const https = require("https");
const { UA } = require("../data/constants");

// MANRS Participants Cache (scraped from public HTML page, 24h TTL)
let manrsAsnSet = null;        // Set<string> of member ASNs
let manrsLastFetch = 0;
let manrsFetching = false;
const MANRS_CACHE_TTL = 24 * 60 * 60 * 1000; // 24 hours

async function ensureManrsCache() {
  const now = Date.now();
  if (manrsAsnSet && (now - manrsLastFetch) < MANRS_CACHE_TTL) return;
  if (manrsFetching) {
    // Wait up to 8s for in-progress fetch
    for (let i = 0; i < 80; i++) {
      await new Promise(r => setTimeout(r, 100));
      if (manrsAsnSet) return;
    }
    return;
  }
  manrsFetching = true;
  try {
    const html = await new Promise((resolve, reject) => {
      const opts = { hostname: "www.manrs.org", path: "/netops/participants/", method: "GET", timeout: 15000,
        headers: { "User-Agent": UA, "Accept": "text/html" } };
      const req = https.request(opts, res => {
        let body = "";
        res.on("data", d => { body += d; });
        res.on("end", () => resolve(body));
      });
      req.on("error", reject);
      req.on("timeout", () => { req.destroy(); reject(new Error("MANRS fetch timeout")); });
      req.end();
    });
    // Extract ASNs from <td class="asns">267490</td> — may contain multiple space-separated ASNs
    const set = new Set();
    const re = /<td[^>]*class="asns"[^>]*>([\d\s,]+)<\/td>/gi;
    for (const m of html.matchAll(re)) {
      m[1].split(/[\s,]+/).forEach(a => { const n = a.trim(); if (n) set.add(n); });
    }
    if (set.size > 0) {
      manrsAsnSet = set;
      manrsLastFetch = Date.now();
      console.log("[MANRS] Loaded " + set.size + " participant ASNs from manrs.org");
    }
  } catch (e) {
    console.warn("[MANRS] Failed to fetch participants:", e.message);
  } finally {
    manrsFetching = false;
  }
}

function checkManrsMembership(asn) {
  if (!manrsAsnSet) return { status: "info", participant: "unknown", message: "MANRS data not yet loaded", note: "https://www.manrs.org/netops/participants/" };
  const isMember = manrsAsnSet.has(String(asn));
  return {
    status: isMember ? "pass" : "fail",
    participant: isMember,
    member_count: manrsAsnSet.size,
    note: isMember ? "Confirmed MANRS Network Operator participant" : "Not listed as MANRS participant — https://www.manrs.org/beamanrs/",
  };
}

module.exports = { ensureManrsCache, checkManrsMembership };