feat(api): execute settlement if negative settle_to is provided durin…

…g account creation

crates/interledger-api/src/routes/accounts.rs

@@ -173,7 +173,14 @@ where
             async move {
                 let account = store.insert_account(account_details.clone()).await?;
 
-                connect_to_external_services(handler, account.clone(), store_clone, btp).await?;
+                connect_to_external_services(
+                    handler,
+                    account.clone(),
+                    store_clone,
+                    btp,
+                    account_details.settle_to,
+                )
+                .await?;
                 Ok::<Json, Rejection>(warp::reply::json(&account))
             }
         })
@@ -212,8 +219,16 @@ where
                 btp.close_connection(&id);
             }
             async move {
+                let settle_to = account_details.settle_to;
                 let account = store.update_account(id, account_details).await?;
-                connect_to_external_services(outgoing_handler, account.clone(), store, btp).await?;
+                connect_to_external_services(
+                    outgoing_handler,
+                    account.clone(),
+                    store,
+                    btp,
+                    settle_to,
+                )
+                .await?;
 
                 Ok::<Json, Rejection>(warp::reply::json(&account))
             }
@@ -308,6 +323,7 @@ where
                     modified_account.clone(),
                     store,
                     btp,
+                    None,
                 )
                 .await?;
                 Ok::<Json, Rejection>(warp::reply::json(&modified_account))
@@ -554,6 +570,7 @@ async fn connect_to_external_services<O, A, S, B>(
     account: A,
     store: S,
     btp: BtpOutgoingService<B, A>,
+    settle_to: Option<i64>,
 ) -> Result<A, warp::reject::Rejection>
 where
     O: OutgoingService<A> + Clone + Send + Sync + 'static,
@@ -596,14 +613,31 @@ where
         );
 
         let response = http_client
-            .create_engine_account(id, se_url)
+            .create_engine_account(id, se_url.clone())
             .map_err(|err| {
                 Rejection::from(ApiError::internal_server_error().detail(err.to_string()))
             })
             .await?;
 
         if response.status().is_success() {
             trace!("Account {} created on the SE", id);
+
+            // On successful account creation, if the settle_to was negative, we should send a
+            // settlement request to them
+            if let Some(settle_to) = settle_to {
+                // prefund the absolute value
+                if settle_to < 0 {
+                    let amount = settle_to.abs() as u64;
+                    http_client
+                        .send_settlement(id, se_url, amount, account.asset_scale())
+                        .map_err(|err| {
+                            Rejection::from(
+                                ApiError::internal_server_error().detail(err.to_string()),
+                            )
+                        })
+                        .await?;
+                }
+            }
         } else {
             error!(
                 "Error creating account. Settlement engine responded with HTTP code: {}",

crates/interledger-settlement/src/core/settlement_client.rs

@@ -53,7 +53,7 @@ impl SettlementClient {
         // The `Prepare` packet's data was sent by the peer's settlement
         // engine so we assume it is in a format that our settlement engine
         // will understand
-        // format. `to_vec()` needed to work around lifetime error
+        // format.
         let mut settlement_engine_url = engine_url;
         settlement_engine_url
             .path_segments_mut()