package sorting;

import java.util.Comparator;

/**
 * Class full of static sorting methods. Used to sort packets received from a
 * server containing image metadata.
 * 
 * TODO: Implement mergeSort() and selectionSort().
 * 
 * insertionSort is implemented for you as an example.
 * 
 * @author pattersp
 *
 */

public class PacketSorter {
    /**
     * Sorts the given array of packets in ascending order according to the
     * comparator using mergesort. You may create as many private helper
     * functions as you wish to implement this method.
     * 
     * A note about ascending order:
     * 
     * When the method is finished, it should be true that:
     * comparator.compare(array[i - 1], array[i]) <= 0 for all i from 1 through
     * array.length.
     * 
     * @param array
     *            the packets to sort
     * @param comparator
     *            The comparator the will be used to compare two packets.
     */
    public static void mergeSort(Packet[] array, Comparator<Packet> comparator) {
        // TODO: Add your merge sort algorithm here.
        throw new UnsupportedOperationException();
    }

    /**
     * Sort the array of packets in ascending order using selection sort.
     * 
     * A note about ascending order:
     * 
     * When the method is finished, it should be true that:
     * comparator.compare(array[i - 1], array[i]) <= 0 for all i from 1 through
     * array.length.
     * 
     * @param array
     *            the array of packets that will be sorted.
     * @param comparator
     *            The comparator the will be used to compare two packets.
     */
    public static void selectionSort(Packet[] array,
            Comparator<Packet> comparator) {
        // TODO: Add your selection sort algorithm here.
        throw new UnsupportedOperationException();
    }

    /**
     * Sort the array of packets in ascending order using insertion sort.
     * 
     * A note about ascending order:
     * 
     * When the method is finished, it should be true that:
     * comparator.compare(array[i - 1], array[i]) <= 0 for all i from 1 through
     * array.length.
     * 
     * @param array
     *            the array of packets that will be sorted.
     * @param comparator
     *            The comparator the will be used to compare two packets.
     */
    public static void insertionSort(Packet[] array,
            Comparator<Packet> comparator) {
        for (int outerIndex = 1; outerIndex < array.length; outerIndex++) {
            Packet currentPacket = array[outerIndex];
            int innerIndex = outerIndex - 1;
            while (innerIndex >= 0
                    && comparator.compare(currentPacket, array[innerIndex]) < 0) {
                array[innerIndex + 1] = array[innerIndex];
                innerIndex--;
            }
            array[innerIndex + 1] = currentPacket;
        }
    }
}