refactor: Modularize server stats widget collectors

src/backend/ssh/widgets/memory-collector.ts

@@ -0,0 +1,41 @@
+import type { Client } from "ssh2";
+import { execCommand, toFixedNum, kibToGiB } from "./common-utils.js";
+
+export async function collectMemoryMetrics(client: Client): Promise<{
+  percent: number | null;
+  usedGiB: number | null;
+  totalGiB: number | null;
+}> {
+  let memPercent: number | null = null;
+  let usedGiB: number | null = null;
+  let totalGiB: number | null = null;
+
+  try {
+    const memInfo = await execCommand(client, "cat /proc/meminfo");
+    const lines = memInfo.stdout.split("\n");
+    const getVal = (key: string) => {
+      const line = lines.find((l) => l.startsWith(key));
+      if (!line) return null;
+      const m = line.match(/\d+/);
+      return m ? Number(m[0]) : null;
+    };
+    const totalKb = getVal("MemTotal:");
+    const availKb = getVal("MemAvailable:");
+    if (totalKb && availKb && totalKb > 0) {
+      const usedKb = totalKb - availKb;
+      memPercent = Math.max(0, Math.min(100, (usedKb / totalKb) * 100));
+      usedGiB = kibToGiB(usedKb);
+      totalGiB = kibToGiB(totalKb);
+    }
+  } catch (e) {
+    memPercent = null;
+    usedGiB = null;
+    totalGiB = null;
+  }
+
+  return {
+    percent: toFixedNum(memPercent, 0),
+    usedGiB: usedGiB ? toFixedNum(usedGiB, 2) : null,
+    totalGiB: totalGiB ? toFixedNum(totalGiB, 2) : null,
+  };
+}