sdk_relay/src/main.rs

use std::{
    collections::HashMap,
    env,
    fmt::Debug,
    fs,
    net::SocketAddr,
    path::PathBuf,
    str::FromStr,
    sync::{Arc, Mutex, MutexGuard, OnceLock},
    time::{Duration, Instant},
};

use bitcoincore_rpc::json::{self as bitcoin_json};
use futures_util::{future, pin_mut, stream::TryStreamExt, FutureExt, StreamExt};
use log::{debug, error, info, warn};
use sdk_common::sp_client::bitcoin::{
    absolute::LockTime,
    consensus::{deserialize, serialize},
    hex::{DisplayHex, FromHex},
    key::TapTweak,
    script::PushBytesBuf,
    sighash::{Prevouts, SighashCache},
    taproot::Signature,
    transaction::Version,
    Amount, Network, OutPoint, Psbt, ScriptBuf, TapSighashType, Transaction, TxIn, TxOut, Witness,
    XOnlyPublicKey,
};
use sdk_common::sp_client::{
    bitcoin::secp256k1::{
        rand::{thread_rng, Rng},
        Keypair, Message as Secp256k1Message, PublicKey, Secp256k1, ThirtyTwoByteHash,
    },
    spclient::SpWallet,
};
use sdk_common::{
    error::AnkError,
    network::{AnkFlag, AnkNetworkMsg, FaucetMessage, NewTxMessage},
    silentpayments::create_transaction_for_address_with_shared_secret,
};

use sdk_common::sp_client::db::{JsonFile, Storage};
use sdk_common::sp_client::silentpayments::sending::{
    generate_recipient_pubkeys, SilentPaymentAddress,
};
use sdk_common::sp_client::silentpayments::utils::receiving::{
    calculate_tweak_data, get_pubkey_from_input,
};
use sdk_common::sp_client::silentpayments::utils::sending::calculate_partial_secret;
use sdk_common::sp_client::spclient::{derive_keys_from_seed, Recipient, SpClient, SpendKey};
use tokio::sync::mpsc::{unbounded_channel, UnboundedSender};
use tokio::{
    net::{TcpListener, TcpStream},
    time,
};
use tokio_stream::wrappers::UnboundedReceiverStream;
use tokio_tungstenite::tungstenite::Message;

use anyhow::{Error, Result};
use zeromq::{Socket, SocketRecv};

mod daemon;
mod electrumclient;
mod scan;

use crate::{daemon::Daemon, scan::scan_blocks};

type Tx = UnboundedSender<Message>;

type PeerMap = Arc<Mutex<HashMap<SocketAddr, Tx>>>;

type SharedDaemon = Arc<Mutex<Daemon>>;

static MESSAGECACHE: OnceLock<MessageCache> = OnceLock::new();

const MESSAGECACHEDURATION: Duration = Duration::from_secs(10);
const MESSAGECACHEINTERVAL: Duration = Duration::from_secs(2);

#[derive(Debug)]
struct MessageCache {
    store: Mutex<HashMap<String, Instant>>,
}

impl MessageCache {
    fn new() -> Self {
        Self {
            store: Mutex::new(HashMap::new()),
        }
    }

    fn insert(&self, key: String) {
        let mut store = self.store.lock().unwrap();
        store.insert(key.clone(), Instant::now());
    }

    fn contains(&self, key: &str) -> bool {
        let store = self.store.lock().unwrap();
        store.contains_key(key)
    }
}

async fn clean_up() {
    let cache = MESSAGECACHE.get().unwrap();

    let mut interval = time::interval(MESSAGECACHEINTERVAL);

    loop {
        interval.tick().await;

        let mut store = cache.store.lock().unwrap();

        let now = Instant::now();
        let to_rm: Vec<String> = store
            .iter()
            .filter_map(|(entry, entrytime)| {
                if let Some(duration) = now.checked_duration_since(*entrytime) {
                    if duration > MESSAGECACHEDURATION {
                        Some(entry.clone())
                    } else {
                        None
                    }
                } else {
                    None
                }
            })
            .collect();

        for key in to_rm {
            store.remove(&key);
        }
    }
}

const FAUCET_AMT: Amount = Amount::from_sat(100_000);

pub(crate) trait MutexExt<T> {
    fn lock_anyhow(&self) -> Result<MutexGuard<T>, Error>;
}

impl<T: Debug> MutexExt<T> for Mutex<T> {
    fn lock_anyhow(&self) -> Result<MutexGuard<T>, Error> {
        self.lock()
            .map_err(|e| Error::msg(format!("Failed to lock: {}", e)))
    }
}

