initiating swaps in a separate task and handling shutdown signals with broadcast queues

swap/src/api.rs

@@ -129,7 +129,7 @@ impl Context {
         let tor_socks5_port = tor.map(|tor| tor.tor_socks5_port);
 
         START.call_once(|| {
-            let _ = cli::tracing::init(debug, json, data_dir.join("logs"), None);
+            let _ = cli::tracing::init(debug, json, data_dir.join("logs"));
         });
 
         let context = Context {

swap/src/api/request.rs

@@ -1,5 +1,5 @@
 use crate::api::Context;
-use crate::bitcoin::{Amount, TxLock};
+use crate::bitcoin::{Amount, ExpiredTimelocks, TxLock};
 use crate::cli::{list_sellers, EventLoop, SellerStatus};
 use crate::libp2p_ext::MultiAddrExt;
 use crate::network::quote::{BidQuote, ZeroQuoteReceived};
@@ -18,81 +18,90 @@ use std::future::Future;
 use std::net::SocketAddr;
 use std::sync::Arc;
 use std::time::Duration;
+use structopt::lazy_static::lazy_static;
 use tracing::{debug_span, Instrument};
 use uuid::Uuid;
+use tokio::sync::RwLock;
+
+lazy_static! {
+    static ref SWAP_LOCK: RwLock<Option<Uuid>> = RwLock::new(None);
+}
 
 #[derive(PartialEq, Debug)]
 pub struct Request {
-    pub params: Params,
     pub cmd: Method
 }
 
 
-#[derive(Default, PartialEq, Debug)]
-pub struct Params {
-    pub seller: Option<Multiaddr>,
-    pub bitcoin_change_address: Option<bitcoin::Address>,
-    pub monero_receive_address: Option<monero::Address>,
-    pub rendezvous_point: Option<Multiaddr>,
-    pub swap_id: Option<Uuid>,
-    pub amount: Option<Amount>,
-    pub server_address: Option<SocketAddr>,
-    pub address: Option<bitcoin::Address>,
-}
-
 #[derive(Debug, PartialEq)]
 pub enum Method {
-    BuyXmr,
+    BuyXmr {
+        seller: Multiaddr,
+        bitcoin_change_address: bitcoin::Address,
+        monero_receive_address: monero::Address,
+        swap_id: Uuid,
+    },
     History,
     RawHistory,
     Config,
-    WithdrawBtc,
+    WithdrawBtc {
+        amount: Option<Amount>,
+        address: bitcoin::Address,
+    },
     Balance,
-    GetSeller,
+    GetSeller {
-    SwapStartDate,
+        swap_id: Uuid,
-    Resume,
+    },
-    CancelAndRefund,
+    SwapStartDate {
-    ListSellers,
+        swap_id: Uuid,
+    },
+    Resume {
+        swap_id: Uuid,
+    },
+    CancelAndRefund {
+        swap_id: Uuid,
+    },
+    ListSellers {
+        rendezvous_point: Multiaddr,
+    },
     ExportBitcoinWallet,
-    MoneroRecovery,
+    MoneroRecovery {
-    StartDaemon,
+        swap_id: Uuid,
+    },
+    StartDaemon {
+        server_address: Option<SocketAddr>,
+    },
+    GetCurrentSwap,
+    GetSwapExpiredTimelock {
+        swap_id: Uuid,
+    },
 }
 
 impl Request {
-    pub fn new(cmd: Method, params: Params) -> Request {
+    pub fn new(cmd: Method) -> Request {
         Request {
-            params,
             cmd
         }
     }
 
-    async fn handle_cmd(&mut self, context: Arc<Context>) -> Result<serde_json::Value> {
+    fn has_lockable_swap_id(&self) -> Option<Uuid> {
         match self.cmd {
-            Method::BuyXmr => {
+            Method::BuyXmr { swap_id, .. }
-                let swap_id = self
+            | Method::Resume { swap_id }
-                    .params
+            | Method::CancelAndRefund { swap_id } => Some(swap_id),
-                    .swap_id
+            _ => None,
-                    .context("Parameter swap_id is missing")?;
+        }
+    }
+
+    async fn handle_cmd(self, context: Arc<Context>) -> Result<serde_json::Value> {
+        match self.cmd {
+            Method::BuyXmr { seller, bitcoin_change_address, monero_receive_address, swap_id } => {
                 let seed = context.config.seed.as_ref().context("Could not get seed")?;
                 let env_config = context.config.env_config;
                 let btc = context
                     .bitcoin_wallet
                     .as_ref()
                     .context("Could not get Bitcoin wallet")?;
-                let seller = self
-                    .params
-                    .seller
-                    .clone()
-                    .context("Parameter seller is missing")?;
-                let monero_receive_address = self
-                    .params
-                    .monero_receive_address
-                    .context("Parameter monero_receive_address is missing")?;
-                let bitcoin_change_address = self
-                    .params
-                    .bitcoin_change_address
-                    .clone()
-                    .context("Parameter bitcoin_change_address is missing")?;
 
                 let bitcoin_wallet = btc;
                 let seller_peer_id = seller
@@ -224,8 +233,7 @@ impl Request {
 
