/*
    * Copyright 2004-2006 the Seasar Foundation and the Others.
    *
    * 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.
   */
  package org.seasar.tuigwaa.model.common;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Set;
  
  import org.seasar.framework.container.factory.SingletonS2ContainerFactory;
  import org.seasar.tuigwaa.model.ModelService;
  import org.seasar.tuigwaa.model.core.TgwAttribute;
  import org.seasar.tuigwaa.model.core.TgwDomain;
  import org.seasar.tuigwaa.model.core.TgwEntity;
  import org.seasar.tuigwaa.model.core.impl.FkAttribute;
  import org.seasar.tuigwaa.util.TgwUtils;
  
  
  public class DomainUtils {
  
  	public static Collection getEntityTree(TgwDomain domain) {
  		return null;
  	}
  
  	public static Collection getReferencedEntities(TgwEntity entity) {
  		Set inverseRefSet = new HashSet();
  		// inverseRefSet.add(entity);
  		entity.accept(ADD_INVERSEREF_ENTITY_VISITOR, inverseRefSet);
  		return inverseRefSet;
  	}
  
  	public static Collection getReferenceEntities(TgwEntity entity) {
  		throw new UnsupportedOperationException();
  	}
  
  	public static Collection getCrossReferenceEntities(TgwEntity entity) {
  		Set refSet = new HashSet();
  		addCrossReferenceEntities(entity, refSet);
  		return refSet;
  	}
  
  	private static void addCrossReferenceEntities(TgwEntity entity,
  			Collection entities) {
  		Iterator itr = entity.getFieldList().iterator();
  		while (itr.hasNext()) {
  			TgwAttribute attr = (TgwAttribute) itr.next();
  			if (attr instanceof FkAttribute
  					&& ((FkAttribute) attr).getInverseField() != null) {
  				TgwEntity refEntity = ((FkAttribute) attr).getRefEntity();
  				if (!entities.contains(refEntity)) {
  					entities.add(refEntity);
  					addCrossReferenceEntities(refEntity, entities);
  				}
  			}
  		}
  	}
  
  	public static List getSortedTalbeNames(String schema){
  		List list = sortByReference(schema);
  		List ret = new ArrayList();
  		if(list == null){
  			return ret;
  		}
  		for(Iterator i=list.iterator();i.hasNext();){
  			String tableName = TgwUtils.toTableName((TgwEntity)i.next());
  			ret.add(tableName);
  		}
  		return ret;
  	}
  	
  	public static List sortByReference(String domainName) {
  		TgwDomain domain = ((ModelService) SingletonS2ContainerFactory
  				.getContainer().getComponent(ModelService.class))
  				.getDomain(domainName);
  		return sortByReference(domain);
  	}
  
  	public static List sortByNoReference(TgwDomain domain) {
  		List entityList = domain.getEntityList();
  		return sortByNoReference(entityList);
  	}
  
  	public static List sortByReference(TgwDomain domain) {
  		List entityList = domain.getEntityList();
 		return sortByNoReference(entityList);
 	}
 
 	public static List sortByReference(Collection entities) {
 		List sortedList = new ArrayList();
 		sortByReference(sortedList, entities);
 		return sortedList;
 	}
 
 	public static List sortByNoReference(Collection entities) {
 		List sortedList = new ArrayList();
 		sortByNoReference(sortedList, entities);
 		return sortedList;
 	}
 
 	private static void sortByNoReference(List sortedList, Collection entityList) {
 		List notSortedList = new ArrayList();
 		for (Iterator i = entityList.iterator(); i.hasNext();) {
 			TgwEntity entity = (TgwEntity) i.next();
 			if (Boolean.TRUE.equals(entity.accept(SORT_VISITOR, sortedList))) {
 				sortedList.add(entity);
 			} else {
 				notSortedList.add(entity);
 			}
 		}
 		if (notSortedList.size() > 0) {
 			sortByNoReference(sortedList, notSortedList);
 		}
 	}
 
 	private static void sortByReference(List sortedList, Collection entityList) {
 		List notSortedList = new ArrayList();
 		for (Iterator i = entityList.iterator(); i.hasNext();) {
 			TgwEntity entity = (TgwEntity) i.next();
 			if (hasReferenced(entity, sortedList)) {
 				sortedList.add(entity);
 			} else {
 				notSortedList.add(entity);
 			}
 		}
 		if (notSortedList.size() > 0) {
 			sortByReference(sortedList, notSortedList);
 		}
 	}
 
 	private static boolean hasReferenced(TgwEntity entity, List sortedList) {
 		List referencedList = entity.getReferencedFkFieldList();
 		boolean flag = true;
 		for (Iterator i = referencedList.iterator(); i.hasNext();) {
 			FkAttribute fk = (FkAttribute) i.next();
 			TgwEntity refedEntity = fk.getEntity();
 			if (!sortedList.contains(refedEntity)) {
 				return false;
 			}
 		}
 		return flag;
 	}
 
 	private static TgwElementVisitor SORT_VISITOR = new DefaultTuigwaaElementVisitor() {
 
 		/***
 		 * @return if true , the entity has no foreign key or an entity of the
 		 *         foreign key has already inserted into sorted set.
 		 */
 		public Object visit(TgwEntity entity, Object sortedList) {
 			boolean flag = true;
 			Collection col = entity.getFieldList();
 			for (Iterator i = col.iterator(); i.hasNext();) {
 				TgwAttribute attr = (TgwAttribute) i.next();
 				if (attr instanceof FkAttribute) {
 					if (Boolean.FALSE.equals(attr.accept(this, sortedList))) {
 						return Boolean.FALSE;
 					}
 				}
 			}
 			return new Boolean(flag);
 		}
 
 		public Object visit(FkAttribute attr, Object data) {
 			TgwEntity refEntity = attr.getRefEntity();
 			List sortedList = (List) data;
 			if (!sortedList.contains(refEntity)) {
 				return Boolean.FALSE;
 			}
 			return refEntity.accept(this, data);
 		}
 
 	};
 
 	private static final TgwElementVisitor ADD_INVERSEREF_ENTITY_VISITOR = new DefaultTuigwaaElementVisitor() {
 
 		public Object visit(FkAttribute attr, Object obj) {
 			Set entityList = (Set) obj;
 			TgwEntity entity = attr.getEntity();
 			entityList.add(entity);
 			entity.accept(this, entityList);
 			return null;
 		}
 
 		public Object visit(TgwEntity entity, Object obj) {
 			Set entityList = (Set) obj;
 			List list = entity.getReferencedFkFieldList();
 			for (Iterator i = list.iterator(); i.hasNext();) {
 				FkAttribute fkFiled = (FkAttribute) i.next();
 				fkFiled.accept(this, entityList);
 			}
 			return null;
 		}
 	};
 }