EDIT

/**

* Copyright (C) 2016 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.model.common;

import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.regex.Pattern;

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

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

/**

 * A class to handle tree indexes as used in {@link TaxonNode}, {@link FeatureNode}

 * etc.<BR>

 * Might be come a hibernate user type in future.

 *

 * @author a.mueller

 * @since 02.12.2016

 *

 */

public class TreeIndex {

    public static TreeIndex NewInstance(String treeIndex){

        return new TreeIndex(treeIndex);

    }

    /**

     * @param subtree

     * @return

     */

    public static TreeIndex NewInstance(TaxonNode node) {

        if (node == null){

            return null;

        }else{

            return new TreeIndex(node.treeIndex());

        }

    }

    /**

     * @param stringList

     * @return

     */

    public static List<TreeIndex> NewListInstance(List<String> stringList) {

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

        for (String string: stringList){

            result.add(new TreeIndex(string));

        }

        return result;

    }

    //regEx, we also allow the tree itself to have a tree index (e.g. #t1#)

    //this may change in future as not necessarily needed

    private static String regEx = "#[a-z](\\d+#)+";

    private static Pattern pattern = Pattern.compile(regEx);

    private static TreeIndexComparator comparator = new TreeIndexComparator();

    private String treeIndex;

    private TreeIndex(String treeIndex){

        if (! pattern.matcher(treeIndex).matches()){

            throw new IllegalArgumentException("Given string is not a valid tree index");

        }

        this.treeIndex = treeIndex;

    }

// ************** METHODS ***************************************/

    /**

     * @param taxonTreeIndex

     * @return

     */

    public boolean hasChild(TreeIndex childCandidateTreeIndex) {

        return childCandidateTreeIndex.treeIndex.startsWith(treeIndex);

    }

    /**

     * Returns a new TreeIndex instance which represents the parent of this tree index.

     * Returns null if this tree index already represents the root node of the tree.

     * @return

     */

    public TreeIndex parent(){

        int index = treeIndex.substring(0, treeIndex.length()-1).lastIndexOf(ITreeNode.separator);

        try {

            TreeIndex result = index < 0 ? null : NewInstance(treeIndex.substring(0, index+1));

            return result;

        } catch (Exception e) {

            //it is not a valid treeindex anymore

            return null;

        }

    }

    public boolean isTreeRoot(){

        int count = 0;

        for (char c : this.treeIndex.toCharArray()){

            if (c == '#') {

                count++;

            }

        }

        return count == 3;

    }

    public boolean isTree(){

        int count = 0;

        for (char c : this.treeIndex.toCharArray()){

            if (c == '#') {

                count++;

            }

        }

        return count == 2;

    }

// ********************** STATIC METHODS  *****************************/

    /**

     * Creates a list for the given tree indexes and sorts them in ascending

     * order.

     * @param treeIndexSet

     * @return

     */

    public static List<TreeIndex> sort(Collection<TreeIndex> treeIndexSet) {

        List<TreeIndex> result = new ArrayList<>(treeIndexSet);

        Collections.sort(result, comparator);

        return result;

    }

    /**

     * Creates a list for the given tree indexes and sorts them in descending

     * order.

     * @param treeIndexSet

     * @return

     */

    public static List<TreeIndex> sortDesc(Collection<TreeIndex> treeIndexSet) {

        List<TreeIndex> result = sort(treeIndexSet);

        Collections.reverse(result);

        return result;

    }

    public static Map<TreeIndex, TreeIndex> group(Collection<TreeIndex> groupingIndexes, Collection<TreeIndex> toBeGroupedIndexes){

        //for larger groupingIndexes we could optimize this by sorting both collections

        //prior to loop. This way we do traverse both lists once

        Map<TreeIndex, TreeIndex> result = new HashMap<>();

        List<TreeIndex> descSortedGroupingIndexes = sortDesc(groupingIndexes);

        for (TreeIndex toBeGrouped : toBeGroupedIndexes) {

            boolean groupFound = false;

            for (TreeIndex groupingIndex : descSortedGroupingIndexes){

                if (groupingIndex.hasChild(toBeGrouped)){

                    result.put(toBeGrouped, groupingIndex);

                    groupFound = true;

                    break;

                }

            }

            if (!groupFound){

                result.put(toBeGrouped, null);

            }

        }

        return result;

    }

// **************************** EQUALS *****************************/

    @Override

    public int hashCode() {

        return treeIndex.hashCode();

    }

    @Override

    public boolean equals(Object obj) {

        if (obj instanceof TreeIndex){

            return treeIndex.equals(((TreeIndex)obj).treeIndex);

        }else{

            return false;

        }

    }

// *************************** toString() ***********************

    @Override

    public String toString(){

        return treeIndex;

    }

    /**

     * Null save toString method.

     * @param treeIndex

     * @return

     */

    public static String toString(TreeIndex treeIndex) {

        return treeIndex == null? null: treeIndex.toString();

    }

    /**

     * @param treeIndexes

     * @return

     */

    public static List<String> toString(Collection<TreeIndex> treeIndexes) {

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

        for (TreeIndex treeIndex : treeIndexes){

            result.add(treeIndex.toString());

        }

        return result;

    }

}