Merge changes Idbdec7b3,I643dadac,I2f54e1d5,I2ead5203

* changes:
  Provide initial a1-pe-sim docs
  Initial code check-in for A1 Policy Enforcement Simulator
  Add basic .gitignore
  Add linters setup

1 files changed, 46 insertions, 0 deletions

diff --git a/src/main/java/org/onap/a1pesimulator/util/DistanceCalculator.java b/src/main/java/org/onap/a1pesimulator/util/DistanceCalculator.java
new file mode 100644
index 0000000..e487ed3
--- /dev/null
+++ b/src/main/java/org/onap/a1pesimulator/util/DistanceCalculator.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2021 Samsung Electronics
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package org.onap.a1pesimulator.util;
+
+public class DistanceCalculator {
+
+    private static final int EARTH_RADIUS = 6371; // Earth radius in KM
+
+    private DistanceCalculator() {
+    }
+
+    /**
+     * Calculate distance in KM using Haversine formula
+     */
+    public static double calculate(double startLat, double startLong, double endLat, double endLong) {
+        return haversine(startLat, startLong, endLat, endLong);
+    }
+
+    public static boolean isInRange(double startLat, double startLong, double endLat, double endLong, double range) {
+        double distance = calculate(startLat, startLong, endLat, endLong);
+        return distance < range;
+    }
+
+    private static double haversine(double startLat, double startLong, double endLat, double endLong) {
+        double dLat = Math.toRadians(endLat - startLat);
+        double dLon = Math.toRadians(endLong - startLong);
+        double startLatInRadians = Math.toRadians(startLat);
+        double endLatInRadians = Math.toRadians(endLat);
+
+        double a = Math.pow(Math.sin(dLat / 2), 2) + Math.pow(Math.sin(dLon / 2), 2) * Math.cos(startLatInRadians)
+                                                             * Math.cos(endLatInRadians);
+        double c = 2 * Math.asin(Math.sqrt(a));
+        return EARTH_RADIUS * c;
+    }
+}