#[derive(Debug)]
struct SilentPaymentWallet {
    sp_wallet: Mutex<SpWallet>,
    storage: Mutex<JsonFile>,
}

impl SilentPaymentWallet {
    pub fn get_wallet(&self) -> Result<MutexGuard<SpWallet>> {
        self.sp_wallet.lock_anyhow()
    }

    pub fn save(&self) -> Result<()> {
        self.storage.lock_anyhow()?.save(&self.sp_wallet)
    }
}

enum BroadcastType {
    Sender(SocketAddr),
    #[allow(dead_code)]
    ExcludeSender(SocketAddr),
    #[allow(dead_code)]
    ToAll,
}

fn broadcast_message(
    peers: PeerMap,
    flag: AnkFlag,
    payload: String,
    broadcast: BroadcastType,
) -> Result<()> {
    let ank_msg = AnkNetworkMsg {
        flag,
        content: payload,
    };
    let msg = Message::Text(serde_json::to_string(&ank_msg)?);
    log::debug!("Broadcasting message: {}", msg);
    match broadcast {
        BroadcastType::Sender(addr) => {
            peers
                .lock()
                .map_err(|e| Error::msg(format!("Failed to lock peers: {}", e.to_string())))?
                .iter()
                .find(|(peer_addr, _)| peer_addr == &&addr)
                .ok_or(Error::msg("Failed to find the sender in the peer_map"))?
                .1
                .send(msg)?;
        }
        BroadcastType::ExcludeSender(addr) => {
            peers
                .lock()
                .map_err(|e| Error::msg(format!("Failed to lock peers: {}", e.to_string())))?
                .iter()
                .filter(|(peer_addr, _)| peer_addr != &&addr)
                .for_each(|(_, peer_tx)| {
                    let _ = peer_tx.send(msg.clone());
                });
        }
        BroadcastType::ToAll => {
            peers
                .lock()
                .map_err(|e| Error::msg(format!("Failed to lock peers: {}", e.to_string())))?
                .iter()
                .for_each(|(_, peer_tx)| {
                    let _ = peer_tx.send(msg.clone());
                });
        }
    }
    Ok(())
}

fn spend_from_core(
    dest: XOnlyPublicKey,
    daemon: Arc<Mutex<Daemon>>,
) -> Result<(Transaction, Amount)> {
    let core = daemon
        .lock()
        .map_err(|e| Error::msg(format!("Failed to lock daemon: {}", e.to_string())))?;
    let unspent_list: Vec<bitcoin_json::ListUnspentResultEntry> =
        core.list_unspent_from_to(None)?;

    if !unspent_list.is_empty() {
        let network = core.get_network()?;

        let spk = ScriptBuf::new_p2tr_tweaked(dest.dangerous_assume_tweaked());

        let new_psbt = core.create_psbt(&unspent_list, spk, network)?;
        let processed_psbt = core.process_psbt(new_psbt)?;
        let finalize_psbt_result = core.finalize_psbt(processed_psbt)?;
        let final_psbt = Psbt::from_str(&finalize_psbt_result)?;
        let total_fee = final_psbt.fee()?;
        let final_tx = final_psbt.extract_tx()?;
        let fee_rate = total_fee
            .checked_div(final_tx.weight().to_vbytes_ceil())
            .unwrap();

        Ok((final_tx, fee_rate))
    } else {
        // we don't have enough available coins to pay for this faucet request
        Err(Error::msg("No spendable outputs"))
    }
}

fn faucet_send(
    sp_address: SilentPaymentAddress,
    commitment: &str,
    sp_wallet: Arc<SilentPaymentWallet>,
    shared_daemon: SharedDaemon,
) -> Result<Transaction> {
    let mut first_tx: Option<Transaction> = None;
    let final_tx: Transaction;

    // do we have a sp output available ?
    let available_outpoints = sp_wallet.get_wallet()?.get_outputs().to_spendable_list();

    let available_amt = available_outpoints
        .iter()
        .fold(Amount::from_sat(0), |acc, (_, x)| acc + x.amount);

