Refactored the code in subscription management.

-This commit addresses an improvement to code redundancy and repetition.

Testing:
- Verified successful installation on multiple environments.

components/application-mgt/io.entgra.device.mgt.core.application.mgt.common/src/main/java/io/entgra/device/mgt/core/application/mgt/common/services/SubscriptionManager.java

@@ -252,7 +252,6 @@ public interface SubscriptionManager {
     SubscriptionResponse getStatusBaseSubscriptions(SubscriptionInfo subscriptionInfo, int limit, int offset)
             throws ApplicationManagementException;
 
-
     /**
      * Get subscription statistics related data describes by the {@link SubscriptionInfo}
      * @param subscriptionInfo {@link SubscriptionInfo}

components/application-mgt/io.entgra.device.mgt.core.application.mgt.core/src/main/java/io/entgra/device/mgt/core/application/mgt/core/impl/SubscriptionManagerImpl.java

@@ -19,13 +19,42 @@
 package io.entgra.device.mgt.core.application.mgt.core.impl;
 
 import com.google.gson.Gson;
-import io.entgra.device.mgt.core.application.mgt.common.*;
+import io.entgra.device.mgt.core.application.mgt.common.ApplicationInstallResponse;
-import io.entgra.device.mgt.core.application.mgt.common.dto.*;
+import io.entgra.device.mgt.core.application.mgt.common.ApplicationSubscriptionInfo;
+import io.entgra.device.mgt.core.application.mgt.common.ApplicationType;
+import io.entgra.device.mgt.core.application.mgt.common.CategorizedSubscriptionResult;
+import io.entgra.device.mgt.core.application.mgt.common.DeviceSubscription;
+import io.entgra.device.mgt.core.application.mgt.common.DeviceSubscriptionData;
+import io.entgra.device.mgt.core.application.mgt.common.DeviceSubscriptionFilterCriteria;
+import io.entgra.device.mgt.core.application.mgt.common.DeviceTypes;
+import io.entgra.device.mgt.core.application.mgt.common.ExecutionStatus;
+import io.entgra.device.mgt.core.application.mgt.common.SubAction;
+import io.entgra.device.mgt.core.application.mgt.common.SubscribingDeviceIdHolder;
+import io.entgra.device.mgt.core.application.mgt.common.SubscriptionEntity;
+import io.entgra.device.mgt.core.application.mgt.common.SubscriptionInfo;
+import io.entgra.device.mgt.core.application.mgt.common.SubscriptionMetadata;
+import io.entgra.device.mgt.core.application.mgt.common.SubscriptionResponse;
+import io.entgra.device.mgt.core.application.mgt.common.SubscriptionStatistics;
+import io.entgra.device.mgt.core.application.mgt.common.SubscriptionType;
+import io.entgra.device.mgt.core.application.mgt.common.dto.ApplicationDTO;
+import io.entgra.device.mgt.core.application.mgt.common.dto.ApplicationPolicyDTO;
+import io.entgra.device.mgt.core.application.mgt.common.dto.ApplicationReleaseDTO;
+import io.entgra.device.mgt.core.application.mgt.common.dto.CategorizedSubscriptionCountsDTO;
+import io.entgra.device.mgt.core.application.mgt.common.dto.DeviceOperationDTO;
+import io.entgra.device.mgt.core.application.mgt.common.dto.DeviceSubscriptionDTO;
+import io.entgra.device.mgt.core.application.mgt.common.dto.ScheduledSubscriptionDTO;
+import io.entgra.device.mgt.core.application.mgt.common.dto.SubscriptionStatisticDTO;
+import io.entgra.device.mgt.core.application.mgt.common.dto.VppAssetDTO;
+import io.entgra.device.mgt.core.application.mgt.common.dto.VppUserDTO;
 import io.entgra.device.mgt.core.application.mgt.common.services.VPPApplicationManager;
 import io.entgra.device.mgt.core.application.mgt.core.dao.ApplicationReleaseDAO;
 import io.entgra.device.mgt.core.application.mgt.core.dao.VppApplicationDAO;
 import io.entgra.device.mgt.core.application.mgt.core.exception.BadRequestException;
 import io.entgra.device.mgt.core.application.mgt.core.util.SubscriptionManagementHelperUtil;
+import io.entgra.device.mgt.core.device.mgt.common.Device;
+import io.entgra.device.mgt.core.device.mgt.common.DeviceIdentifier;
+import io.entgra.device.mgt.core.device.mgt.common.EnrolmentInfo;
+import io.entgra.device.mgt.core.device.mgt.common.MDMAppConstants;
 import io.entgra.device.mgt.core.device.mgt.common.PaginationRequest;
 import io.entgra.device.mgt.core.device.mgt.common.PaginationResult;
 import io.entgra.device.mgt.core.device.mgt.core.DeviceManagementConstants;
@@ -70,7 +99,6 @@ import io.entgra.device.mgt.core.application.mgt.core.util.ConnectionManagerUtil
 import io.entgra.device.mgt.core.application.mgt.core.util.Constants;
 import io.entgra.device.mgt.core.application.mgt.core.util.HelperUtil;
 import io.entgra.device.mgt.core.application.mgt.core.util.OAuthUtils;
-import io.entgra.device.mgt.core.device.mgt.common.*;
 import io.entgra.device.mgt.core.device.mgt.common.app.mgt.App;
 import io.entgra.device.mgt.core.device.mgt.common.app.mgt.MobileAppTypes;
 import io.entgra.device.mgt.core.device.mgt.common.app.mgt.android.CustomApplication;
@@ -103,7 +131,16 @@ import java.net.URL;
 import java.security.KeyManagementException;
 import java.security.KeyStoreException;
 import java.security.NoSuchAlgorithmException;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Properties;
+import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.stream.Collectors;
 