                 Ok(json!({ "raw_history": raw_history }))
             }
-            Method::GetSeller => {
+            Method::GetSeller { swap_id }  => {
-                let swap_id = self.params.swap_id.context("Parameter swap_id is needed")?;
                 let peerId = context
                     .db
                     .get_peer_id(swap_id)
@@ -243,12 +251,7 @@ impl Request {
                     "addresses": addresses
                 }))
             }
-            Method::SwapStartDate => {
+            Method::SwapStartDate { swap_id } => {
-                let swap_id = self
-                    .params
-                    .swap_id
-                    .context("Parameter swap_id is missing")?;
-
                 let start_date = context.db.get_swap_start_date(swap_id).await?;
 
                 Ok(json!({
@@ -272,19 +275,13 @@ impl Request {
                     "bitcoin_wallet": format!("{}/wallet", data_dir_display),
                 }))
             }
-            Method::WithdrawBtc => {
+            Method::WithdrawBtc {address, amount} => {
                 let bitcoin_wallet = context
                     .bitcoin_wallet
                     .as_ref()
                     .context("Could not get Bitcoin wallet")?;
 
-                let address = self
+                let amount = match amount {
-                    .params
-                    .address
-                    .clone()
-                    .context("Parameter address is missing")?;
-
-                let amount = match self.params.amount {
                     Some(amount) => amount,
                     None => {
                         bitcoin_wallet
@@ -307,12 +304,9 @@ impl Request {
                     "txid": signed_tx.txid(),
                 }))
             }
-            Method::StartDaemon => {
+            Method::StartDaemon {server_address} => {
                 // Default to 127.0.0.1:1234
-                let server_address = self
+                let server_address = server_address.unwrap_or("127.0.0.1:1234".parse().unwrap());
-                    .params
-                    .server_address
-                    .unwrap_or("127.0.0.1:1234".parse().unwrap());
 
                 let (_, server_handle) =
                     rpc::run_server(server_address, Arc::clone(&context)).await?;
@@ -347,12 +341,7 @@ impl Request {
                     "balance": bitcoin_balance.to_sat()
                 }))
             }
-            Method::Resume => {
+            Method::Resume {swap_id} => {
-                let swap_id = self
-                    .params
-                    .swap_id
-                    .context("Parameter swap_id is missing")?;
-
                 let seller_peer_id = context.db.get_peer_id(swap_id).await?;
                 let seller_addresses = context.db.get_addresses(seller_peer_id).await?;
 
@@ -431,16 +420,14 @@ impl Request {
                     "result": []
                 }))
             }
-            Method::CancelAndRefund => {
+            Method::CancelAndRefund {swap_id} => {
                 let bitcoin_wallet = context
                     .bitcoin_wallet
                     .as_ref()
                     .context("Could not get Bitcoin wallet")?;
 
                 let state = cli::cancel_and_refund(
-                    self.params
+                    swap_id,
-                        .swap_id
-                        .context("Parameter swap_id is missing")?,
                     Arc::clone(bitcoin_wallet),
                     Arc::clone(&context.db),
                 )
@@ -450,12 +437,7 @@ impl Request {
                     "result": state,
                 }))
             }
-            Method::ListSellers => {
+            Method::ListSellers {rendezvous_point} => {
-                let rendezvous_point = self
-                    .params
-                    .rendezvous_point
-                    .clone()
-                    .context("Parameter rendezvous_point is missing")?;
                 let rendezvous_node_peer_id = rendezvous_point
                     .extract_peer_id()
                     .context("Rendezvous node address must contain peer ID")?;
@@ -512,16 +494,14 @@ impl Request {
                 let wallet_export = bitcoin_wallet.wallet_export("cli").await?;
                 tracing::info!(descriptor=%wallet_export.to_string(), "Exported bitcoin wallet");
                 Ok(json!({
-                    "result": []
+                    "descriptor": wallet_export.to_string(),
                 }))
             }
-            Method::MoneroRecovery => {
+            Method::MoneroRecovery {swap_id} => {
                 let swap_state: BobState = context
                     .db
                     .get_state(
-                        self.params
+                        swap_id,
-                            .swap_id
-                            .context("Parameter swap_id is missing")?,
                     )
                     .await?
                     .try_into()?;
@@ -560,28 +540,71 @@ impl Request {
                 Ok(json!({
                     "result": []
                 }))
-            }
+            },
+            Method::GetCurrentSwap => {
+                Ok(json!({
+                    "swap_id": SWAP_LOCK.read().await.clone()
+                }))
+            },
+            Method::GetSwapExpiredTimelock { swap_id } => {
+                let swap_state: BobState = context
+                    .db
+                    .get_state(
+                        swap_id,
+                    )
+                    .await?
+                    .try_into()?;
+
+                let bitcoin_wallet = context.bitcoin_wallet.as_ref().context("Could not get Bitcoin wallet")?;
+
+                let timelock = match swap_state {
+                    BobState::Started { .. }
+                    | BobState::SafelyAborted
+                    | BobState::SwapSetupCompleted(_) => bail!("Bitcoin lock transaction has not been published yet"),
+                    BobState::BtcLocked { state3: state, .. }
+                    | BobState::XmrLockProofReceived { state, .. } => state.expired_timelock(bitcoin_wallet).await,
+                    BobState::XmrLocked(state)
+                    | BobState::EncSigSent(state) => state.expired_timelock(bitcoin_wallet).await,
+                    BobState::CancelTimelockExpired(state)
+                    | BobState::BtcCancelled(state) => state.expired_timelock(bitcoin_wallet).await,
+                    BobState::BtcPunished { .. } => Ok(ExpiredTimelocks::Punish),
+                    // swap is already finished
+                    BobState::BtcRefunded(_)
+                    | BobState::BtcRedeemed(_)
+                    | BobState::XmrRedeemed { .. } => bail!("Bitcoin have already been redeemed or refunded")
+                }?;
+
+                Ok(json!({
+                    "timelock": timelock,
+                }))
+            },
         }
     }
 
