import java.awt.Color;
import java.util.*;
import uwcse.io.*;
import uwcse.graphics.*;
import javax.swing.*;

/**
 * A class to create and manipulate graphics elements stored in an ArrayList
 * (the graphics elements are squares)
 */

public class GraphicsElements {

	/** Maximum number of disks in a pile of disks */
	public static final int MAXIMUM_NUMBER_OF_SQUARES = 100;

	/** Width of the window (from ViewWindow) */
	public static final int WIDTH = ViewWindow.WINDOW_WIDTH;

	/** Height of the window (from ViewWindow) */
	public static final int HEIGHT = ViewWindow.WINDOW_HEIGHT;

	/**
	 * Generate a list of squares randomly located in the window. Use filled
	 * squares. The color of each square is either yellow, blue or red. <br>
	 * Store the squares in an ArrayList and return that ArrayList <br>
	 * The number of squares is given by the user (use a dialog box). If that
	 * number is less than or equal to 0 or greater than
	 * MAXIMUM_NUMBER_OF_SQUARES, display an error message (use
	 * JOptionPane.showMessageDialog)and ask for it again.
	 */
	public ArrayList getRandomSquares() {
		// Get the number of squares from the user
		Input in = new Input();
		int n;
		do {
			n = in.readIntDialog("Enter the number of squares "
					+ "(between 1 and " + MAXIMUM_NUMBER_OF_SQUARES + ")");
			if (n <= 0 || n > MAXIMUM_NUMBER_OF_SQUARES) {
				// display an error message
				JOptionPane.showMessageDialog(null, "Invalid input",
						"Input error", JOptionPane.WARNING_MESSAGE);
			}
		} while (n <= 0 || n > MAXIMUM_NUMBER_OF_SQUARES);

		// Create the list of squares
		ArrayList list = new ArrayList(n);
		for (int i = 1; i <= n; i++) {
			// random location (in the window)
			int x = (int) ((WIDTH - 20) * Math.random());
			int y = (int) ((HEIGHT - 20) * Math.random());
			// random color among yellow, blue and red
			Color c = null;
			switch((int)(Math.random() * 3)) {
			case 0: 
				c = Color.YELLOW;
				break;
			case 1:
				c = Color.RED;
				break;
			case 2:
				c = Color.BLUE;
				break;
			}
			Rectangle r = new Rectangle(x,y,20,20,c,true);
			list.add(r);
		}
		return list;
	}

	/**
	 * Erase the square at location (x,y) if any.
	 */
	public void eraseElementAt(int x, int y, ArrayList list) {
		for (int i = list.size()-1; i >= 0; i --) {
			Rectangle r =  (Rectangle) list.get(i);
			// Is (x,y) within r?
			if (x >= r.getX() && x <= r.getX() + r.getWidth() &&
			    y >= r.getY() && y <= r.getY() + r.getHeight()) {
				list.remove(i);
				break; // exit the for loop
				// here return would work as well
			}
		}
	}

	/**
	 * Display the number of red squares, blue squares and yellow squares
	 */
	public void displayStatistics(ArrayList<Rectangle> list) {
		// color counters
		int blue = 0, red = 0, yellow = 0;
		for (int i = 0; i < list.size(); i ++) {
			// with generics, there is no need to cast
			// to a Rectangle type
			Rectangle r = list.get(i); //(Rectangle) list.get(i);
			Color c = r.getColor();
			if (c.equals(Color.RED)) {
				red ++;
			} else if (c.equals(Color.BLUE)) {
				blue ++;
			} else {
				yellow ++;
			}
		}
		String message = "Blue = " + blue + 
				         "\nRed = " + red + 
				         "\nYellow = " + yellow + 
				         "\nTotal = " + list.size();
		JOptionPane.showMessageDialog(null, message, 
				"Statistics", JOptionPane.INFORMATION_MESSAGE);
		
		// 2nd approach: using an iterator
		blue = red = yellow = 0;
		Iterator<Rectangle> it = list.iterator();
		while(it.hasNext()) {
			Rectangle r = it.next();
			Color c = r.getColor();
			if (c.equals(Color.RED)) {
				red ++;
			} else if (c.equals(Color.BLUE)) {
				blue ++;
			} else {
				yellow ++;
			}
		}
		message = "Blue = " + blue + 
				         "\nRed = " + red + 
				         "\nYellow = " + yellow + 
				         "\nTotal = " + list.size();
		JOptionPane.showMessageDialog(null, message, 
				"Statistics", JOptionPane.INFORMATION_MESSAGE);
		
		// using a for-each loop
		blue = red = yellow = 0;
		for (Rectangle r: list) {
			Color c = r.getColor();
			if (c.equals(Color.RED)) {
				red ++;
			} else if (c.equals(Color.BLUE)) {
				blue ++;
			} else {
				yellow ++;
			}
		}
		message = "Blue = " + blue + 
				         "\nRed = " + red + 
				         "\nYellow = " + yellow + 
				         "\nTotal = " + list.size();
		JOptionPane.showMessageDialog(null, message, 
				"Statistics", JOptionPane.INFORMATION_MESSAGE);
	}
}