swap_setup instead of spot_price and execution_setup

Having `spot_price` and `execution_setup` as separate protocols did not bring any advantages, but was problematic because we had to ensure that `execution_setup` would be triggered after `spot_price`. Because of this dependency it is better to combine the protocols into one.

Combining the protocols also allows a refactoring to get rid of the `libp2p-async-await` dependency.

Alice always listens for the `swap_setup` protocol. When Bob opens a substream on that protocol the spot price is communicated, and then all execution setup messages (swap-id and signature exchange).

swap/src/protocol/alice/behaviour.rs

@@ -1,34 +1,34 @@
-use crate::network::quote::BidQuote;
-use crate::network::{encrypted_signature, quote, transfer_proof};
-use crate::protocol::alice::event_loop::LatestRate;
-use crate::protocol::alice::{execution_setup, spot_price, State3};
-use crate::{env, monero};
 use anyhow::{anyhow, Error};
 use libp2p::ping::{Ping, PingEvent};
 use libp2p::request_response::{RequestId, ResponseChannel};
 use libp2p::{NetworkBehaviour, PeerId};
 use uuid::Uuid;
 
+use crate::env;
+use crate::network::quote::BidQuote;
+use crate::network::{encrypted_signature, quote, transfer_proof};
+use crate::protocol::alice::event_loop::LatestRate;
+use crate::protocol::alice::swap_setup::WalletSnapshot;
+use crate::protocol::alice::{swap_setup, State3};
+
 #[derive(Debug)]
 pub enum OutEvent {
-    SwapRequestDeclined {
-        peer: PeerId,
-        error: spot_price::Error,
+    SwapSetupInitiated {
+        send_wallet_snapshot: bmrng::RequestReceiver<bitcoin::Amount, WalletSnapshot>,
     },
-    ExecutionSetupStart {
+    SwapSetupCompleted {
+        peer_id: PeerId,
+        swap_id: Uuid,
+        state3: Box<State3>,
+    },
+    SwapDeclined {
         peer: PeerId,
-        btc: bitcoin::Amount,
-        xmr: monero::Amount,
+        error: swap_setup::Error,
     },
     QuoteRequested {
         channel: ResponseChannel<BidQuote>,
         peer: PeerId,
     },
-    ExecutionSetupDone {
-        bob_peer_id: PeerId,
-        swap_id: Uuid,
-        state3: Box<State3>,
-    },
     TransferProofAcknowledged {
         peer: PeerId,
         id: RequestId,
@@ -72,8 +72,7 @@ where
     LR: LatestRate + Send + 'static,
 {
     pub quote: quote::Behaviour,
-    pub spot_price: spot_price::Behaviour<LR>,
-    pub execution_setup: execution_setup::Behaviour,
+    pub swap_setup: swap_setup::Behaviour<LR>,
     pub transfer_proof: transfer_proof::Behaviour,
     pub encrypted_signature: encrypted_signature::Behaviour,
 
@@ -88,8 +87,6 @@ where
     LR: LatestRate + Send + 'static,
 {
     pub fn new(
-        balance: monero::Amount,
-        lock_fee: monero::Amount,
         min_buy: bitcoin::Amount,
         max_buy: bitcoin::Amount,
         latest_rate: LR,
@@ -98,16 +95,13 @@ where
     ) -> Self {
         Self {
             quote: quote::alice(),
-            spot_price: spot_price::Behaviour::new(
-                balance,
-                lock_fee,
+            swap_setup: swap_setup::Behaviour::new(
                 min_buy,
                 max_buy,
                 env_config,
                 latest_rate,
                 resume_only,
             ),
-            execution_setup: Default::default(),
             transfer_proof: transfer_proof::alice(),
             encrypted_signature: encrypted_signature::alice(),
             ping: Ping::default(),