package drone.test;

import java.util.Arrays;
import java.util.Random;

import net.mokyu.threading.MultithreadedExecutor;
import drone.util.sort.InsertionSort;
import drone.util.sort.ParallelInsertionSort;
import engine.etc.SimpleComparator;

public class SortTest {
   
   private static final int numElements = 5_000_000;
   private static final int numThreads = 8;
   private static final int numChunks = 32;
   private static final int shuffleDisplacement = 25;
   
   public static void main(String[] args) {
      
      MultithreadedExecutor executor = new MultithreadedExecutor(numThreads);
      ParallelInsertionSort<Element> parallelInsertionSort = new ParallelInsertionSort<>(numChunks);
      
      Element[] array1 = new Element[numElements];
      Element[] array2 = new Element[numElements];
      Element[] array3 = new Element[numElements];
      Element[] array4 = new Element[numElements];
      
      SimpleComparator<Element> comparator = new SimpleComparator<Element>() {
         public int compare(Element e1, Element e2) {
            return Integer.compare(e1.value, e2.value);
         }
      };

      System.out.println("Generating values...");
      Random r = new Random();
      for(int i = 0; i < numElements; i++){
         array1[i] = new Element(r.nextInt());
      }
      System.out.println("Sorting values...");
      Arrays.sort(array1, 0, numElements, comparator);
      
      System.out.println("Copying values to other arrays...");
      for(int i = 0; i < numElements; i++){
         Element e = array1[i];
         array2[i] = e;
         array3[i] = e;
         array4[i] = e;
      }
      
      
      System.out.println("Done.");
      
      while(true){

         shuffle(array1);
         shuffle(array2);
         shuffle(array3);
         shuffle(array4);
         
         long startTime;
         
         
         startTime = System.nanoTime();
         Arrays.sort(array1, 0, numElements, comparator);
         System.out.println("Java sort unsorted: " + (System.nanoTime() - startTime) / 1000 / 1000f + " ms");

         startTime = System.nanoTime();
         Arrays.sort(array1, 0, numElements, comparator);
         System.out.println("Java sort sorted:   " + (System.nanoTime() - startTime) / 1000 / 1000f + " ms");
         
         
         startTime = System.nanoTime();
         Arrays.parallelSort(array2, 0, numElements, comparator);
         System.out.println("Java parallel sort unsorted: " + (System.nanoTime() - startTime) / 1000 / 1000f + " ms");

         startTime = System.nanoTime();
         Arrays.parallelSort(array2, 0, numElements, comparator);
         System.out.println("Java parallel sort sorted:   " + (System.nanoTime() - startTime) / 1000 / 1000f + " ms");
         
         startTime = System.nanoTime();
         InsertionSort.sort(array3, 0, numElements, comparator);
         System.out.println("Insertion sort unsorted: " + (System.nanoTime() - startTime) / 1000 / 1000f + " ms");

         startTime = System.nanoTime();
         InsertionSort.sort(array3, 0, numElements, comparator);
         System.out.println("Insertion sort sorted:   " + (System.nanoTime() - startTime) / 1000 / 1000f + " ms");
         
         
         startTime = System.nanoTime();
         parallelInsertionSort.sort(array4, 0, numElements, comparator, executor);
         System.out.println("Parallel insertion sort unsorted: " + (System.nanoTime() - startTime) / 1000 / 1000f + " ms");

         startTime = System.nanoTime();
         parallelInsertionSort.sort(array4, 0, numElements, comparator, executor);
         System.out.println("Parallel insertion sort sorted:   " + (System.nanoTime() - startTime) / 1000 / 1000f + " ms");
         
         
         System.out.println("First elements: " + array1[0] + ", " + array2[0] + ", " + array3[0] + ", " + array4[0] + '\n');
      
      }
      
   }
   
   private static void shuffle(Object[] ar){
      Random rnd = new Random();
      
      for(int i = shuffleDisplacement; i < ar.length; i++){
         
         int index = i - rnd.nextInt(shuffleDisplacement);
         
         Object a = ar[index];
         ar[index] = ar[i];
         ar[i] = a;
      }
   }
   
   private static class Element{
      
      private int value;
      
      public Element(int value) {
         this.value = value;
      }
   }
}