EDIT

package eu.etaxonomy.cdm.api.service;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import java.util.Set;

import eu.etaxonomy.cdm.common.Tree;

import eu.etaxonomy.cdm.common.TreeNode;

import eu.etaxonomy.cdm.model.location.NamedArea;

import eu.etaxonomy.cdm.model.location.NamedAreaLevel;

public class NamedAreaTree extends Tree<NamedArea>{

	public NamedAreaTree() {

		NamedArea data = new NamedArea();

		TreeNode<NamedArea> rootElement = new TreeNode<NamedArea>();

		List<TreeNode<NamedArea>> children = new ArrayList<TreeNode<NamedArea>>();

		rootElement.setData(data);

		rootElement.setChildren(children);

		setRootElement(rootElement);

    }

/*	

    public NamedAreaTree getHiearchieTree(List<NamedArea> areaList) {

    	NamedAreaTree result = new NamedAreaTree();

    	for (NamedArea area : areaList) {

			List<NamedArea> levelList = area.getAreaLevelPathList(area);

			result.merge(levelList);

		}	    	

    	return result;

    }

*/	

	public void merge(List<NamedArea> areaList, Set<NamedAreaLevel> omitLevels){

		for (NamedArea area : areaList) {

			List<NamedArea> levelList = this.getAreaLevelPathList(area, omitLevels);

			mergeAux(levelList, this.getRootElement());

		}

		//mergeAux(areaHierarchieList, this.getRootElement());

	}

	public void sortChildren(){

		sortChildrenAux(this.getRootElement());

	}	

	private void sortChildrenAux(TreeNode<NamedArea> TreeNode){

		NamedAreaNodeComparator comp = new NamedAreaNodeComparator();

		if (TreeNode.children == null){

			//nothing => stop condition

			return;

		}else{

			Collections.sort(TreeNode.children, comp);

			for (TreeNode<NamedArea> child : TreeNode.children) {

				sortChildrenAux(child);

			}

		}

	}

	private void mergeAux(List<NamedArea> areaHierarchieList, TreeNode<NamedArea> root) {

		TreeNode<NamedArea> child; // the new child to add or the child to follow through the tree

		//if the list to merge is empty finish the execution

		if (areaHierarchieList.isEmpty()){

			return;

		}

		//getting the highest area and inserting it into the tree

		NamedArea highestArea = areaHierarchieList.get(0);

		TreeNode<NamedArea> highestAreaNode = new TreeNode<NamedArea>(highestArea);

		//NamedAreaLevel level = highestArea.getLevel();

		//List<TreeNode<NamedArea>> children = root.getChildren();

		//if(children == null || !children.contains(highestAreaNode)){

		if (root.getChildren().isEmpty() || !root.containsChild(highestAreaNode)){

			//if the highest level is not on the depth-1 of the tree we add it. 

			child = new TreeNode<NamedArea>(highestArea);

			root.addChild(child);

			//children.add(child);

		}else{

			//if the deepth-1 of the tree contains the highest area level

			//get the subtree or create it in order to continuing merging

			child = root.getChild(highestAreaNode);				

		}

		//continue merging with the next highest area of the list.

		List<NamedArea> newList = areaHierarchieList.subList(1, areaHierarchieList.size());

		mergeAux(newList, child);

	}

	private List<NamedArea> getAreaLevelPathList(NamedArea area, Set<NamedAreaLevel> omitLevels){

		List<NamedArea> result = new ArrayList<NamedArea>();

		if (!omitLevels.contains(area.getLevel())){

			result.add(area);		

		}

		while (area.getPartOf() != null) {

			area = area.getPartOf();

			if (!omitLevels.contains(area.getLevel())){

				result.add(0, area);

			}

		}

		return result;

	}

}