handle optional response results

src/main.rs

@@ -40,9 +40,14 @@ fn main() -> Result<()> {
         todo!()
     }
     // start crawler
-    for peer in p.response.unwrap().peers {
+    match p.response {
+        Some(response) => {
+            for peer in response.peers {
                 crawl(peer.key, &config, &mut ygg, &mut key, &mut tcp, &mut udp)?;
             }
+        }
+        None => println!("node has no peers to connect."),
+    }
     Ok(())
 }
 
@@ -54,14 +59,17 @@ fn crawl(
     tcp: &mut Option<Vec<SocketAddr>>,
     udp: &mut Option<(Vec<SocketAddr>, Udp)>,
 ) -> Result<()> {
-    if !key.contains(&k) {
+    if key.contains(&k) {
+        return Ok(());
+    }
     if config.debug {
         println!("get peers for `{k}`...");
     }
     let p = ygg.remote_peers(&k)?;
     if p.status == "success" {
         key.push(k);
-            for (host, peers) in p.response.unwrap() {
+        if let Some(response) = p.response {
+            for (host, peers) in response {
                 for port in &config.port {
                     let address = SocketAddr::new(IpAddr::V6(host), *port);
                     if let Some(index) = tcp
@@ -94,6 +102,7 @@ fn crawl(
                     crawl(k, config, ygg, key, tcp, udp)?;
                 }
             }
+        }
     } else if config.debug {
         println!(
             "\t{}: peer `{k}` return status `{}`, skip.",
@@ -102,7 +111,6 @@ fn crawl(
         );
         key.push(k) // ban
     }
-    }
     Ok(())
 }