Initial commit: FunConnect project with server, relay, client and admin panel

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/network/relay.rs

@@ -0,0 +1,68 @@
+/// QUIC relay client — used when P2P hole punch fails
+
+use anyhow::{anyhow, Result};
+use quinn::Connection;
+use std::net::SocketAddr;
+use std::time::Duration;
+use tokio::time::timeout;
+use uuid::Uuid;
+
+use crate::network::quic::open_endpoint;
+use crate::network::relay_selector::DEFAULT_RELAY_PORT;
+
+/// Connect to a relay server's QUIC endpoint
+pub async fn connect_relay(
+    relay_url: &str,
+    room_id: Uuid,
+    access_token: &str,
+) -> Result<Connection> {
+    let (host, port) = parse_relay_url(relay_url);
+
+    let relay_addr: SocketAddr = {
+        let addrs: Vec<SocketAddr> = tokio::net::lookup_host(format!("{}:{}", host, port))
+            .await?
+            .collect();
+        addrs.into_iter().next().ok_or_else(|| anyhow!("relay DNS failed"))?
+    };
+
+    let ep = open_endpoint("0.0.0.0:0".parse()?)?;
+
+    tracing::info!("Connecting to relay at {}", relay_addr);
+    let connecting = ep.connect(relay_addr, &host)?;
+    let conn = timeout(Duration::from_secs(10), connecting).await
+        .map_err(|_| anyhow!("relay connection timed out"))?
+        .map_err(|e| anyhow!("relay QUIC error: {}", e))?;
+
+    // Send auth handshake on a unidirectional stream using write_chunk
+    let mut stream = conn.open_uni().await?;
+    let handshake = serde_json::json!({
+        "token": access_token,
+        "room_id": room_id.to_string(),
+    });
+    let msg = serde_json::to_vec(&handshake)?;
+    let len = (msg.len() as u32).to_be_bytes();
+    stream.write_chunk(bytes::Bytes::copy_from_slice(&len)).await
+        .map_err(|e| anyhow!("{}", e))?;
+    stream.write_chunk(bytes::Bytes::from(msg)).await
+        .map_err(|e| anyhow!("{}", e))?;
+    let _ = stream.finish();
+    let _ = stream.stopped().await;
+
+    tracing::info!("Relay handshake sent for room {}", room_id);
+    Ok(conn)
+}
+
+fn parse_relay_url(url: &str) -> (String, u16) {
+    let cleaned = url
+        .trim_start_matches("https://")
+        .trim_start_matches("http://")
+        .trim_start_matches("quic://");
+
+    if let Some((host, port_str)) = cleaned.rsplit_once(':') {
+        if let Ok(port) = port_str.parse::<u16>() {
+            return (host.to_string(), port);
+        }
+    }
+
+    (cleaned.to_string(), DEFAULT_RELAY_PORT)
+}