/*
 * 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.yangtools.yang.data.impl.schema.builder.impl;

import com.google.common.collect.Maps;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
import org.eclipse.jdt.annotation.NonNull;
import org.opendaylight.yangtools.util.MapAdaptor;
import org.opendaylight.yangtools.util.UnmodifiableCollection;
import org.opendaylight.yangtools.yang.common.QName;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeWithValue;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
import org.opendaylight.yangtools.yang.data.api.schema.LeafSetEntryNode;
import org.opendaylight.yangtools.yang.data.api.schema.LeafSetNode;
import org.opendaylight.yangtools.yang.data.impl.schema.builder.api.ListNodeBuilder;
import org.opendaylight.yangtools.yang.data.impl.schema.builder.api.NormalizedNodeContainerBuilder;
import org.opendaylight.yangtools.yang.data.impl.schema.nodes.AbstractImmutableNormalizedNode;
import org.opendaylight.yangtools.yang.data.impl.schema.nodes.AbstractImmutableNormalizedValueNode;

public class ImmutableLeafSetNodeBuilder<T> implements ListNodeBuilder<T, LeafSetEntryNode<T>> {
    private static final int DEFAULT_CAPACITY = 4;

    private final Map<NodeWithValue, LeafSetEntryNode<T>> value;
    private NodeIdentifier nodeIdentifier;

    protected ImmutableLeafSetNodeBuilder() {
        value = new HashMap<>(DEFAULT_CAPACITY);
    }

    protected ImmutableLeafSetNodeBuilder(final int sizeHint) {
        if (sizeHint >= 0) {
            value = Maps.newHashMapWithExpectedSize(sizeHint);
        } else {
            value = new HashMap<>(DEFAULT_CAPACITY);
        }
    }

    protected ImmutableLeafSetNodeBuilder(final ImmutableLeafSetNode<T> node) {
        nodeIdentifier = node.getIdentifier();
        value = MapAdaptor.getDefaultInstance().takeSnapshot(node.children);
    }

    public static <T> @NonNull ListNodeBuilder<T, LeafSetEntryNode<T>> create() {
        return new ImmutableLeafSetNodeBuilder<>();
    }

    public static <T> @NonNull ListNodeBuilder<T, LeafSetEntryNode<T>> create(final int sizeHint) {
        return new ImmutableLeafSetNodeBuilder<>(sizeHint);
    }

    public static <T> @NonNull ListNodeBuilder<T, LeafSetEntryNode<T>> create(final LeafSetNode<T> node) {
        if (!(node instanceof ImmutableLeafSetNode<?>)) {
            throw new UnsupportedOperationException(String.format("Cannot initialize from class %s", node.getClass()));
        }

        return new ImmutableLeafSetNodeBuilder<>((ImmutableLeafSetNode<T>) node);
    }

    @Override
    public ListNodeBuilder<T, LeafSetEntryNode<T>> withChild(final LeafSetEntryNode<T> child) {
        this.value.put(child.getIdentifier(), child);
        return this;
    }

    @Override
    public ListNodeBuilder<T, LeafSetEntryNode<T>> withoutChild(final PathArgument key) {
        this.value.remove(key);
        return this;
    }

    @Override
    public LeafSetNode<T> build() {
        return new ImmutableLeafSetNode<>(nodeIdentifier, MapAdaptor.getDefaultInstance().optimize(value));
    }

    @Override
    public ListNodeBuilder<T, LeafSetEntryNode<T>> withNodeIdentifier(final NodeIdentifier withNodeIdentifier) {
        this.nodeIdentifier = withNodeIdentifier;
        return this;
    }

    @Override
    public ListNodeBuilder<T, LeafSetEntryNode<T>> withValue(final Collection<LeafSetEntryNode<T>> withValue) {
        for (final LeafSetEntryNode<T> leafSetEntry : withValue) {
            withChild(leafSetEntry);
        }
        return this;
    }


    @Override
    public ListNodeBuilder<T, LeafSetEntryNode<T>> withChildValue(final T childValue,
            final Map<QName, String> attributes) {
        final ImmutableLeafSetEntryNodeBuilder<T> b = ImmutableLeafSetEntryNodeBuilder.create();
        b.withNodeIdentifier(new NodeWithValue<>(nodeIdentifier.getNodeType(), childValue));
        b.withValue(childValue);
        b.withAttributes(attributes);
        return withChild(b.build());
    }

    @Override
    public ListNodeBuilder<T, LeafSetEntryNode<T>> withChildValue(final T childValue) {
        return withChildValue(childValue, Collections.emptyMap());
    }

    protected static final class ImmutableLeafSetNode<T> extends
            AbstractImmutableNormalizedValueNode<NodeIdentifier, Collection<LeafSetEntryNode<T>>> implements
            LeafSetNode<T> {

        private final Map<NodeWithValue, LeafSetEntryNode<T>> children;

        ImmutableLeafSetNode(final NodeIdentifier nodeIdentifier,
                final Map<NodeWithValue, LeafSetEntryNode<T>> children) {
            super(nodeIdentifier, UnmodifiableCollection.create(children.values()));
            this.children = children;
        }

        @Override
        public Optional<LeafSetEntryNode<T>> getChild(final NodeWithValue child) {
            return Optional.ofNullable(children.get(child));
        }

        @Override
        protected int valueHashCode() {
            return children.hashCode();
        }

        @Override
        protected boolean valueEquals(final AbstractImmutableNormalizedNode<?, ?> other) {
            return children.equals(((ImmutableLeafSetNode<?>) other).children);
        }
    }

    @Override
    public NormalizedNodeContainerBuilder<NodeIdentifier, PathArgument, LeafSetEntryNode<T>, LeafSetNode<T>> addChild(
            final LeafSetEntryNode<T> child) {
        return withChild(child);
    }

    @Override
    public NormalizedNodeContainerBuilder<NodeIdentifier, PathArgument, LeafSetEntryNode<T>, LeafSetNode<T>>
            removeChild(final PathArgument key) {
        return withoutChild(key);
    }

}