/*
 * Copyright (c) 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.mdsal.binding.dom.codec.impl;

import static java.util.Objects.requireNonNull;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.ImmutableSet;
import org.opendaylight.mdsal.binding.dom.codec.api.BindingObjectCodecTreeNode;
import org.opendaylight.mdsal.binding.dom.codec.impl.LeafNodeCodecContext.OfTypeObject;
import org.opendaylight.yangtools.yang.binding.BindingObject;

/**
 * Abstract Holder of Binding to Normalized Node caches indexed by {@link DataContainerCodecContext} to which cache is
 * associated.
 */
abstract class AbstractBindingNormalizedNodeCacheHolder {
    @SuppressWarnings("rawtypes")
    private final LoadingCache<NodeCodecContext, AbstractBindingNormalizedNodeCache> caches = CacheBuilder
            .newBuilder().build(new CacheLoader<NodeCodecContext, AbstractBindingNormalizedNodeCache>() {
                @Override
                public AbstractBindingNormalizedNodeCache load(final NodeCodecContext key) {
                    if (key instanceof DataContainerCodecContext) {
                        return new DataObjectNormalizedNodeCache(AbstractBindingNormalizedNodeCacheHolder.this,
                            (DataContainerCodecContext<?, ?>) key);
                    } else if (key instanceof OfTypeObject) {
                        return new TypeObjectNormalizedNodeCache<>((OfTypeObject)key);
                    } else {
                        throw new IllegalStateException("Unhandled context " + key);
                    }
                }
            });

    private final ImmutableSet<Class<? extends BindingObject>> cacheSpec;

    AbstractBindingNormalizedNodeCacheHolder(final ImmutableSet<Class<? extends BindingObject>> cacheSpec) {
        this.cacheSpec = requireNonNull(cacheSpec);
    }

    @SuppressWarnings("unchecked")
    <T extends BindingObject, C extends NodeCodecContext & BindingObjectCodecTreeNode<?>>
            AbstractBindingNormalizedNodeCache<T, C> getCachingSerializer(final C childCtx) {
        return isCached(childCtx.getBindingClass()) ? caches.getUnchecked(childCtx) : null;
    }

    final boolean isCached(final Class<? extends BindingObject> type) {
        return cacheSpec.contains(type);
    }
}