/*******************************************************************************
 * Copyright (c) 2014, 2015 Cisco Systems, Inc. and others.  All rights reserved.
 *  
 *  This program and the accompanying materials are made available under the
 *  terms of the Eclipse Public License v1.0 which accompanies this distribution,
 *  and is available at http://www.eclipse.org/legal/epl-v10.html
 *  
 *******************************************************************************/
package com.cisco.yangide.core.buffer;

/**
 * @author Konstantin Zaitsev
 * @date Jun 24, 2014
 */
public class ToStringSorter {
    Object[] sortedObjects;
    String[] sortedStrings;

    /**
     * Returns true if stringTwo is 'greater than' stringOne This is the 'ordering' method of the
     * sort operation.
     */
    public boolean compare(String stringOne, String stringTwo) {
        return stringOne.compareTo(stringTwo) < 0;
    }

    /**
     * Sort the objects in sorted collection and return that collection.
     */
    private void quickSort(int left, int right) {
        int originalLeft = left;
        int originalRight = right;
        int midIndex = left + (right - left) / 2;
        String midToString = this.sortedStrings[midIndex];

        do {
            while (compare(this.sortedStrings[left], midToString))
                left++;
            while (compare(midToString, this.sortedStrings[right]))
                right--;
            if (left <= right) {
                Object tmp = this.sortedObjects[left];
                this.sortedObjects[left] = this.sortedObjects[right];
                this.sortedObjects[right] = tmp;
                String tmpToString = this.sortedStrings[left];
                this.sortedStrings[left] = this.sortedStrings[right];
                this.sortedStrings[right] = tmpToString;
                left++;
                right--;
            }
        } while (left <= right);

        if (originalLeft < right)
            quickSort(originalLeft, right);
        if (left < originalRight)
            quickSort(left, originalRight);
    }

    /**
     * Return a new sorted collection from this unsorted collection. Sort using quick sort.
     */
    public void sort(Object[] unSortedObjects, String[] unsortedStrings) {
        int size = unSortedObjects.length;
        this.sortedObjects = new Object[size];
        this.sortedStrings = new String[size];

        // copy the array so can return a new sorted collection
        System.arraycopy(unSortedObjects, 0, this.sortedObjects, 0, size);
        System.arraycopy(unsortedStrings, 0, this.sortedStrings, 0, size);
        if (size > 1)
            quickSort(0, size - 1);
    }
}