/*
 * ============LICENSE_START=======================================================
 * ONAP : ccsdk features
 * ================================================================================
 * Copyright (C) 2019 highstreet technologies GmbH Intellectual Property.
 * All rights reserved.
 * ================================================================================
 * Update Copyright (C) 2021 Samsung Electronics Intellectual Property. All rights reserved.
 * =================================================================================================
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * ============LICENSE_END=========================================================
 *
 */
package org.onap.ccsdk.features.sdnr.wt.dataprovider.impl;

import com.google.common.util.concurrent.ListenableFuture;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Arrays;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;
import org.eclipse.jdt.annotation.NonNull;
import org.onap.ccsdk.features.sdnr.wt.common.configuration.ConfigurationFileRepresentation;
import org.onap.ccsdk.features.sdnr.wt.common.database.HtDatabaseClient;
import org.onap.ccsdk.features.sdnr.wt.dataprovider.database.DatabaseDataProvider;
import org.onap.ccsdk.features.sdnr.wt.dataprovider.database.elasticsearch.impl.ElasticSearchDataProvider;
import org.onap.ccsdk.features.sdnr.wt.dataprovider.database.elasticsearch.impl.HtUserdataManagerImpl;
import org.onap.ccsdk.features.sdnr.wt.dataprovider.database.sqldb.data.SqlDBDataProvider;
import org.onap.ccsdk.features.sdnr.wt.dataprovider.http.MsServlet;
import org.onap.ccsdk.features.sdnr.wt.dataprovider.model.DataProvider;
import org.onap.ccsdk.features.sdnr.wt.dataprovider.model.HtDatabaseMaintenance;
import org.onap.ccsdk.features.sdnr.wt.dataprovider.model.HtUserdataManager;
import org.onap.ccsdk.features.sdnr.wt.dataprovider.model.IEsConfig;
import org.onap.ccsdk.features.sdnr.wt.dataprovider.model.SdnrDbType;
import org.opendaylight.mdsal.binding.api.DataBroker;
import org.opendaylight.mdsal.binding.api.ReadTransaction;
import org.opendaylight.mdsal.binding.api.RpcProviderService;
import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.keystore.rev171017.Keystore;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.keystore.rev171017.keystore.entry.KeyCredential;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.keystore.rev171017.keystore.entry.KeyCredentialKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.CreateMaintenanceInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.CreateMaintenanceOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.CreateMediatorServerInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.CreateMediatorServerOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.CreateNetworkElementConnectionInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.CreateNetworkElementConnectionOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.DataProviderService;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.DeleteMaintenanceInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.DeleteMaintenanceOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.DeleteMediatorServerInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.DeleteMediatorServerOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.DeleteNetworkElementConnectionInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.DeleteNetworkElementConnectionOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadCmlogListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadCmlogListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadConnectionlogListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadConnectionlogListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadEventlogListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadEventlogListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadFaultcurrentListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadFaultcurrentListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadFaultlogListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadFaultlogListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadGuiCutThroughEntryInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadGuiCutThroughEntryOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadInventoryListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadInventoryListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadMaintenanceListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadMaintenanceListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadMediatorServerListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadMediatorServerListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadNetworkElementConnectionListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadNetworkElementConnectionListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata15mDeviceListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata15mDeviceListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata15mListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata15mListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata15mLtpListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata15mLtpListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata24hDeviceListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata24hDeviceListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata24hListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata24hListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata24hLtpListInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadPmdata24hLtpListOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadStatusInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadStatusOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadTlsKeyEntryInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadTlsKeyEntryOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.ReadTlsKeyEntryOutputBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.UpdateMaintenanceInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.UpdateMaintenanceOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.UpdateMediatorServerInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.UpdateMediatorServerOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.UpdateNetworkElementConnectionInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.UpdateNetworkElementConnectionOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.read.tls.key.entry.output.Pagination;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.read.tls.key.entry.output.PaginationBuilder;
import org.opendaylight.yangtools.concepts.Builder;
import org.opendaylight.yangtools.concepts.ObjectRegistration;
import org.opendaylight.yangtools.yang.binding.DataObject;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.opendaylight.yangtools.yang.common.RpcError.ErrorType;
import org.opendaylight.yangtools.yang.common.RpcResult;
import org.opendaylight.yangtools.yang.common.RpcResultBuilder;
import org.opendaylight.yangtools.yang.common.Uint32;
import org.opendaylight.yangtools.yang.common.Uint64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DataProviderServiceImpl implements DataProviderService, AutoCloseable {

