/*-
 * ============LICENSE_START=======================================================
 * ONAP-PDP
 * ================================================================================
 * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * 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.
 * ============LICENSE_END=========================================================
 */
package org.onap.policy.xacml.custom;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.Map;

import org.onap.policy.common.logging.flexlogger.FlexLogger;
import org.onap.policy.common.logging.flexlogger.Logger;
import org.onap.policy.xacml.pdp.std.functions.FunctionDefinitionCustomRegexpMatch;

import com.att.research.xacml.api.Identifier;
import com.att.research.xacml.std.IdentifierImpl;
import com.att.research.xacml.std.datatypes.DataTypes;
import com.att.research.xacmlatt.pdp.policy.FunctionDefinition;
import com.att.research.xacmlatt.pdp.policy.FunctionDefinitionFactory;
import com.att.research.xacmlatt.pdp.std.StdFunctions;

public class OnapFunctionDefinitionFactory extends FunctionDefinitionFactory {
	private static Logger logger = FlexLogger.getLogger(OnapFunctionDefinitionFactory.class);
	private static Map<Identifier,FunctionDefinition> 	mapFunctionDefinitions	= new HashMap<>();
	private static boolean								needMapInit				= true;

	public static final Identifier ID_FUNCTION_CUSTOM_REGEXP_MATCH						= new IdentifierImpl("org.onap.function.regex-match");
	
	private static final FunctionDefinition FD_CUSTOM_REGEXP_MATCH = new FunctionDefinitionCustomRegexpMatch<>(ID_FUNCTION_CUSTOM_REGEXP_MATCH, DataTypes.DT_STRING);

	private static void register(FunctionDefinition functionDefinition) {
		mapFunctionDefinitions.put(functionDefinition.getId(), functionDefinition);
	}
		
	private static void initMap() {

			synchronized(mapFunctionDefinitions) {
				if (needMapInit) {
					needMapInit	= false;
					Field[] declaredFields	= StdFunctions.class.getDeclaredFields();
					for (Field field : declaredFields) {
						if (Modifier.isStatic(field.getModifiers()) && 
							field.getName().startsWith(StdFunctions.FD_PREFIX) &&
							FunctionDefinition.class.isAssignableFrom(field.getType()) &&
							Modifier.isPublic(field.getModifiers())
						) {
							try {
								register((FunctionDefinition)(field.get(null)));
							} catch (IllegalAccessException ex) {
								logger.error(ex.getMessage() +ex);
							}
						}
					}
					//
					// Our custom function
					//
					//register(FunctionDefinitionCustomRegexpMatch);
					register(FD_CUSTOM_REGEXP_MATCH);
				}
			}
	}
	
	public OnapFunctionDefinitionFactory() {
		initMap();
	}

	@Override
	public FunctionDefinition getFunctionDefinition(Identifier functionId) {
		return mapFunctionDefinitions.get(functionId);
	}
}