feat: add new file

src/api/websocket.ts

@@ -0,0 +1,30 @@
+type Handler = (data: unknown) => void
+
+let ws: WebSocket | null = null
+let handler: Handler | null = null
+
+function getUrl(): string {
+  return `${window.location.origin.replace(/^http/, 'ws')}/ws`
+}
+
+export function connectSituationWebSocket(onData: Handler): () => void {
+  handler = onData
+  if (ws?.readyState === WebSocket.OPEN) return () => {}
+
+  ws = new WebSocket(getUrl())
+  ws.onmessage = (e) => {
+    try {
+      const msg = JSON.parse(e.data)
+      if (msg.type === 'situation' && msg.data) handler?.(msg.data)
+    } catch (_) {}
+  }
+  ws.onclose = () => {
+    ws = null
+    setTimeout(() => handler && connectSituationWebSocket(handler), 3000)
+  }
+  return () => {
+    handler = null
+    ws?.close()
+    ws = null
+  }
+}