add test and minor refactoring for gateway selection

app/build.gradle

@@ -159,6 +159,7 @@ dependencies {
   testImplementation 'org.powermock:powermock-module-junit4:1.7.3'
   testImplementation 'org.powermock:powermock-core:1.7.3'
   testImplementation 'org.powermock:powermock-module-junit4-rule:1.7.3'
+  testImplementation group: 'com.tngtech.java', name: 'junit-dataprovider', version: '1.10.0'
 
   androidTestImplementation 'org.mockito:mockito-core:2.8.9'
   androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'

app/src/main/java/se/leap/bitmaskclient/eip/GatewaySelector.java

@@ -2,7 +2,13 @@ package se.leap.bitmaskclient.eip;
 
 import android.util.Log;
 
-import java.util.*;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeMap;
+
+import static se.leap.bitmaskclient.utils.ConfigHelper.getCurrentTimezone;
 
 public class GatewaySelector {
     private final static String TAG = GatewaySelector.class.getSimpleName();
@@ -19,16 +25,14 @@ public class GatewaySelector {
         return closestGateway();
     }
 
-    public Gateway select(int nClosest) throws IndexOutOfBoundsException{
+    public Gateway select(int nClosest) {
         int i = 0;
         for (Map.Entry<Integer,Set<Gateway>> entrySet : offsets.entrySet()) {
-            Iterator<Gateway> iterator = entrySet.getValue().iterator();
-            while (iterator.hasNext()) {
-                Gateway gateway = iterator.next();
-                if (i == nClosest)  {
+            for (Gateway gateway : entrySet.getValue()) {
+                if (i == nClosest) {
                     return gateway;
                 }
-                i = i+1;
+                i = i + 1;
             }
         }
 
@@ -42,7 +46,7 @@ public class GatewaySelector {
 
     private TreeMap<Integer, Set<Gateway>> calculateOffsets() {
         TreeMap<Integer, Set<Gateway>> offsets = new TreeMap<Integer, Set<Gateway>>();
-        int localOffset = Calendar.getInstance().get(Calendar.ZONE_OFFSET) / 3600000;
+        int localOffset = getCurrentTimezone();
         for (Gateway gateway : gateways) {
             int dist = timezoneDistance(localOffset, gateway.getTimezone());
             Set<Gateway> set = (offsets.get(dist) != null) ?

app/src/main/java/se/leap/bitmaskclient/utils/ConfigHelper.java

@@ -39,6 +39,7 @@ import java.security.cert.X509Certificate;
 import java.security.interfaces.RSAPrivateKey;
 import java.security.spec.InvalidKeySpecException;
 import java.security.spec.PKCS8EncodedKeySpec;
+import java.util.Calendar;
 
 import se.leap.bitmaskclient.BuildConfig;
 import se.leap.bitmaskclient.ProviderAPI;
@@ -177,4 +178,8 @@ public class ConfigHelper {
     public static boolean preferAnonymousUsage() {
         return BuildConfig.priotize_anonymous_usage;
     }
+
+    public static int getCurrentTimezone() {
+        return Calendar.getInstance().get(Calendar.ZONE_OFFSET) / 3600000;
+    }
 }