-    pub async fn call(&mut self, context: Arc<Context>) -> Result<serde_json::Value> {
+    pub async fn call(self, context: Arc<Context>) -> Result<serde_json::Value> {
         // If the swap ID is set, we add it to the span
-        let call_span = self.params.swap_id.map_or_else(
+        let call_span = debug_span!(
-            || {
+            "cmd",
-                debug_span!(
-                    "call",
             method = ?self.cmd,
-                )
-            },
-            |swap_id| {
-                debug_span!(
-                    "call",
-                    method = ?self.cmd,
-                    swap_id = swap_id.to_string(),
-                )
-            },
         );
 
+        if let Some(swap_id) = self.has_lockable_swap_id() {
+            println!("taking lock for swap_id: {}", swap_id);
+            let mut guard = SWAP_LOCK.write().await;
+            if let Some(running_swap_id) = guard.as_ref() {
+                bail!("Another swap is already running: {}", running_swap_id);
+            }
+            let _ = guard.insert(swap_id.clone());
+            drop(guard);
+
+            let result = self.handle_cmd(context).instrument(call_span).await;
+
+            SWAP_LOCK.write().await.take();
+
+            println!("releasing lock for swap_id: {}", swap_id);
+
+            return result;
+        }
         self.handle_cmd(context).instrument(call_span).await
     }
 }
@@ -604,7 +627,7 @@ pub async fn determine_btc_to_swap<FB, TB, FMG, TMG, FS, TS, FFE, TFE>(
     sync: FS,
     estimate_fee: FFE,
 ) -> Result<(bitcoin::Amount, bitcoin::Amount)>
-where
+    where
         TB: Future<Output = Result<bitcoin::Amount>>,
         FB: Fn() -> TB,
         TMG: Future<Output = Result<bitcoin::Amount>>,
@@ -687,3 +710,4 @@ where
 
     Ok((btc_swap_amount, fees))
 }
+

swap/src/bitcoin.rs

@@ -244,10 +244,14 @@ pub fn current_epoch(
     }
 
     if tx_lock_status.is_confirmed_with(cancel_timelock) {
-        return ExpiredTimelocks::Cancel;
+        return ExpiredTimelocks::Cancel {
+            blocks_left: tx_cancel_status.blocks_left_until(punish_timelock),
+        }
     }
 
-    ExpiredTimelocks::None
+    ExpiredTimelocks::None {
+        blocks_left: tx_lock_status.blocks_left_until(cancel_timelock),
+    }
 }
 
 pub mod bitcoin_address {

swap/src/bitcoin/cancel.rs

@@ -24,6 +24,12 @@ use std::ops::Add;
 #[serde(transparent)]
 pub struct CancelTimelock(u32);
 
+impl From<CancelTimelock> for u32 {
+    fn from(cancel_timelock: CancelTimelock) -> Self {
+        cancel_timelock.0
+    }
+}
+
 impl CancelTimelock {
     pub const fn new(number_of_blocks: u32) -> Self {
         Self(number_of_blocks)
@@ -64,6 +70,12 @@ impl fmt::Display for CancelTimelock {
 #[serde(transparent)]
 pub struct PunishTimelock(u32);
 
