EDIT

import java.util.HashSet;

import java.util.Set;

import eu.etaxonomy.cdm.hibernate.HibernateProxyHelper;

import eu.etaxonomy.cdm.model.description.TaxonDescription;

import eu.etaxonomy.cdm.model.name.TaxonNameBase;

import eu.etaxonomy.cdm.model.reference.Reference;

import eu.etaxonomy.cdm.model.taxon.Synonym;

import eu.etaxonomy.cdm.model.taxon.SynonymRelationship;

import eu.etaxonomy.cdm.model.taxon.SynonymRelationshipType;

import eu.etaxonomy.cdm.model.taxon.Taxon;

import eu.etaxonomy.cdm.model.taxon.TaxonRelationship;

	/* (non-Javadoc)

	 * @see eu.etaxonomy.cdm.api.service.ITaxonService#makeTaxonSynonym(eu.etaxonomy.cdm.model.taxon.Taxon, eu.etaxonomy.cdm.model.taxon.Taxon)

	 */

	@Transactional(readOnly = false)

	public Synonym makeTaxonNodeASynonymOfAnotherTaxonNode(TaxonNode oldTaxonNode, TaxonNode newAcceptedTaxonNode, SynonymRelationshipType synonymRelationshipType, Reference citation, String citationMicroReference) {

		// TODO at the moment this method only moves synonym-, concept relations and descriptions to the new accepted taxon

		// in a future version we also want to move cdm data like annotations, marker, so., but we will need a policy for that

		if (oldTaxonNode == null || newAcceptedTaxonNode == null || oldTaxonNode.getTaxon().getName() == null){

			throw new IllegalArgumentException("A mandatory parameter was null.");

		}

		if(oldTaxonNode.equals(newAcceptedTaxonNode)){

			throw new IllegalArgumentException("Taxon can not be made synonym of its own.");

		}

		Taxon oldTaxon = (Taxon) HibernateProxyHelper.deproxy(oldTaxonNode.getTaxon());

		Taxon newAcceptedTaxon = (Taxon) HibernateProxyHelper.deproxy(newAcceptedTaxonNode.getTaxon());

		// Move oldTaxon to newTaxon

		TaxonNameBase<?,?> synonymName = oldTaxon.getName();

		if (synonymRelationshipType == null){

			if (synonymName.isHomotypic(newAcceptedTaxon.getName())){

				synonymRelationshipType = SynonymRelationshipType.HOMOTYPIC_SYNONYM_OF();

			}else{

				synonymRelationshipType = SynonymRelationshipType.HETEROTYPIC_SYNONYM_OF();

			}

		}

		SynonymRelationship synonmyRelationship = newAcceptedTaxon.addSynonymName(synonymName, synonymRelationshipType, citation, citationMicroReference);

		//Move Synonym Relations to new Taxon

		for(SynonymRelationship synRelation : oldTaxon.getSynonymRelations()){

			newAcceptedTaxon.addSynonym(synRelation.getSynonym(), synRelation.getType(), 

					synRelation.getCitation(), synRelation.getCitationMicroReference());

		}

		// CHILD NODES

		if(oldTaxonNode.getChildNodes() != null && oldTaxonNode.getChildNodes().size() != 0){

			for(TaxonNode childNode : oldTaxonNode.getChildNodes()){

				newAcceptedTaxonNode.addChildNode(childNode, childNode.getReference(), childNode.getMicroReference(), childNode.getSynonymToBeUsed());

			}

		}

		//Move Taxon RelationShips to new Taxon

		Set<TaxonRelationship> obsoleteTaxonRelationships = new HashSet<TaxonRelationship>();

		for(TaxonRelationship taxonRelationship : oldTaxon.getTaxonRelations()){

			Taxon fromTaxon = (Taxon) HibernateProxyHelper.deproxy(taxonRelationship.getFromTaxon());

			Taxon toTaxon = (Taxon) HibernateProxyHelper.deproxy(taxonRelationship.getToTaxon());

			if (fromTaxon == oldTaxon){

				newAcceptedTaxon.addTaxonRelation(taxonRelationship.getToTaxon(), taxonRelationship.getType(), 

						taxonRelationship.getCitation(), taxonRelationship.getCitationMicroReference());

			}else if(toTaxon == oldTaxon){

				taxonRelationship.getFromTaxon().addTaxonRelation(newAcceptedTaxon, taxonRelationship.getType(), 

						taxonRelationship.getCitation(), taxonRelationship.getCitationMicroReference());

			}else{

				logger.warn("Taxon is not part of its own Taxonrelationship");

			}

			// Remove old relationships

			taxonRelationship.setToTaxon(null);

			taxonRelationship.setFromTaxon(null);

		}

		//Move descriptions to new taxon

		for(TaxonDescription description : oldTaxon.getDescriptions()){

			description.setTitleCache("Description copied from former accepted taxon: " + oldTaxon.getTitleCache() + "(Old title: " + description.getTitleCache()  + ")");

			newAcceptedTaxon.addDescription(description);

		}

		oldTaxonNode.delete();

		return synonmyRelationship.getSynonym();

	}