From c1bd51eb48c27b8d8cf357445fde0b22c5b4087f Mon Sep 17 00:00:00 2001
From: fiatcode <fiatcode@noreply.codeberg.org>
Date: Thu, 30 Apr 2026 11:00:03 +0700
Subject: [PATCH] feat: add DistanceFilterProcessor with Haversine formula

---
 .../location/DistanceFilterProcessor.kt       | 97 +++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 android/app/src/main/kotlin/com/traccar/traccar_client/location/DistanceFilterProcessor.kt

diff --git a/android/app/src/main/kotlin/com/traccar/traccar_client/location/DistanceFilterProcessor.kt b/android/app/src/main/kotlin/com/traccar/traccar_client/location/DistanceFilterProcessor.kt
new file mode 100644
index 0000000..5e74019
--- /dev/null
+++ b/android/app/src/main/kotlin/com/traccar/traccar_client/location/DistanceFilterProcessor.kt
@@ -0,0 +1,97 @@
+package com.traccar.traccar_client.location
+
+import android.location.Location
+import kotlin.math.abs
+import kotlin.math.atan2
+import kotlin.math.cos
+import kotlin.math.sin
+import kotlin.math.sqrt
+
+data class FilterConfig(
+    val distanceFilter: Int = 75,
+    val intervalFilter: Int = 300,
+    val angleFilter: Int = 0
+)
+
+class DistanceFilterProcessor {
+    private var lastLatitude: Double? = null
+    private var lastLongitude: Double? = null
+    private var lastTimestamp: Long = 0
+    private var lastHeading: Float? = null
+
+    fun shouldAccept(location: Location, config: FilterConfig): Boolean {
+        val now = System.currentTimeMillis()
+
+        // Distance filter
+        if (config.distanceFilter > 0 && lastLatitude != null && lastLongitude != null) {
+            val distance = haversineDistance(lastLatitude!!, lastLongitude!!, location.latitude, location.longitude)
+            if (distance < config.distanceFilter) {
+                // Check interval as fallback
+                if (config.intervalFilter > 0) {
+                    val elapsed = (now - lastTimestamp) / 1000
+                    if (elapsed < config.intervalFilter) {
+                        return false
+                    }
+                } else {
+                    return false
+                }
+            }
+        }
+
+        // Interval filter (when distance filter is 0)
+        if (config.distanceFilter == 0 && config.intervalFilter > 0) {
+            val elapsed = (now - lastTimestamp) / 1000
+            if (elapsed < config.intervalFilter && lastTimestamp > 0) {
+                return false
+            }
+        }
+
+        // Angle filter
+        if (config.angleFilter > 0 && lastHeading != null && location.hasBearing()) {
+            val headingDelta = abs(location.bearing - lastHeading!!)
+            // Handle wrap-around at 360 degrees
+            val normalizedDelta = if (headingDelta > 180) 360 - headingDelta else headingDelta
+            if (normalizedDelta < config.angleFilter && lastTimestamp > 0) {
+                return false
+            }
+        }
+
+        // Update last known values
+        lastLatitude = location.latitude
+        lastLongitude = location.longitude
+        lastTimestamp = now
+        if (location.hasBearing()) {
+            lastHeading = location.bearing
+        }
+
+        return true
+    }
+
+    fun reset() {
+        lastLatitude = null
+        lastLongitude = null
+        lastTimestamp = 0
+        lastHeading = null
+    }
+
+    companion object {
+        /**
+         * Calculate distance between two coordinates using Haversine formula
+         * @return distance in meters
+         */
+        fun haversineDistance(lat1: Double, lon1: Double, lat2: Double, lon2: Double): Double {
+            val earthRadius = 6371000.0 // meters
+
+            val dLat = Math.toRadians(lat2 - lat1)
+            val dLon = Math.toRadians(lon2 - lon1)
+
+            val a = sin(dLat / 2) * sin(dLat / 2) +
+                    cos(Math.toRadians(lat1)) * cos(Math.toRadians(lat2)) *
+                    sin(dLon / 2) * sin(dLon / 2)
+
+            val c = 2 * atan2(sqrt(a), sqrt(1 - a))
+
+            return earthRadius * c
+        }
+    }
+}
\ No newline at end of file