const { atlasState } = require("../atlas-probes");
const { pdbOrgState } = require("../pdb-org-countries");
const { fetchPeeringDB } = require("../services/peeringdb");
const { cacheGet, cacheSet } = require("../caches/response-caches");

// Lia's Atlas Paradise: Atlas probe coverage endpoint
function handleAtlasCoverage(req, res) {
  res.setHeader("Content-Type", "application/json");
  if (!atlasState.cache) {
    res.writeHead(503);
    return res.end(JSON.stringify({ error: "Atlas probe data is still loading. Please try again in a minute." }));
  }
  return res.end(JSON.stringify(atlasState.cache, null, 2));
}

// Lia's Paradise: File parsing endpoint (for binary uploads)
function handleParseFile(req, res) {
  res.setHeader("Content-Type", "application/json");
  let body = "";
  req.on("data", function(chunk) { body += chunk; });
  req.on("end", function() {
    try {
      var parsed = JSON.parse(body);
      var filename = parsed.filename || "";
      var ext = filename.split(".").pop().toLowerCase();
      // For text-based formats, decode base64 and extract text
      if (ext === "csv" || ext === "txt") {
        var text = Buffer.from(parsed.data, "base64").toString("utf8");
        return res.end(JSON.stringify({ text: text }));
      }
      // For binary formats (PDF, XLS, DOC), we can't parse server-side without
      // heavy dependencies. Return helpful error.
      return res.end(JSON.stringify({
        error: "Binary file parsing (" + ext.toUpperCase() + ") requires client-side extraction. Please use CSV or TXT format, or copy-paste the content.",
        suggestion: "Export your spreadsheet as CSV first, then upload the CSV file."
      }));
    } catch(e) {
      return res.end(JSON.stringify({ error: "Parse error: " + e.message }));
    }
  });
  return;
}

// Lia's Paradise: Combined PeeringDB + Atlas coverage data
function handleLiaCoverage(req, res) {
  res.setHeader("Content-Type", "application/json");
  if (!atlasState.cache) {
    res.writeHead(503);
    return res.end(JSON.stringify({ error: "Atlas probe data is still loading. Please try again in a minute." }));
  }

  // Cache this expensive response for 30 min
  var liaCacheKey = "lia_coverage";
  var liaCached = cacheGet(liaCacheKey);
  if (liaCached) return res.end(liaCached);

  // Fetch PeeringDB network list (all networks with status "ok")
  // Use pre-cached org→country map (loaded at startup, 16MB response cached in memory)
  fetchPeeringDB("/net?status=ok&depth=0").then(function(pdbData) {
    if (!pdbData || !pdbData.data) {
      return res.end(JSON.stringify({ error: "Could not fetch PeeringDB networks" }));
    }

    var probeAsns = new Set(atlasState.cache.asns_with_probes || []);

    var enriched = pdbData.data.map(function(n) {
      var org = pdbOrgState.map.get(n.org_id) || {};
      var cc = org.country || "";
      return {
        asn: n.asn,
        name: n.name || "",
        org_name: org.name || "",
        country: cc,
        country_name: cc,
        info_type: n.info_type || "",
        has_probe: probeAsns.has(n.asn),
      };
    }).filter(function(n) { return n.asn > 0 && n.country; });

    var result = JSON.stringify({
      networks: enriched,
      total: enriched.length,
      with_probes: enriched.filter(function(n) { return n.has_probe; }).length,
      without_probes: enriched.filter(function(n) { return !n.has_probe; }).length,
      atlas_unique_asns: probeAsns.size,
      org_countries_loaded: pdbOrgState.map.size,
      fetched_at: new Date().toISOString(),
    });

    cacheSet(liaCacheKey, result, 30 * 60 * 1000);
    res.end(result);
  }).catch(function(e) {
    res.end(JSON.stringify({ error: "PeeringDB fetch failed: " + e.message }));
  });
  return;
}

module.exports = { handleAtlasCoverage, handleParseFile, handleLiaCoverage };