    // If we don't have at least 4 times the amount we need to send, we take some reserves out
    if available_amt > FAUCET_AMT.checked_mul(4).unwrap() {
        let mut total_amt = Amount::from_sat(0);
        let mut inputs = HashMap::new();
        for (outpoint, output) in available_outpoints {
            total_amt += output.amount;
            inputs.insert(outpoint, output);
            if total_amt >= FAUCET_AMT {
                break;
            }
        }

        let recipient = Recipient {
            address: sp_address.into(),
            amount: FAUCET_AMT,
            nb_outputs: 1,
        };

        let fee_estimate = shared_daemon
            .lock_anyhow()?
            .estimate_fee(6)
            .unwrap_or(Amount::from_sat(1000))
            .checked_div(1000)
            .unwrap();

        log::debug!("fee estimate for 6 blocks: {}", fee_estimate);

        let wallet = sp_wallet.get_wallet()?;

        let signed_psbt = create_transaction_for_address_with_shared_secret(
            recipient,
            &wallet,
            Some(commitment),
            fee_estimate,
        )?;

        let psbt = Psbt::from_str(&signed_psbt)?;

        final_tx = psbt.extract_tx()?;
    } else {
        // let's try to spend directly from the mining address
        let secp = Secp256k1::signing_only();
        let keypair = Keypair::new(&secp, &mut thread_rng());

        // we first spend from core to the pubkey we just created
        let (core_tx, fee_rate) =
            spend_from_core(keypair.x_only_public_key().0, shared_daemon.clone())?;

        // check that the first output of the transaction pays to the key we just created
        debug_assert!(
            core_tx.output[0].script_pubkey
                == ScriptBuf::new_p2tr_tweaked(
                    keypair.x_only_public_key().0.dangerous_assume_tweaked()
                )
        );

        // This is ugly and can be streamlined
        // create a new transaction that spends the newly created UTXO to the sp_address
        let mut faucet_tx = Transaction {
            input: vec![TxIn {
                previous_output: OutPoint::new(core_tx.txid(), 0),
                ..Default::default()
            }],
            output: vec![],
            version: Version::TWO,
            lock_time: LockTime::ZERO,
        };

        // now do the silent payment operations with the final recipient address
        let partial_secret = calculate_partial_secret(
            &[(keypair.secret_key(), true)],
            &[(core_tx.txid().to_string(), 0)],
        )?;

        let ext_output_key: XOnlyPublicKey =
            generate_recipient_pubkeys(vec![sp_address.into()], partial_secret)?
                .into_values()
                .flatten()
                .collect::<Vec<XOnlyPublicKey>>()
                .get(0)
                .expect("Failed to generate keys")
                .to_owned();
        let change_sp_address = sp_wallet.get_wallet()?.get_client().get_receiving_address();
        let change_output_key: XOnlyPublicKey =
            generate_recipient_pubkeys(vec![change_sp_address], partial_secret)?
                .into_values()
                .flatten()
                .collect::<Vec<XOnlyPublicKey>>()
                .get(0)
                .expect("Failed to generate keys")
                .to_owned();

        let ext_spk = ScriptBuf::new_p2tr_tweaked(ext_output_key.dangerous_assume_tweaked());
        let change_spk = ScriptBuf::new_p2tr_tweaked(change_output_key.dangerous_assume_tweaked());

        let mut op_return = PushBytesBuf::new();
        op_return.extend_from_slice(&Vec::from_hex(commitment)?)?;
        let data_spk = ScriptBuf::new_op_return(op_return);

        // Take some margin to pay for the fees
        if core_tx.output[0].value < FAUCET_AMT * 4 {
            return Err(Error::msg("Not enough funds"));
        }

        let change_amt = core_tx.output[0].value.checked_sub(FAUCET_AMT).unwrap();

        faucet_tx.output.push(TxOut {
            value: FAUCET_AMT,
            script_pubkey: ext_spk,
        });
        faucet_tx.output.push(TxOut {
            value: change_amt,
            script_pubkey: change_spk,
        });
        faucet_tx.output.push(TxOut {
            value: Amount::from_sat(0),
            script_pubkey: data_spk,
        });

