/*
 * Copyright (c) 2017 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */

package org.opendaylight.netconf.sal.connect.util;

import com.google.common.util.concurrent.CheckedFuture;
import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.MoreExecutors;
import com.google.common.util.concurrent.SettableFuture;
import java.util.List;
import java.util.concurrent.Future;
import java.util.stream.Collectors;
import javax.annotation.Nullable;
import org.opendaylight.aaa.encrypt.AAAEncryptionService;
import org.opendaylight.controller.md.sal.binding.api.DataBroker;
import org.opendaylight.controller.md.sal.binding.api.WriteTransaction;
import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.keystore.rev171017.AddKeystoreEntryInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.keystore.rev171017.Keystore;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.keystore.rev171017.KeystoreBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.keystore.rev171017.NetconfKeystoreService;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.keystore.rev171017.RemoveKeystoreEntryInput;
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.KeyCredentialBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.keystore.rev171017.keystore.entry.KeyCredentialKey;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.opendaylight.yangtools.yang.common.RpcResult;
import org.opendaylight.yangtools.yang.common.RpcResultBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class NetconfSalKeystoreService implements NetconfKeystoreService {

    private static final Logger LOG = LoggerFactory.getLogger(NetconfSalKeystoreService.class);

    private final DataBroker dataBroker;
    private final AAAEncryptionService encryptionService;

    private final InstanceIdentifier<Keystore> keystoreIid = InstanceIdentifier.create(Keystore.class);

    public NetconfSalKeystoreService(final DataBroker dataBroker,
                                     final AAAEncryptionService encryptionService) {
        LOG.info("Starting NETCONF keystore service.");

        this.dataBroker = dataBroker;
        this.encryptionService = encryptionService;

        initKeystore();
    }

    private void initKeystore() {
        final Keystore keystore = new KeystoreBuilder().build();

        final WriteTransaction writeTransaction = dataBroker.newWriteOnlyTransaction();
        writeTransaction.merge(LogicalDatastoreType.CONFIGURATION, keystoreIid, keystore);

        final CheckedFuture<Void, TransactionCommitFailedException> submit = writeTransaction.submit();

        try {
            submit.checkedGet();
            LOG.debug("init keystore done");
        } catch (TransactionCommitFailedException exception) {
            LOG.error("Unable to initialize Netconf key-pair store.", exception);
        }
    }

    @Override
    public Future<RpcResult<Void>> removeKeystoreEntry(final RemoveKeystoreEntryInput input) {
        LOG.debug("Removing keypairs: {}", input);

        final WriteTransaction writeTransaction = dataBroker.newWriteOnlyTransaction();
        final List<String> ids = input.getKeyId();

        for (final String id : ids) {
            writeTransaction.delete(LogicalDatastoreType.CONFIGURATION,
                    keystoreIid.child(KeyCredential.class, new KeyCredentialKey(id)));
        }

        final SettableFuture<RpcResult<Void>> rpcResult = SettableFuture.create();

        final CheckedFuture<Void, TransactionCommitFailedException> submit = writeTransaction.submit();
        Futures.addCallback(submit, new FutureCallback<Void>() {
            @Override
            public void onSuccess(@Nullable final Void result) {
                LOG.debug("remove-key-pair success. Input: {}");
                final RpcResult<Void> success = RpcResultBuilder.<Void>success().build();
                rpcResult.set(success);
            }

            @Override
            public void onFailure(final Throwable throwable) {
                LOG.warn("remove-key-pair failed. Input: {}", input, throwable);
                rpcResult.setException(throwable);
            }
        }, MoreExecutors.directExecutor());

        return rpcResult;
    }

    @Override
    public Future<RpcResult<Void>> addKeystoreEntry(final AddKeystoreEntryInput input) {
        LOG.debug("Adding keypairs: {}", input);

        final WriteTransaction writeTransaction = dataBroker.newWriteOnlyTransaction();
        final List<KeyCredential> keypairs = input.getKeyCredential().stream().map(keypair ->
                new KeyCredentialBuilder(keypair)
                        .setPrivateKey(encryptionService.encrypt(keypair.getPrivateKey()))
                        .setPassphrase(encryptionService.encrypt(keypair.getPassphrase()))
                        .build()).collect(Collectors.toList());

        for (KeyCredential keypair : keypairs) {
            writeTransaction.merge(LogicalDatastoreType.CONFIGURATION,
                    keystoreIid.child(KeyCredential.class, keypair.getKey()), keypair);
        }

        final SettableFuture<RpcResult<Void>> rpcResult = SettableFuture.create();

        final CheckedFuture<Void, TransactionCommitFailedException> submit = writeTransaction.submit();
        Futures.addCallback(submit, new FutureCallback<Void>() {
            @Override
            public void onSuccess(@Nullable final Void result) {
                LOG.debug("add-key-pair success. Input: {}");
                final RpcResult<Void> success = RpcResultBuilder.<Void>success().build();
                rpcResult.set(success);
            }

            @Override
            public void onFailure(final Throwable throwable) {
                LOG.warn("add-key-pair failed. Input: {}", input, throwable);
                rpcResult.setException(throwable);
            }
        }, MoreExecutors.directExecutor());

        return rpcResult;
    }
}