From d2b9359fee924bbe07e78b6c83d575d0978836dc Mon Sep 17 00:00:00 2001
From: Christian Weimann <christian@qx9.de>
Date: Sun, 9 Feb 2025 08:02:41 +0100
Subject: [PATCH] feat(helpers): add debounceFunction and distanceBetween

---
 utils/helpers.js | 51 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 utils/helpers.js

diff --git a/utils/helpers.js b/utils/helpers.js
new file mode 100644
index 0000000..f9d74c1
--- /dev/null
+++ b/utils/helpers.js
@@ -0,0 +1,51 @@
+// Load dependencies
+const { TimerMgr } = require('../utils');
+const tm = new TimerMgr();
+
+function debounceFunction(id, debounceTimeout, func, params) {
+    console.warn('debounce', id, debounceTimeout);
+
+    timeout = time.ZonedDateTime.now().plusNanos(debounceTimeout * 1000000);
+    
+    if (tm.hasTimer(id) && tm.isActive(id)) {
+        log.info(`Skip evaluation of function with id ${id} as function is already running. Reschedule timer`);
+        tm.reschedule(id, timeout);
+    } else {
+        log.info(`Create timer to execute function ${id}`);
+        if (tm.hasTimer(id)) {
+            tm.cancel(id);
+        }
+        tm.create(id, timeout, func, params);
+    }
+}
+
+function distanceBetween(locationA, locationB) {
+    const [lat1, lon1] = locationA.split(',').map(Number);
+    const [lat2, lon2] = locationB.split(',').map(Number);
+
+    const toRadians = (degree) => degree * (Math.PI / 180);
+    
+    const radLat1 = toRadians(lat1);
+    const radLon1 = toRadians(lon1);
+    const radLat2 = toRadians(lat2);
+    const radLon2 = toRadians(lon2);
+    
+    if (lat1 === lat2 && lon1 === lon2) return '0 m';
+
+    const dlon = radLon2 - radLon1;
+    const dlat = radLat2 - radLat1;
+
+    const a = Math.pow(Math.sin(dlat / 2), 2)
+            + Math.cos(radLat1) * Math.cos(radLat2)
+            * Math.pow(Math.sin(dlon / 2), 2);
+  
+    const c = 2 * Math.asin(Math.sqrt(a));
+    const r = 6371000; // Radius of earth in meters
+
+    return `${(c * r).toFixed()} m`;
+}
+
+module.exports = {
+    debounceFunction,
+    distanceBetween
+};
\ No newline at end of file