Use the fallback AP when apresolve fails.

This matches the desktop client’s behaviour.

Fixes #136

src/apresolve.rs

@@ -1,4 +1,5 @@
 const APRESOLVE_ENDPOINT : &'static str = "http://apresolve.spotify.com/";
+const AP_FALLBACK : &'static str = "ap.spotify.com:80";
 
 use hyper;
 use std::io::Read;
@@ -9,14 +10,17 @@ pub struct APResolveData {
     ap_list: Vec<String>
 }
 
-pub fn apresolve() -> Result<Vec<String>, ()> {
+pub fn apresolve() -> String {
     let client = hyper::client::Client::new();
-    
-    let mut response = client.get(APRESOLVE_ENDPOINT).send().unwrap();
-    let mut data = String::new();
-    response.read_to_string(&mut data).unwrap();
+    (|| {
+        let mut response = client.get(APRESOLVE_ENDPOINT).send().map_err(|_| ())?;
+        let mut data = String::new();
+        response.read_to_string(&mut data).map_err(|_| ())?;
 
-    let data : APResolveData = serde_json::from_str(&data).unwrap();
-
-    Ok(data.ap_list)
+        let data : APResolveData = serde_json::from_str(&data).map_err(|_| ())?;
+        data.ap_list.first().map(Clone::clone).ok_or(())
+    })().unwrap_or_else(|_| {
+        warn!("failed to resolve AP, using fallback");
+        AP_FALLBACK.into()
+    })
 }

src/session.rs

@@ -7,7 +7,6 @@ use eventual::Future;
 use eventual::Async;
 use protobuf::{self, Message};
 use rand::thread_rng;
-use rand::Rng;
 use std::io::{Read, Write, Cursor};
 use std::result::Result;
 use std::sync::{Mutex, RwLock, Arc, mpsc};
@@ -95,11 +94,10 @@ impl Session {
     fn connect(&self) -> CipherConnection {
         let local_keys = DHLocalKeys::random(&mut thread_rng());
 
-        let aps = apresolve().unwrap();
-        let ap = thread_rng().choose(&aps).expect("No APs found");
+        let ap = apresolve();
 
         info!("Connecting to AP {}", ap);
-        let mut connection = PlainConnection::connect(ap).unwrap();
+        let mut connection = PlainConnection::connect(&ap).unwrap();
 
         let request = protobuf_init!(protocol::keyexchange::ClientHello::new(), {
             build_info => {