feat: add real-time server log streaming via WebSocket

packages/backend/src/services/server.service.ts

@@ -1,5 +1,6 @@
 import fs from "fs/promises";
 import path from "path";
+import chokidar from "chokidar";
 import { getWorkspacePath } from "./workspace.service.js";
 import { getDockerClient } from "./docker.service.js";
 import { broadcast } from "./ws.service.js";
@@ -210,3 +211,45 @@ export async function seedDatabase(cdKey: string, playerName: string): Promise<v
   });
   await dmExec.start({});
 }
+
+let logWatcher: ReturnType<typeof chokidar.watch> | null = null;
+
+export function startLogStreaming(): void {
+  const logPath = path.join(getWorkspacePath(), "logs/nwserverLog1.txt");
+
+  if (logWatcher) logWatcher.close();
+
+  logWatcher = chokidar.watch(logPath, {
+    persistent: true,
+    usePolling: true,
+    interval: 1000,
+  });
+
+  let lastSize = 0;
+  logWatcher.on("change", async () => {
+    try {
+      const stats = await fs.stat(logPath);
+      if (stats.size > lastSize) {
+        const fd = await fs.open(logPath, "r");
+        const buffer = Buffer.alloc(stats.size - lastSize);
+        await fd.read(buffer, 0, buffer.length, lastSize);
+        await fd.close();
+        lastSize = stats.size;
+
+        const newLines = buffer.toString("utf-8");
+        broadcast("log", "server", { text: newLines });
+      } else if (stats.size < lastSize) {
+        lastSize = 0;
+      }
+    } catch {
+      /* log file may not exist yet */
+    }
+  });
+}
+
+export function stopLogStreaming(): void {
+  if (logWatcher) {
+    logWatcher.close();
+    logWatcher = null;
+  }
+}