        // dummy signature only used for fee estimation
        faucet_tx.input[0].witness.push([1; 64].to_vec());

        let abs_fee = fee_rate
            .checked_mul(faucet_tx.weight().to_vbytes_ceil())
            .ok_or_else(|| Error::msg("Fee rate multiplication overflowed"))?;

        // reset the witness to empty
        faucet_tx.input[0].witness = Witness::new();

        faucet_tx.output[1].value -= abs_fee;

        let first_tx_outputs = vec![core_tx.output[0].clone()];
        let prevouts = Prevouts::All(&first_tx_outputs);

        let hash_ty = TapSighashType::Default;

        let mut cache = SighashCache::new(&faucet_tx);

        let sighash = cache.taproot_key_spend_signature_hash(0, &prevouts, hash_ty)?;

        let msg = Secp256k1Message::from_digest(sighash.into_32());

        let sig = secp.sign_schnorr_with_rng(&msg, &keypair, &mut thread_rng());
        let final_sig = Signature { sig, hash_ty };

        faucet_tx.input[0].witness.push(final_sig.to_vec());

        first_tx = Some(core_tx);

        final_tx = faucet_tx;
    }

    if let Ok(daemon) = shared_daemon.lock() {
        // broadcast one or two transactions
        if first_tx.is_some() {
            daemon.broadcast(&first_tx.unwrap())?;
        }
        let txid = daemon.broadcast(&final_tx)?;
        debug!("Sent tx {}", txid);
    } else {
        return Err(Error::msg("Failed to lock daemon"));
    }

    Ok(final_tx)
}

fn handle_faucet_request(
    msg: &FaucetMessage,
    sp_wallet: Arc<SilentPaymentWallet>,
    shared_daemon: SharedDaemon,
) -> Result<NewTxMessage> {
    let sp_address = SilentPaymentAddress::try_from(msg.sp_address.as_str())?;
    debug!("Sending bootstrap coins to {}", sp_address);
    // send bootstrap coins to this sp_address
    let tx = faucet_send(
        sp_address,
        &msg.commitment,
        sp_wallet.clone(),
        shared_daemon.clone(),
    )?;

    // get the tweak
    let partial_tweak = compute_partial_tweak_to_transaction(&tx, shared_daemon.clone())?;

    // get current blockheight
    let blkheight: u32 = shared_daemon
        .lock_anyhow()?
        .get_current_height()?
        .try_into()?;

    // update our sp_client with the change output(s)
    sp_wallet
        .get_wallet()?
        .update_wallet_with_transaction(&tx, blkheight, partial_tweak)?;

    debug!("{:?}", sp_wallet);

    debug!("updated the wallet");
    // save to disk
    sp_wallet.save()?;

    debug!("saved the wallet");
    Ok(NewTxMessage::new(
        serialize(&tx).to_lower_hex_string(),
        Some(partial_tweak.to_string()),
    ))
}

fn handle_new_tx_request(new_tx_msg: &mut NewTxMessage, shared_daemon: SharedDaemon) -> Result<()> {
    let tx = deserialize::<Transaction>(&Vec::from_hex(&new_tx_msg.transaction)?)?;
    let mempool_accept = shared_daemon.lock_anyhow()?.test_mempool_accept(&tx)?;
    if !mempool_accept.allowed {
        return Err(AnkError::NewTxError(mempool_accept.reject_reason.unwrap()))?;
    }
    if new_tx_msg.tweak_data.is_none() {
        // we add the tweak_data
        let partial_tweak = compute_partial_tweak_to_transaction(&tx, shared_daemon.clone())?;
        new_tx_msg.tweak_data = Some(partial_tweak.to_string());
    }

    // we try to broadcast it
    shared_daemon.lock_anyhow()?.broadcast(&tx)?;

    Ok(())
}

async fn handle_connection(
    peers: PeerMap,
    shared_daemon: SharedDaemon,
    sp_wallet: Arc<SilentPaymentWallet>,
    raw_stream: TcpStream,
    addr: SocketAddr,
) {
    debug!("Incoming TCP connection from: {}", addr);

    let ws_stream = tokio_tungstenite::accept_async(raw_stream)
        .await
        .expect("Error during the websocket handshake occurred");
    debug!("WebSocket connection established");

