Implements login process when user is login starting Main Activity else Login Activity .

ui/src/main/java/com/wireguard/android/activity/LoginActivity.java

@@ -49,7 +49,7 @@ public class LoginActivity extends AppCompatActivity {
         final String inputPassword = password.getText().toString();
         data.put("username",username);
         data.put("password",inputPassword);
-        loginViewModel.login(data).observe(this, new Observer<StatusResource<User>>() {
+        loginViewModel.login(data,this).observe(this, new Observer<StatusResource<User>>() {
             @Override public void onChanged(final StatusResource<User> userStatusResource) {
                 switch (userStatusResource.status){
                     case SUCCESS:

ui/src/main/java/com/wireguard/android/activity/MainActivity.java

@@ -2,15 +2,25 @@ package com.wireguard.android.activity;
 
 import androidx.appcompat.app.AppCompatActivity;
 
+import android.content.Intent;
 import android.os.Bundle;
 
 import com.wireguard.android.R;
+import com.wireguard.android.util.UserStore;
 
 public class MainActivity extends AppCompatActivity {
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_main);
+        if("-1".equals(UserStore.getInstance(this).getUserResponse())) {
+            Intent intent = new Intent(this, LoginActivity.class);
+            startActivity(intent);
+            finish();
+        }
+        else
+        {
+            setContentView(R.layout.activity_main);
+        }
     }
 }

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

@@ -1,10 +1,14 @@
 package com.wireguard.android.repository;
 
+import android.content.Context;
+
 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 com.wireguard.android.util.UserStore;
+
 import java.util.HashMap;
 import androidx.lifecycle.MutableLiveData;
 import retrofit2.Call;
@@ -35,13 +39,15 @@ public class DataRepository {
         return instance;
     }
 
-    public MutableLiveData<StatusResource<User>> login(final HashMap<String, String> params){
+    public MutableLiveData<StatusResource<User>> login(final HashMap<String, String> params , Context context){
         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()) {
+                            String token = response.body().getToken();
+                            UserStore.getInstance(context).setUserResponse(token);
                             setMutableLiveData(StatusResource.success());
                         }
                         else {

ui/src/main/java/com/wireguard/android/viewmodel/LoginViewModel.java

@@ -1,5 +1,7 @@
 package com.wireguard.android.viewmodel;
 
+import android.content.Context;
+
 import com.wireguard.android.model.User;
 import com.wireguard.android.repository.DataRepository;
 import com.wireguard.android.resource.StatusResource;
@@ -10,7 +12,7 @@ import androidx.lifecycle.LiveData;
 import androidx.lifecycle.ViewModel;
 
 public class LoginViewModel extends ViewModel {
-    public LiveData<StatusResource<User>> login(HashMap<String,String> params){
-        return DataRepository.getRepositoryInstance().login(params);
+    public LiveData<StatusResource<User>> login(HashMap<String,String> params, Context context){
+        return DataRepository.getRepositoryInstance().login(params,context);
     }
 }