WIP: store and get relation between rooms and channels:

* rebuildData
* handling video update (to check for channel changes)

server/lib/prosody/api/host.ts

@@ -0,0 +1,41 @@
+interface ProsodyHost {
+  host: string
+  port: string
+}
+
+let current: ProsodyHost | undefined
+
+/**
+ * When loading Prosody, keep track of the current host and port.
+ * @param host host
+ * @param port port
+ */
+function setCurrentProsody (host: string, port: string): void {
+  current = {
+    host,
+    port
+  }
+}
+
+/**
+ * When stopping Prosody, delete current host and port.
+ */
+function delCurrentProsody (): void {
+  current = undefined
+}
+
+/**
+ * Get the current Prosody host infos.
+ * @returns Prosody host info
+ */
+function getCurrentProsody (): ProsodyHost | null {
+  // cloning to avoid issues
+  if (!current) { return null }
+  return Object.assign({}, current)
+}
+
+export {
+  setCurrentProsody,
+  delCurrentProsody,
+  getCurrentProsody
+}