    // Insert the write part of this peer to the peer map.
    let (tx, rx) = unbounded_channel();
    match peers.lock_anyhow() {
        Ok(mut peer_map) => peer_map.insert(addr, tx),
        Err(e) => {
            log::error!("{}", e);
            panic!();
        }
    };

    let (outgoing, incoming) = ws_stream.split();

    let broadcast_incoming = incoming.try_for_each(|msg| {
        let peers = peers.clone();
        if let Ok(raw_msg) = msg.to_text() {
            debug!("Received msg: {}", raw_msg);
            let cache = MESSAGECACHE.get().expect("Cache should be initialized");
            if cache.contains(raw_msg) {
                debug!("Message already processed, dropping");
                return future::ok(());
            } else {
                cache.insert(raw_msg.to_owned());
            }
            let parsed = serde_json::from_str::<AnkNetworkMsg>(raw_msg);
            match parsed {
                Ok(ank_msg) => match ank_msg.flag {
                    AnkFlag::Faucet => {
                        debug!("Received a faucet message");
                        if let Ok(mut content) =
                            serde_json::from_str::<FaucetMessage>(&ank_msg.content)
                        {
                            match handle_faucet_request(
                                &content,
                                sp_wallet.clone(),
                                shared_daemon.clone(),
                            ) {
                                Ok(new_tx_msg) => {
                                    debug!(
                                        "Obtained new_tx_msg: {}",
                                        serde_json::to_string(&new_tx_msg).unwrap()
                                    );
                                }
                                Err(e) => {
                                    log::error!("Failed to send faucet tx: {}", e);
                                    content.error = Some(e.into());
                                    let payload = serde_json::to_string(&content)
                                        .expect("Message type shouldn't fail");
                                    if let Err(e) = broadcast_message(
                                        peers.clone(),
                                        AnkFlag::Faucet,
                                        payload,
                                        BroadcastType::Sender(addr),
                                    ) {
                                        log::error!("Failed to broadcast message: {}", e);
                                    }
                                }
                            }
                        } else {
                            log::error!("Invalid content for faucet message");
                        }
                    }
                    AnkFlag::NewTx => {
                        debug!("Received a new tx message");
                        if let Ok(mut new_tx_msg) =
                            serde_json::from_str::<NewTxMessage>(&ank_msg.content)
                        {
                            match handle_new_tx_request(&mut new_tx_msg, shared_daemon.clone()) {
                                Ok(new_tx_msg) => {
                                    // Repeat the msg to all except sender
                                    if let Err(e) = broadcast_message(
                                        peers.clone(),
                                        AnkFlag::NewTx,
                                        serde_json::to_string(&new_tx_msg)
                                            .expect("This should not fail"),
                                        BroadcastType::ExcludeSender(addr),
                                    ) {
                                        log::error!("Failed to send message with error: {}", e);
                                    }
                                }
                                Err(e) => {
                                    log::error!("handle_new_tx_request returned error: {}", e);
                                    new_tx_msg.error = Some(e.into());
                                    if let Err(e) = broadcast_message(
                                        peers.clone(),
                                        AnkFlag::NewTx,
                                        serde_json::to_string(&new_tx_msg)
                                            .expect("This shouldn't fail"),
                                        BroadcastType::Sender(addr),
                                    ) {
                                        log::error!("Failed to broadcast message: {}", e);
                                    }
                                }
                            }
                        } else {
                            log::error!("Invalid content for new_tx message");
                        }
                    }
                    AnkFlag::Cipher => {
                        // For now we just send it to everyone
                        debug!("Received a cipher message");
                        if let Err(e) = broadcast_message(
                            peers.clone(),
                            AnkFlag::Cipher,
                            ank_msg.content,
                            BroadcastType::ExcludeSender(addr),
                        ) {
                            log::error!("Failed to send message with error: {}", e);
                        }
                    }
                    AnkFlag::Unknown => {
                        debug!("Received an unknown message");
                        if let Err(e) = broadcast_message(
                            peers.clone(),
                            AnkFlag::Unknown,
                            ank_msg.content,
                            BroadcastType::ExcludeSender(addr),
                        ) {
                            log::error!("Failed to send message with error: {}", e);
                        }
                    }
                },
                Err(_) => log::error!("Failed to parse network message"),
            }
        } else {
            // we don't care
            log::debug!("Received non-text message {} from peer {}", msg, addr);
        }
        future::ok(())
    });

