Localize exception messages

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/src/main/java/com/wireguard/android/backend/Backend.java

@@ -57,7 +57,7 @@ public interface Backend {
      *
      * @return Type name
      */
-    String getTypeName();
+    String getTypePrettyName();
 
     /**
      * Determine version of underlying backend.

app/src/main/java/com/wireguard/android/backend/GoBackend.java

@@ -14,6 +14,7 @@ import android.support.v4.util.ArraySet;
 import android.util.Log;
 
 import com.wireguard.android.Application;
+import com.wireguard.android.R;
 import com.wireguard.android.activity.MainActivity;
 import com.wireguard.android.model.Tunnel;
 import com.wireguard.android.model.Tunnel.State;
@@ -26,6 +27,7 @@ import com.wireguard.config.Peer;
 
 import java.net.InetAddress;
 import java.util.Collections;
+import java.util.Locale;
 import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
@@ -93,8 +95,8 @@ public final class GoBackend implements Backend {
     }
 
     @Override
-    public String getTypeName() {
-        return "Go userspace";
+    public String getTypePrettyName() {
+        return context.getResources().getString(R.string.type_name_go_userspace);
     }
 
     @Override
@@ -110,7 +112,7 @@ public final class GoBackend implements Backend {
         if (state == originalState)
             return originalState;
         if (state == State.UP && currentTunnel != null)
-            throw new IllegalStateException("Only one userspace tunnel can run at a time");
+            throw new IllegalStateException(context.getResources().getString(R.string.multiple_tunnels_error));
         Log.d(TAG, "Changing tunnel " + tunnel.getName() + " to state " + state);
         setStateInternal(tunnel, tunnel.getConfig(), state);
         return getState(tunnel);
@@ -122,10 +124,10 @@ public final class GoBackend implements Backend {
         if (state == State.UP) {
             Log.i(TAG, "Bringing tunnel up");
 
-            Objects.requireNonNull(config, "Trying to bring up a tunnel with no config");
+            Objects.requireNonNull(config, context.getResources().getString(R.string.no_config_error));
 
             if (VpnService.prepare(context) != null)
-                throw new Exception("VPN service not authorized by user");
+                throw new Exception(context.getResources().getString(R.string.vpn_not_authed_error));
 
             final VpnService service;
             if (!vpnService.isDone())
@@ -134,7 +136,7 @@ public final class GoBackend implements Backend {
             try {
                 service = vpnService.get(2, TimeUnit.SECONDS);
             } catch (final TimeoutException e) {
-                throw new Exception("Unable to start Android VPN service", e);
+                throw new Exception(context.getResources().getString(R.string.vpn_start_error), e);
             }
 
             if (currentTunnelHandle != -1) {
@@ -172,12 +174,12 @@ public final class GoBackend implements Backend {
             builder.setBlocking(true);
             try (final ParcelFileDescriptor tun = builder.establish()) {
                 if (tun == null)
-                    throw new Exception("Unable to create tun device");
+                    throw new Exception(context.getResources().getString(R.string.tun_create_error));
                 Log.d(TAG, "Go backend v" + wgVersion());
                 currentTunnelHandle = wgTurnOn(tunnel.getName(), tun.detachFd(), goConfig);
             }
             if (currentTunnelHandle < 0)
-                throw new Exception("Unable to turn tunnel on (wgTurnOn return " + currentTunnelHandle + ')');
+                throw new Exception(String.format(Locale.getDefault(), context.getResources().getString(R.string.tunnel_on_error), currentTunnelHandle));
 
             currentTunnel = tunnel;
 

app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java

@@ -10,6 +10,7 @@ import android.support.annotation.Nullable;
 import android.util.Log;
 
 import com.wireguard.android.Application;
+import com.wireguard.android.R;
 import com.wireguard.android.model.Tunnel;
 import com.wireguard.android.model.Tunnel.State;
 import com.wireguard.android.model.Tunnel.Statistics;
@@ -36,9 +37,11 @@ public final class WgQuickBackend implements Backend {
     private static final String TAG = "WireGuard/" + WgQuickBackend.class.getSimpleName();
 
     private final File localTemporaryDir;
+    private final Context context;
 
     public WgQuickBackend(final Context context) {
         localTemporaryDir = new File(context.getCacheDir(), "tmp");
+        this.context = context;
     }
 
     @Override
@@ -84,8 +87,8 @@ public final class WgQuickBackend implements Backend {
     }
 
     @Override
-    public String getTypeName() {
-        return "Kernel module";
+    public String getTypePrettyName() {
+        return context.getResources().getString(R.string.type_name_kernel_module);
     }
 
     @Override
@@ -93,7 +96,7 @@ public final class WgQuickBackend implements Backend {
         final List<String> output = new ArrayList<>();
         if (Application.getRootShell()
                 .run(output, "cat /sys/module/wireguard/version") != 0 || output.isEmpty())
-            throw new Exception("Unable to determine kernel module version");
+            throw new Exception(context.getResources().getString(R.string.module_version_error));
         return output.get(0);
     }
 
@@ -125,6 +128,6 @@ public final class WgQuickBackend implements Backend {
         // noinspection ResultOfMethodCallIgnored
         tempFile.delete();
         if (result != 0)
-            throw new Exception("Unable to configure tunnel (wg-quick returned " + result + ')');
+            throw new Exception(context.getResources().getString(R.string.tunnel_config_error));
     }
 }