@@ -165,7 +202,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
             // Only for iOS devices
             int tenantId = PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantId(true);
             // Ignore checking device type if app is a web clip
-            if(!applicationDTO.getType().equals("WEB_CLIP")){
+            if (!applicationDTO.getType().equals("WEB_CLIP")) {
                 if (DeviceTypes.IOS.toString().equalsIgnoreCase(APIUtil.getDeviceTypeData(applicationDTO
                         .getDeviceTypeId()).getName())) {
                     // TODO: replace getAssetByAppId with the correct one in DAO
@@ -495,7 +532,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
      * @throws ApplicationManagementException if error occurred while getting Application subscription info
      */
     private <T> ApplicationSubscriptionInfo getAppSubscriptionInfo(ApplicationDTO applicationDTO, String subType,
-            List<T> params) throws ApplicationManagementException {
+                                                                   List<T> params) throws ApplicationManagementException {
 
         DeviceManagementProviderService deviceManagementProviderService = HelperUtil
                 .getDeviceManagementProviderService();
@@ -542,7 +579,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
                         String username = (String) param;
                         subscribers.add(username);
                         devices.addAll(deviceManagementProviderService.getDevicesOfUser(username,
-                                allowingDeviceStatuses, false  ));
+                                allowingDeviceStatuses, false));
                     }
                 } else {
                     if (SubscriptionType.ROLE.toString().equalsIgnoreCase(subType)) {
@@ -608,7 +645,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
      * @throws ApplicationManagementException if error occurred while getting or updating subscription data.
      */
     private void updateSubscriptionsForEntInstall(int applicationReleaseId, List<Integer> appSubscribingDeviceIds,
-            List<Integer> appReSubscribingDeviceIds, List<String> params, String subType, String action)
+                                                  List<Integer> appReSubscribingDeviceIds, List<String> params, String subType, String action)
             throws ApplicationManagementException {
         int tenantId = PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantId(true);
         String username = PrivilegedCarbonContext.getThreadLocalCarbonContext().getUsername();
@@ -679,14 +716,14 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
     /**
      * This method perform given action (i.e APP INSTALL or APP UNINSTALL) on given set of devices.
      *
-     * @param deviceType     Application supported device type.
+     * @param deviceType                     Application supported device type.
-     * @param devices        List of devices that action is triggered.
+     * @param devices                        List of devices that action is triggered.
-     * @param applicationDTO Application data
+     * @param applicationDTO                 Application data
-     * @param subType        Subscription type (i.e USER, ROLE, GROUP or DEVICE)
+     * @param subType                        Subscription type (i.e USER, ROLE, GROUP or DEVICE)
-     * @param subscribers    Subscribers
+     * @param subscribers                    Subscribers
-     * @param action         Performing action. (i.e INSTALL or UNINSTALL)
+     * @param action                         Performing action. (i.e INSTALL or UNINSTALL)
      * @param isOperationReExecutingDisabled To prevent adding the application subscribing operation to devices that are
-     *                                      already subscribed application successfully.
+     *                                       already subscribed application successfully.
      * @return {@link ApplicationInstallResponse}
      * @throws ApplicationManagementException if error occurred when adding operation on device or updating subscription
      *                                        data.
@@ -905,7 +942,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
      * @throws ApplicationManagementException if error occurred while getting or updating subscription data.
      */
     private void updateSubscriptions(int applicationReleaseId, List<Activity> activities,
-            SubscribingDeviceIdHolder subscribingDeviceIdHolder, List<String> params, String subType, String action)
+                                     SubscribingDeviceIdHolder subscribingDeviceIdHolder, List<String> params, String subType, String action)
             throws ApplicationManagementException {
         int tenantId = PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantId(true);
         String username = PrivilegedCarbonContext.getThreadLocalCarbonContext().getUsername();
@@ -981,7 +1018,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
      * @throws ApplicationManagementDAOException if error occurred while updating or inserting subscriber entities
      */
     private void updateBulkSubscribers(int applicationReleaseId, List<String> params, String subType, String action,
-            int tenantId, String username) throws ApplicationManagementDAOException {
+                                       int tenantId, String username) throws ApplicationManagementDAOException {
         List<String> subscribedEntities = new ArrayList<>();
         if (SubscriptionType.USER.toString().equalsIgnoreCase(subType)) {
             subscribedEntities = subscriptionDAO.getAppSubscribedUserNames(params, applicationReleaseId, tenantId);
@@ -1067,7 +1104,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
      * @throws ApplicationManagementException if found an invalid device.
      */
     private Activity addAppOperationOnDevices(ApplicationDTO applicationDTO,
-            List<DeviceIdentifier> deviceIdentifierList, String deviceType, String action, Properties properties)
+                                              List<DeviceIdentifier> deviceIdentifierList, String deviceType, String action, Properties properties)
             throws ApplicationManagementException {
         DeviceManagementProviderService deviceManagementProviderService = HelperUtil
                 .getDeviceManagementProviderService();
@@ -1217,10 +1254,11 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
 
