/*
    * Copyright 2016 The Lannister Project
    * 
    * Licensed 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 net.anyflow.lannister.cluster;
  
  import java.util.HashMap;
  
  import com.google.common.collect.Maps;
  import com.hazelcast.core.IdGenerator;
  
  public class HazelcastSetValueMap<K, V> implements Map<K, Set<V>> {
  	private static final IdGenerator ID_GENERATOR = Hazelcast.INSTANCE.getIdGenerator("HazelcastSetValueMap");
  
  	private final com.hazelcast.core.IMap<K, String> engine;
  	private final HashMap<String, Set<V>> values;
  	private final String valueKeyPrefix;
  
  	public HazelcastSetValueMap(String name) {
  		engine = Hazelcast.INSTANCE.getMap(name);
  		values = Maps.newHashMap();
  		valueKeyPrefix = Long.toString(ID_GENERATOR.newId());
  	}
  
  	@Override
  	public void put(K key, Set<V> value) {
  		String valueKey = valueKey(key);
  
  		Set<V> prev = values.put(valueKey, value);
  		if (prev != null) {
  			prev.dispose();
  		}
  
  		engine.set(key, valueKey);
  	}
  
  	private String valueKey(K key) {
  		return valueKeyPrefix + "_" + key.toString();
  	}
  
  	@Override
  	public Set<V> get(K key) {
  		return values.get(engine.get(key));
  	}
  
  	@Override
  	public Set<V> remove(K key) {
  		String valueKey = engine.remove(key);
  		if (valueKey == null) { return null; }
  
  		return values.remove(valueKey);
  	}
  
  	@Override
  	public int size() {
  		return engine.size();
  	}
  
  	@Override
  	public void dispose() {
  		engine.destroy();
  	}
  
  	@Override
  	public boolean containsKey(K key) {
  		return engine.containsKey(key);
  	}
  
  	@Override
  	public java.util.Set<K> keySet() {
  		return engine.keySet();
  	}
  }