first commit

backend/src/main.rs

@@ -0,0 +1,39 @@
+//! Showdown backend: WebSocket rooms held entirely in memory, plus static
+//! file serving for the built frontend. No database — a room lives exactly
+//! as long as someone has it open. See ../PROTOCOL.md for the wire format.
+
+mod room;
+mod ws;
+
+use std::env;
+use std::path::PathBuf;
+
+use axum::routing::get;
+use axum::Router;
+use tower_http::services::{ServeDir, ServeFile};
+
+use crate::room::Rooms;
+
+#[tokio::main]
+async fn main() {
+    let rooms = Rooms::default();
+
+    let static_dir =
+        PathBuf::from(env::var("STATIC_DIR").unwrap_or_else(|_| "../frontend/dist".into()));
+    // Unknown paths fall back to index.html so deep links like /room/abc work.
+    let spa = ServeDir::new(&static_dir).fallback(ServeFile::new(static_dir.join("index.html")));
+
+    let app = Router::new()
+        .route("/ws/room/{room_id}", get(ws::ws_handler))
+        .fallback_service(spa)
+        .with_state(rooms);
+
+    let port: u16 = env::var("PORT").ok().and_then(|p| p.parse().ok()).unwrap_or(8080);
+    let listener = tokio::net::TcpListener::bind(("0.0.0.0", port))
+        .await
+        .expect("failed to bind port");
+
+    println!("🤠 Showdown saloon open at http://localhost:{port}");
+    println!("   serving frontend from {}", static_dir.display());
+    axum::serve(listener, app).await.expect("server error");
+}