     /**
      * Get the bundle id of the iOS public application.
+     *
      * @param appId Application Id
      * @return {@link String} bundle Id
      * @throws ApplicationManagementException if error occurred while getting the bundle if of the requesting public
-     * application
+     *                                        application
      */
     private String getBundleId(String appId) throws ApplicationManagementException {
         try {
@@ -1261,7 +1299,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
             throws SubscriptionManagementException {
         try {
             int tenantId = PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantId(true);
-            List<Integer> operationIds =  getOperationIdsForSubId(subId, tenantId);
+            List<Integer> operationIds = getOperationIdsForSubId(subId, tenantId);
             APIUtil.getApplicationManager().updateSubStatus(deviceId, operationIds, status);
         } catch (DBConnectionException e) {
             String msg = "Error occurred while observing the database connection to get operation Ids for " + subId;
@@ -1309,7 +1347,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
 
     public int installEnrollmentApplications(ApplicationPolicyDTO applicationPolicyDTO)
             throws ApplicationManagementException {
-        String requestUrl =null;
+        String requestUrl = null;
         try {
             requestUrl = Constants.ApplicationInstall.ENROLLMENT_APP_INSTALL_PROTOCOL + System
                     .getProperty(Constants.ApplicationInstall.IOT_GATEWAY_HOST) + Constants.ApplicationInstall.COLON
@@ -1320,7 +1358,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
             HttpPost httpPost = new HttpPost(requestUrl);
 
             StringEntity stringEntity = new StringEntity(payload, Constants.ApplicationInstall.ENCODING);
-            httpPost.addHeader("Content-Type",MediaType.APPLICATION_JSON);
+            httpPost.addHeader("Content-Type", MediaType.APPLICATION_JSON);
             httpPost.setEntity(stringEntity);
             return invokeIOTCoreAPI(httpPost);
         } catch (UserStoreException e) {
@@ -1346,7 +1384,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
             builder.loadTrustMaterial(null, new TrustSelfSignedStrategy());
             SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(builder.build());
             return HttpClients.custom().setSSLSocketFactory(sslsf).useSystemProperties().build();
-        }  catch (NoSuchAlgorithmException e) {
+        } catch (NoSuchAlgorithmException e) {
             String msg = "Failed while building the http client for EntApp installation. " +
                     "Used SSL algorithm not available";
             log.error(msg, e);
@@ -1674,17 +1712,18 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
 
