EDIT

// $Id$

/**

* Copyright (C) 2007 EDIT

* European Distributed Institute of Taxonomy 

* http://www.e-taxonomy.eu

* 

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.strategy.match;

import java.lang.annotation.Annotation;

import java.lang.reflect.Field;

import java.lang.reflect.GenericDeclaration;

import java.lang.reflect.Type;

import java.net.URI;

import java.util.ArrayList;

import java.util.Collection;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.Set;

import java.util.UUID;

import org.apache.log4j.Logger;

import sun.reflect.generics.reflectiveObjects.ParameterizedTypeImpl;

import sun.reflect.generics.reflectiveObjects.TypeVariableImpl;

import eu.etaxonomy.cdm.common.CdmUtils;

import eu.etaxonomy.cdm.common.DoubleResult;

import eu.etaxonomy.cdm.hibernate.HibernateProxyHelper;

import eu.etaxonomy.cdm.model.common.CdmBase;

import eu.etaxonomy.cdm.strategy.StrategyBase;

import eu.etaxonomy.cdm.strategy.match.Match.ReplaceMode;

/**

 * @author a.mueller

 * @created 06.08.2009

 * @version 1.0

 */

public class DefaultMatchStrategy extends StrategyBase implements IMatchStrategy {

	private static final long serialVersionUID = 5045874493910155162L;

	private static final Logger logger = Logger.getLogger(DefaultMatchStrategy.class);

	final static UUID uuid = UUID.fromString("69467b70-07ec-43a6-b779-3ec8d013837b");

	public static DefaultMatchStrategy NewInstance(Class<? extends IMatchable> matchClazz){

		return new DefaultMatchStrategy(matchClazz);

	}

//	protected Map<String, MatchMode> matchModeMap = new HashMap<String, MatchMode>();

	protected MatchMode defaultMatchMode = MatchMode.EQUAL;

	protected MatchMode defaultCollectionMatchMode = MatchMode.IGNORE;

	protected MatchMode defaultMatchMatchMode = MatchMode.MATCH;

	protected Class<? extends IMatchable> matchClass;

	protected Map<String, Field> matchFields;

	protected Matching matching = new Matching();

	protected DefaultMatchStrategy(Class<? extends IMatchable> matchClazz) {

		super();

		if (matchClazz == null){

			throw new IllegalArgumentException("Match class must not be null");

		}

		this.matchClass = matchClazz;

		initMapping();

	}

	/**

	 * @return the merge class

	 */

	public Class<? extends IMatchable> getMatchClass() {

		return matchClass;

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.cdm.strategy.StrategyBase#getUuid()

	 */

	@Override

	protected UUID getUuid() {

		return uuid;

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.cdm.strategy.match.IMatchStrategy#getMatching()

	 */

	public Matching getMatching() {

		return matching;

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.cdm.strategy.match.IMatchStrategy#setMatchMode(java.lang.String, eu.etaxonomy.cdm.strategy.match.MatchMode)

	 */

	public void setMatchMode(String propertyName, MatchMode matchMode)

			throws MatchException {

		if (matchFields.containsKey(propertyName)){

			FieldMatcher fieldMatcher = FieldMatcher.NewInstance(matchFields.get(propertyName), matchMode);

			matching.setFieldMatcher(fieldMatcher);

		}else{

			throw new MatchException("The class " + matchClass.getName() + " does not contain a field named " + propertyName);

		}

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.cdm.strategy.match.IMatchStrategy#getMatchMode(java.lang.String)

	 */

	public MatchMode getMatchMode(String propertyName) {

		FieldMatcher fieldMatcher = matching.getFieldMatcher(propertyName);

		return fieldMatcher == null ? defaultMatchMode : fieldMatcher.getMatchMode();

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.cdm.strategy.match.IMatchStrategy#invoke(eu.etaxonomy.cdm.strategy.match.IMatchable, eu.etaxonomy.cdm.strategy.match.IMatchable)

	 */

	public <T extends IMatchable> boolean invoke(T matchFirst, T matchSecond)

			throws MatchException {

		boolean result = true;

		if (matchFirst == null || matchSecond == null){

			return false;

		}else if (matchFirst == matchSecond){

			return true;

		}else if (matchFirst.getClass() != matchSecond.getClass()){

			matchFirst = (T) HibernateProxyHelper.deproxy(matchFirst);

			matchSecond = (T) HibernateProxyHelper.deproxy(matchSecond);

			if (matchFirst.getClass() != matchSecond.getClass()){

				return false;

