/**
 * Licensed to Cloudera, Inc. under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  Cloudera, Inc. licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.cloudera.flume.conf;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import com.cloudera.flume.core.EventSink;
import com.cloudera.flume.core.EventSinkDecorator;
import com.google.common.base.Preconditions;

/**
 * This provides a linked symbol table structure useful for handling symbolic
 * sinks generated by let declarations contexts.
 */
public class LinkedSinkFactory extends SinkFactory {
  SinkFactory parent;
  String sinkname;
  EventSink sink;

  public LinkedSinkFactory(SinkFactory parent, String name, EventSink snk) {
    Preconditions.checkArgument(parent != null);
    Preconditions.checkArgument(name != null);
    Preconditions.checkArgument(snk != null);

    this.parent = parent;
    this.sinkname = name;
    this.sink = snk;
  }

  @Override
  public EventSinkDecorator<EventSink> getDecorator(Context context,
      String name, String... args) throws FlumeSpecException {
    return parent.getDecorator(context, name, args);
  }

  @Override
  public EventSink getSink(Context context, String name, String... args)
      throws FlumeSpecException {
    if (sinkname.equals(name)) {
      // TODO (jon) we are actually close to allowing in sink templates
      return sink;
    }

    return parent.getSink(context, name, args);
  }

  @Override
  public Set<String> getSinkNames() {
    HashSet<String> set = new HashSet<String>(parent.getSinkNames());
    set.add(sinkname);
    return Collections.unmodifiableSet(set);
  }

  @Override
  public Set<String> getDecoratorNames() {
    return parent.getDecoratorNames();
  }
}