+impl From<PunishTimelock> for u32 {
+    fn from(punish_timelock: PunishTimelock) -> Self {
+        punish_timelock.0
+    }
+}
+
 impl PunishTimelock {
     pub const fn new(number_of_blocks: u32) -> Self {
         Self(number_of_blocks)

swap/src/bitcoin/timelocks.rs

@@ -37,9 +37,13 @@ impl Add<u32> for BlockHeight {
     }
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Serialize, Debug, Clone, Copy, PartialEq, Eq)]
 pub enum ExpiredTimelocks {
-    None,
+    None {
-    Cancel,
+        blocks_left: u32,
+    },
+    Cancel {
+        blocks_left: u32,
+    },
     Punish,
 }

swap/src/bitcoin/wallet.rs

@@ -274,7 +274,7 @@ impl Subscription {
 
     pub async fn wait_until_confirmed_with<T>(&self, target: T) -> Result<()>
     where
-        u32: PartialOrd<T>,
+        T: Into<u32>,
         T: Copy,
     {
         self.wait_until(|status| status.is_confirmed_with(target))
@@ -926,10 +926,19 @@ impl Confirmed {
     }
 
     pub fn meets_target<T>(&self, target: T) -> bool
-    where
+    where T: Into<u32>
-        u32: PartialOrd<T>,
     {
-        self.confirmations() >= target
+        self.confirmations() >= target.into()
+    }
+
+    pub fn blocks_left_until<T>(&self, target: T) -> u32
+    where T: Into<u32>, T: Copy
+    {
+        if self.meets_target(target) {
+            0
+        } else {
+            target.into() - self.confirmations()
+        }
     }
 }
 
@@ -941,8 +950,7 @@ impl ScriptStatus {
 
     /// Check if the script has met the given confirmation target.
     pub fn is_confirmed_with<T>(&self, target: T) -> bool
-    where
+    where T: Into<u32>
-        u32: PartialOrd<T>,
     {
         match self {
             ScriptStatus::Confirmed(inner) => inner.meets_target(target),
@@ -950,6 +958,18 @@ impl ScriptStatus {
         }
     }
 
+    // Calculate the number of blocks left until the target is met.
+    pub fn blocks_left_until<T>(&self, target: T) -> u32
+    where T: Into<u32>, T: Copy
+    {
+        match self {
+            ScriptStatus::Confirmed(inner) => {
+                inner.blocks_left_until(target)
+            }
+            _ => target.into(),
+        }
+    }
+
     pub fn has_been_seen(&self) -> bool {
         matches!(self, ScriptStatus::InMempool | ScriptStatus::Confirmed(_))
     }
@@ -1005,6 +1025,33 @@ mod tests {
         assert_eq!(confirmed.depth, 0)
     }
 
+    #[test]
+    fn given_depth_0_should_return_0_blocks_left_until_1() {
+        let script = ScriptStatus::Confirmed(Confirmed { depth: 0 });
+
+        let blocks_left = script.blocks_left_until(1);
+
+        assert_eq!(blocks_left, 0)
+    }
+
+    #[test]
+    fn given_depth_1_should_return_0_blocks_left_until_1() {
+        let script = ScriptStatus::Confirmed(Confirmed { depth: 1 });
+
+        let blocks_left = script.blocks_left_until(1);
+
+        assert_eq!(blocks_left, 0)
+    }
+
+    #[test]
+    fn given_depth_0_should_return_1_blocks_left_until_2() {
+        let script = ScriptStatus::Confirmed(Confirmed { depth: 0 });
+
+        let blocks_left = script.blocks_left_until(2);
+
+        assert_eq!(blocks_left, 1)
+    }
+
     #[test]
     fn given_one_BTC_and_100k_sats_per_vb_fees_should_not_hit_max() {
         // 400 weight = 100 vbyte

swap/src/cli/command.rs

@@ -1,4 +1,4 @@
-use crate::api::request::{Method, Params, Request};
+use crate::api::request::{Method, Request};
 use crate::api::Context;
 use crate::bitcoin::{bitcoin_address, Amount};
 use crate::monero;
@@ -79,13 +79,12 @@ where
                 bitcoin_address::validate(bitcoin_change_address, is_testnet)?;
 
             let request = Request::new(
-                Method::BuyXmr,
+                Method::BuyXmr {
-                Params {
+                    seller,
-                    bitcoin_change_address: Some(bitcoin_change_address),
+                    bitcoin_change_address,
-                    monero_receive_address: Some(monero_receive_address),
+                    monero_receive_address,
-                    seller: Some(seller),
+                    swap_id: Uuid::new_v4(),
-                    ..Default::default()
+                }
-                },
             );
 
             let context = Context::build(
@@ -103,21 +102,21 @@ where
             (context, request)
         }
         CliCommand::History => {
-            let request = Request::new(Method::History, Params::default());
+            let request = Request::new(Method::History);
 
             let context =
                 Context::build(None, None, None, data, is_testnet, debug, json, None, rx).await?;
             (context, request)
         }
         CliCommand::Config => {
-            let request = Request::new(Method::Config, Params::default());
+            let request = Request::new(Method::Config);
 
