Local database cache for TX ID

Locally cache transmitter database for TX ID and visually show when multiple matches on frontend

server/datahandler.js

@@ -416,7 +416,8 @@ function handleData(wss, receivedData, rdsWss) {
               azi: currentTx.azimuth,
               id: currentTx.id,
               pi: currentTx.pi,
-              reg: currentTx.reg
+              reg: currentTx.reg,
+              otherMatches: currentTx.others
           };
       }
   })

server/tx_search.js

@@ -2,7 +2,7 @@ const fetch = require('node-fetch');
 const { serverConfig } = require('./server_config');
 const consoleCmd = require('./console');
 
-let cachedData = {};
+let localDb = {};
 let lastFetchTime = 0;
 const fetchInterval = 1000;
 const esSwitchCache = {"lastCheck":0, "esSwitch":false};
@@ -28,6 +28,19 @@ if (typeof algorithms[algoSetting] !== 'undefined') {
     weightedDist = algorithms[algoSetting][1];
 }
 
+// IIFE to build the local TX DB cache from the endpoint.
+(async () => {
+    try {
+        consoleCmd.logInfo('Fetching transmitter database...');
+        const response = await fetch(`https://maps.fmdx.org/api?qth=${serverConfig.identification.lat},${serverConfig.identification.lon}`);
+        if (!response.ok) throw new Error(`HTTP error! Status: ${response.status}`);
+        localDb = await response.json();
+        consoleCmd.logInfo('Transmitter database successfully loaded.');
+    } catch (error) {
+        consoleCmd.logError("Failed to fetch transmitter database:", error);
+    }
+})();
+
 // Load the US states GeoJSON data
 async function loadUsStatesGeoJson() {
     if (!usStatesGeoJson) {
@@ -118,8 +131,28 @@ function validPsCompare(rdsPs, stationPs) {
     return false;
 }
 
+function evaluateStation(station) {
+    let esMode = checkEs();
+    let weightDistance = station.distanceKm;
+    if (esMode && station.distanceKm > 500) {
+        weightDistance = Math.abs(station.distanceKm - 1500);
+    }
+    let erp = station.erp && station.erp > 0 ? station.erp : 1;
+    let extraWeight = erp > 30 && station.distanceKm <= 500 ? 0.3 : 0;
+    let score = 0;
+    // If ERP is 1W, use a simpler formula to avoid zero-scoring.
+    if (erp === 0.001) {
+        score = erp / station.distanceKm;
+    } else {
+        score = ((10 * (Math.log10(erp * 1000))) / weightDistance) + extraWeight;
+    }
+    return score;
+}
+
 // Fetch data from maps
 async function fetchTx(freq, piCode, rdsPs) {
+    let match = null;
+    let multiMatches = [];
     const now = Date.now();
     freq = parseFloat(freq);
 
@@ -127,161 +160,74 @@ async function fetchTx(freq, piCode, rdsPs) {
     if (now - lastFetchTime < fetchInterval
         || serverConfig.identification.lat.length < 2
         || freq < 87
+        || Object.keys(localDb).length === 0
         || (currentPiCode == piCode && currentRdsPs == rdsPs)) {
         return Promise.resolve();
     }
 
     lastFetchTime = now;
+    if (serverConfig.webserver.rdsMode === true) await loadUsStatesGeoJson();
 