			}

		}

		matching.deleteTemporaryMatchers(); //just in case they are not yet deleted during last invoke

		if (! matchClass.isAssignableFrom(matchFirst.getClass()) ){

			throw new MatchException("Match object are of different type than the match class (" + matchClass + ") this match strategy was created with");

		}else if (matchClass != matchFirst.getClass()){

			initializeSubclass(matchFirst.getClass());

		}

		try {

			result = invokeChecked(matchFirst, matchSecond, result);

		}catch (MatchException e) {

			throw e;

		}finally{

			matching.deleteTemporaryMatchers();

		}

		return result;

	}

	/**

	 * @param class1

	 */

	private void initializeSubclass(Class<? extends IMatchable> instanceClass) {

		Map<String, Field> subClassFields = CdmUtils.getAllFields(instanceClass, matchClass, false, false, true, false);

		for (Field field: subClassFields.values()){

			initField(field, true);

		}

	}

	/**

	 * @param <T>

	 * @param matchFirst

	 * @param matchSecond

	 * @param result

	 * @return

	 * @throws MatchException

	 */

	private <T extends IMatchable> boolean invokeChecked(T matchFirst, T matchSecond,

			boolean result) throws MatchException {

		//matchFirst != matchSecond != null

		try {

			Map<String, List<MatchMode>> replaceMatchers = new HashMap<String, List<MatchMode>>();

			for (CacheMatcher cacheMatcher: matching.getCacheMatchers()){

				Field protectedField = cacheMatcher.getProtectedField(matching);

				boolean protected1 = protectedField.getBoolean(matchFirst);

				boolean protected2 = protectedField.getBoolean(matchFirst);

				if (protected1 != protected2){

					return false;

				}else if (protected1 == false){

					//ignore

				}else{

					String cache1 = (String)cacheMatcher.getField().get(matchFirst);

					String cache2 = (String)cacheMatcher.getField().get(matchSecond);

					result = cacheMatcher.getMatchMode().matches(cache1, cache2, null);

					if (result == false){

						return false;

					}

					List<DoubleResult<String, MatchMode>> replacementModes = cacheMatcher.getReplaceMatchModes(matching);

					for (DoubleResult<String, MatchMode> replacementMode: replacementModes ){

						String propertyName = replacementMode.getFirstResult();

						List<MatchMode> replaceMatcherList = replaceMatchers.get(propertyName);

						if (replaceMatcherList == null){

							replaceMatcherList = new ArrayList<MatchMode>();

							replaceMatchers.put(propertyName, replaceMatcherList);

						}

						replaceMatcherList.add(replacementMode.getSecondResult());

					}

				}

			}

			for (FieldMatcher fieldMatcher : matching.getFieldMatchers(true)){

				Field field = fieldMatcher.getField();

				List<MatchMode> replaceModeList = replaceMatchers.get(fieldMatcher.getPropertyName());

				if (replaceModeList == null){

					replaceModeList = new ArrayList<MatchMode>();

				}

				Class<?> fieldType = field.getType();

				logger.debug(field.getName() + ": ");

				if (isPrimitive(fieldType)){

					result &= matchPrimitiveField(matchFirst, matchSecond, fieldMatcher, replaceModeList);

				}else if (fieldType == String.class ){

					result &= matchPrimitiveField(matchFirst, matchSecond, fieldMatcher, replaceModeList);

				}else if(isUserType(fieldType)){

					result &= matchPrimitiveField(matchFirst, matchSecond, fieldMatcher, replaceModeList);

				}else if(fieldType == UUID.class){

					//result &= matchPrimitiveField(matchFirst, matchSecond, fieldMatcher, replaceModeList);

				}else if(fieldType == URI.class){

					result &= matchPrimitiveField(matchFirst, matchSecond, fieldMatcher, replaceModeList);

				}else if(isSingleCdmBaseObject(fieldType)){

					result &= matchPrimitiveField(matchFirst, matchSecond, fieldMatcher, replaceModeList);

				}else if (isCollection(fieldType)){

					result &= matchCollectionField(matchFirst, matchSecond, fieldMatcher, replaceModeList);

				}else if(fieldType.isInterface()){

					result &= matchPrimitiveField(matchFirst, matchSecond, fieldMatcher, replaceModeList);

				}else if(fieldType.isEnum()){

					result &= matchPrimitiveField(matchFirst, matchSecond, fieldMatcher, replaceModeList);

