feat: add ws server for agent

app/utils/ws.ts

@@ -0,0 +1,47 @@
+// This is a "side-effect" but we want a lifecycle cache map of
+// peer statuses to prevent unnecessary fetches to the agent.
+import type { LoaderFunctionArgs } from 'remix'
+
+type Context = LoaderFunctionArgs['context']
+const cache: { [nodeID: string]: unknown } = {}
+
+export async function queryWS(context: Context, nodeIDs: string[]) {
+	const ws = context.ws
+	const firstClient = ws.clients.values().next().value
+	if (!firstClient) {
+		return cache
+	}
+
+	const cached = nodeIDs.map((nodeID) => {
+		const cached = cache[nodeID]
+		if (cached) {
+			return cached
+		}
+	})
+
+	// We only need to query the nodes that are not cached
+	const uncached = nodeIDs.filter((nodeID) => !cached.includes(nodeID))
+	if (uncached.length === 0) {
+		return cache
+	}
+
+	firstClient.send(JSON.stringify({ NodeIDs: uncached }))
+	await new Promise((resolve) => {
+		const timeout = setTimeout(() => {
+			resolve()
+		}, 3000)
+
+		firstClient.on('message', (message) => {
+			const data = JSON.parse(message.toString())
+			if (Object.keys(data).length === 0) {
+				resolve()
+			}
+
+			for (const [nodeID, status] of Object.entries(data)) {
+				cache[nodeID] = status
+			}
+		})
+	})
+
+	return cache
+}