     /**
      * Get subscription data describes by {@link SubscriptionInfo} entity
+     *
      * @param subscriptionInfo {@link SubscriptionInfo}
-     * @param limit Limit value
+     * @param limit            Limit value
-     * @param offset Offset value
+     * @param offset           Offset value
      * @return {@link SubscriptionResponse}
      * @throws ApplicationManagementException Throws when error encountered while getting subscription data
      */
-
     @Override
     public SubscriptionResponse getSubscriptions(SubscriptionInfo subscriptionInfo, int limit, int offset)
             throws ApplicationManagementException {
-        final boolean isUnsubscribe = Objects.equals(SubscriptionMetadata.SUBSCRIPTION_STATUS_UNSUBSCRIBED, subscriptionInfo.getSubscriptionStatus());
+        final boolean isUnsubscribe = Objects.equals(SubscriptionMetadata.SUBSCRIPTION_STATUS_UNSUBSCRIBED,
+                subscriptionInfo.getSubscriptionStatus());
         final int tenantId = PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantId();
         try {
             ConnectionManagerUtil.openDBConnection();
@@ -1702,13 +1741,15 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
                 int subscriptionCount = isUnsubscribe ? subscriptionDAO.getGroupUnsubscriptionCount(applicationReleaseDTO.getId(), tenantId) :
                         subscriptionDAO.getGroupSubscriptionCount(applicationReleaseDTO.getId(), tenantId);
                 return new SubscriptionResponse(subscriptionInfo.getApplicationUUID(), subscriptionCount, subscriptionEntities);
-            } if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.ROLE)){
+            }
+            if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.ROLE)) {
                 List<SubscriptionEntity> subscriptionEntities = subscriptionDAO.
                         getRoleSubscriptionsByAppReleaseID(applicationReleaseDTO.getId(), isUnsubscribe, tenantId, offset, limit);
                 int subscriptionCount = isUnsubscribe ? subscriptionDAO.getRoleUnsubscriptionCount(applicationReleaseDTO.getId(), tenantId) :
                         subscriptionDAO.getRoleSubscriptionCount(applicationReleaseDTO.getId(), tenantId);
                 return new SubscriptionResponse(subscriptionInfo.getApplicationUUID(), subscriptionCount, subscriptionEntities);
-            } if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.USER)){
+            }
+            if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.USER)) {
                 List<SubscriptionEntity> subscriptionEntities = subscriptionDAO.
                         getUserSubscriptionsByAppReleaseID(applicationReleaseDTO.getId(), isUnsubscribe, tenantId, offset, limit);
                 int subscriptionCount = isUnsubscribe ? subscriptionDAO.getUserUnsubscriptionCount(applicationReleaseDTO.getId(), tenantId) :
@@ -1717,7 +1758,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
             } else {
                 return new SubscriptionResponse(subscriptionInfo.getApplicationUUID(), Collections.emptyList());
             }
-            } catch (DBConnectionException | ApplicationManagementDAOException e) {
+        } catch (DBConnectionException | ApplicationManagementDAOException e) {
             String msg = "Error encountered while connecting to the database";
             log.error(msg, e);
             throw new ApplicationManagementException(msg, e);
@@ -1728,17 +1769,18 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
 
