/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.dialect.function;

import java.util.Map;
import java.util.TreeMap;

import org.hibernate.dialect.Dialect;

/**
 * Defines a registry for SQLFunction instances
 *
 * @author Steve Ebersole
 */
public class SQLFunctionRegistry {
	private final Map<String,SQLFunction> functionMap = new TreeMap<String, SQLFunction>(String.CASE_INSENSITIVE_ORDER);

	/**
	 * Constructs a SQLFunctionRegistry
	 *
	 * @param dialect The dialect
	 * @param userFunctionMap Any application-supplied function definitions
	 */
	public SQLFunctionRegistry(Dialect dialect, Map<String, SQLFunction> userFunctionMap) {
		// Apply the Dialect functions first
		functionMap.putAll( dialect.getFunctions() );
		// so that user supplied functions "override" them
		if ( userFunctionMap != null ) {
			functionMap.putAll( userFunctionMap );
		}
	}

	/**
	 * Find a SQLFunction by name
	 *
	 * @param functionName The name of the function to locate
	 *
	 * @return The located function, maye return {@code null}
	 */
	public SQLFunction findSQLFunction(String functionName) {
		return functionMap.get( functionName );
	}

	/**
	 * Does this registry contain the named function
	 *
	 * @param functionName The name of the function to attempt to locate
	 *
	 * @return {@code true} if the registry contained that function
	 */
	@SuppressWarnings("UnusedDeclaration")
	public boolean hasFunction(String functionName) {
		return functionMap.containsKey( functionName );
	}

}