import { readFileSync } from "fs";

const VERSION_CHECK_URL =
  "https://raw.githubusercontent.com/bulwarkmail/webmail/main/VERSION";

const SEMVER_RE = /^\d+\.\d+\.\d+$/;

function compareVersions(current: string, remote: string): number {
  const a = current.split(".").map(Number);
  const b = remote.split(".").map(Number);
  for (let i = 0; i < 3; i++) {
    if ((b[i] ?? 0) > (a[i] ?? 0)) return 1;
    if ((b[i] ?? 0) < (a[i] ?? 0)) return -1;
  }
  return 0;
}

const pkg = JSON.parse(
  readFileSync(`${process.cwd()}/package.json`, "utf-8")
);
const current: string = pkg.version ?? "0.0.0";
console.info(`Bulwark Webmail v${current}`);

if (process.env.NODE_ENV === "production") {
  fetch(VERSION_CHECK_URL, {
    cache: "no-store",
    signal: AbortSignal.timeout(5000),
  })
    .then((res) => {
      if (!res.ok) return;
      return res.text();
    })
    .then((text) => {
      if (!text) return;
      const remote = text.trim();
      if (!SEMVER_RE.test(remote)) return;
      if (compareVersions(current, remote) > 0) {
        console.info(
          `Update available: v${remote} — https://github.com/bulwarkmail/webmail`
        );
      }
    })
    .catch(() => {});
}