const localDb = require("../../local-db-client");
const { fetchTopology } = require("../topology");

// Feature 25: Topology endpoint
async function handleTopology(req, res, url) {
    const rawAsn = (url.searchParams.get("asn") || "").replace(/[^0-9]/g, "");
    const depth = parseInt(url.searchParams.get("depth") || "2") || 2;
    if (!rawAsn) {
      res.writeHead(400);
      return res.end(JSON.stringify({ error: "Missing or invalid ASN parameter" }));
    }
    const start = Date.now();
    try {
      const topology = await fetchTopology(parseInt(rawAsn), depth);

      // ---- Threat Intelligence Enrichment for Topology Nodes ----
      const threatMap = {};
      const threatPromises = topology.nodes.slice(0, 100).map(async (node) => {
        try {
          const asNum = String(node.asn);
          const threat = await localDb.getThreatIntel(asNum);
          if (threat) {
            threatMap[node.asn] = {
              threat_level: threat.threat_level,
              confidence_score: threat.confidence_score,
              source: threat.source,
            };
          }
        } catch (e) {
          console.error(`[Topology Threat Lookup] Error checking ASN ${node.asn}:`, e.message);
        }
      });
      await Promise.race([
        Promise.all(threatPromises),
        new Promise(r => setTimeout(r, 3000)),
      ]);

      // Attach threat status to node objects
      topology.nodes.forEach((node) => {
        if (threatMap[node.asn]) {
          node.threat_level = threatMap[node.asn].threat_level;
          node.threat_confidence = threatMap[node.asn].confidence_score;
          node.threat_source = threatMap[node.asn].source;
        }
      });

      topology.meta = {
        query: "AS" + rawAsn, depth: depth, duration_ms: Date.now() - start,
        timestamp: new Date().toISOString(), node_count: topology.nodes.length, edge_count: topology.edges.length,
      };
      return res.end(JSON.stringify(topology, null, 2));
    } catch (err) {
      res.writeHead(500);
      return res.end(JSON.stringify({ error: "Topology query failed", message: err.message }));
    }

}

module.exports = { handleTopology };