/*
 * Copyright (c) 2014, 2015 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.cluster.datastore.node.utils;

import com.google.common.base.Preconditions;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
import org.opendaylight.yangtools.yang.data.api.schema.DataContainerNode;
import org.opendaylight.yangtools.yang.data.api.schema.MixinNode;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNodeContainer;

/**
 * NormalizedNodeNavigator walks a {@link NormalizedNodeVisitor} through the NormalizedNode.
 */
public class NormalizedNodeNavigator {

    private final org.opendaylight.controller.cluster.datastore.node.utils.NormalizedNodeVisitor visitor;

    public NormalizedNodeNavigator(
            org.opendaylight.controller.cluster.datastore.node.utils.NormalizedNodeVisitor visitor) {
        Preconditions.checkNotNull(visitor, "visitor should not be null");
        this.visitor = visitor;
    }

    public void navigate(String parentPath, NormalizedNode<?, ?> normalizedNode) {
        if (parentPath == null) {
            parentPath = "";
        }
        navigateNormalizedNode(0, parentPath, normalizedNode);
    }

    private void navigateDataContainerNode(int level, final String parentPath,
            final DataContainerNode<?> dataContainerNode) {
        visitor.visitNode(level, parentPath, dataContainerNode);

        String newParentPath = parentPath + "/" + dataContainerNode.getIdentifier().toString();

        final Iterable<DataContainerChild<? extends YangInstanceIdentifier.PathArgument, ?>> value = dataContainerNode
                .getValue();
        for (NormalizedNode<?, ?> node : value) {
            if (node instanceof MixinNode && node instanceof NormalizedNodeContainer) {
                navigateNormalizedNodeContainerMixin(level, newParentPath, (NormalizedNodeContainer<?, ?, ?>) node);
            } else {
                navigateNormalizedNode(level, newParentPath, node);
            }
        }

    }

    private void navigateNormalizedNodeContainerMixin(int level, final String parentPath,
            NormalizedNodeContainer<?, ?, ?> node) {
        visitor.visitNode(level, parentPath, node);

        String newParentPath = parentPath + "/" + node.getIdentifier().toString();

        final Iterable<? extends NormalizedNode<?, ?>> value = node.getValue();
        for (NormalizedNode<?, ?> normalizedNode : value) {
            if (normalizedNode instanceof MixinNode && normalizedNode instanceof NormalizedNodeContainer) {
                navigateNormalizedNodeContainerMixin(level + 1, newParentPath,
                        (NormalizedNodeContainer<?, ?, ?>) normalizedNode);
            } else {
                navigateNormalizedNode(level, newParentPath, normalizedNode);
            }
        }

    }

    private void navigateNormalizedNode(int level, String parentPath, NormalizedNode<?, ?> normalizedNode) {
        if (normalizedNode instanceof DataContainerNode) {

            final DataContainerNode<?> dataContainerNode = (DataContainerNode<?>) normalizedNode;

            navigateDataContainerNode(level + 1, parentPath, dataContainerNode);
        } else {
            visitor.visitNode(level + 1, parentPath, normalizedNode);
        }
    }
}