     /**
      * Retrieves subscription statistics described by the {@link SubscriptionInfo} entity.
+     *
      * @param subscriptionInfo The {@link SubscriptionInfo} containing details about the subscription type and identifier.
      * @return {@link SubscriptionStatistics} The subscription statistics for the specified subscription type and identifier.
      * @throws ApplicationManagementException Throws when an error is encountered while getting subscription statistics.
      */
-
     public SubscriptionStatistics getSubscriptionStatistics(SubscriptionInfo subscriptionInfo)
             throws ApplicationManagementException {
-        if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.DEVICE)){
+        if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.DEVICE)) {
             return null;
         }
-        final boolean isUnsubscribe = Objects.equals(SubscriptionMetadata.SUBSCRIPTION_STATUS_UNSUBSCRIBED, subscriptionInfo.getSubscriptionStatus());
+        final boolean isUnsubscribe = Objects.equals(SubscriptionMetadata.SUBSCRIPTION_STATUS_UNSUBSCRIBED,
+                subscriptionInfo.getSubscriptionStatus());
         int tenantId = PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantId();
         try {
             ConnectionManagerUtil.openDBConnection();
@@ -1751,29 +1793,31 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
                 throw new NotFoundException(msg);
             }
             if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.GROUP)) {
-                List<Device> devices = HelperUtil.getGroupManagementProviderService().
+                return SubscriptionManagementHelperUtil.getSubscriptionStatistics(
-                        getAllDevicesOfGroup(subscriptionInfo.getIdentifier(), false);
+                        subscriptionDAO.getSubscriptionStatistic(
-                List<Integer> deviceIdsOwnByGroup = devices.stream().map(Device::getId).collect(Collectors.toList());
+                                HelperUtil.getGroupManagementProviderService()
-                SubscriptionStatisticDTO subscriptionStatisticDTO = subscriptionDAO.
+                                        .getAllDevicesOfGroup(subscriptionInfo.getIdentifier(), false)
-                        getSubscriptionStatistic(deviceIdsOwnByGroup, isUnsubscribe, tenantId, applicationReleaseDTO.getId());
+                                        .stream().map(Device::getId).collect(Collectors.toList()),
-                int allDeviceCount = HelperUtil.getGroupManagementProviderService().getDeviceCount(subscriptionInfo.getIdentifier());
+                                isUnsubscribe, tenantId, applicationReleaseDTO.getId()),
-                return SubscriptionManagementHelperUtil.getSubscriptionStatistics(subscriptionStatisticDTO, allDeviceCount);
+                        HelperUtil.getGroupManagementProviderService().getDeviceCount(subscriptionInfo.getIdentifier())
-            } if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.ROLE)){
+                );
-                List<Integer> deviceIdsOwnByRole = getDeviceIdsOwnByRole(subscriptionInfo.getIdentifier(), tenantId);
+            }
-                SubscriptionStatisticDTO subscriptionStatisticDTO = subscriptionDAO.
+            if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.ROLE)) {
-                        getSubscriptionStatistic(deviceIdsOwnByRole, isUnsubscribe, tenantId, applicationReleaseDTO.getId());
+                return SubscriptionManagementHelperUtil.getSubscriptionStatistics(subscriptionDAO.getSubscriptionStatistic(
-                int allDeviceCount = deviceIdsOwnByRole.size();
+                        getDeviceIdsOwnByRole(subscriptionInfo.getIdentifier(), tenantId), isUnsubscribe, tenantId,
-                return SubscriptionManagementHelperUtil.getSubscriptionStatistics(subscriptionStatisticDTO, allDeviceCount);
+                        applicationReleaseDTO.getId()
-            } if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.USER)){
+                ), getDeviceIdsOwnByRole(subscriptionInfo.getIdentifier(), tenantId).size());
-                List<Integer> deviceIdsOwnByUser = getDeviceIdsOwnByUser(subscriptionInfo.getIdentifier());
+            }
-                SubscriptionStatisticDTO subscriptionStatisticDTO = subscriptionDAO.
+            if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.USER)) {
-                        getSubscriptionStatistic(deviceIdsOwnByUser, isUnsubscribe, tenantId, applicationReleaseDTO.getId());
+                return SubscriptionManagementHelperUtil.getSubscriptionStatistics(
-                int allDeviceCount = deviceIdsOwnByUser.size();
+                        subscriptionDAO.getSubscriptionStatistic(getDeviceIdsOwnByUser(subscriptionInfo.getIdentifier()),
-                return SubscriptionManagementHelperUtil.getSubscriptionStatistics(subscriptionStatisticDTO, allDeviceCount);
+                                isUnsubscribe, tenantId, applicationReleaseDTO.getId()),
+                        getDeviceIdsOwnByUser(subscriptionInfo.getIdentifier()).size()
+                );
             } else {
                 return null;
             }
-            } catch (ApplicationManagementDAOException e) {
+        } catch (ApplicationManagementDAOException e) {
             String msg = "Error encountered while getting subscription statistics for group: " + subscriptionInfo.getIdentifier();
             log.error(msg, e);
             throw new ApplicationManagementException(msg, e);
@@ -1796,13 +1840,14 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
 
     /**
      * Get status based subscription data describes by {@link SubscriptionInfo} entity
+     *
      * @param subscriptionInfo {@link SubscriptionInfo}
-     * @param limit Limit value
+     * @param limit            Limit value
-     * @param offset Offset value
+     * @param offset           Offset value
      * @return {@link SubscriptionResponse}
      * @throws ApplicationManagementException Throws when error encountered while getting subscription data
      */
-
+    @Override
     public SubscriptionResponse getStatusBaseSubscriptions(SubscriptionInfo subscriptionInfo, int limit, int offset)
             throws ApplicationManagementException {
         if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.DEVICE)) {
@@ -1810,14 +1855,14 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
         } else if (Objects.equals(subscriptionInfo.getSubscriptionType(), SubscriptionMetadata.SubscriptionTypes.GROUP)) {
             return getStatusBaseSubscriptionsGroup(subscriptionInfo, limit, offset);
         } else {
-            return getStatusBaseSubscriptionsRoleUser(subscriptionInfo, limit, offset);
+            return getStatusBaseSubscriptionsRoleAndUser(subscriptionInfo, limit, offset);
         }
     }
 