             let context =
                 Context::build(None, None, None, data, is_testnet, debug, json, None, rx).await?;
             (context, request)
         }
         CliCommand::Balance { bitcoin } => {
-            let request = Request::new(Method::Balance, Params::default());
+            let request = Request::new(Method::Balance);
 
             let context = Context::build(
                 Some(bitcoin),
@@ -140,11 +139,9 @@ where
             tor,
         } => {
             let request = Request::new(
-                Method::StartDaemon,
+                Method::StartDaemon {
-                Params {
+                    server_address
-                    server_address,
+                }
-                    ..Default::default()
-                },
             );
 
             let context = Context::build(
@@ -169,11 +166,9 @@ where
             let address = bitcoin_address::validate(address, is_testnet)?;
 
             let request = Request::new(
-                Method::WithdrawBtc,
+                Method::WithdrawBtc {
-                Params {
                     amount,
-                    address: Some(address),
+                    address,
-                    ..Default::default()
                 },
             );
 
@@ -198,11 +193,9 @@ where
             tor,
         } => {
             let request = Request::new(
-                Method::Resume,
+                Method::Resume {
-                Params {
+                    swap_id
-                    swap_id: Some(swap_id),
+                }
-                    ..Default::default()
-                },
             );
 
             let context = Context::build(
@@ -225,11 +218,9 @@ where
             tor,
         } => {
             let request = Request::new(
-                Method::CancelAndRefund,
+                Method::CancelAndRefund {
-                Params {
+                    swap_id
-                    swap_id: Some(swap_id),
+                }
-                    ..Default::default()
-                },
             );
 
             let context = Context::build(
@@ -251,11 +242,9 @@ where
             tor,
         } => {
             let request = Request::new(
-                Method::ListSellers,
+                Method::ListSellers {
-                Params {
+                    rendezvous_point
-                    rendezvous_point: Some(rendezvous_point),
+                }
-                    ..Default::default()
-                },
             );
 
             let context = Context::build(
@@ -276,7 +265,6 @@ where
         CliCommand::ExportBitcoinWallet { bitcoin } => {
             let request = Request::new(
                 Method::ExportBitcoinWallet,
-                Params::default(),
             );
 
             let context = Context::build(
@@ -297,11 +285,9 @@ where
             swap_id: SwapId { swap_id },
         } => {
             let request = Request::new(
-                Method::MoneroRecovery,
+                Method::MoneroRecovery {
-                Params {
+                    swap_id
-                    swap_id: Some(swap_id),
+                }
-                    ..Default::default()
-                },
             );
 
             let context =

swap/src/cli/tracing.rs

@@ -7,17 +7,14 @@ use tracing::{Event, Level, Subscriber};
 use tracing_subscriber::fmt::format::{DefaultFields, Format, JsonFields};
 use tracing_subscriber::fmt::time::UtcTime;
 use tracing_subscriber::layer::{Context, SubscriberExt};
-use tracing_subscriber::{fmt, EnvFilter, FmtSubscriber, Layer, Registry};
+use tracing_subscriber::{fmt, EnvFilter, Layer, Registry};
-use uuid::Uuid;
 
-pub fn init(debug: bool, json: bool, dir: impl AsRef<Path>, swap_id: Option<Uuid>) -> Result<()> {
+pub fn init(debug: bool, json: bool, dir: impl AsRef<Path>) -> Result<()> {
-    if let Some(swap_id) = swap_id {
     let level_filter = EnvFilter::try_new("swap=debug")?;
-
     let registry = Registry::default().with(level_filter);
 
     let appender =
-            tracing_appender::rolling::never(dir.as_ref(), format!("swap-{}.log", swap_id));
+        tracing_appender::rolling::never(dir.as_ref(), "swap-all.log");
     let (appender, guard) = tracing_appender::non_blocking(appender);
 
     std::mem::forget(guard);
@@ -26,6 +23,7 @@ pub fn init(debug: bool, json: bool, dir: impl AsRef<Path>, swap_id: Option<Uuid
         fmt::layer()
             .with_ansi(false)
             .with_target(false)
+            .with_span_events(fmt::format::FmtSpan::FULL)
             .json()
             .with_writer(appender),
     );
@@ -39,23 +37,6 @@ pub fn init(debug: bool, json: bool, dir: impl AsRef<Path>, swap_id: Option<Uuid
     } else {
         set_global_default(file_logger.with(info_terminal_printer()))?;
     }
-    } else {
-        let level = if debug { Level::DEBUG } else { Level::INFO };
-        let is_terminal = atty::is(atty::Stream::Stderr);
-
-        let builder = FmtSubscriber::builder()
-            .with_env_filter(format!("swap={}", level))
-            .with_writer(std::io::stderr)
-            .with_ansi(is_terminal)
-            .with_timer(UtcTime::rfc_3339())
-            .with_target(false);
-
-        if json {
-            builder.json().init();
-        } else {
-            builder.init();
-        }
-    };
 
     tracing::info!("Logging initialized to {}", dir.as_ref().display());
     Ok(())
@@ -66,17 +47,17 @@ pub struct StdErrPrinter<L> {
     level: Level,
 }
 
