Re-organize connection management

src/target/Plex.ts

@@ -0,0 +1,28 @@
+import {EventEmitter} from 'events'
+import {Connection} from '../Connection'
+import type {PlexMessage, Message} from '../util/Socket'
+
+export class Plex extends EventEmitter {
+  constructor(readonly urls: string[], readonly connection: Connection) {
+    super()
+
+    this.connection.on('receive', this.onMessage)
+  }
+
+  get connections() {
+    return [this.connection]
+  }
+
+  send = (...payload: Message) => {
+    this.connection.send([{relays: this.urls}, payload])
+  }
+
+  onMessage = (connection: Connection, [{relays}, [verb, ...payload]]: PlexMessage) => {
+    this.emit(verb, relays[0], ...payload)
+  }
+
+  cleanup = () => {
+    this.removeAllListeners()
+    this.connection.off('receive', this.onMessage)
+  }
+}