/*
 * Copyright (c) 2013 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.controller.netconf.confignetconfconnector.operations.getconfig;

import com.google.common.base.Optional;
import com.google.common.collect.Maps;
import org.opendaylight.controller.config.util.ConfigRegistryClient;
import org.opendaylight.controller.config.yang.store.api.YangStoreSnapshot;
import org.opendaylight.controller.config.yangjmxgenerator.ModuleMXBeanEntry;
import org.opendaylight.controller.netconf.api.NetconfDocumentedException;
import org.opendaylight.controller.netconf.api.NetconfDocumentedException.ErrorSeverity;
import org.opendaylight.controller.netconf.api.NetconfDocumentedException.ErrorTag;
import org.opendaylight.controller.netconf.api.NetconfDocumentedException.ErrorType;
import org.opendaylight.controller.netconf.confignetconfconnector.mapping.config.Config;
import org.opendaylight.controller.netconf.confignetconfconnector.mapping.config.InstanceConfig;
import org.opendaylight.controller.netconf.confignetconfconnector.mapping.config.ModuleConfig;
import org.opendaylight.controller.netconf.confignetconfconnector.operations.AbstractConfigNetconfOperation;
import org.opendaylight.controller.netconf.confignetconfconnector.operations.Datastore;
import org.opendaylight.controller.netconf.confignetconfconnector.transactions.TransactionProvider;
import org.opendaylight.controller.netconf.util.xml.XmlElement;
import org.opendaylight.controller.netconf.util.xml.XmlNetconfConstants;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

import javax.management.ObjectName;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class GetConfig extends AbstractConfigNetconfOperation {

    public static final String GET_CONFIG = "get-config";

    private final YangStoreSnapshot yangStoreSnapshot;
    private final Optional<String> maybeNamespace;

    private final TransactionProvider transactionProvider;

    private static final Logger logger = LoggerFactory.getLogger(GetConfig.class);

    public GetConfig(YangStoreSnapshot yangStoreSnapshot, Optional<String> maybeNamespace,
            TransactionProvider transactionProvider, ConfigRegistryClient configRegistryClient,
            String netconfSessionIdForReporting) {
        super(configRegistryClient, netconfSessionIdForReporting);
        this.yangStoreSnapshot = yangStoreSnapshot;
        this.maybeNamespace = maybeNamespace;
        this.transactionProvider = transactionProvider;
    }

    public static Datastore fromXml(XmlElement xml) {
        xml.checkName(GET_CONFIG);
        xml.checkNamespace(XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0);

        XmlElement sourceElement = xml.getOnlyChildElement(XmlNetconfConstants.SOURCE_KEY,
                XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0);
        XmlElement sourceNode = sourceElement.getOnlyChildElement();
        String sourceParsed = sourceNode.getName();
        logger.debug("Setting source datastore to '{}'", sourceParsed);
        Datastore sourceDatastore = Datastore.valueOf(sourceParsed);

        // Filter option - unsupported
        if (xml.getChildElements(XmlNetconfConstants.FILTER).size() != 0)
            throw new UnsupportedOperationException("Unsupported option " + XmlNetconfConstants.FILTER + " for "
                    + GET_CONFIG);

        return sourceDatastore;

    }

    private Element getResponseInternal(final Document document, final ConfigRegistryClient configRegistryClient,
            final Datastore source) throws NetconfDocumentedException {
        Element dataElement = document.createElement(XmlNetconfConstants.DATA_KEY);
        final Set<ObjectName> instances = Datastore.getInstanceQueryStrategy(source, this.transactionProvider)
                .queryInstances(configRegistryClient);

        final Config configMapping = new Config(transform(configRegistryClient,
                yangStoreSnapshot.getModuleMXBeanEntryMap()));
        dataElement = configMapping.toXml(instances, this.maybeNamespace, document, dataElement);

        logger.info("{} operation successful", GET_CONFIG);

        return dataElement;
    }

    // TODO refactor ... duplicate code
    public static Map<String, Map<String, ModuleConfig>> transform(final ConfigRegistryClient configRegistryClient,
            Map<String, Map<String, ModuleMXBeanEntry>> mBeanEntries) {
        return Maps.transformEntries(mBeanEntries,
                new Maps.EntryTransformer<String, Map<String, ModuleMXBeanEntry>, Map<String, ModuleConfig>>() {

                    @Override
                    public Map<String, ModuleConfig> transformEntry(String arg0, Map<String, ModuleMXBeanEntry> arg1) {
                        return Maps.transformEntries(arg1,
                                new Maps.EntryTransformer<String, ModuleMXBeanEntry, ModuleConfig>() {

                                    @Override
                                    public ModuleConfig transformEntry(String key, ModuleMXBeanEntry value) {
                                        return new ModuleConfig(key, new InstanceConfig(configRegistryClient, value
                                                .getAttributes()), value.getProvidedServices().values());
                                    }
                                });
                    }
                });
    }

    @Override
    protected String getOperationName() {
        return GET_CONFIG;
    }

    @Override
    public Element handle(Document document, XmlElement xml) throws NetconfDocumentedException {
        Datastore source;
        try {
            source = fromXml(xml);
        } catch (final IllegalArgumentException e) {
            logger.warn("Rpc error: {}", ErrorTag.bad_attribute, e);
            final Map<String, String> errorInfo = new HashMap<>();
            errorInfo.put(ErrorTag.bad_attribute.name(), e.getMessage());
            throw new NetconfDocumentedException(e.getMessage(), e, ErrorType.rpc, ErrorTag.bad_attribute,
                    ErrorSeverity.error, errorInfo);
        } catch (final IllegalStateException e) {
            logger.warn("Rpc error: {}", ErrorTag.missing_attribute, e);
            final Map<String, String> errorInfo = new HashMap<>();
            errorInfo.put(ErrorTag.missing_attribute.name(), "Missing datasource attribute value");
            throw new NetconfDocumentedException(e.getMessage(), e, ErrorType.rpc, ErrorTag.missing_attribute,
                    ErrorSeverity.error, errorInfo);
        } catch (final UnsupportedOperationException e) {
            logger.warn("Unsupported", e);
            final Map<String, String> errorInfo = new HashMap<>();
            errorInfo.put(ErrorTag.operation_not_supported.name(), "Unsupported option for get");
            throw new NetconfDocumentedException(e.getMessage(), e, ErrorType.application,
                    ErrorTag.operation_not_supported, ErrorSeverity.error, errorInfo);
        }
        return getResponseInternal(document, configRegistryClient, source);
    }
}