-type StdErrLayer<S, T> = tracing_subscriber::fmt::Layer<
+type StdErrLayer<S, T> = fmt::Layer<
     S,
     DefaultFields,
-    Format<tracing_subscriber::fmt::format::Full, T>,
+    Format<fmt::format::Full, T>,
     fn() -> std::io::Stderr,
 >;
 
-type StdErrJsonLayer<S, T> = tracing_subscriber::fmt::Layer<
+type StdErrJsonLayer<S, T> = fmt::Layer<
     S,
     JsonFields,
-    Format<tracing_subscriber::fmt::format::Json, T>,
+    Format<fmt::format::Json, T>,
     fn() -> std::io::Stderr,
 >;
 

swap/src/protocol/alice/swap.rs

@@ -112,7 +112,7 @@ where
         }
         AliceState::BtcLocked { state3 } => {
             match state3.expired_timelocks(bitcoin_wallet).await? {
-                ExpiredTimelocks::None => {
+                ExpiredTimelocks::None {..} => {
                     // Record the current monero wallet block height so we don't have to scan from
                     // block 0 for scenarios where we create a refund wallet.
                     let monero_wallet_restore_blockheight = monero_wallet.block_height().await?;
@@ -135,7 +135,7 @@ where
             transfer_proof,
             state3,
         } => match state3.expired_timelocks(bitcoin_wallet).await? {
-            ExpiredTimelocks::None => {
+            ExpiredTimelocks::None {..} => {
                 monero_wallet
                     .watch_for_transfer(state3.lock_xmr_watch_request(transfer_proof.clone(), 1))
                     .await
@@ -221,7 +221,7 @@ where
             encrypted_signature,
             state3,
         } => match state3.expired_timelocks(bitcoin_wallet).await? {
-            ExpiredTimelocks::None => {
+            ExpiredTimelocks::None {..} => {
                 let tx_lock_status = bitcoin_wallet.subscribe_to(state3.tx_lock.clone()).await;
                 match state3.signed_redeem_transaction(*encrypted_signature) {
                     Ok(tx) => match bitcoin_wallet.broadcast(tx, "redeem").await {

swap/src/protocol/bob/state.rs

@@ -440,7 +440,7 @@ impl State3 {
         self.tx_lock.txid()
     }
 
-    pub async fn current_epoch(
+    pub async fn expired_timelock(
         &self,
         bitcoin_wallet: &bitcoin::Wallet,
     ) -> Result<ExpiredTimelocks> {

swap/src/protocol/bob/swap.rs

@@ -117,7 +117,7 @@ async fn next_state(
         } => {
             let tx_lock_status = bitcoin_wallet.subscribe_to(state3.tx_lock.clone()).await;
 
-            if let ExpiredTimelocks::None = state3.current_epoch(bitcoin_wallet).await? {
+            if let ExpiredTimelocks::None {..} = state3.expired_timelock(bitcoin_wallet).await? {
                 let transfer_proof_watcher = event_loop_handle.recv_transfer_proof();
                 let cancel_timelock_expires =
                     tx_lock_status.wait_until_confirmed_with(state3.cancel_timelock);
@@ -156,7 +156,7 @@ async fn next_state(
         } => {
             let tx_lock_status = bitcoin_wallet.subscribe_to(state.tx_lock.clone()).await;
 
-            if let ExpiredTimelocks::None = state.current_epoch(bitcoin_wallet).await? {
+            if let ExpiredTimelocks::None {..} = state.expired_timelock(bitcoin_wallet).await? {
                 let watch_request = state.lock_xmr_watch_request(lock_transfer_proof);
 
                 select! {
@@ -185,7 +185,7 @@ async fn next_state(
         BobState::XmrLocked(state) => {
             let tx_lock_status = bitcoin_wallet.subscribe_to(state.tx_lock.clone()).await;
 
-            if let ExpiredTimelocks::None = state.expired_timelock(bitcoin_wallet).await? {
+            if let ExpiredTimelocks::None {..} = state.expired_timelock(bitcoin_wallet).await? {
                 // Alice has locked Xmr
                 // Bob sends Alice his key
 
@@ -209,7 +209,7 @@ async fn next_state(
         BobState::EncSigSent(state) => {
             let tx_lock_status = bitcoin_wallet.subscribe_to(state.tx_lock.clone()).await;
 