    let receive_from_others = UnboundedReceiverStream::new(rx)
        .map(Ok)
        .forward(outgoing)
        .map(|result| {
            if let Err(e) = result {
                debug!("Error sending message: {}", e);
            }
        });

    pin_mut!(broadcast_incoming, receive_from_others);
    future::select(broadcast_incoming, receive_from_others).await;

    debug!("{} disconnected", &addr);
    peers.lock().unwrap().remove(&addr);
}

fn compute_partial_tweak_to_transaction(
    tx: &Transaction,
    daemon: Arc<Mutex<Daemon>>,
) -> Result<PublicKey> {
    let mut outpoints: Vec<(String, u32)> = Vec::with_capacity(tx.input.len());
    let mut pubkeys: Vec<PublicKey> = Vec::with_capacity(tx.input.len());
    for input in tx.input.iter() {
        outpoints.push((
            input.previous_output.txid.to_string(),
            input.previous_output.vout,
        ));
        let prev_tx = daemon
            .lock_anyhow()?
            .get_transaction(&input.previous_output.txid, None)
            .map_err(|e| Error::msg(format!("Failed to find previous transaction: {}", e)))?;

        if let Some(output) = prev_tx.output.get(input.previous_output.vout as usize) {
            match get_pubkey_from_input(
                &input.script_sig.to_bytes(),
                &input.witness.to_vec(),
                &output.script_pubkey.to_bytes(),
            ) {
                Ok(Some(pubkey)) => pubkeys.push(pubkey),
                Ok(None) => continue,
                Err(e) => {
                    return Err(Error::msg(format!(
                        "Can't extract pubkey from input: {}",
                        e
                    )))
                }
            }
        } else {
            return Err(Error::msg("Transaction with a non-existing input"));
        }
    }

    let input_pub_keys: Vec<&PublicKey> = pubkeys.iter().collect();
    let partial_tweak = calculate_tweak_data(&input_pub_keys, &outpoints)?;
    Ok(partial_tweak)
}

fn create_new_tx_message(transaction: Vec<u8>, daemon: Arc<Mutex<Daemon>>) -> Result<NewTxMessage> {
    // debug!("Creating tx message");
    let tx: Transaction = deserialize(&transaction)?;

    if tx.is_coinbase() {
        return Err(Error::msg("Can't process coinbase transaction"));
    }

    let partial_tweak = compute_partial_tweak_to_transaction(&tx, daemon)?;
    Ok(NewTxMessage::new(
        transaction.to_lower_hex_string(),
        Some(partial_tweak.to_string()),
    ))
}

async fn handle_zmq(peers: PeerMap, shared_daemon: SharedDaemon) {
    debug!("Starting listening on Core");
    let mut socket = zeromq::SubSocket::new();
    socket.connect("tcp://127.0.0.1:29100").await.unwrap();
    socket.subscribe("rawtx").await.unwrap();
    // socket.subscribe("hashblock");
    loop {
        let core_msg = match socket.recv().await {
            Ok(m) => m,
            Err(e) => {
                error!("Zmq error: {}", e);
                continue;
            }
        };
        debug!("Received a message");

        let payload: String = if let (Some(topic), Some(data)) = (core_msg.get(0), core_msg.get(1))
        {
            // debug!("topic: {}", std::str::from_utf8(&topic).unwrap());
            match std::str::from_utf8(&topic) {
                Ok("rawtx") => match create_new_tx_message(data.to_vec(), shared_daemon.clone()) {
                    Ok(m) => {
                        debug!("Created message");
                        serde_json::to_string(&m).expect("This shouldn't fail")
                    }
                    Err(e) => {
                        error!("{}", e);
                        continue;
                    }
                },
                Ok("hashblock") => todo!(),
                _ => {
                    error!("Unexpected message in zmq");
                    continue;
                }
            }
        } else {
            error!("Empty message");
            continue;
        };

        debug!("Broadcasting message {}", payload);
        if let Err(e) =
            broadcast_message(peers.clone(), AnkFlag::NewTx, payload, BroadcastType::ToAll)
        {
            log::error!("{}", e.to_string());
        }
    }
}