-
+    private SubscriptionResponse getStatusBaseSubscriptionsDevice(SubscriptionInfo subscriptionInfo, int limit, int offset)
-   public SubscriptionResponse getStatusBaseSubscriptionsDevice(SubscriptionInfo subscriptionInfo, int limit, int offset)
             throws ApplicationManagementException {
-        final boolean isUnsubscribe = Objects.equals(SubscriptionMetadata.SUBSCRIPTION_STATUS_UNSUBSCRIBED, subscriptionInfo.getSubscriptionStatus());
+        final boolean isUnsubscribe = Objects.equals(SubscriptionMetadata.SUBSCRIPTION_STATUS_UNSUBSCRIBED,
+                subscriptionInfo.getSubscriptionStatus());
         List<DeviceSubscriptionDTO> deviceSubscriptionDTOS;
         int deviceCount = 0;
         int tenantId = PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantId();
@@ -1843,25 +1888,25 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
             String deviceSubscriptionStatus = SubscriptionManagementHelperUtil.getDeviceSubscriptionStatus(subscriptionInfo);
             DeviceSubscriptionFilterCriteria deviceSubscriptionFilterCriteria = subscriptionInfo.getDeviceSubscriptionFilterCriteria();
             DeviceManagementProviderService deviceManagementProviderService = HelperUtil.getDeviceManagementProviderService();
-            List<String> dbSubscriptionStatus = SubscriptionManagementHelperUtil.getDBSubscriptionStatus(subscriptionInfo.getDeviceSubscriptionStatus());
+            List<String> dbSubscriptionStatus = SubscriptionManagementHelperUtil.getDBSubscriptionStatus
+                    (subscriptionInfo.getDeviceSubscriptionStatus());
 
-                if (Objects.equals(SubscriptionMetadata.DeviceSubscriptionStatus.NEW, deviceSubscriptionStatus)) {
+            if (Objects.equals(SubscriptionMetadata.DeviceSubscriptionStatus.NEW, deviceSubscriptionStatus)) {
-                    deviceSubscriptionDTOS = subscriptionDAO.getAllSubscriptionsDetails(applicationReleaseDTO.
+                deviceSubscriptionDTOS = subscriptionDAO.getAllSubscriptionsDetails(applicationReleaseDTO.
-                                    getId(), isUnsubscribe, tenantId, null, null,
+                                getId(), isUnsubscribe, tenantId, null, null,
-                            deviceSubscriptionFilterCriteria.getTriggeredBy(), -1, -1);
+                        deviceSubscriptionFilterCriteria.getTriggeredBy(), -1, -1);
-
-                    List<Integer> deviceIdsOfSubscription = deviceSubscriptionDTOS.stream().
-                            map(DeviceSubscriptionDTO::getDeviceId).collect(Collectors.toList());
 
-                    List<Integer> newDeviceIds = deviceManagementProviderService.getDevicesNotInGivenIdList(deviceIdsOfSubscription);
+                List<Integer> deviceIdsOfSubscription = deviceSubscriptionDTOS.stream().
+                        map(DeviceSubscriptionDTO::getDeviceId).collect(Collectors.toList());
 
-                    deviceSubscriptionDTOS = newDeviceIds.stream().map(DeviceSubscriptionDTO::new).collect(Collectors.toList());
+                List<Integer> newDeviceIds = deviceManagementProviderService.getDevicesNotInGivenIdList(deviceIdsOfSubscription);
-                } else {
-                    deviceSubscriptionDTOS = subscriptionDAO.getAllSubscriptionsDetails(applicationReleaseDTO.
-                                    getId(), isUnsubscribe, tenantId, dbSubscriptionStatus, null,
-                            deviceSubscriptionFilterCriteria.getTriggeredBy(), -1, -1);
-                }
 
+                deviceSubscriptionDTOS = newDeviceIds.stream().map(DeviceSubscriptionDTO::new).collect(Collectors.toList());
+            } else {
+                deviceSubscriptionDTOS = subscriptionDAO.getAllSubscriptionsDetails(applicationReleaseDTO.
+                                getId(), isUnsubscribe, tenantId, dbSubscriptionStatus, null,
+                        deviceSubscriptionFilterCriteria.getTriggeredBy(), -1, -1);
+            }
 