-    if (cachedData[freq]) {
-        return processData(cachedData[freq], piCode, rdsPs);
+    const filteredLocations = Object.values(localDb.locations)
+    .map(locData => ({
+      ...locData,
+      stations: locData.stations.filter(station => 
+        station.freq === freq &&
+        (station.pi === piCode.toUpperCase() || station.pireg === piCode.toUpperCase() ) &&
+        validPsCompare(rdsPs, station.ps)
+      )
+    }))
+    .filter(locData => locData.stations.length > 0); // Ensure locations with at least one matching station remain
+  
+    for (loc of filteredLocations) {
+      loc = Object.assign(loc, loc.stations[0]);
+      delete loc.stations;
+      const dist = haversine(serverConfig.identification.lat, serverConfig.identification.lon, loc.lat, loc.lon);
+      loc = Object.assign(loc, dist);
+      loc.detectedByPireg = (loc.pireg === piCode.toUpperCase());
     }
-
-    const url = "https://maps.fmdx.org/api/?freq=" + freq;
-
-    try {
-        // Try POST first
-        const postResponse = await fetch(url, {
-            method: 'POST',
-            headers: { 'Content-Type': 'application/json' },
-            body: JSON.stringify({ freq }), // You can omit or customize this
-            redirect: 'manual'
-        });
-
-        if (!postResponse.ok) throw new Error(`POST failed: ${postResponse.status}`);
-        const data = await postResponse.json();
-        cachedData[freq] = data;
-        if (serverConfig.webserver.rdsMode === true) await loadUsStatesGeoJson();
-        return processData(data, piCode, rdsPs);
-    } catch (postError) {
-        console.warn("POST failed, trying GET:", postError);
-
-        try {
-            const getResponse = await fetch(url, { redirect: 'manual' });
-            if (!getResponse.ok) throw new Error(`GET failed: ${getResponse.status}`);
-            const data = await getResponse.json();
-            cachedData[freq] = data;
-            if (serverConfig.webserver.rdsMode === true) await loadUsStatesGeoJson();
-            return processData(data, piCode, rdsPs);
-        } catch (getError) {
-            console.error("GET also failed:", getError);
-            return null;
+  
+    if (filteredLocations.length > 1) {
+        for (loc of filteredLocations) {
+            loc.score = evaluateStation(loc);
         }
+        match = filteredLocations.reduce((max, obj) => obj.score > max.score ? obj : max, filteredLocations[0]);
+        multiMatches = filteredLocations.filter(obj => obj !== match);
+    } else if (filteredLocations.length === 1) {
+        match = filteredLocations[0];
     }
-}
 
-async function processData(data, piCode, rdsPs) {
-    let matchingStation = null;
-    let matchingCity = null;
-    let maxScore = -Infinity;
-    let txAzimuth;
-    let maxDistance;
-    let esMode = checkEs();
-    let detectedByPireg = false;
-    currentPiCode = piCode;
-    currentRdsPs = rdsPs;
-
-    // First, collect all stations that match the piCode (without PS comparison).
-    let stationsForPi = [];
-    for (const cityId in data.locations) {
-        const city = data.locations[cityId];
-        if (city.stations) {
-            for (const station of city.stations) {
-                if (station.pi === piCode.toUpperCase() && !station.extra) {
-                    stationsForPi.push({ station, city });
-                }
+    if (match) {
+        if (match.itu === 'USA') {
+            const state = getStateForCoordinates(match.lat, match.lon);
+            if (state) {
+                match.state = state;  // Add state to matchingCity
             }
         }
-    }
-
-    if (stationsForPi.length > 0) {
-        for (const { station, city } of stationsForPi) {
-            if (station.ps && validPsCompare(rdsPs, station.ps)) {
-                const distance = haversine(serverConfig.identification.lat, serverConfig.identification.lon, city.lat, city.lon);
-                evaluateStation(station, city, distance);
-                detectedByPireg = false;
-            }
-        }
-    }
-
-    // Fallback: Check using pireg if no match was found using the piCode (with valid PS comparison)
-    if (!matchingStation) {
-        for (const cityId in data.locations) {
-            const city = data.locations[cityId];
-            if (city.stations) {
-                for (const station of city.stations) {
-                    if (
-                        station.pireg &&
-                        station.pireg.toUpperCase() === piCode.toUpperCase() &&
-                        !station.extra &&
-                        station.ps &&
-                        validPsCompare(rdsPs, station.ps)
-                    ) {
-                        const distance = haversine(serverConfig.identification.lat, serverConfig.identification.lon, city.lat, city.lon);
-                        evaluateStation(station, city, distance);
-                        detectedByPireg = true;
-                    }
-                }
-            }
-        }
-    }
-
-    // Determine the state if the city is in the USA
-    if (matchingStation && matchingCity.itu === 'USA') {
-        const state = getStateForCoordinates(matchingCity.lat, matchingCity.lon);
-        if (state) {
-            matchingCity.state = state;  // Add state to matchingCity
-        }
-    }
-
-    if (matchingStation) {
         return {
-            station: detectedByPireg
-            ? `${matchingStation.station.replace("R.", "Radio ")}${matchingStation.regname ? ' ' + matchingStation.regname : ''}`
-            : matchingStation.station.replace("R.", "Radio "),
-            pol: matchingStation.pol.toUpperCase(),
-            erp: matchingStation.erp && matchingStation.erp > 0 ? matchingStation.erp : '?',
-            city: matchingCity.name,
-            itu: matchingCity.state ? matchingCity.state + ', ' + matchingCity.itu : matchingCity.itu,
-            distance: maxDistance.toFixed(0),
-            azimuth: txAzimuth.toFixed(0),
-            id: matchingStation.id,
-            pi: matchingStation.pi,
+            station: match.detectedByPireg
+            ? `${match.station.replace("R.", "Radio ")}${match.regname ? ' ' + match.regname : ''}`
+            : match.station.replace("R.", "Radio "),
+            pol: match.pol.toUpperCase(),
+            erp: match.erp && match.erp > 0 ? match.erp : '?',
+            city: match.name,
+            itu: match.state ? match.state + ', ' + match.itu : match.itu,
+            distance: match.distanceKm.toFixed(0),
+            azimuth: match.azimuth.toFixed(0),
+            id: match.id,
+            pi: match.pi,
             foundStation: true,
-            reg: detectedByPireg,
+            reg: match.detectedByPireg,
+            others: multiMatches.length,
         };
     } else {
-        return;
-    }
-
-    function evaluateStation(station, city, distance) {
-        let weightDistance = distance.distanceKm;
-        if (esMode && distance.distanceKm > 500) {
-            weightDistance = Math.abs(distance.distanceKm - 1500);
-        }
-        let erp = station.erp && station.erp > 0 ? station.erp : 1;
-        let extraWeight = erp >= weightedErp && distance.distanceKm <= weightedDist ? 0.3 : 0;
-        let score = 0;
-        // If ERP is 1W, use a simpler formula to avoid zero-scoring.
-        if (erp === 0.001) {
-            score = erp / distance.distanceKm;
-        } else {
-            score = ((10 * Math.log10(erp * 1000)) / weightDistance) + extraWeight;
-        }
-        if (score > maxScore) {
-            maxScore = score;
-            txAzimuth = distance.azimuth;
-            matchingStation = station;
-            matchingCity = city;
-            maxDistance = distance.distanceKm;
-        }
+        return Promise.resolve();
     }
 }
 