				}else{

					throw new RuntimeException("Unknown Object type for matching: " + fieldType);

				}

//				if (result == false){

//					return result;

//				}

			}

		} catch (Exception e) {

			throw new MatchException("Match Exception in invoke", e);

		}

		return result;

	}

	/**

	 * @throws Exception 

	 * 

	 */

	private <T extends IMatchable> boolean matchPrimitiveField(T matchFirst, T matchSecond, FieldMatcher fieldMatcher, List<MatchMode> replaceModeList) throws Exception {

		Field field = fieldMatcher.getField();

		Object value1 = checkEmpty(field.get(matchFirst));

		Object value2 = checkEmpty(field.get(matchSecond));

		IMatchStrategy matchStrategy = fieldMatcher.getMatchStrategy();

		boolean result = fieldMatcher.getMatchMode().matches(value1, value2, matchStrategy);

		for (MatchMode replaceMode : replaceModeList){

			if (result == true){

				break; 

			}

			result |= replaceMode.matches(value1, value2, null);

		}

		logger.debug(fieldMatcher.getMatchMode() + ", " + field.getType().getName()+ ": " + result);

		return result;

	}

	/**

	 * @throws Exception 

	 * 

	 */

	private <T extends IMatchable> boolean matchCollectionField(T matchFirst, T matchSecond, FieldMatcher fieldMatcher, List<MatchMode> replaceModeList) throws Exception {

		boolean result;

		Field field = fieldMatcher.getField();

		Collection value1 = (Collection)field.get(matchFirst);

		Collection value2 = (Collection)field.get(matchSecond);

		MatchMode matchMode = fieldMatcher.getMatchMode();

		Class<?> fieldType = fieldMatcher.getField().getType();

		IMatchStrategy matchStrategy = fieldMatcher.getMatchStrategy();

		if (matchMode.isMatch()){

			Class collectionType = getTypeOfSet(field);

			if (! IMatchable.class.isAssignableFrom(collectionType)){

				//TODO

				return fieldMatcher.getMatchMode().matches(value1, value2, matchStrategy);	

			}

			if (matchStrategy == null){

				matchStrategy = DefaultMatchStrategy.NewInstance(collectionType);

			}

			if (Set.class.isAssignableFrom(fieldType)){

				result = matchSet(value1, value2, matchStrategy);

			}else if (List.class.isAssignableFrom(fieldType)){

				result = matchList(value1, value2, matchStrategy);

			}else{

				throw new MatchException("Collection type not yet supported: " + fieldType);

			}

		}else{

			result = fieldMatcher.getMatchMode().matches(value1, value2, matchStrategy);

		}

		//cache replace modes

		for (MatchMode replaceMode : replaceModeList){

			if (result == true){

				break; 

			}

			result |= replaceMode.matches(value1, value2, null);

		}

		logger.debug(fieldMatcher.getMatchMode() + ", " + field.getType().getName()+ ": " + result);

		return result;

	}

	/**

	 * @param object

	 * @return

	 */

	private Object checkEmpty(Object object) {

		if (object instanceof String){

			if (CdmUtils.isEmpty((String)object)){

				return null;

			}

		}

		return HibernateProxyHelper.deproxy(object);

	}

	/**

	 * @param value1

	 * @param matchStrategy

	 * @return

	 * @throws MatchException

	 */

	private boolean matchSet(Collection value1, Collection value2, IMatchStrategy matchStrategy)

			throws MatchException {

		boolean result;

		Set<IMatchable> set1 = (Set<IMatchable>)value1;

		Set<IMatchable> set2 = (Set<IMatchable>)value2;

		if (set1.size()!= set2.size()){

			return false;

		}

		result = true;

		for (IMatchable setItem1: set1){

			boolean matches = false;

			for (IMatchable setItem2: set2){

				matches |= matchStrategy.invoke(setItem1, setItem2);

			}

			if (matches == false){

				return false;

			}

		}

		return result;

	}

	/**

	 * @param value1

	 * @param matchStrategy

	 * @return

	 * @throws MatchException

	 */

	private boolean matchList(Collection value1, Collection value2, IMatchStrategy matchStrategy)

			throws MatchException {

		boolean result;

		List<IMatchable> list1 = (List<IMatchable>)value1;

		List<IMatchable> list2 = (List<IMatchable>)value2;

		if(list1 == null && list2 == null) {

			return true;

