init backend presensi

app/Modules/Geo/Services/GeoFenceService.php

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+<?php
+
+namespace App\Modules\Geo\Services;
+
+/**
+ * Geo Fence Service
+ * 
+ * Handles geofencing logic using Haversine formula for distance calculation.
+ */
+class GeoFenceService
+{
+    /**
+     * Earth's radius in meters
+     */
+    private const EARTH_RADIUS_METERS = 6371000;
+
+    /**
+     * Check if a point (latitude, longitude) is inside a zone
+     * 
+     * Uses Haversine formula to calculate distance between two points
+     * on Earth's surface and compares it to zone radius.
+     * 
+     * @param float $lat Latitude of the point to check
+     * @param float $lng Longitude of the point to check
+     * @param array $zone Zone data with 'latitude', 'longitude', and 'radius_meters'
+     * @return bool True if point is inside zone, false otherwise
+     */
+    public function isInsideZone(float $lat, float $lng, array $zone): bool
+    {
+        // Validate zone data
+        if (!isset($zone['latitude']) || !isset($zone['longitude']) || !isset($zone['radius_meters'])) {
+            return false;
+        }
+
+        $zoneLat = (float) $zone['latitude'];
+        $zoneLng = (float) $zone['longitude'];
+        $radiusMeters = (int) $zone['radius_meters'];
+
+        // Calculate distance using Haversine formula
+        $distance = $this->calculateHaversineDistance($lat, $lng, $zoneLat, $zoneLng);
+
+        // Check if distance is within radius
+        return $distance <= $radiusMeters;
+    }
+
+    /**
+     * Calculate distance between two points using Haversine formula
+     * 
+     * Haversine formula calculates the great-circle distance between
+     * two points on a sphere given their longitudes and latitudes.
+     * 
+     * @param float $lat1 Latitude of first point
+     * @param float $lng1 Longitude of first point
+     * @param float $lat2 Latitude of second point
+     * @param float $lng2 Longitude of second point
+     * @return float Distance in meters
+     */
+    private function calculateHaversineDistance(float $lat1, float $lng1, float $lat2, float $lng2): float
+    {
+        // Convert degrees to radians
+        $lat1Rad = deg2rad($lat1);
+        $lng1Rad = deg2rad($lng1);
+        $lat2Rad = deg2rad($lat2);
+        $lng2Rad = deg2rad($lng2);
+
+        // Calculate differences
+        $deltaLat = $lat2Rad - $lat1Rad;
+        $deltaLng = $lng2Rad - $lng1Rad;
+
+        // Haversine formula
+        $a = sin($deltaLat / 2) * sin($deltaLat / 2) +
+             cos($lat1Rad) * cos($lat2Rad) *
+             sin($deltaLng / 2) * sin($deltaLng / 2);
+
+        $c = 2 * atan2(sqrt($a), sqrt(1 - $a));
+
+        // Distance in meters
+        $distance = self::EARTH_RADIUS_METERS * $c;
+
+        return $distance;
+    }
+
+    /**
+     * Calculate distance between two points (public helper method)
+     * 
+     * @param float $lat1 Latitude of first point
+     * @param float $lng1 Longitude of first point
+     * @param float $lat2 Latitude of second point
+     * @param float $lng2 Longitude of second point
+     * @return float Distance in meters
+     */
+    public function calculateDistance(float $lat1, float $lng1, float $lat2, float $lng2): float
+    {
+        return $this->calculateHaversineDistance($lat1, $lng1, $lat2, $lng2);
+    }
+}