-            if let ExpiredTimelocks::None = state.expired_timelock(bitcoin_wallet).await? {
+            if let ExpiredTimelocks::None {..} = state.expired_timelock(bitcoin_wallet).await? {
                 select! {
                     state5 = state.watch_for_redeem_btc(bitcoin_wallet) => {
                         BobState::BtcRedeemed(state5?)
@@ -269,12 +269,12 @@ async fn next_state(
         BobState::BtcCancelled(state) => {
             // Bob has cancelled the swap
             match state.expired_timelock(bitcoin_wallet).await? {
-                ExpiredTimelocks::None => {
+                ExpiredTimelocks::None {..} => {
                     bail!(
                         "Internal error: canceled state reached before cancel timelock was expired"
                     );
                 }
-                ExpiredTimelocks::Cancel => {
+                ExpiredTimelocks::Cancel { .. } => {
                     state.publish_refund_btc(bitcoin_wallet).await?;
                     BobState::BtcRefunded(state)
                 }

swap/src/rpc/methods.rs

@@ -1,4 +1,4 @@
-use crate::api::request::{Method, Params, Request};
+use crate::api::request::{Method, Request};
 use crate::api::Context;
 use crate::bitcoin::bitcoin_address;
 use crate::monero::monero_address;
@@ -18,19 +18,19 @@ pub fn register_modules(context: Arc<Context>) -> RpcModule<Arc<Context>> {
         .register_async_method("get_bitcoin_balance", |_, context| async move {
             get_bitcoin_balance(&context).await
         })
-        .expect("Could not register RPC method get_bitcoin_balance");
+        .unwrap();
 
     module
         .register_async_method("get_history", |_, context| async move {
             get_history(&context).await
         })
-        .expect("Could not register RPC method get_history");
+        .unwrap();
 
     module
         .register_async_method("get_raw_history", |_, context| async move {
             get_raw_history(&context).await
         })
-        .expect("Could not register RPC method get_raw_history");
+        .unwrap();
 
     module
         .register_async_method("get_seller", |params, context| async move {
@@ -42,7 +42,7 @@ pub fn register_modules(context: Arc<Context>) -> RpcModule<Arc<Context>> {
 
             get_seller(*swap_id, &context).await
         })
-        .expect("Could not register RPC method get_seller");
+        .unwrap();
 
     module
         .register_async_method("get_swap_start_date", |params, context| async move {
@@ -54,7 +54,7 @@ pub fn register_modules(context: Arc<Context>) -> RpcModule<Arc<Context>> {
 
             get_swap_start_date(*swap_id, &context).await
         })
-        .expect("Could not register RPC method get_swap_start_date");
+        .unwrap();
 
     module
         .register_async_method("resume_swap", |params, context| async move {
@@ -66,7 +66,18 @@ pub fn register_modules(context: Arc<Context>) -> RpcModule<Arc<Context>> {
 
             resume_swap(*swap_id, &context).await
         })
-        .expect("Could not register RPC method resume_swap");
+        .unwrap();
+
+    module.register_async_method("get_swap_expired_timelock", |params, context| async move {
+        let params: HashMap<String, Uuid> = params.parse()?;
+
+        let swap_id = params.get("swap_id").ok_or_else(|| {
+            jsonrpsee_core::Error::Custom("Does not contain swap_id".to_string())
+        })?;
+
+        get_swap_timelock(*swap_id, &context).await
+    }).unwrap();
+
     module
         .register_async_method("cancel_refund_swap", |params, context| async move {
             let params: HashMap<String, Uuid> = params.parse()?;
@@ -77,7 +88,7 @@ pub fn register_modules(context: Arc<Context>) -> RpcModule<Arc<Context>> {
 
             cancel_and_refund_swap(*swap_id, &context).await
         })
-        .expect("Could not register RPC method cancel_refund_swap");
+        .unwrap();
     module
         .register_async_method("withdraw_btc", |params, context| async move {
             let params: HashMap<String, String> = params.parse()?;
@@ -145,7 +156,7 @@ pub fn register_modules(context: Arc<Context>) -> RpcModule<Arc<Context>> {
             )
             .await
         })
-        .expect("Could not register RPC method buy_xmr");
+        .unwrap();
     module
         .register_async_method("list_sellers", |params, context| async move {
             let params: HashMap<String, Multiaddr> = params.parse()?;
@@ -155,93 +166,99 @@ pub fn register_modules(context: Arc<Context>) -> RpcModule<Arc<Context>> {
 
             list_sellers(rendezvous_point.clone(), &context).await
         })
-        .expect("Could not register RPC method list_sellers");
+        .unwrap();
+    module.register_async_method("get_current_swap", |_, context| async move {
+        get_current_swap(&context).await
+    }).unwrap();
+
     module
 }
 
 async fn execute_request(
     cmd: Method,
-    params: Params,
     context: &Arc<Context>,
 ) -> Result<serde_json::Value, jsonrpsee_core::Error> {
-    let mut request = Request::new(cmd, params);
+    let request = Request::new(cmd);
     request
         .call(Arc::clone(context))
         .await
         .map_err(|err| jsonrpsee_core::Error::Custom(err.to_string()))
 }
 