    private static final Logger LOG = LoggerFactory.getLogger(DataProviderServiceImpl.class);
    public static final String CONFIGURATIONFILE = "etc/dataprovider.properties";
    private static final long DATABASE_TIMEOUT_MS = 120 * 1000L;
    private static final @NonNull InstanceIdentifier<Keystore> KEYSTORE_IIF = InstanceIdentifier.create(Keystore.class);
    private static final Pagination EMPTY_PAGINATION = new PaginationBuilder().setSize(Uint32.valueOf(20))
            .setTotal(Uint64.valueOf(0)).setPage(Uint64.valueOf(1)).build();
    private static final long DEFAULT_PAGESIZE = 20;
    private static final long DEFAULT_PAGE = 1;

    private final ObjectRegistration<@NonNull DataProviderServiceImpl> rpcReg;
    private final DatabaseDataProvider dataProvider;
    private final ConfigurationFileRepresentation configuration;
    private final DataProviderConfig dbConfig;
    private final HtUserdataManager dbUserManager;
    private final DataBroker dataBroker;
    private final MsServlet mediatorServerServlet;

    public DataProviderServiceImpl(final RpcProviderService rpcProviderService, MsServlet mediatorServerServlet,
            DataBroker dataBroker) throws Exception {
        this.configuration = new ConfigurationFileRepresentation(CONFIGURATIONFILE);
        this.dbConfig = new DataProviderConfig(configuration);
        this.dataBroker = dataBroker;
        this.mediatorServerServlet = mediatorServerServlet;
        if (this.dbConfig.getDbType() == SdnrDbType.ELASTICSEARCH) {
            this.dataProvider = new ElasticSearchDataProvider(this.dbConfig.getEsConfig());
         } else {
            this.dataProvider = new SqlDBDataProvider(this.dbConfig.getMariadbConfig());
        }
        this.dbUserManager = this.dataProvider.getUserManager();
        this.dataProvider.waitForYellowDatabaseStatus(DATABASE_TIMEOUT_MS, TimeUnit.MILLISECONDS);
        mediatorServerServlet.setDataProvider(this.dataProvider.getHtDatabaseMediatorServer());
        // Register ourselves as the REST API RPC implementation
        LOG.info("Register RPC Service {}", DataProviderServiceImpl.class.getSimpleName());
        this.rpcReg = rpcProviderService.registerRpcImplementation(DataProviderService.class, this);
    }

    private void sendResyncCallbackToApiGateway() {
        this.mediatorServerServlet.triggerReloadSync();
    }

    /**
     * @return dataProvider
     */
    public DataProvider getDataProvider() {
        return dataProvider.getDataProvider();
    }

    public HtDatabaseClient getRawClient() {
        return this.dataProvider.getRawClient();
    }

    /**
     * @return data provider for Maintenance()
     */
    public HtDatabaseMaintenance getHtDatabaseMaintenance() {
        return dataProvider.getHtDatabaseMaintenance();
    }

    /**
     * @return configuration object
     */
    public IEsConfig getEsConfig() {
        return dbConfig.getEsConfig();
    }


    @Override
    public void close() throws Exception {
        LOG.info("Close RPC Service");
        if (rpcReg != null) {
            rpcReg.close();
        }
    }

    @Override
    public ListenableFuture<RpcResult<ReadFaultcurrentListOutput>> readFaultcurrentList(
            ReadFaultcurrentListInput input) {
        LOG.debug("RPC Request: readFaultCurrentList with input {}", input);
        RpcResultBuilder<ReadFaultcurrentListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readFaultCurrentList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadFaultlogListOutput>> readFaultlogList(ReadFaultlogListInput input) {
        LOG.debug("RPC Request: readFaultlogList with input {}", input);
        RpcResultBuilder<ReadFaultlogListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readFaultLogList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadCmlogListOutput>> readCmlogList(ReadCmlogListInput input) {
        LOG.debug("RPC Request: readCMlogList with input {}", input);
        RpcResultBuilder<ReadCmlogListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readCMLogList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadMaintenanceListOutput>> readMaintenanceList(ReadMaintenanceListInput input) {
        LOG.debug("RPC Request: readMaintenanceList with input {}", input);
        RpcResultBuilder<ReadMaintenanceListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readMaintenanceList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadMediatorServerListOutput>> readMediatorServerList(
            ReadMediatorServerListInput input) {
        LOG.debug("RPC Request: readMediatorServerList with input {}", input);
        RpcResultBuilder<ReadMediatorServerListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readMediatorServerList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadNetworkElementConnectionListOutput>> readNetworkElementConnectionList(
            ReadNetworkElementConnectionListInput input) {
        LOG.debug("RPC Request: readNetworkElementConnectionList with input {}", input);
        RpcResultBuilder<ReadNetworkElementConnectionListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readNetworkElementConnectionList(input));
        return result.buildFuture();

