1 files changed, 43 insertions, 0 deletions
diff --git a/app/public/sock.js b/app/public/sock.js
new file mode 100644
index 0000000..b4905e5
--- /dev/null
+++ b/app/public/sock.js
@@ -0,0 +1,43 @@
+const sock = (() => { "use strict";
+const refresh = () => setTimeout(() => location.reload(), 1e3);
+
+let ws, pingTimeout;
+const prequeue = [];
+const handlers = {
+  "reset": [refresh],
+  "ping": [() => {
+    clearTimeout(pingTimeout);
+    pingTimeout = setTimeout(refresh, 3e4);
+    sock.send("pong", {});
+  }],
+};
+
+const sock = {
+  init: url => {
+    ws = new WebSocket(url);
+    ws.addEventListener("close", refresh);
+    ws.addEventListener("error", refresh);
+    ws.addEventListener("message", e => {
+      const d = JSON.parse(e.data);
+      (handlers[d.type]||[]).forEach(cb => cb(d.data));
+    });
+    ws.addEventListener("open", e => {
+      while (prequeue.length) sock.send(...prequeue.shift());
+      (handlers["open"]||[]).forEach(cb => cb());
+      delete handlers["open"];
+    });
+  },
+
+  on: (type, cb) => {
+    if (type === "open" && ws && ws.readyState === WebSocket.OPEN) cb();
+    else (handlers[type]||(handlers[type]=[])).push(cb);
+  },
+
+  send: (type, data) => {
+    if (ws && ws.readyState === WebSocket.OPEN)
+      ws.send(JSON.stringify({type, data}));
+    else prequeue.push([type, data]);
+  },
+};
+
+return sock })();