Use server naming for shared API/events

packages/ui/src/lib/server-events.ts

@@ -0,0 +1,65 @@
+import type { WorkspaceEventPayload, WorkspaceEventType } from "../../../server/src/api-types"
+import { serverApi } from "./api-client"
+
+const RETRY_BASE_DELAY = 1000
+const RETRY_MAX_DELAY = 10000
+const SSE_PREFIX = "[SSE]"
+
+function logSse(message: string, context?: Record<string, unknown>) {
+  if (context) {
+    console.log(`${SSE_PREFIX} ${message}`, context)
+    return
+  }
+  console.log(`${SSE_PREFIX} ${message}`)
+}
+
+class ServerEvents {
+  private handlers = new Map<WorkspaceEventType | "*", Set<(event: WorkspaceEventPayload) => void>>()
+  private source: EventSource | null = null
+  private retryDelay = RETRY_BASE_DELAY
+
+  constructor() {
+    this.connect()
+  }
+
+  private connect() {
+    if (this.source) {
+      this.source.close()
+    }
+    logSse("Connecting to backend events stream")
+    this.source = serverApi.connectEvents((event) => this.dispatch(event), () => this.scheduleReconnect())
+    this.source.onopen = () => {
+      logSse("Events stream connected")
+      this.retryDelay = RETRY_BASE_DELAY
+    }
+  }
+
+  private scheduleReconnect() {
+    if (this.source) {
+      this.source.close()
+      this.source = null
+    }
+    logSse("Events stream disconnected, scheduling reconnect", { delayMs: this.retryDelay })
+    setTimeout(() => {
+      this.retryDelay = Math.min(this.retryDelay * 2, RETRY_MAX_DELAY)
+      this.connect()
+    }, this.retryDelay)
+  }
+
+  private dispatch(event: WorkspaceEventPayload) {
+    logSse(`event ${event.type}`)
+    this.handlers.get("*")?.forEach((handler) => handler(event))
+    this.handlers.get(event.type)?.forEach((handler) => handler(event))
+  }
+
+  on(type: WorkspaceEventType | "*", handler: (event: WorkspaceEventPayload) => void): () => void {
+    if (!this.handlers.has(type)) {
+      this.handlers.set(type, new Set())
+    }
+    const bucket = this.handlers.get(type)!
+    bucket.add(handler)
+    return () => bucket.delete(handler)
+  }
+}
+
+export const serverEvents = new ServerEvents()