 function checkEs() {
     const now = Date.now();
     const url = "https://fmdx.org/includes/tools/get_muf.php";
-    let esSwitch = false;
 
     if (now - esSwitchCache.lastCheck < esFetchInterval) {
         return esSwitchCache.esSwitch;

web/css/breadcrumbs.css

@@ -119,6 +119,14 @@ label {
     font-size: 20px;
 }
 
+#data-station-others span {
+    color: var(--color-main);
+    background: var(--color-4);
+    margin-left: 4px;
+    padding: 0 5px;
+    border-radius: 3px;
+}
+
 .highest-signal-container {
     margin-bottom: -20px !important;
 }

web/index.ejs

@@ -287,7 +287,7 @@
                   <span id="data-station-city" style="font-size: 16px;"></span> <span class="text-small">[<span id="data-station-itu"></span>]</span>
                 </h4>
                 <span class="text-small">
-                  <span id="data-station-erp"></span> kW [<span id="data-station-pol"></span>] <span class="text-gray">•</span> <span id="data-station-distance"></span> <span class="text-gray">•</span> <span id="data-station-azimuth"></span>
+                  <span id="data-station-erp"></span> kW [<span id="data-station-pol"></span>] <span class="text-gray">•</span> <span id="data-station-distance"></span> <span class="text-gray">•</span> <span id="data-station-azimuth"></span> <span id="data-station-others"></span>
                 </span>
               </div>
             </div>

web/js/main.js

@@ -976,6 +976,7 @@ const updateDataElements = throttle(function(parsedData) {
         updateTextIfChanged($('#data-station-itu'), parsedData.txInfo.itu);
         updateTextIfChanged($('#data-station-pol'), parsedData.txInfo.pol);
         updateHtmlIfChanged($('#data-station-azimuth'), parsedData.txInfo.azi + '°');
+        updateHtmlIfChanged($('#data-station-others'), parsedData.txInfo.otherMatches > 0 ? ('<span>+' + parsedData.txInfo.otherMatches +'</span>') : '');
         const txDistance = localStorage.getItem('imperialUnits') == "true" ? (Number(parsedData.txInfo.dist) * 0.621371192).toFixed(0) + " mi" : parsedData.txInfo.dist + " km";
         updateTextIfChanged($('#data-station-distance'), txDistance);
         $dataStationContainer.css('display', 'block');