import java.util.Date;
import java.awt.*;

//=================================== Lab1 ===============================
//
// Input: n the number of points
//
// Output: A pair of closest points and their distance
//
//========================================================================

public class Lab1 {

   //================================ main ===============================
   //
   // You can use command line arguments to have the output and/or input
   // come from a file versus the command line.
   //
   // If there are two arguments then the first one is the file from where
   //   the input is read and the second is the file where a transcript is
   //   saved.
   //
   // If there is just one argument then it is the file where a transcript
   //   is saved.

   public static void main(String args[]){
   	  if (args.length == 2) {
   	  	 Terminal.readInputFromFile(args[0]);
         Terminal.startTranscript(args[1]);
      }
      else if (args.length == 1) {
      	Terminal.startTranscript(args[0]);
      }

   // If you don't know how to use command line arguments and want to
   //    save a transcript in a file called "myTranscript.txt" you can
   //    uncomment out the following line (and change the filename to
   //    whatever you want).
   //
   // Terminal.startTranscript("myTranscript.txt");

   // If you would like the points to be read from "sample-pointfile" then
   //  you can replace the code below through the call to generateRandomPoints by
   //
   // XYPoint points[] = PointReader.readXYPoints("sample-pointfile"); 
  
      Terminal.println("How many points? ");
      int n = Terminal.readInt();

   // Use this line if you want a different random set of points each time the
   //   program is run.  However, for your submitted output you are required to
   //   use 3.14 * n as the seed as it is currently done.
   //
   // java.util.Random randseq = new java.util.Random();
      java.util.Random randseq = new java.util.Random((long) 3.14 * n);
      XYPoint points[] = generateRandomPoints(n,randseq);

      Date startTime = new Date();      //start clock since data is created

   // Call ClosestPair algorithm here -- feel free to change the class or method
   //   name to match what you use.
      PointPair closest = ClosestPair.closestPair(points);
      
      Date endTime = new Date();       //stop clock since closest pair computed
      if (points.length <= 50){
	Terminal.println("The points are:");
	for (int i=0; i<points.length; i++)
	  Terminal.println("   " + points[i]);
      }
	
      //THESE LINES DEMONSTRATES HOW TO USE THE PROVIDED PLOTTER ROUTINE. Use these
      //as you want for debugging purposes here and in your closest pair routine.
      //You could, as an example, color all points in the left half red and all
      //points in the right half blue and then visually check that you divided them
      //properly by calling the plotter before you recurse.  Note that if you make
      //several calls, all the plots will initially be on top of each other -- just
      // move them so you can see everything. For a XYPoint p, you could color p
      //(say red) with the statement:  p.color = Color.red;

      if (n <= 20)
	new Plotter(points,true,"Point Set");
      else
	new Plotter(points,false,"Point Set");
      
//   Finally, here is a line demonstrating how you compute (and print) the
//     execution time.  For your submitted output you must also print out the
//     coordinates for a closest pair of points and their distance.  You can
//     use the provided toString method in the PointpPair class to do this.

      Terminal.println("For n = " + n + ", the elapsed time is " +
		       (endTime.getTime() - startTime.getTime()) + " milliseconds.");
   }

  // Generate a random sequence of nPoints
  static XYPoint[] generateRandomPoints(int nPoints,java.util.Random randseq){
    XYPoint points[] = new XYPoint[nPoints];
    double x = 0.0;
    double y = 0.0;
    double step = Math.sqrt(nPoints);
    for (int j=0; j<nPoints; j++){
      x += 2.715*Math.abs(randseq.nextGaussian());
      y += step * (randseq.nextDouble()+1);
      y = y % nPoints;
      points[j] = new XYPoint((int) Math.round(x),(int) Math.round(y));
    }
    return points;
  }
}