From ddaf46c83a59d597fc88c44b64603af86b15de1d Mon Sep 17 00:00:00 2001
From: accius <chris@cjhlighting.com>
Date: Mon, 23 Mar 2026 21:04:09 -0400
Subject: [PATCH] fix: use DXpedition entity coordinates for active DXpedition
 spots
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DXpedition callsigns like TX5EU (Austral Islands) were showing at
the generic prefix location (TX → France) because CTY.DAT maps TX
to Metropolitan France.

Now cross-references DX cluster spots against the active DXpedition
list from NG3K. If a spotted callsign matches a known active
DXpedition, uses the DXpedition's DXCC entity coordinates from
cty.dat instead of the generic prefix. This runs after grid square
resolution but before HamQTH/prefix fallbacks.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 server/routes/dxcluster.js   | 36 ++++++++++++++++++++++++++++++++++++
 server/routes/dxpeditions.js |  6 +++++-
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/server/routes/dxcluster.js b/server/routes/dxcluster.js
index f9a03260..68782948 100644
--- a/server/routes/dxcluster.js
+++ b/server/routes/dxcluster.js
@@ -39,6 +39,34 @@ module.exports = function (app, ctx) {
 
   const CALLSIGN_CACHE_TTL = 24 * 60 * 60 * 1000; // 24 hours
 
+  // Cross-reference a callsign against active DXpeditions.
+  // Returns { lat, lon, entity } if the call matches a known DXpedition,
+  // using the DXpedition's DXCC entity coordinates from cty.dat.
+  const { lookupCall } = require('../../src/server/ctydat.js');
+
+  function lookupDXpeditionLocation(call) {
+    const cache = ctx.dxpeditionCache;
+    if (!cache?.data?.dxpeditions) return null;
+    const upper = (call || '').toUpperCase();
+    const dxped = cache.data.dxpeditions.find((d) => d.isActive && d.callsign?.toUpperCase() === upper);
+    if (!dxped || !dxped.entity) return null;
+
+    // Look up the DXpedition entity in cty.dat's entity list
+    const { getCtyData } = require('../../src/server/ctydat.js');
+    const cty = getCtyData();
+    if (!cty?.entities) return null;
+
+    const entityName = dxped.entity.toLowerCase().replace(/\s+/g, ' ').trim();
+    const match = cty.entities.find((e) => {
+      const eName = (e.entity || '').toLowerCase().replace(/\s+/g, ' ').trim();
+      return eName === entityName || eName.includes(entityName) || entityName.includes(eName);
+    });
+    if (match && match.lat != null && match.lon != null) {
+      return { lat: match.lat, lon: match.lon, country: match.entity, source: 'dxpedition' };
+    }
+    return null;
+  }
+
   // DX Spider Proxy URL (sibling service on Railway or external)
   const DXSPIDER_PROXY_URL = process.env.DXSPIDER_PROXY_URL || 'https://spider-production-1ec7.up.railway.app';
 
@@ -1651,6 +1679,14 @@ module.exports = function (app, ctx) {
             }
           }
 
+          // Check if this callsign is a known active DXpedition — use entity coordinates
+          if (!dxLoc) {
+            const dxpedLoc = lookupDXpeditionLocation(spot.dxCall);
+            if (dxpedLoc) {
+              dxLoc = dxpedLoc;
+            }
+          }
+
           // Fall back to HamQTH cached location (more accurate than prefix)
           // HamQTH uses home callsign — but for portable ops, prefix location wins
           if (!dxLoc && hamqthLocations[baseCallMap[spot.dxCall] || spot.dxCall]) {
diff --git a/server/routes/dxpeditions.js b/server/routes/dxpeditions.js
index e9df4430..5eab9b12 100644
--- a/server/routes/dxpeditions.js
+++ b/server/routes/dxpeditions.js
@@ -7,7 +7,11 @@ module.exports = function (app, ctx) {
   const { fetch, logDebug, logErrorOnce } = ctx;
 
   // DXpedition Calendar - fetches from NG3K ADXO plain text version
-  let dxpeditionCache = { data: null, timestamp: 0, maxAge: 30 * 60 * 1000 }; // 30 min cache
+  const dxpeditionCache = { data: null, timestamp: 0, maxAge: 30 * 60 * 1000 }; // 30 min cache
+
+  // Expose cache so dxcluster.js can cross-reference spotted callsigns
+  // against active DXpeditions for accurate entity coordinates
+  ctx.dxpeditionCache = dxpeditionCache;
 
   app.get('/api/dxpeditions', async (req, res) => {
     try {