package cn.hutool.core.map.multi;

import java.util.Collection;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;

/**
 * 值作为集合Set（LinkedHashSet）的Map实现，通过调用putValue可以在相同key时加入多个值，多个值用集合表示
 * 
 * @author looly
 *
 * @param <K> 键类型
 * @param <V> 值类型
 * @since 4.3.3
 */
public class SetValueMap<K, V> extends CollectionValueMap<K, V> {
	private static final long serialVersionUID = 6044017508487827899L;

	// ------------------------------------------------------------------------- Constructor start
	/**
	 * 构造
	 */
	public SetValueMap() {
		this(DEFAULT_INITIAL_CAPACITY);
	}

	/**
	 * 构造
	 * 
	 * @param initialCapacity 初始大小
	 */
	public SetValueMap(int initialCapacity) {
		this(initialCapacity, DEFAULT_LOAD_FACTOR);
	}

	/**
	 * 构造
	 * 
	 * @param m Map
	 */
	public SetValueMap(Map<? extends K, ? extends Collection<V>> m) {
		this(DEFAULT_LOAD_FACTOR, m);
	}

	/**
	 * 构造
	 * 
	 * @param loadFactor 加载因子
	 * @param m Map
	 */
	public SetValueMap(float loadFactor, Map<? extends K, ? extends Collection<V>> m) {
		this(m.size(), loadFactor);
		this.putAll(m);
	}

	/**
	 * 构造
	 * 
	 * @param initialCapacity 初始大小
	 * @param loadFactor 加载因子
	 */
	public SetValueMap(int initialCapacity, float loadFactor) {
		super(new HashMap<K, Collection<V>>(initialCapacity, loadFactor));
	}
	// ------------------------------------------------------------------------- Constructor end

	@Override
	public Set<V> get(Object key) {
		return (Set<V>) super.get(key);
	}
	
	@Override
	protected Collection<V> createCollction() {
		return new LinkedHashSet<>(DEFAULT_COLLCTION_INITIAL_CAPACITY);
	}
}