    }

    @Override
    public ListenableFuture<RpcResult<ReadPmdata15mListOutput>> readPmdata15mList(ReadPmdata15mListInput input) {
        LOG.debug("RPC Request: readPmdata15mList with input {}", input);
        RpcResultBuilder<ReadPmdata15mListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readPmdata15mList(input));
        return result.buildFuture();

    }

    @Override
    public ListenableFuture<RpcResult<ReadPmdata24hListOutput>> readPmdata24hList(ReadPmdata24hListInput input) {
        LOG.debug("RPC Request: readPmdata24hList with input {}", input);
        RpcResultBuilder<ReadPmdata24hListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readPmdata24hList(input));
        return result.buildFuture();

    }

    @Override
    public ListenableFuture<RpcResult<ReadStatusOutput>> readStatus(ReadStatusInput input) {
        LOG.debug("RPC Request: readStatusEntityList with input {}", input);
        RpcResultBuilder<ReadStatusOutput> result = read(() -> DataProviderServiceImpl.this.dataProvider.readStatus());
        return result.buildFuture();

    }

    @Override
    public ListenableFuture<RpcResult<ReadInventoryListOutput>> readInventoryList(ReadInventoryListInput input) {
        LOG.debug("RPC Request: readInventoryList with input {}", input);
        RpcResultBuilder<ReadInventoryListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readInventoryList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadPmdata15mLtpListOutput>> readPmdata15mLtpList(
            ReadPmdata15mLtpListInput input) {
        LOG.debug("RPC Request: readPmdata15mLtpList with input {}", input);
        RpcResultBuilder<ReadPmdata15mLtpListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readPmdata15mLtpList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadPmdata15mDeviceListOutput>> readPmdata15mDeviceList(
            ReadPmdata15mDeviceListInput input) {
        LOG.debug("RPC Request: readPmdata15mDeviceList with input {}", input);
        RpcResultBuilder<ReadPmdata15mDeviceListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readPmdata15mDeviceList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadPmdata24hLtpListOutput>> readPmdata24hLtpList(
            ReadPmdata24hLtpListInput input) {
        LOG.debug("RPC Request: readPmdata24hLtpList with input {}", input);
        RpcResultBuilder<ReadPmdata24hLtpListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readPmdata24hLtpList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadPmdata24hDeviceListOutput>> readPmdata24hDeviceList(
            ReadPmdata24hDeviceListInput input) {
        LOG.debug("RPC Request: readPmdata24hDeviceList with input {}", input);
        RpcResultBuilder<ReadPmdata24hDeviceListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readPmdata24hDeviceList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadConnectionlogListOutput>> readConnectionlogList(
            ReadConnectionlogListInput input) {
        LOG.debug("RPC Request: readConnectionlogList with input {}", input);
        RpcResultBuilder<ReadConnectionlogListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readConnectionlogList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<CreateNetworkElementConnectionOutput>> createNetworkElementConnection(
            CreateNetworkElementConnectionInput input) {
        LOG.debug("RPC Request: createNetworkElementConnection with input {}", input);
        RpcResultBuilder<CreateNetworkElementConnectionOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.createNetworkElementConnection(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<UpdateNetworkElementConnectionOutput>> updateNetworkElementConnection(
            UpdateNetworkElementConnectionInput input) {
        LOG.debug("RPC Request: updateNetworkElementConnection with input {}", input);
        RpcResultBuilder<UpdateNetworkElementConnectionOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.updateNetworkElementConnection(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<DeleteNetworkElementConnectionOutput>> deleteNetworkElementConnection(
            DeleteNetworkElementConnectionInput input) {
        LOG.debug("RPC Request: deleteNetworkElementConnection with input {}", input);
        RpcResultBuilder<DeleteNetworkElementConnectionOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.deleteNetworkElementConnection(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<DeleteMediatorServerOutput>> deleteMediatorServer(
            DeleteMediatorServerInput input) {
        LOG.debug("RPC Request: deleteMediatorServer with input {}", input);
        RpcResultBuilder<DeleteMediatorServerOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.deleteMediatorServer(input));
        this.sendResyncCallbackToApiGateway();
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<CreateMediatorServerOutput>> createMediatorServer(
            CreateMediatorServerInput input) {
        LOG.debug("RPC Request: createMediatorServer with input {}", input);
        RpcResultBuilder<CreateMediatorServerOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.createMediatorServer(input));
        this.sendResyncCallbackToApiGateway();
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<CreateMaintenanceOutput>> createMaintenance(CreateMaintenanceInput input) {
        LOG.debug("RPC Request: createMaintenance with input {}", input);
        RpcResultBuilder<CreateMaintenanceOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.createMaintenance(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<DeleteMaintenanceOutput>> deleteMaintenance(DeleteMaintenanceInput input) {
        LOG.debug("RPC Request: deleteMaintenance with input {}", input);
        RpcResultBuilder<DeleteMaintenanceOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.deleteMaintenance(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<UpdateMediatorServerOutput>> updateMediatorServer(
            UpdateMediatorServerInput input) {
        LOG.debug("RPC Request: updateMediatorServer with input {}", input);
        RpcResultBuilder<UpdateMediatorServerOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.updateMediatorServer(input));
        this.sendResyncCallbackToApiGateway();
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<UpdateMaintenanceOutput>> updateMaintenance(UpdateMaintenanceInput input) {
        LOG.debug("RPC Request: updateMaintenance with input {}", input);
        RpcResultBuilder<UpdateMaintenanceOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.updateMaintenance(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadEventlogListOutput>> readEventlogList(ReadEventlogListInput input) {
        LOG.debug("RPC Request: readEventlogList with input {}", input);
        RpcResultBuilder<ReadEventlogListOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readEventlogList(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadGuiCutThroughEntryOutput>> readGuiCutThroughEntry(
            ReadGuiCutThroughEntryInput input) {
        LOG.debug("RPC Request: getGuiCutThroughEntry with input {}", input);
        RpcResultBuilder<ReadGuiCutThroughEntryOutput> result =
                read(() -> DataProviderServiceImpl.this.dataProvider.readGuiCutThroughEntry(input));
        return result.buildFuture();
    }