             List<DeviceSubscription> deviceSubscriptions = SubscriptionManagementHelperUtil.getDeviceSubscriptionData(deviceSubscriptionDTOS,
                     subscriptionInfo.getDeviceSubscriptionFilterCriteria(), isUnsubscribe, applicationDTO.getDeviceTypeId(), limit, offset);
@@ -1879,10 +1924,11 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
         }
     }
 
-    public SubscriptionResponse getStatusBaseSubscriptionsGroup(SubscriptionInfo subscriptionInfo, int limit, int offset)
+    private SubscriptionResponse getStatusBaseSubscriptionsGroup(SubscriptionInfo subscriptionInfo, int limit, int offset)
             throws ApplicationManagementException {
 
-        final boolean isUnsubscribe = Objects.equals(SubscriptionMetadata.SUBSCRIPTION_STATUS_UNSUBSCRIBED, subscriptionInfo.getSubscriptionStatus());
+        final boolean isUnsubscribe = Objects.equals(SubscriptionMetadata.SUBSCRIPTION_STATUS_UNSUBSCRIBED,
+                subscriptionInfo.getSubscriptionStatus());
         List<DeviceSubscriptionDTO> deviceSubscriptionDTOS;
         int deviceCount = 0;
         int tenantId = PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantId();
@@ -1912,12 +1958,15 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
 
             GroupManagementProviderService groupManagementProviderService = HelperUtil.getGroupManagementProviderService();
             GroupDetailsDTO groupDetailsDTO;
-            List<String> dbSubscriptionStatus = SubscriptionManagementHelperUtil.getDBSubscriptionStatus(subscriptionInfo.getDeviceSubscriptionStatus());
+            List<String> dbSubscriptionStatus = SubscriptionManagementHelperUtil.getDBSubscriptionStatus
+                    (subscriptionInfo.getDeviceSubscriptionStatus());
 
             if (Objects.equals(SubscriptionMetadata.DeviceSubscriptionStatus.NEW, deviceSubscriptionStatus)) {
-                List<Integer> allDeviceIdsOwnByGroup = groupManagementProviderService.getGroupDetailsWithDevices(subscriptionInfo.getIdentifier(),
+                List<Integer> allDeviceIdsOwnByGroup = groupManagementProviderService.getGroupDetailsWithDevices
-                        applicationDTO.getDeviceTypeId(), deviceSubscriptionFilterCriteria.getOwner(), deviceSubscriptionFilterCriteria.getName(),
+                        (subscriptionInfo.getIdentifier(),
-                        deviceSubscriptionFilterCriteria.getDeviceStatus(), -1, -1).getDeviceIds();
+                                applicationDTO.getDeviceTypeId(), deviceSubscriptionFilterCriteria.getOwner(),
+                                deviceSubscriptionFilterCriteria.getName(),
+                                deviceSubscriptionFilterCriteria.getDeviceStatus(), -1, -1).getDeviceIds();
 
                 deviceSubscriptionDTOS = subscriptionDAO.getSubscriptionDetailsByDeviceIds(applicationReleaseDTO.getId(),
                         isUnsubscribe, tenantId, allDeviceIdsOwnByGroup, null,
@@ -1964,10 +2013,10 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
         }
     }
 
-
+    private SubscriptionResponse getStatusBaseSubscriptionsRoleAndUser(SubscriptionInfo subscriptionInfo, int limit, int offset)
-    public SubscriptionResponse getStatusBaseSubscriptionsRoleUser(SubscriptionInfo subscriptionInfo, int limit, int offset)
             throws ApplicationManagementException {
-        final boolean isUnsubscribe = Objects.equals(SubscriptionMetadata.SUBSCRIPTION_STATUS_UNSUBSCRIBED, subscriptionInfo.getSubscriptionStatus());
+        final boolean isUnsubscribe = Objects.equals(SubscriptionMetadata.SUBSCRIPTION_STATUS_UNSUBSCRIBED,
+                subscriptionInfo.getSubscriptionStatus());
         List<DeviceSubscriptionDTO> deviceSubscriptionDTOS;
         int deviceCount = 0;
         int tenantId = PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantId();
@@ -1995,7 +2044,8 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
             String deviceSubscriptionStatus = SubscriptionManagementHelperUtil.getDeviceSubscriptionStatus(subscriptionInfo);
             DeviceSubscriptionFilterCriteria deviceSubscriptionFilterCriteria = subscriptionInfo.getDeviceSubscriptionFilterCriteria();
             DeviceManagementProviderService deviceManagementProviderService = HelperUtil.getDeviceManagementProviderService();
-            List<String> dbSubscriptionStatus = SubscriptionManagementHelperUtil.getDBSubscriptionStatus(subscriptionInfo.getDeviceSubscriptionStatus());
+            List<String> dbSubscriptionStatus = SubscriptionManagementHelperUtil.getDBSubscriptionStatus
+                    (subscriptionInfo.getDeviceSubscriptionStatus());
 
