import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import java.lang.*;

public class BasicRecipeJ2D extends Frame {
    public BasicRecipeJ2D() throws InterruptedException {
        //constructor

        super("Elevator Algorithm");
        myCustomCanvas canvas = new myCustomCanvas();
        this.add(canvas);
        this.setSize(700,400);
        this.setVisible(true);
        addWindowListener(new WindowEventHandler());
        
        //Setup the table
        LinkedList<Integer>[] table = setup();
        //print the table for testing
        //print(table);
        boolean direction = true;
        boolean flag = false;
        boolean start = true;
        int headPosition = 5;
        canvas.setPosition(headPosition);
        //System.out.println("Repaint");
        Thread.sleep(500);
        
        do
        {
            /** Moving upward */
            if(direction == true)
            {
                if(table[headPosition].size() == 0)
                {
                    /** If no request for the current cylinder then go to next or if at the end of the cylinders change direction */
                    if(headPosition == (table.length-1))
                    {
                        direction = false;
                        canvas.increaseX(false);
                        //System.out.println("Repaint");
                        //Thread.sleep(500);
                    }
                    else
                    {
                        if(start == true)
                        {
                            start = false;
                            headPosition++;
                            //System.out.println("Repaint");
                            //Thread.sleep(500);
                        }
                        else
                        {
                            headPosition++;
                            canvas.increaseX(false);
                            //System.out.println("Repaint");
                            //Thread.sleep(500);
                        }
                    }
                }
                else
                {
                    table[headPosition].clear();
                    //System.out.println(headPosition);
                                        
                    /** checking to see if head is at the end of the cylinders */
                    if(headPosition == (table.length-1))
                    {
                        direction = false;
                        canvas.increaseX(true);
                        //System.out.println("Repaint");
                        Thread.sleep(1500);
                    }
                    else
                    {
                        if(start == true)
                        {
                            start = false;
                            headPosition++;
                            //System.out.println("Repaint");
                            Thread.sleep(1500);
                        }
                        else
                        {
                            headPosition++;
                            canvas.increaseX(true);
                            //System.out.println("Repaint");
                            Thread.sleep(1500);
                        }
                    }
                }
            }

            /** Moving downward */
            else if(direction == false)
            {
                if(table[headPosition].size() == 0)
                {
                    /** If no request for the current cylinder then go to next or if at the end of the cylinders then end */
                    if(headPosition == 0)
                    {
                        flag = true;
                        //Thread.sleep(500);
                        //System.out.println("Repaint");
                    }
                    else
                    {
                        headPosition--;
                        //Thread.sleep(500);
                        canvas.decreaseX(false);
                        //System.out.println("Repaint");
                    }
                }
                else
                {
                    table[headPosition].clear();
                    //System.out.println(headPosition);
                    /** if the at the bottom of the cylinders it ends */
                    if(headPosition == 0)
                    {
                        /** ends the program */
                        flag = true;
                        canvas.decreaseX(true);
                        //System.out.println("Repaint");
                    }
                    else
                    {
                        headPosition--;
                        //Thread.sleep(1500);
                        canvas.decreaseX(true);
                        //System.out.println("Repaint");
                    }
                }
            }
        }while(flag == false);
    }

    class WindowEventHandler extends WindowAdapter {
        public void windowClosing(WindowEvent e) {
            System.exit(0);
        }
    }

    public static void main(String[] args) throws InterruptedException {
        new BasicRecipeJ2D();

    }

    public static LinkedList<Integer>[] setup(){
        //Create starting load of requests
        int[] startingRequests = new int[6];
        for(int i=0;i<6;i++){
            startingRequests[i] = randomNumber(11);
        }

        //Create Array of linked lists
        LinkedList<Integer>[] table = new LinkedList[11];
        for(int i = 0; i < table.length; i++)
        {
            table[i] = new LinkedList<Integer>();
        }
        //Put starting requests into array of linked lists
        for(int i = 0; i < startingRequests.length; i++){
            table[startingRequests[i]].add(startingRequests[i]);
        }

        return table;
    }

    public static int randomNumber(int input){
        Random randomGenerator = new Random();
        int randomInt = randomGenerator.nextInt(input);
        return randomInt;
    }

    public static void print(LinkedList<Integer>[] table){
        //Print array of linked list
        for(int i = 0; i < table.length; i++){
            Object[] current = table[i].toArray();
            for(int j = 0; j < current.length; j++){
                System.out.print(current[j] + ", ");
            }
            System.out.println();
        }
    }
}

//Part 2; Java 2D specific-extend the drawing Component -Canvas-
// and override it's paint method.
class myCustomCanvas extends Canvas {
    float x = 0.0f;

    public void paintComponent(Graphics g){

    }

    public void paint(Graphics g) {
        //System.out.println("in paint");

        // step one of the recipe; cast Graphics object as Graphics2D
        Graphics2D g2d = (Graphics2D) g;

        float inc = 0;
        g2d.setColor(Color.black);
        g2d.fill(new Rectangle2D.Float(610.0f ,140.0f,60.0f,70.0f));
        for(int k = 0; k < 11; k++){
            g2d.setColor(Color.black);

            g2d.drawString("" + k, 10.0f + inc , 220.0f); // draws text

            g2d.fill(new Rectangle2D.Float(0.0f + inc ,140.0f,60.0f,70.0f)); //draws black background
            g2d.setColor(Color.GRAY);
            g2d.fill(new Rectangle2D.Float(10.0f + inc ,150.0f,50.0f,50.0f)); //draws gray squares, used to represent locations
            inc += 60.0f;
        }

        g2d.setColor(Color.yellow);
        g2d.fill(new Rectangle2D.Float(70.0f + x,150.0f,50.0f,50.0f)); //animated arm location

    }

    public void increaseX(boolean print){
        x+=60.0f;
        if(print)
        {
            repaint();
        }
    }
    
    public void decreaseX(boolean print) throws InterruptedException{
        if(print)
        {
            repaint();
            Thread.sleep(1500);
        }
        x-=60.0f;
    }
    
    public void setPosition(int start){
        for(int i = 0;i < start-1; i++){
            x+=60.0f;
        }
    }
}