app/src/test/java/se/leap/bitmaskclient/eip/GatewaySelectorTest.java

+package se.leap.bitmaskclient.eip;
+
+import com.tngtech.java.junit.dataprovider.DataProvider;
+import com.tngtech.java.junit.dataprovider.DataProviderRunner;
+import com.tngtech.java.junit.dataprovider.UseDataProvider;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+import org.powermock.modules.junit4.PowerMockRunnerDelegate;
+
+import java.io.IOException;
+import java.util.ArrayList;
+
+import se.leap.bitmaskclient.Provider;
+import se.leap.bitmaskclient.utils.ConfigHelper;
+
+import static junit.framework.Assert.assertEquals;
+import static junit.framework.Assert.assertTrue;
+import static org.powermock.api.mockito.PowerMockito.mockStatic;
+import static org.powermock.api.mockito.PowerMockito.when;
+import static se.leap.bitmaskclient.Constants.PROVIDER_PRIVATE_KEY;
+import static se.leap.bitmaskclient.Constants.PROVIDER_VPN_CERTIFICATE;
+import static se.leap.bitmaskclient.testutils.TestSetupHelper.getInputAsString;
+
+/**
+ * Created by cyberta on 18.12.18.
+ */
+@RunWith(PowerMockRunner.class)
+@PowerMockRunnerDelegate(DataProviderRunner.class)
+@PrepareForTest({ConfigHelper.class})
+public class GatewaySelectorTest {
+    public static final String TAG = GatewaySelectorTest.class.getSimpleName();
+
+    /**
+     * locations": {
+     "name": ""Frankfurt"",
+     "timezone": "+1"
+     },
+     ""Seattle, WA"__wa": {
+     "name": ""Seattle, WA", WA",
+     "timezone": "-7"
+     },
+     ""Moscow"": {
+     "country_code": "RU",
+     "hemisphere": "N",
+     "name": ""Moscow"",
+     "timezone": "+3"
+     },
+     ""Manila"": {
+     "country_code": "PH",
+     "hemisphere": "N",
+     "name": ""Manila"",
+     "timezone": "+8"
+     }
+     },
+     */
+
+
+    GatewaySelector gatewaySelector;
+    JSONObject eipDefinition;
+    ArrayList<Gateway> gatewayList = new ArrayList<>();
+
+    @Before
+    public void setup() throws IOException, JSONException {
+        mockStatic(ConfigHelper.class);
+        eipDefinition = new JSONObject(getInputAsString(getClass().getClassLoader().getResourceAsStream("eip-service-four-gateways.json")));
+        JSONArray gateways = eipDefinition.getJSONArray("gateways");
+        for (int i = 0; i < gateways.length(); i++) {
+            JSONObject gw = gateways.getJSONObject(i);
+            JSONObject secrets = secretsConfiguration();
+            Gateway aux = new Gateway(eipDefinition, secrets, gw);
+            gatewayList.add(aux);
+        }
+
+    }
+
+    private JSONObject secretsConfiguration() throws IOException, JSONException {
+        JSONObject result = new JSONObject();
+        result.put(Provider.CA_CERT, getInputAsString(getClass().getClassLoader().getResourceAsStream("riseup.net.pem")));
+        result.put(PROVIDER_PRIVATE_KEY, getInputAsString(getClass().getClassLoader().getResourceAsStream("private_rsa_key.pem")));
+        result.put(PROVIDER_VPN_CERTIFICATE, getInputAsString(getClass().getClassLoader().getResourceAsStream("riseup.net.vpn_cert.pem")));
+        return result;
+    }
+
+    @DataProvider
+    public static Object[][] dataProviderTimezones() {
+        // @formatter:off
+        return new Object[][] {
+                //{ -12,  "Seattle, WA" }
+                { -11,  "Seattle, WA" },
+                { -10, "Seattle, WA" },
+                { -9, "Seattle, WA" },
+                { -8, "Seattle, WA" },
+                { -7, "Seattle, WA" }, // <-"Seattle, WA"
+                { -6, "Seattle, WA" },
+                { -5, "Seattle, WA" },
+                { -4, "Seattle, WA" },
+               // { -3, "Seattle, WA" },
+                { -2, "Frankfurt" },
+                { -1, "Frankfurt" },
+                { 0, "Frankfurt" },
+                { 1, "Frankfurt" }, // <- "Frankfurt"
+               // { 2, "Moscow" },
+                { 3, "Moscow" }, // <- "Moscow"
+                { 4, "Moscow" },
+                { 5, "Moscow" },
+                { 6, "Manila" },
+                { 7, "Manila" },
+                { 8, "Manila" }, // <- "Manila"
+                { 9, "Manila" },
+                { 10, "Manila" },
+                { 11, "Manila" },
+                { 12, "Manila" }
+        };
+        // @formatter:on
+    }
+
+    @DataProvider
+    public static Object[][] dataProviderSameDistanceTimezones() {
+        // @formatter:off
+        return new Object[][] {
+                { -12,  "Seattle, WA", "Manila" },
+                { -3, "Seattle, WA", "Frankfurt" },
+                { 2, "Moscow", "Frankfurt" },
+
+        };
+        // @formatter:on
+    }
+
+    @Test
+    @UseDataProvider("dataProviderTimezones")
+    public void testSelect(int timezone, String expected) {
+        when(ConfigHelper.getCurrentTimezone()).thenReturn(timezone);
+        gatewaySelector = new GatewaySelector(gatewayList);
+        assertEquals(expected, gatewaySelector.select().getName());
+    }
+
+    @Test
+    @UseDataProvider("dataProviderSameDistanceTimezones")
+    public void testSelectSameTimezoneDistance(int timezone, String expected1, String expected2) {
+        when(ConfigHelper.getCurrentTimezone()).thenReturn(timezone);
+        gatewaySelector = new GatewaySelector(gatewayList);
+        assertTrue(gatewaySelector.select().getName().equals(expected1) || gatewaySelector.select().getName().equals(expected2));
+    }
+
+    @Test
+    @UseDataProvider("dataProviderSameDistanceTimezones")
+    public void testNClostest_SameTimezoneDistance_chooseGatewayWithSameDistance(int timezone, String expected1, String expected2) {
+        when(ConfigHelper.getCurrentTimezone()).thenReturn(timezone);
+        gatewaySelector = new GatewaySelector(gatewayList);
+        ArrayList<String> gateways = new ArrayList<>();
+        gateways.add(gatewaySelector.select(0).getName());
+        gateways.add(gatewaySelector.select(1).getName());
+
+        assertTrue(gateways.contains(expected1) && gateways.contains(expected2));
+
+    }
+
+    @Test
+    public void testNClostest_OneTimezonePerSet_choseSecondClosestTimezone() {
+        when(ConfigHelper.getCurrentTimezone()).thenReturn(-4);
+        gatewaySelector = new GatewaySelector(gatewayList);
+
+        assertTrue("Frankfurt".equals(gatewaySelector.select(1).getName()));
+    }
+}
\ No newline at end of file