             if (Objects.equals(SubscriptionMetadata.DeviceSubscriptionStatus.NEW, deviceSubscriptionStatus)) {
                 deviceSubscriptionDTOS = subscriptionDAO.getSubscriptionDetailsByDeviceIds(applicationReleaseDTO.getId(),
@@ -2021,7 +2071,8 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
 
             List<DeviceSubscription> deviceSubscriptions = SubscriptionManagementHelperUtil.
                     getDeviceSubscriptionData(deviceSubscriptionDTOS,
-                            subscriptionInfo.getDeviceSubscriptionFilterCriteria(), isUnsubscribe, applicationDTO.getDeviceTypeId(), limit, offset);
+                            subscriptionInfo.getDeviceSubscriptionFilterCriteria(), isUnsubscribe,
+                            applicationDTO.getDeviceTypeId(), limit, offset);
             return new SubscriptionResponse(subscriptionInfo.getApplicationUUID(), deviceCount, deviceSubscriptions);
 
         } catch (UserStoreException e) {
@@ -2041,7 +2092,6 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
         }
     }
 
-
     @SuppressWarnings("unchecked")
     private List<Integer> getDeviceIdsOwnByRole(String roleName, int tenantId) throws UserStoreException, DeviceManagementException {
         UserStoreManager userStoreManager = DataHolder.getInstance().getRealmService().
@@ -2076,21 +2126,31 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
         return deviceListOwnByUser.stream().map(Device::getId).collect(Collectors.toList());
     }
 
-    private List<Integer> getAllDeviceIds (SubscriptionInfo subscriptionInfo) throws DeviceManagementException, UserStoreException {
+    /**
+     * Retrieves a list of device IDs associated with the subscription described by the {@link SubscriptionInfo}.
+     * The device IDs are determined based on the subscription type, which could be either a role or a user.
+     *
+     * @param subscriptionInfo {@link SubscriptionInfo} containing the subscription details.
+     * @return A {@link List} of device IDs corresponding to the subscription type, or {@code null} if the type is not recognized.
+     * @throws DeviceManagementException Thrown when an error occurs while retrieving device IDs.
+     * @throws UserStoreException        Thrown when an error occurs while accessing the user store.
+     */
+    private List<Integer> getAllDeviceIds(SubscriptionInfo subscriptionInfo) throws DeviceManagementException, UserStoreException {
         String type = subscriptionInfo.getSubscriptionType();
         int tenantId = PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantId();
-        if (Objects.equals(type, SubscriptionMetadata.SubscriptionTypes.ROLE)){
+        if (Objects.equals(type, SubscriptionMetadata.SubscriptionTypes.ROLE)) {
-            return getDeviceIdsOwnByRole(subscriptionInfo.getIdentifier(),tenantId);
+            return getDeviceIdsOwnByRole(subscriptionInfo.getIdentifier(), tenantId);
         }
-        if (Objects.equals(type,SubscriptionMetadata.SubscriptionTypes.USER)){
+        if (Objects.equals(type, SubscriptionMetadata.SubscriptionTypes.USER)) {
             return getDeviceIdsOwnByUser(subscriptionInfo.getIdentifier());
-        }else
+        } else {
             return null;
+        }
     }
 
-
     /**
      * Get subscription statistics related data describes by the {@link SubscriptionInfo}
+     *
      * @param subscriptionInfo {@link SubscriptionInfo}
      * @return {@link SubscriptionStatistics}
      * @throws ApplicationManagementException Throws when error encountered while getting statistics
@@ -2100,7 +2160,6 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
         return getSubscriptionStatistics(subscriptionInfo);
     }
 
-
     @Override
     public List<DeviceOperationDTO> getSubscriptionOperationsByUUIDAndDeviceID(int deviceId, String uuid)
             throws ApplicationManagementException {