import { loadavg, totalmem, freemem, uptime } from "node:os";
import { execSync } from "node:child_process";
import { snapshots } from "./schema.ts";

export async function compute(db, _peers) {
  const [load1, load5, load15] = loadavg();

  const memTotal = totalmem();
  const memFree = freemem();
  const memUsed = memTotal - memFree;
  const memTotalMB = Math.round(memTotal / 1024 / 1024);
  const memUsedMB = Math.round(memUsed / 1024 / 1024);
  const memUsedPct = Math.round((memUsed / memTotal) * 10000) / 100;

  let diskTotalGB = 0, diskUsedGB = 0, diskUsedPct = 0;
  try {
    const df = execSync("df -B1 / | tail -1", { encoding: "utf-8" }).trim();
    const parts = df.split(/\s+/);
    const total = Number(parts[1]);
    const used = Number(parts[2]);
    diskTotalGB = Math.round(total / 1024 / 1024 / 1024 * 100) / 100;
    diskUsedGB = Math.round(used / 1024 / 1024 / 1024 * 100) / 100;
    diskUsedPct = total > 0 ? Math.round((used / total) * 10000) / 100 : 0;
  } catch {}

  const ts = Date.now();
  const uptimeSec = Math.round(uptime());

  await db.insert(snapshots).values({
    ts, cpuLoad1m: load1, cpuLoad5m: load5, cpuLoad15m: load15,
    memTotalMB, memUsedMB, memUsedPct,
    diskTotalGB, diskUsedGB, diskUsedPct,
    uptimeSec,
  });

  return {
    cpu: { load1m: load1, load5m: load5, load15m: load15 },
    memory: { totalMB: memTotalMB, usedMB: memUsedMB, usedPct: memUsedPct },
    disk: { totalGB: diskTotalGB, usedGB: diskUsedGB, usedPct: diskUsedPct },
    uptimeSec,
  };
}