feat: lots of fixes

lib/util.dart

@@ -1,3 +1,5 @@
+import 'dart:math';
+
 String formatDuration(Duration duration) {
   final days = duration.inDays;
   final hours = duration.inHours.remainder(24);
@@ -16,3 +18,81 @@ String formatDuration(Duration duration) {
     return '$seconds second${plural(seconds)}';
   }
 }
+
+String formatDistance(int distanceInMeters) {
+  if (distanceInMeters < 1000) {
+    // If the distance is less than 1 kilometer, display it in meters.
+    return '${distanceInMeters}m';
+  } else {
+    // If the distance is 1 kilometer or more, display it in kilometers and meters.
+    final kilometers = distanceInMeters ~/ 1000; // Integer division to get whole kilometers.
+    final meters = distanceInMeters % 1000; // Remainder to get the remaining meters.
+    if (meters == 0) {
+      // If there are no remaining meters, display only kilometers.
+      return '${kilometers}km';
+    } else {
+      // If there are remaining meters, display both kilometers and meters.
+      return '${kilometers}km ${meters}m';
+    }
+  }
+}
+
+
+double degreesToRadians(double degrees) {
+  return degrees * (pi / 180);
+}
+
+double radiansToDegrees(double radians) {
+  return radians * (180 / pi);
+}
+
+double bearingBetween(double lat1, double lon1, double lat2, double lon2) {
+  var dLon = degreesToRadians(lon2 - lon1);
+  var y = sin(dLon) * cos(degreesToRadians(lat2));
+  var x = cos(degreesToRadians(lat1)) * sin(degreesToRadians(lat2)) -
+      sin(degreesToRadians(lat1)) * cos(degreesToRadians(lat2)) * cos(dLon);
+  var angle = atan2(y, x);
+  return (radiansToDegrees(angle) + 360) % 360;
+}
+
+double distanceBetween(
+    double lat1, double lon1, double lat2, double lon2, String unit) {
+  const earthRadius = 6371; // in km
+  // assuming earth is a perfect sphere(it's not)
+
+  // Convert degrees to radians
+  final lat1Rad = degreesToRadians(lat1);
+  final lon1Rad = degreesToRadians(lon1);
+  final lat2Rad = degreesToRadians(lat2);
+  final lon2Rad = degreesToRadians(lon2);
+
+  final dLat = lat2Rad - lat1Rad;
+  final dLon = lon2Rad - lon1Rad;
+
+  // Haversine formula
+  final a = pow(sin(dLat / 2), 2) +
+      cos(lat1Rad) * cos(lat2Rad) * pow(sin(dLon / 2), 2);
+  final c = 2 * atan2(sqrt(a), sqrt(1 - a));
+
+  final distance = earthRadius * c;
+
+  return toRequestedUnit(unit, distance);
+
+  // return distance; // in km
+}
+
+double toRequestedUnit(String unit, double distanceInKm) {
+  switch (unit) {
+    case 'kilometers':
+      return distanceInKm;
+    case 'meters':
+      return distanceInKm * 1000;
+    case 'miles':
+      return (distanceInKm * 1000) / 1609.344;
+    case 'yards':
+      return distanceInKm * 1093.61;
+    case '':
+      return distanceInKm;
+  }
+  return distanceInKm;
+}