import java.awt.*;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Scanner;

/**
 * Represents the path that the monsters follow in a tower defense game. The path is a collection
 * of discrete Point objects
 *
 * @author Elizabeth
 *
 */
public class Path {
	private ArrayList<Point> points;
	private final int STEP = 5; //distance between points

	/**
	 * Constructs a path from a text file. The first line of the text file is the starting x and y
	 * coordinates of the path. Every line thereafter contains a direction, and a distance. All
	 * distances should be in increments of 5
	 *
	 * @param pathFile the name of the file to be read from
	 */
	public Path(String pathFile){
		points = new ArrayList<Point>();
		File f = new File(pathFile);
		try {
			Scanner scan = new Scanner(f);
			String s = scan.next();
			String[] coords = s.split(",");
			points.add(new Point(Integer.parseInt(coords[0]),Integer.parseInt(coords[1])));
			while(scan.hasNext()){
				s = scan.next();
				coords = s.split(",");
				int dist = Integer.parseInt(coords[1]);
				Point last = points.get(points.size()-1);

				if(coords[0].equals("r")){
					for(int i = STEP; i<=dist;i+=STEP){
						points.add(new Point(last.x+i,last.y));
					}
				}

				if(coords[0].equals("l")){
					for(int i = STEP; i<=dist;i+=STEP){
						points.add(new Point(last.x-i,last.y));
					}
				}

				if(coords[0].equals("u")){
					for(int i = STEP; i<=dist;i+=STEP){
						points.add(new Point(last.x,last.y-i));
					}
				}

				if(coords[0].equals("d")){
					for(int i = STEP; i<=dist;i+=STEP){
						points.add(new Point(last.x,last.y+i));
					}
				}
			}
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}



	}

	/**
	 * Gets the next point in the path based on a current point and a speed.
	 * A speed of one will take you to the next point in the path - 5 pixels away.
	 *
	 * @param current starting Point
	 * @param speed int determining how far down the path to travel
	 * @return the new position
	 */
	public Point nextPosition(Point current, int speed){
		int index = points.indexOf(current);
		if(index+speed < points.size())
			return points.get(index+speed);
		else
			return getEnd();
	}

	/**
	 * Draws the path
	 *
	 * @param g - the Graphics object on which the path is drawn
	 */
	public void draw(Graphics g){
		g.setColor(Color.red);
		for(int i = 0; i<points.size()-1; i++){
			g.drawLine(points.get(i).x,points.get(i).y,points.get(i+1).x,points.get(i+1).y);
		}
		g.setColor(Color.black);
	}

	/**
	 * Gets the starting point of the path
	 *
	 * @return the starting Point of the path
	 */
	public Point getStart(){
		return points.get(0);
	}

	/**
	 * Gets the ending point of the path
	 *
	 * @return the ending Point of the path
	 */
	public Point getEnd(){
		return points.get(points.size()-1);
	}

}