/*
 * Copyright (c) 2016 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.restconf.nb.rfc8040.utils.mapping;

import static org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.restconf.monitoring.rev170126.$YangModuleInfoImpl.qnameOf;

import com.google.common.annotations.VisibleForTesting;
import java.net.URI;
import java.time.Instant;
import java.time.OffsetDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.Collection;
import java.util.Optional;
import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
import org.opendaylight.restconf.nb.rfc8040.utils.parser.IdentifierCodec;
import org.opendaylight.restconf.nb.rfc8040.utils.parser.ParserIdentifier;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.restconf.monitoring.rev170126.restconf.state.streams.Stream;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.restconf.monitoring.rev170126.restconf.state.streams.stream.Access;
import org.opendaylight.yangtools.yang.common.QName;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
import org.opendaylight.yangtools.yang.data.api.schema.MapNode;
import org.opendaylight.yangtools.yang.data.api.schema.builder.DataContainerNodeBuilder;
import org.opendaylight.yangtools.yang.data.impl.schema.Builders;
import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
import org.opendaylight.yangtools.yang.model.api.NotificationDefinition;
import org.opendaylight.yangtools.yang.model.api.SchemaNode;

/**
 * Util class for mapping nodes.
 */
public final class RestconfMappingNodeUtil {
    @VisibleForTesting
    static final QName DESCRIPTION_QNAME = qnameOf("description");
    @VisibleForTesting
    static final QName ENCODING_QNAME = qnameOf("encoding");
    @VisibleForTesting
    static final QName LOCATION_QNAME = qnameOf("location");
    @VisibleForTesting
    static final QName NAME_QNAME = qnameOf("name");
    @VisibleForTesting
    static final QName REPLAY_SUPPORT_QNAME = qnameOf("replay-support");
    @VisibleForTesting
    static final QName REPLAY_LOG_CREATION_TIME = qnameOf("replay-log-creation-time");

    private RestconfMappingNodeUtil() {
        // Hidden on purpose
    }

    /**
     * Map data of yang notification to normalized node according to ietf-restconf-monitoring.
     *
     * @param notifiQName qname of notification from listener
     * @param notifications list of notifications for find schema of notification by notifiQName
     * @param start start-time query parameter of notification
     * @param outputType output type of notification
     * @param uri location of registered listener for sending data of notification
     * @return mapped data of notification - map entry node if parent exists,
     *         container streams with list and map entry node if not
     */
    public static MapEntryNode mapYangNotificationStreamByIetfRestconfMonitoring(final QName notifiQName,
            final Collection<? extends NotificationDefinition> notifications, final Instant start,
            final String outputType, final URI uri) {
        for (final NotificationDefinition notificationDefinition : notifications) {
            if (notificationDefinition.getQName().equals(notifiQName)) {
                final String streamName = notifiQName.getLocalName();
                final DataContainerNodeBuilder<NodeIdentifierWithPredicates, MapEntryNode> streamEntry =
                    Builders.mapEntryBuilder()
                        .withNodeIdentifier(NodeIdentifierWithPredicates.of(Stream.QNAME, NAME_QNAME, streamName))
                        .withChild(ImmutableNodes.leafNode(NAME_QNAME, streamName));

                notificationDefinition.getDescription().ifPresent(
                    desc -> streamEntry.withChild(ImmutableNodes.leafNode(DESCRIPTION_QNAME, desc)));
                streamEntry.withChild(ImmutableNodes.leafNode(REPLAY_SUPPORT_QNAME, Boolean.TRUE));
                if (start != null) {
                    streamEntry.withChild(ImmutableNodes.leafNode(REPLAY_LOG_CREATION_TIME,
                        DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(OffsetDateTime.ofInstant(start,
                            ZoneId.systemDefault()))));
                }

                return streamEntry
                    .withChild(createAccessList(outputType, uri))
                    .build();
            }
        }

        throw new RestconfDocumentedException(notifiQName + " doesn't exist in any modul");
    }

    private static MapNode createAccessList(final String outputType, final URI uriToWebsocketServer) {
        return Builders.mapBuilder()
            .withNodeIdentifier(new NodeIdentifier(Access.QNAME))
            .withChild(Builders.mapEntryBuilder()
                .withNodeIdentifier(NodeIdentifierWithPredicates.of(Access.QNAME, ENCODING_QNAME, outputType))
                .withChild(ImmutableNodes.leafNode(ENCODING_QNAME, outputType))
                .withChild(ImmutableNodes.leafNode(LOCATION_QNAME, uriToWebsocketServer.toString()))
                .build())
            .build();
    }

    /**
     * Map data of data change notification to normalized node according to ietf-restconf-monitoring.
     *
     * @param path path of data to listen on
     * @param start start-time query parameter of notification
     * @param outputType output type of notification
     * @param uri location of registered listener for sending data of notification
     * @param schemaContext schemaContext for parsing instance identifier to get schema node of data
     * @return mapped data of notification - map entry node if parent exists,
     *         container streams with list and map entry node if not
     */
    public static MapEntryNode mapDataChangeNotificationStreamByIetfRestconfMonitoring(
            final YangInstanceIdentifier path, final Instant start, final String outputType, final URI uri,
            final EffectiveModelContext schemaContext, final String streamName) {
        final SchemaNode schemaNode = ParserIdentifier.toInstanceIdentifier(
            IdentifierCodec.serialize(path, schemaContext), schemaContext, Optional.empty()).getSchemaNode();
        final DataContainerNodeBuilder<NodeIdentifierWithPredicates, MapEntryNode> streamEntry =
            Builders.mapEntryBuilder()
                .withNodeIdentifier(NodeIdentifierWithPredicates.of(Stream.QNAME, NAME_QNAME, streamName))
                .withChild(ImmutableNodes.leafNode(NAME_QNAME, streamName));

        schemaNode.getDescription().ifPresent(desc ->
            streamEntry.withChild(ImmutableNodes.leafNode(DESCRIPTION_QNAME, desc)));

        return streamEntry
            .withChild(ImmutableNodes.leafNode(REPLAY_SUPPORT_QNAME, Boolean.TRUE))
            .withChild(ImmutableNodes.leafNode(REPLAY_LOG_CREATION_TIME,
                DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(OffsetDateTime.ofInstant(start, ZoneId.systemDefault()))))
            .withChild(createAccessList(outputType, uri))
            .build();
    }
}