+async fn get_current_swap(context: &Arc<Context>) -> Result<serde_json::Value, jsonrpsee_core::Error> {
+    execute_request(Method::GetCurrentSwap, context).await
+}
+
 async fn get_bitcoin_balance(
     context: &Arc<Context>,
 ) -> Result<serde_json::Value, jsonrpsee_core::Error> {
-    execute_request(Method::Balance, Params::default(), context).await
+    execute_request(Method::Balance, context).await
 }
 
 async fn get_history(context: &Arc<Context>) -> Result<serde_json::Value, jsonrpsee_core::Error> {
-    execute_request(Method::History, Params::default(), context).await
+    execute_request(Method::History, context).await
 }
 
 async fn get_raw_history(
     context: &Arc<Context>,
 ) -> Result<serde_json::Value, jsonrpsee_core::Error> {
-    execute_request(Method::RawHistory, Params::default(), context).await
+    execute_request(Method::RawHistory, context).await
 }
 
 async fn get_seller(
     swap_id: Uuid,
     context: &Arc<Context>,
 ) -> Result<serde_json::Value, jsonrpsee_core::Error> {
-    let params = Params {
+    execute_request(Method::GetSeller {
-        swap_id: Some(swap_id),
+        swap_id
-        ..Default::default()
+    }, context).await
-    };
-    execute_request(Method::GetSeller, params, context).await
 }
 
 async fn get_swap_start_date(
     swap_id: Uuid,
     context: &Arc<Context>,
 ) -> Result<serde_json::Value, jsonrpsee_core::Error> {
-    let params = Params {
+    execute_request(Method::SwapStartDate {
-        swap_id: Some(swap_id),
+        swap_id
-        ..Default::default()
+    }, context).await
-    };
-    execute_request(Method::SwapStartDate, params, context).await
 }
 
 async fn resume_swap(
     swap_id: Uuid,
     context: &Arc<Context>,
 ) -> Result<serde_json::Value, jsonrpsee_core::Error> {
-    let params = Params {
+    execute_request(Method::Resume {
-        swap_id: Some(swap_id),
+        swap_id
-        ..Default::default()
+    }, context).await
-    };
+}
-    execute_request(Method::Resume, params, context).await
+
+async fn get_swap_timelock(
+    swap_id: Uuid,
+    context: &Arc<Context>,
+) -> Result<serde_json::Value, jsonrpsee_core::Error> {
+    execute_request(Method::GetSwapExpiredTimelock {
+        swap_id
+    }, context).await
 }
 
 async fn cancel_and_refund_swap(
     swap_id: Uuid,
     context: &Arc<Context>,
 ) -> Result<serde_json::Value, jsonrpsee_core::Error> {
-    let params = Params {
+    execute_request(Method::CancelAndRefund {
-        swap_id: Some(swap_id),
+        swap_id
-        ..Default::default()
+    }, context).await
-    };
-    execute_request(Method::CancelAndRefund, params, context).await
 }
 
 async fn withdraw_btc(
-    withdraw_address: bitcoin::Address,
+    address: bitcoin::Address,
     amount: Option<bitcoin::Amount>,
     context: &Arc<Context>,
 ) -> Result<serde_json::Value, jsonrpsee_core::Error> {
-    let params = Params {
+    execute_request(Method::WithdrawBtc {
         amount,
-        address: Some(withdraw_address),
+        address,
-        ..Default::default()
+    }, context).await
-    };
-    execute_request(Method::WithdrawBtc, params, context).await
 }
 
 async fn buy_xmr(
@@ -250,24 +267,19 @@ async fn buy_xmr(
     seller: Multiaddr,
     context: &Arc<Context>,
 ) -> Result<serde_json::Value, jsonrpsee_core::Error> {
-    let params = Params {
+    execute_request(Method::BuyXmr {
-        bitcoin_change_address: Some(bitcoin_change_address),
+        seller,
-        monero_receive_address: Some(monero_receive_address),
+        swap_id: Uuid::new_v4(),
-        seller: Some(seller),
+        bitcoin_change_address,
-        swap_id: Some(Uuid::new_v4()),
+        monero_receive_address
-        ..Default::default()
+    }, context).await
-    };
-
-    execute_request(Method::BuyXmr, params, context).await
 }
 
 async fn list_sellers(
     rendezvous_point: Multiaddr,
     context: &Arc<Context>,
 ) -> Result<serde_json::Value, jsonrpsee_core::Error> {
-    let params = Params {
+    execute_request(Method::ListSellers {
-        rendezvous_point: Some(rendezvous_point),
+        rendezvous_point
-        ..Default::default()
+    }, context).await
-    };
-    execute_request(Method::ListSellers, params, context).await
 }