/**
 * Pi/host fleet heartbeat: self-report local pm2 process health to Postgres so a
 * central detector on Erik can catch crash-loops (restart_time velocity + near-0
 * uptime) and stale/dead hosts — which a naive "pm2 status == online" check misses.
 * Runs on each Pi via cron (every 5 min). DB via the local tunnel (127.0.0.1:5433).
 */
import { execFileSync } from "node:child_process";
import os from "node:os";
import { config } from "dotenv";
import pg from "pg";

config({ path: new URL("../.env", import.meta.url) }); // ~/tip/.env

const host = os.hostname();
let procs = [];
try { procs = JSON.parse(execFileSync("pm2", ["jlist"], { encoding: "utf8", maxBuffer: 8 * 1024 * 1024 })); }
catch { process.exit(0); }

const pool = new pg.Pool({
  host: "127.0.0.1", port: 5433,
  user: process.env.POSTGRES_USER || "tip",
  database: process.env.POSTGRES_DB || "transceiver_db",
  password: process.env.POSTGRES_PASSWORD,
  max: 1, connectionTimeoutMillis: 8000, statement_timeout: 8000,
});

try {
  for (const p of procs) {
    const e = p.pm2_env || {};
    const uptimeS = Math.round((Date.now() - (e.pm_uptime || Date.now())) / 1000);
    await pool.query(
      "insert into fleet_health(host,pm_name,status,restart_time,uptime_s) values($1,$2,$3,$4,$5)",
      [host, p.name, e.status || null, e.restart_time ?? 0, uptimeS],
    );
  }
} catch { /* heartbeat is best-effort; never crash the host */ }
finally { await pool.end().catch(() => {}); }