// CSE 142, Spring 2010, Marty Stepp
// A Snake is a critter that "slithers" in a pattern, going EAST once, then
// SOUTH once, then WEST twice, then SOUTH once, then EAST 3 times, then SOUTH
// once, then WEST 4 times, ... and so on.

public class Snake extends Critter {
    private int horizontal;   // number of horizontal moves to be made on this pass
    private int stepsTaken;   // number of horizontal steps taken within this pass so far
    
    public Snake() {
        stepsTaken = 0;
        horizontal = 1;
    }
    
    public String toString() {
        return "S";
    }
    
    public Direction getMove() {
        stepsTaken++;
        if (stepsTaken > horizontal) {
            // the snake has reached the end of his horizontal pass;
            // we'll go south this time and start over on a longer pass next time
            stepsTaken = 0;
            horizontal++;
            return Direction.SOUTH;
        } else if (horizontal % 2 == 1) {
            return Direction.EAST;
        } else {  // horizontal % 2 == 0
            return Direction.WEST;
        }
    }
}