		}

		if ((list1 != null && list2 == null) || (list1 == null && list2 != null) || (list1.size()!= list2.size())){

			return false;

		}

		result = true;

		for (int i = 0; i < list1.size(); i++){

			IMatchable listObject1 = list1.get(i);

			IMatchable listObject2 = list2.get(i);

			if (! matchStrategy.invoke(listObject1, listObject2)){

				return false;

			}

		}

		return result;

	}

	private Class getTypeOfSet(Field field) throws MatchException{

		Type genericType = (ParameterizedTypeImpl)field.getGenericType();

		if (genericType instanceof ParameterizedTypeImpl){

			ParameterizedTypeImpl paraType = (ParameterizedTypeImpl)genericType;

			paraType.getRawType();

			Type[] arguments = paraType.getActualTypeArguments();

			if (arguments.length == 1){

				Class collectionClass;

				try {

					if (arguments[0] instanceof Class){

						return (Class)arguments[0];

					}else if(arguments[0] instanceof TypeVariableImpl){

						TypeVariableImpl typeVariable = (TypeVariableImpl)arguments[0];

						GenericDeclaration genericDeclaration = typeVariable.getGenericDeclaration();

						return (Class)genericDeclaration;

					}else{

						logger.warn("Unknown Type");

						throw new MatchException("");

					}

				} catch (Exception e) {

					logger.warn(e.getMessage());

					throw new MatchException("");

				}

			}else{

				logger.warn("Length of arguments <> 1");

				throw new MatchException("");

			}

		}else{

			logger.warn("Not a generic type of type ParameterizedTypeImpl");

			throw new MatchException("Collection type could not be determined. Generic type is not of type ParamterizedTypeImpl");

		}

	}

	/**

	 * 

	 */

	private void initMapping() {

		boolean includeStatic = false;

		boolean includeTransient = false;

		boolean makeAccessible = true;

		matchFields = CdmUtils.getAllFields(matchClass, CdmBase.class, includeStatic, includeTransient, makeAccessible, true);

		for (Field field: matchFields.values()){

			initField(field, false);

		}

	}

	/**

	 * Initializes the matching for a single field

	 * @param field

	 */

	private void initField(Field field, boolean temporary) {

		MatchMode matchMode = null;

		IMatchStrategy matchStrategy = null;

		for (Annotation annotation : field.getAnnotations()){

			if (annotation.annotationType() == Match.class){

				Match match = ((Match)annotation);

				matchMode = match.value();

				if (matchMode == MatchMode.CACHE){

					ReplaceMode replaceMode = match.cacheReplaceMode();

					String[] cachePropertyReplaces = match.cacheReplacedProperties();

					MatchMode replaceMatchMode = match.replaceMatchMode();

					matching.addCacheMatcher(CacheMatcher.NewInstance(field, replaceMode, cachePropertyReplaces, replaceMatchMode));

				}else{

					matching.setFieldMatcher(FieldMatcher.NewInstance(field, matchMode), temporary);

				}

			}

		}

		Class fieldType = field.getType();

		if (matchMode == null){

			if (isCollection(fieldType)){

				matchMode = defaultCollectionMatchMode;

				matching.setFieldMatcher(FieldMatcher.NewInstance(field, matchMode), temporary);

			}else if (fieldType.isInterface()){

				//TODO could be handled more sophisticated

				matchMode = defaultMatchMatchMode;

				matching.setFieldMatcher(FieldMatcher.NewInstance(field, matchMode, matchStrategy), temporary);

			}else if (isSingleCdmBaseObject(fieldType)){

				if (IMatchable.class.isAssignableFrom(fieldType)){

					matchMode = defaultMatchMatchMode;

					if (matchStrategy == null){

						if (fieldType == this.matchClass){

							matchStrategy = this;

						}else{

							matchStrategy = DefaultMatchStrategy.NewInstance(fieldType);

						}

					}

					matching.setFieldMatcher(FieldMatcher.NewInstance(field, matchMode, matchStrategy), temporary);

				}else{

					matchMode = defaultMatchMode;

					matching.setFieldMatcher(FieldMatcher.NewInstance(field, matchMode), temporary);

				}

			}else{

				matchMode = defaultMatchMode;

				matching.setFieldMatcher(FieldMatcher.NewInstance(field, matchMode), temporary);

			}	

		}

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.cdm.strategy.match.IMatchStrategy#getMatchFields()

	 */

	public Set<String> getMatchFieldPropertyNames() {

		return matchFields.keySet();

	}

}