    @Override
    public ListenableFuture<RpcResult<ReadTlsKeyEntryOutput>> readTlsKeyEntry(ReadTlsKeyEntryInput input) {
        LOG.debug("RPC Request: readTlsKeyEntry with input {}", input);
        RpcResultBuilder<ReadTlsKeyEntryOutput> result = read(() -> DataProviderServiceImpl.this.readTlsKeys(input));
        return result.buildFuture();
    }

    // -- private classes and functions

    private ReadTlsKeyEntryOutputBuilder readTlsKeys(ReadTlsKeyEntryInput input) {
        Optional<Keystore> result = Optional.empty();
        // The implicite close is not handled correctly by underlaying opendaylight netconf service
        ReadTransaction transaction = this.dataBroker.newReadOnlyTransaction();
        try {
            result = transaction.read(LogicalDatastoreType.CONFIGURATION, KEYSTORE_IIF).get();
        } catch (ExecutionException e) {
            LOG.warn("problem reading netconf-keystore: ", e);

        } catch (InterruptedException e) {
            LOG.warn("Interrupted!", e);
            // Restore interrupted state...
            Thread.currentThread().interrupt();
        }
        ReadTlsKeyEntryOutputBuilder output = new ReadTlsKeyEntryOutputBuilder();
        if (result.isEmpty()) {
            return output.setData(Arrays.asList()).setPagination(EMPTY_PAGINATION);
        }
        Map<KeyCredentialKey, KeyCredential> keyCredential = result.get().getKeyCredential();
        if (keyCredential == null) {
            return output.setData(Arrays.asList()).setPagination(EMPTY_PAGINATION);
        }
        org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.data.provider.rev201110.entity.input.Pagination pagination =
                input.getPagination();
        long pageNum = pagination == null ? DEFAULT_PAGE
                : pagination.getPage() == null ? DEFAULT_PAGE : pagination.getPage().longValue();
        long size = pagination == null ? DEFAULT_PAGESIZE
                : pagination.getSize() == null ? DEFAULT_PAGESIZE : pagination.getSize().longValue();
        long from = pageNum > 0 ? (pageNum - 1) * size : 0;
        output.setData(keyCredential.keySet().stream().skip(from).limit(size).map(e -> e.getKeyId())
                .collect(Collectors.toList()));
        output.setPagination(new PaginationBuilder().setPage(Uint64.valueOf(pageNum))
                .setSize(Uint32.valueOf(output.getData().size())).setTotal(Uint64.valueOf(keyCredential.size()))
                .build());
        return output;
    }

    private static String assembleExceptionMessage(Exception e) {
        StringWriter sw = new StringWriter();
        PrintWriter pw = new PrintWriter(sw);
        e.printStackTrace(pw);

        StringBuffer buf = new StringBuffer();
        buf.append("Exception: ");
        buf.append(sw.toString());
        return buf.toString();
    }

    private interface GetEntityInput<O extends DataObject> {
        Builder<O> get() throws IOException;
    }

    private static <O extends DataObject, I extends DataObject> RpcResultBuilder<O> read(
            GetEntityInput<O> inputgetter) {
        RpcResultBuilder<O> result;
        try {
            Builder<O> outputBuilder = inputgetter.get();
            result = RpcResultBuilder.success(outputBuilder);
        } catch (Exception e) {
            LOG.info("Exception", e);
            result = RpcResultBuilder.failed();
            result.withError(ErrorType.APPLICATION, assembleExceptionMessage(e));
        }
        return result;
    }

    public HtUserdataManager getHtDatabaseUserManager() {
        return this.dbUserManager;
    }



}