+/*
+ * 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.concepts.lang;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Set;
+import java.util.TreeSet;
+
+/**
+ * Composite transformer which aggregates multiple implementation and selects
+ * the one which accepts the input.
+ *
+ *
+ * @author Tony Tkacik
+ *
+ * @param <I>
+ * Input class for transformation
+ * @param <P>
+ * Product of transformation
+ */
+public class CompositeConditionalTransformer<I, P> implements
+ SimpleConditionalTransformer<I, P>,
+ AggregateTransformer<I,P> {
+
+ private final Comparator<TransformerWithPriority<I, P>> comparator = new Comparator<TransformerWithPriority<I, P>>() {
+
+ @Override
+ public int compare(TransformerWithPriority<I, P> o1,
+ TransformerWithPriority<I, P> o2) {
+ return Integer.valueOf(o1.priority).compareTo(Integer.valueOf(o2.priority));
+ }
+
+ };
+ private final Set<TransformerWithPriority<I, P>> transformers;
+
+ public CompositeConditionalTransformer() {
+ // FIXME: Add Ordering
+ transformers = new TreeSet<TransformerWithPriority<I, P>>(comparator);
+ }
+
+ @Override
+ public boolean isAcceptable(I input) {
+ for (SimpleConditionalTransformer<I, P> trans : transformers) {
+ if (trans.isAcceptable(input)) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ @Override
+ public P transform(I input) {
+ for (SimpleConditionalTransformer<I, P> trans : transformers) {
+ if (trans.isAcceptable(input)) {
+ return trans.transform(input);
+ }
+ }
+ throw new IllegalStateException(
+ "Transformer for provided input is not available.");
+ }
+
+ public void addTransformer(SimpleConditionalTransformer<I, P> transformer,
+ int priority) throws IllegalStateException {
+ if (transformer == null) {
+ throw new IllegalArgumentException(
+ "transformer should not be null.");
+ }
+ TransformerWithPriority<I, P> withPriority = new TransformerWithPriority<I, P>(
+ transformer, priority);
+ if (false == transformers.add(withPriority)) {
+ throw new IllegalStateException("transformer " + transformer
+ + "already registered");
+ }
+ }
+
+ public void removeTransformer(SimpleConditionalTransformer<I, P> transformer)
+ throws IllegalArgumentException {
+ if (transformer == null) {
+ throw new IllegalArgumentException(
+ "transformer should not be null.");
+ }
+ if (false == transformers.remove(transformer)) {
+ throw new IllegalStateException("transformer " + transformer
+ + "already registered");
+ }
+ }
+
+ @Override
+ public Collection<P> transformAll(Collection<? extends I> inputs) {
+ Collection<P> ret = new ArrayList<P>();
+ for (I i : inputs) {
+ ret.add(transform(i));
+ }
+ return ret;
+ }
+
+ private static class TransformerWithPriority<I, P> implements
+ SimpleConditionalTransformer<I, P> {
+ final int priority;
+ final SimpleConditionalTransformer<I, P> transformer;
+
+ public TransformerWithPriority(
+ SimpleConditionalTransformer<I, P> transformer, int priority) {
+ this.priority = priority;
+ this.transformer = transformer;
+ }
+
+ @Override
+ public int hashCode() {
+ final int prime = 31;
+ int result = 1;
+ result = prime * result
+ + ((transformer == null) ? 0 : transformer.hashCode());
+ return result;
+ }
+
+ @Override
+ public boolean equals(Object obj) {
+ if (this == obj)
+ return true;
+ if (obj == null)
+ return false;
+ if (getClass() != obj.getClass())
+ return false;
+ TransformerWithPriority<?,?> other = (TransformerWithPriority<?,?>) obj;
+ if (transformer == null) {
+ if (other.transformer != null)
+ return false;
+ } else if (!transformer.equals(other.transformer))
+ return false;
+ return true;
+ }
+
+ @Override
+ public boolean isAcceptable(I input) {
+ return transformer.isAcceptable(input);
+ }
+
+ @Override
+ public P transform(I input) {
+ return transformer.transform(input);
+ }
+
+
+
+
+
+ }
+}