with a spent UTXO.
        let new_address = bitcoind.client.new_address().unwrap();
        let send_amount = Amount::from_sat(COINBASE_AMOUNT.to_sat() - 2_000); // 2k sats as fees.
        let _send_tx = bitcoind
            .client
            .send_to_address(&new_address, send_amount)
            .unwrap()
            .txid()
            .unwrap();
        let result = client
            .get_tx_out(&coinbase_tx.compute_txid(), 0, true)
            .await;
        trace!(?result, "gettxout result");
        assert!(result.is_err());
    }

    /// Create two transactions.
    /// 1. Normal one: sends 1 BTC to an address that we control.
    /// 2. CFFP: replaces the first transaction with a different one that we also control.
    ///
    /// This is needed because we must SIGN all these transactions, and we can't sign a transaction
    /// that we don't control.
    #[tokio::test()]
    async fn submit_package() {
        init_tracing();

        let (bitcoind, client) = get_bitcoind_and_client();

        // network sanity check
        let got = client.network().await.unwrap();
        let expected = Network::Regtest;
        assert_eq!(expected, got);

        let blocks = mine_blocks(&bitcoind, 101, None).unwrap();
        let last_block = client.get_block(blocks.first().unwrap()).await.unwrap();
        let coinbase_tx = last_block.coinbase().unwrap();

        let destination = client.get_new_address().await.unwrap();
        let change_address = client.get_new_address().await.unwrap();
        let amount = Amount::from_btc(1.0).unwrap();
        let fees = Amount::from_btc(0.0001).unwrap();
        let change_amount = COINBASE_AMOUNT - amount - fees;
        let amount_minus_fees = Amount::from_sat(amount.to_sat() - 2_000);

        let send_back_address = client.get_new_address().await.unwrap();
        let parent_raw_tx = CreateRawTransaction {
            inputs: vec![CreateRawTransactionInput {
                txid: coinbase_tx.compute_txid().to_string(),
                vout: 0,
            }],
            outputs: vec![
                // Destination
                CreateRawTransactionOutput::AddressAmount {
                    address: destination.to_string(),
                    amount: amount.to_btc(),
                },
                // Change
                CreateRawTransactionOutput::AddressAmount {
                    address: change_address.to_string(),
                    amount: change_amount.to_btc(),
                },
            ],
        };
        let parent = client.create_raw_transaction(parent_raw_tx).await.unwrap();
        let signed_parent: Transaction = consensus::encode::deserialize_hex(
            client
                .sign_raw_transaction_with_wallet(&parent, None)
                .await
                .unwrap()
                .hex
                .as_str(),
        )
        .unwrap();

        // sanity check
        let parent_submitted = client.send_raw_transaction(&signed_parent).await.unwrap();

        let child_raw_tx = CreateRawTransaction {
            inputs: vec![CreateRawTransactionInput {
                txid: parent_submitted.to_string(),
                vout: 0,
            }],
            outputs: vec![
                // Send back
                CreateRawTransactionOutput::AddressAmount {
                    address: send_back_address.to_string(),
                    amount: amount_minus_fees.to_btc(),
                },
            ],
        };
        let child = client.create_raw_transaction(child_raw_tx).await.unwrap();
        let signed_child: Transaction = consensus::encode::deserialize_hex(
            client
                .sign_raw_transaction_with_wallet(&child, None)
                .await
                .unwrap()
                .hex
                .as_str(),
        )
        .unwrap();

        // Ok now we have a parent and a child transaction.
        let result = client
            .submit_package(&[signed_parent, signed_child])
            .await
            .unwrap();
        assert_eq!(result.tx_results.len(), 2);
        assert_eq!(result.package_msg, "success");
    }

    /// Similar to [`submit_package`], but with where the parent does not pay fees,
    /// and the child has to pay fees.
    ///
    /// This is called 1P1C because it has one parent and one child.
    /// See <https://bitcoinops.org/en/bitcoin-core-28-wallet-integration-guide/>
    /// for more information.
    #[tokio::test]
    async fn submit_package_1p1c() {
        init_tracing();

        let (bitcoind, client) = get_bitcoind_and_client();

        // 1p1c sanity check
        let server_version = bitcoind.client.server_version().unwrap();
        assert!(server_version > 28);

        let destination = client.get_new_address().await.unwrap();

        let blocks = mine_blocks(&bitcoind, 101, None).unwrap();
        let last_block = client.get_block(blocks.first().unwrap()).await.unwrap();
        let coinbase_tx = last_block.coinbase().unwrap();

        let parent_raw_tx = CreateRawTransaction {
            inputs: vec![CreateRawTransactionInput {
                txid: coinbase_tx.compute_txid().to_string(),
                vout: 0,
            }],
            outputs: vec![CreateRawTransactionOutput::AddressAmount {
                address: destination.to_string(),
                amount: COINBASE_AMOUNT.to_btc(),
            }],
        };
        let mut parent = client.create_raw_transaction(parent_raw_tx).await.unwrap();
        parent.version = transaction::Version(3);
        assert_eq!(parent.version, transaction::Version(3));
        trace!(?parent, "parent:");
        let signed_parent: Transaction = consensus::encode::deserialize_hex(
            client
                .sign_raw_transaction_with_wallet(&parent, None)
                .await
                .unwrap()
                .hex
                .as_str(),
        )
        .unwrap();
        assert_eq!(signed_parent.version, transaction::Version(3));

        // Assert that the parent tx cannot be broadcasted.
        let parent_broadcasted = client.send_raw_transaction(&signed_parent).await;
        assert!(parent_broadcasted.is_err());

        // 5k sats as fees.
        let amount_minus_fees = Amount::from_sat(COINBASE_AMOUNT.to_sat() - 43_000);
        let child_raw_tx = CreateRawTransaction {
            inputs: vec![CreateRawTransactionInput {
                txid: signed_parent.compute_txid().to_string(),
                vout: 0,
            }],
            outputs: vec![CreateRawTransactionOutput::AddressAmount {
                address: destination.to_string(),
                amount: amount_minus_fees.to_btc(),
            }],
        };
        let mut child = client.create_raw_transaction(child_raw_tx).await.unwrap();
        child.version = transaction::Version(3);
        assert_eq!(child.version, transaction::Version(3));
        trace!(?child, "child:");
        let prev_outputs = vec![PreviousTransactionOutput {
            txid: parent.compute_txid(),
            vout: 0,
            script_pubkey: parent.output[0].script_pubkey.to_hex_string(),
            redeem_script: None,
            witness_script: None,
            amount: Some(COINBASE_AMOUNT.to_btc()),
        }];
        let signed_child: Transaction = consensus::encode::deserialize_hex(
            client
                .sign_raw_transaction_with_wallet(&child, Some(prev_outputs))
                .await
                .unwrap()
                .hex
                .as_str(),
        )
        .unwrap();
        assert_eq!(signed_child.version, transaction::Version(3));

        // Assert that the child tx cannot be broadcasted.
        let child_broadcasted = client.send_raw_transaction(&signed_child).await;
        assert!(child_broadcasted.is_err());

        // Let's send as a package 1C1P.
        let result = client
            .submit_package(&[signed_parent, signed_child])
            .await
            .unwrap();
        assert_eq!(result.tx_results.len(), 2);
        assert_eq!(result.package_msg, "success");
    }
}