import java.applet.*;
import java.awt.*;
import java.awt.event.*;

public class CatMouseChase extends Applet implements ActionListener {

	public void init ( ) {
		super.init ( );
		nextStep = new Button ("Move once");
		add (nextStep);
		nextStep.addActionListener (this);
		
		ourWindowWidth = getIntegerParam ("width");
		ourWindowHeight = getIntegerParam ("height");
		myXCenter = ourWindowWidth/2;
		myYCenter = ourWindowHeight/2;
		int smallestDimension 
			= ourWindowWidth < ourWindowHeight? ourWindowWidth: ourWindowHeight;
		
		double mouseAngle = getDoubleParam ("mouseangle");
		double catRadius = getDoubleParam ("catradius");
		double catAngle = getDoubleParam ("catangle");
		myUnit = (smallestDimension/2 - BORDER)/((int) (catRadius+1.0));
		
		myCat = new Cat (new Position (catRadius, catAngle));
		myMouse = new Mouse (new Position (1.0, mouseAngle));
		statusString = "Chase is in progress.";
	}
	
	private int getIntegerParam (String name) {
		String value = this.getParameter (name);
		if (value == "") {
			return 0;
		}
		try {
			return Integer.parseInt (value);
		} catch (Exception e) {
			return 0;
		}
	}
	
	private double getDoubleParam (String name) {
		String value = this.getParameter (name);
		if (value == "") {
			return 0.0;
		}
		try {
			return Double.valueOf (value).doubleValue ( );
		} catch (Exception e) {
			return 0.0;
		}
	}
	
	public void actionPerformed (ActionEvent event) {
		// You fill this in.
	}
	
	public void paint (Graphics g) {
		// The magic numbers used here should really depend on the height of the
		// type face used to display the window annotations.
		// We'll fix that for next semester.
		g.drawOval (myXCenter+5-myUnit, myYCenter+5-myUnit, 2*myUnit-10, 2*myUnit-10);
		g.drawString ("C", 
			myCat.getPosition ( ).xCoord (myXCenter, myUnit)-5, 
			myCat.getPosition ( ).yCoord (myYCenter, myUnit)+5 );
		g.drawString ("M", 
			myMouse.getPosition ( ).xCoord (myXCenter, myUnit)-5, 
			myMouse.getPosition ( ).yCoord (myYCenter, myUnit)+5 );
		g.drawString ("Mouse at " + myMouse.getPosition ( ) 
			+ "; cat at " + myCat.getPosition ( ), 50, ourWindowHeight-30);
		g.drawString (statusString, 50, ourWindowHeight-15);
	}
	
	private Cat myCat;
	private Mouse myMouse;
	private boolean chaseIsOver = false;
	private int timeElapsed;
	private final int TIME_LIMIT = 30;
	
	private Button nextStep;
	private String statusString = "Not yet started.";
	private final int BORDER = 50;	// margin for buttons and status strings
	
	private static int ourWindowWidth, ourWindowHeight;
	private int myXCenter, myYCenter, myUnit;
}