Implements Login API Call in DataRepository.

ui/src/main/java/com/wireguard/android/api/ApiConstants.java

@@ -2,4 +2,5 @@ package com.wireguard.android.api;
 
 public class ApiConstants {
     public static final String BASE_URL = "https://jtest2.bubblesecure.com:1443/api/";
+    public static final String LOGIN_URL = "auth/login";
 }

ui/src/main/java/com/wireguard/android/api/network/ClientApi.java

@@ -1,6 +1,20 @@
 package com.wireguard.android.api.network;
+
+import com.wireguard.android.api.ApiConstants;
+import com.wireguard.android.model.User;
+
+import java.util.Map;
+
+import retrofit2.Call;
+import retrofit2.http.FieldMap;
+import retrofit2.http.FormUrlEncoded;
+import retrofit2.http.POST;
+
 /**
   Interface for API Calls
  **/
 public interface ClientApi {
+    @FormUrlEncoded
+    @POST(ApiConstants.LOGIN_URL)
+    Call<User> login(@FieldMap Map<String,String> params);
 }

ui/src/main/java/com/wireguard/android/repository/DataRepository.java

@@ -2,10 +2,19 @@ package com.wireguard.android.repository;
 
 import com.wireguard.android.api.network.ClientApi;
 import com.wireguard.android.api.network.ClientService;
+import com.wireguard.android.api.network.NetworkBoundStatusResource;
+import com.wireguard.android.model.User;
+import com.wireguard.android.resource.StatusResource;
+import java.util.HashMap;
+import androidx.lifecycle.MutableLiveData;
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
 
 public class DataRepository {
     private static volatile DataRepository instance;
     private ClientApi clientApi;
+    public static final String NO_INTERNET_CONNECTION = "no_internet_connection";
 
     private DataRepository()
     {
@@ -26,4 +35,36 @@ public class DataRepository {
         return instance;
     }
 
+    public MutableLiveData<StatusResource<User>> login(final HashMap<String,String> params){
+        return new NetworkBoundStatusResource<User>(){
+
+            @Override protected void createCall() {
+                clientApi.login(params).enqueue(new Callback<User>() {
+                    @Override public void onResponse(final Call<User> call, final Response<User> response) {
+                        if(response.isSuccessful()) {
+                            setMutableLiveData(StatusResource.success());
+                        }
+                        else {
+                            String errorMessage = createErrorMessage(call,response);
+                            setMutableLiveData(StatusResource.error(errorMessage));
+                        }
+                    }
+
+                    @Override public void onFailure(final Call<User> call, final Throwable t) {
+                        if(t instanceof Exception){
+                            setMutableLiveData(StatusResource.error(NO_INTERNET_CONNECTION));
+                        }
+                    }
+                });
+            }
+        }.getMutableLiveData();
+    }
+
+
+    private String createErrorMessage(Call call, retrofit2.Response response) {
+        return "Error: User agent: " + System.getProperty("http.agent") + ", Request body: " + call.request().body() + ", URL: " +
+                call.request().url() + ", Code: " + response.code() + ", Message: " +
+                response.message();
+    }
+
 }