/**
 * ============LICENSE_START====================================================
 * org.onap.aaf
 * ===========================================================================
 * Copyright (c) 2018 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====================================================
 *
 */

/**
 * JAXBumar.java
 *
 * Created on: Apr 10, 2009
 * Created by: Jonathan
 *
 * Revamped to do away with ThreadLocal 5/27/2011, JonathanGathman
 *
 * (c) 2009 SBC Knowledge Ventures, L.P. All rights reserved.
 ******************************************************************* 
 * RESTRICTED - PROPRIETARY INFORMATION The Information contained 
 * herein is for use only by authorized employees of AT&T Services, 
 * Inc., and authorized Affiliates of AT&T Services, Inc., and is 
 * not for general distribution within or outside the respective 
 * companies. 
 *******************************************************************
 */
package org.onap.aaf.misc.env.jaxb;

import java.io.File;
import java.io.InputStream;
import java.io.Reader;
import java.io.StringReader;
import java.util.HashMap;
import java.util.Map;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLStreamReader;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.Schema;

import org.onap.aaf.misc.env.APIException;
import org.onap.aaf.misc.env.LogTarget;
import org.onap.aaf.misc.env.util.Pool;
import org.onap.aaf.misc.env.util.Pool.Pooled;
import org.w3c.dom.Node;

/**
 * JAXBumar classes are inexpensive for going in and out of scope
 * and have been made thread safe via Pooling
 * 
 * @author Jonathan
 *
 */
public class JAXBumar {
	// Need to store off possible JAXBContexts based on Class, which will be stored in Creator
	private static Map<Class<?>[],Pool<SUnmarshaller>> pools = new HashMap<Class<?>[], Pool<SUnmarshaller>>();

	private Class<?> cls;
	private Schema schema;
	private Pool<SUnmarshaller> mpool;;

	// Handle Marshaller class setting of properties only when needed
	private class SUnmarshaller {
		private Unmarshaller u;
		private Schema s;
		
		public SUnmarshaller(Unmarshaller unmarshaller) throws JAXBException {
			u = unmarshaller;
			s = null;
		}
		
		public Unmarshaller get(Schema schema) throws JAXBException {
			if(s != schema) {
				u.setSchema(s = schema);
			}
			return u;
		}
	}
	
	private class Creator implements Pool.Creator<SUnmarshaller> {
		private JAXBContext jc;
		private String name;
		
		public Creator(Class<?>[] classes) throws JAXBException {
			jc = JAXBContext.newInstance(classes);
			name = "JAXBumar: " + classes[0].getName();
		}
		
		// @Override
		public SUnmarshaller create() throws APIException {
			try {
				return new SUnmarshaller(jc.createUnmarshaller());
			} catch (JAXBException e) {
				throw new APIException(e);
			}
		}
		
		public String toString() {
			return name;
		}

		// @Override
		public void destroy(SUnmarshaller sui) {
			// Nothing to do
		}
		
		// @Override
		public boolean isValid(SUnmarshaller t) {
			return true; 
		}

		// @Override
		public void reuse(SUnmarshaller t) {
			// Nothing to do here
		}

	}

	private Pool<SUnmarshaller> getPool(Class<?> ... classes) throws JAXBException {
		Pool<SUnmarshaller> mp;
		synchronized(pools) {
			mp = pools.get(classes);
			if(mp==null) {
				pools.put(classes,mp = new Pool<SUnmarshaller>(new Creator(classes)));
			}
		}		
		return mp;
	}

	public JAXBumar(Class<?> ... classes) throws JAXBException {
		cls = classes[0];
		mpool = getPool(classes);
		schema = null;
	}
	
	/**
	 * Constructs a new JAXBumar with schema validation enabled.
	 * 
	 * @param schema
	 * @param theClass
	 * @throws JAXBException
	 */
	public JAXBumar(Schema schema, Class<?> ... classes) throws JAXBException {
		cls = classes[0];
		mpool = getPool(classes);
		this.schema = schema;
	}
	
	@SuppressWarnings("unchecked")
	public<O> O unmarshal(LogTarget env, Node node) throws JAXBException, APIException {
		Pooled<SUnmarshaller> s = mpool.get(env);
		try {
			return s.content.get(schema).unmarshal(node,(Class<O>)cls).getValue();
		} finally {
			s.done();
		}

	}
	
	@SuppressWarnings("unchecked")
	public<O> O unmarshal(LogTarget env, String xml) throws JAXBException, APIException {
		if(xml==null) throw new JAXBException("Null Input for String unmarshal");
		Pooled<SUnmarshaller> s = mpool.get(env);
		try {
				return (O)s.content.get(schema).unmarshal(
					new StreamSource(new StringReader(xml))
					,(Class<O>)cls).getValue();
		} finally {
			s.done();
		}
	}
	
	@SuppressWarnings("unchecked")
	public<O> O unmarshal(LogTarget env, File xmlFile) throws JAXBException, APIException {
		Pooled<SUnmarshaller> s = mpool.get(env);
		try {
			return (O)s.content.get(schema).unmarshal(xmlFile);
		} finally {
			s.done();
		}

	}
	
	@SuppressWarnings("unchecked")
	public<O> O unmarshal(LogTarget env,InputStream is) throws JAXBException, APIException {
		Pooled<SUnmarshaller> s = mpool.get(env);
		try {
			return (O)s.content.get(schema).unmarshal(is);
		} finally {
			s.done();
		}
	}

	@SuppressWarnings("unchecked")
	public<O> O unmarshal(LogTarget env, Reader rdr) throws JAXBException, APIException {
		Pooled<SUnmarshaller> s = mpool.get(env);
		try {
			return (O)s.content.get(schema).unmarshal(rdr);
		} finally {
			s.done();
		}
	}

	@SuppressWarnings("unchecked")
	public<O> O unmarshal(LogTarget env, XMLStreamReader xsr) throws JAXBException, APIException {
		Pooled<SUnmarshaller> s = mpool.get(env);
		try {
			return (O)s.content.get(schema).unmarshal(xsr,(Class<O>)cls).getValue();
		} finally {
			s.done();
		}
	}

	@SuppressWarnings("unchecked")
	public<O> O unmarshal(LogTarget env, XMLEventReader xer) throws JAXBException, APIException {
		Pooled<SUnmarshaller> s = mpool.get(env);
		try {
			return (O)s.content.get(schema).unmarshal(xer,(Class<O>)cls).getValue();
		} finally {
			s.done();
		}
	}

	@SuppressWarnings("unchecked")
	public<O> O newInstance() throws InstantiationException, IllegalAccessException{
		return ((Class<O>)cls).newInstance();
	}
}