/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008-2011, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.cache.spi;

import java.io.Serializable;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.hibernate.Filter;
import org.hibernate.engine.spi.TypedValue;
import org.hibernate.internal.FilterImpl;
import org.hibernate.type.Type;

/**
 * Allows cached queries to be keyed by enabled filters.
 * 
 * @author Gavin King
 */
public final class FilterKey implements Serializable {
	private String filterName;
	private Map<String,TypedValue> filterParameters = new HashMap<String,TypedValue>();
	
	public FilterKey(String name, Map<String,?> params, Map<String,Type> types) {
		filterName = name;
		for ( Map.Entry<String, ?> paramEntry : params.entrySet() ) {
			Type type = types.get( paramEntry.getKey() );
			filterParameters.put( paramEntry.getKey(), new TypedValue( type, paramEntry.getValue() ) );
		}
	}
	
	public int hashCode() {
		int result = 13;
		result = 37 * result + filterName.hashCode();
		result = 37 * result + filterParameters.hashCode();
		return result;
	}
	
	public boolean equals(Object other) {
		if ( !(other instanceof FilterKey) ) return false;
		FilterKey that = (FilterKey) other;
		if ( !that.filterName.equals(filterName) ) return false;
		if ( !that.filterParameters.equals(filterParameters) ) return false;
		return true;
	}
	
	public String toString() {
		return "FilterKey[" + filterName + filterParameters + ']';
	}
	
	public static Set<FilterKey> createFilterKeys(Map<String,Filter> enabledFilters) {
		if ( enabledFilters.size()==0 ) {
			return null;
		}
		Set<FilterKey> result = new HashSet<FilterKey>();
		for ( Filter filter : enabledFilters.values() ) {
			FilterKey key = new FilterKey(
					filter.getName(),
					( (FilterImpl) filter ).getParameters(),
					filter.getFilterDefinition().getParameterTypes()
			);
			result.add( key );
		}
		return result;
	}
}