#[tokio::main(flavor = "multi_thread")]
async fn main() -> Result<()> {
    env_logger::init();

    // This is rudimentary, if you change the network don't forget to change rpc_url either, we won't do that for you
    let rpc_url = env::args()
        .nth(1)
        .unwrap_or_else(|| "127.0.0.1:38332".to_owned());
    let listening_addr = env::args()
        .nth(2)
        .unwrap_or_else(|| "127.0.0.1:8090".to_string());
    let wallet_name = env::args().nth(3).unwrap_or_else(|| "default".to_owned());
    let network_arg: String = env::args().nth(4).unwrap_or_else(|| "signet".to_owned());
    let core_wallet: Option<String> = env::args().nth(5);

    let network = Network::from_core_arg(&network_arg)?;

    if network == Network::Bitcoin {
        warn!("Running on mainnet, you're on your own");
    }

    MESSAGECACHE
        .set(MessageCache::new())
        .expect("Message Cache initialization failed");

    tokio::spawn(clean_up());

    let peers = PeerMap::new(Mutex::new(HashMap::new()));

    // Connect the rpc daemon
    let shared_daemon = Arc::new(Mutex::new(Daemon::connect(core_wallet, rpc_url, network)?));

    let current_tip: u32 = shared_daemon
        .lock_anyhow()?
        .get_current_height()?
        .try_into()?;

    let mut config_dir = PathBuf::from_str(&env::var("HOME")?)?;
    config_dir.push(".4nk");
    let sp_wallet_file = JsonFile::new(&config_dir, &PathBuf::from_str(&wallet_name)?);
    fs::create_dir_all(config_dir)?;

    // load an existing sp_wallet, or create a new one
    let is_testnet = if network == Network::Bitcoin {
        false
    } else {
        true
    };
    let sp_wallet = match <JsonFile as Storage<SpWallet>>::load(&sp_wallet_file) {
        Err(_) => {
            let mut seed = [0u8; 64];
            thread_rng().fill(&mut seed);
            let (scan_sk, spend_sk) = derive_keys_from_seed(&seed, is_testnet)
                .expect("Couldn't generate a new sp_wallet");
            let new_client = SpClient::new(
                wallet_name,
                scan_sk,
                SpendKey::Secret(spend_sk),
                None,
                is_testnet,
            )
            .expect("Failed to create a new SpClient");

            let mut wallet = SpWallet::new(new_client, None)?;

            // set birthday to avoid unnecessary scanning
            let outputs = wallet.get_mut_outputs();
            outputs.set_birthday(current_tip);
            outputs.update_last_scan(current_tip);

            wallet
        }
        Ok(wallet) => wallet,
    };

    log::info!(
        "Using wallet {} with address {}",
        sp_wallet.get_client().label,
        sp_wallet.get_client().get_receiving_address()
    );

    log::info!(
        "Found {} outputs for a total balance of {}",
        sp_wallet.get_outputs().to_spendable_list().len(),
        sp_wallet.get_outputs().get_balance()
    );

    let last_scan = sp_wallet.get_outputs().get_last_scan();

    let shared_sp_wallet = Mutex::new(sp_wallet);
    let shared_wallet_storage = Mutex::new(sp_wallet_file);

    let sp_wallet = Arc::new(SilentPaymentWallet {
        sp_wallet: shared_sp_wallet,
        storage: shared_wallet_storage,
    });

    sp_wallet.save()?;

    if last_scan < current_tip {
        log::info!("Scanning for our outputs");
        scan_blocks(
            shared_daemon.clone(),
            sp_wallet.clone(),
            current_tip - last_scan,
        )?;
    }

    // Subscribe to Bitcoin Core
    tokio::spawn(handle_zmq(peers.clone(), shared_daemon.clone()));

    // Create the event loop and TCP listener we'll accept connections on.
    let try_socket = TcpListener::bind(&listening_addr).await;
    let listener = try_socket.expect("Failed to bind");
    debug!("Listening on: {}", listening_addr);

    // Let's spawn the handling of each connection in a separate task.
    while let Ok((stream, addr)) = listener.accept().await {
        tokio::spawn(handle_connection(
            peers.clone(),
            shared_daemon.clone(),
            sp_wallet.clone(),
            stream,
            addr,
        ));
    }

    Ok(())
}