app/src/test/resources/eip-service-four-gateways.json

+{
+  "gateways": [
+    {
+      "capabilities": {
+        "adblock": false,
+        "filter_dns": false,
+        "limited": false,
+        "ports": [
+          "443"
+        ],
+        "protocols": [
+          "tcp",
+          "udp"
+        ],
+        "transport": [
+          "openvpn"
+        ],
+        "user_ips": false
+      },
+      "host": "millipede.demo.bitmask.net",
+      "ip_address": "198.252.153.84",
+      "location": "seattle__wa"
+    },
+    {
+      "capabilities": {
+        "adblock": false,
+        "filter_dns": false,
+        "limited": false,
+        "ports": [
+          "443"
+        ],
+        "protocols": [
+          "tcp",
+          "udp"
+        ],
+        "transport": [
+          "openvpn"
+        ],
+        "user_ips": false
+      },
+      "host": "otter.demo.bitmask.net",
+      "ip_address": "46.165.242.169",
+      "location": "frankfurt"
+    },
+    {
+      "capabilities": {
+        "adblock": false,
+        "filter_dns": false,
+        "limited": false,
+        "ports": [
+          "443"
+        ],
+        "protocols": [
+          "tcp",
+          "udp"
+        ],
+        "transport": [
+          "openvpn"
+        ],
+        "user_ips": false
+      },
+      "host": "orca.demo.bitmask.net",
+      "ip_address": "46.172.242.101",
+      "location": "moscow"
+    },
+    {
+      "capabilities": {
+        "adblock": false,
+        "filter_dns": false,
+        "limited": false,
+        "ports": [
+          "443"
+        ],
+        "protocols": [
+          "tcp",
+          "udp"
+        ],
+        "transport": [
+          "openvpn"
+        ],
+        "user_ips": false
+      },
+      "host": "duck.demo.bitmask.net",
+      "ip_address": "104.165.142.132",
+      "location": "manila"
+    }
+  ],
+  "locations": {
+    "seattle__wa": {
+      "country_code": "US",
+      "hemisphere": "N",
+      "name": "Seattle, WA",
+      "timezone": "-7"
+    },
+    "frankfurt": {
+      "country_code": "DE",
+      "hemisphere": "N",
+      "name": "Frankfurt",
+      "timezone": "+1"
+    },
+    "moscow": {
+      "country_code": "RU",
+      "hemisphere": "N",
+      "name": "Moscow",
+      "timezone": "+3"
+    },
+    "manila": {
+      "country_code": "PH",
+      "hemisphere": "N",
+      "name": "Manila",
+      "timezone": "+8"
+    }
+  },
+  "openvpn_configuration": {
+    "auth": "SHA1",
+    "cipher": "AES-128-CBC",
+    "keepalive": "10 30",
+    "tls-cipher": "DHE-RSA-AES128-SHA",
+    "tun-ipv6": true
+  },
+  "serial": 1,
+  "version": 1
+}
\ No newline at end of file