TX ID, UI fixes

tx_search.js

@@ -0,0 +1,127 @@
+const fetch = require('node-fetch');
+var fs = require('fs');
+
+let cachedData = {};
+
+let serverConfig = {
+    identification: {
+      lat: 0,
+      lon: 0
+    },
+  };
+  
+
+if(fs.existsSync('config.json')) {
+    const configFileContents = fs.readFileSync('config.json', 'utf8');
+    serverConfig = JSON.parse(configFileContents);
+  }
+
+let lastFetchTime = 0;
+const fetchInterval = 3000;
+
+// Fetch data from maps
+function fetchTx(freq, piCode, rdsPs) {
+    const now = Date.now();
+    
+    // Check if it's been at least 3 seconds since the last fetch and if the QTH is correct
+    if (now - lastFetchTime < fetchInterval || serverConfig.identification.lat.length < 2) {
+        return Promise.resolve();
+    }
+
+    lastFetchTime = now;
+
+    // Check if data for the given frequency is already cached
+    if (cachedData[freq]) {
+        return processData(cachedData[freq], piCode, rdsPs);
+    }
+
+    const url = "https://maps.fmdx.pl/controller.php?freq=" + freq;
+
+    return fetch(url)
+        .then(response => response.json())
+        .then(data => {
+            // Cache the fetched data for the specific frequency
+            cachedData[freq] = data;
+            return processData(data, piCode, rdsPs);
+        })
+        .catch(error => {
+            console.error("Error fetching data:", error);
+        });
+}
+
+function processData(data, piCode, rdsPs) {
+    let matchingStation = null;
+    let matchingCity = null;
+    let minDistance = Infinity;
+    let txAzimuth;
+
+    for (const cityId in data.locations) {
+        const city = data.locations[cityId];
+        if (city.stations) {
+            for (const station of city.stations) {
+                if (station.pi === piCode && station.ps.includes(rdsPs.replace(/ /g, '_'))) {
+                    const distance = haversine(serverConfig.identification.lat, serverConfig.identification.lon, city.lat, city.lon);
+                    if (distance.distanceKm < minDistance) {
+                        minDistance = distance.distanceKm;
+                        txAzimuth = distance.azimuth;
+                        matchingStation = station;
+                        matchingCity = city;
+                    }
+                }
+            }
+        }
+    }
+
+    if (matchingStation) {
+        return {
+            station: matchingStation.station.replace("R.", "Radio "),
+            pol: matchingStation.pol.toUpperCase(),
+            erp: matchingStation.erp,
+            city: matchingCity.name,
+            itu: matchingCity.itu,
+            distance: minDistance.toFixed(0),
+            azimuth: txAzimuth.toFixed(0),
+            foundStation: true
+        };
+    } else {
+        return;
+    }
+}
+
+function haversine(lat1, lon1, lat2, lon2) {
+    const R = 6371; // Earth radius in kilometers
+    const dLat = deg2rad(lat2 - lat1);
+    const dLon = deg2rad(lon2 - lon1);
+
+    const a =
+        Math.sin(dLat / 2) * Math.sin(dLat / 2) +
+        Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.sin(dLon / 2) * Math.sin(dLon / 2);
+
+    const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
+
+    // Distance in kilometers
+    const distance = R * c;
+
+    // Azimuth calculation
+    const y = Math.sin(dLon) * Math.cos(deg2rad(lat2));
+    const x = Math.cos(deg2rad(lat1)) * Math.sin(deg2rad(lat2)) -
+              Math.sin(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.cos(dLon);
+    const azimuth = Math.atan2(y, x);
+
+    // Convert azimuth from radians to degrees
+    const azimuthDegrees = (azimuth * 180 / Math.PI + 360) % 360;
+
+    return {
+        distanceKm: distance,
+        azimuth: azimuthDegrees
+    };
+}
+
+
+function deg2rad(deg) {
+    return deg * (Math.PI / 180);
+}
+
+module.exports = {
+    fetchTx
+};