import { readFileSync } from "fs";
import path from "path";

/* What is deployed, and what is running. Two different questions.
 *
 * `.release.json` is written by scripts/deploy.sh just before the build: the sha it pulled, the
 * sha it replaced, and when. `NEXT_PUBLIC_RELEASE` is compiled into the bundle by that same build.
 * Normally the two agree. When they don't — the file names a newer sha than the running bundle —
 * a deploy pulled and built but the process was never restarted, which is the failure the deploy
 * script's own health check exists to catch and the console should show anyway. */
export type Version = {
  deployed: { sha: string; from: string; at: Date } | null;
  running: string | null;
  node: string;
  uptimeMin: number;
};

export function version(): Version {
  let deployed: Version["deployed"] = null;
  try {
    const j = JSON.parse(readFileSync(path.join(process.cwd(), ".release.json"), "utf8")) as { sha?: string; from?: string; at?: string };
    if (j.sha && j.at) deployed = { sha: String(j.sha), from: String(j.from || ""), at: new Date(j.at) };
  } catch { /* no file: a box deployed before the script wrote one, or local dev */ }
  return {
    deployed,
    running: process.env.NEXT_PUBLIC_RELEASE || null,
    node: process.version,
    uptimeMin: Math.floor(process.uptime() / 60),
  };
}