import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Scanner;
/**
 * 
 * @author geoffreytowell
 * Holds a maze.
 */
public class Maze
{
    public static final char START  = 's';
    public static final char FINISH = 'e';
    public static final char WALL   = '*';
    public static final char PATH   = ' ';
    
    /**
     * The internal representation of the maze
     */
    char[][] mazeRep;
    
    Coordinate[] moves = { new Coordinate(-1, -1), new Coordinate(1, -1), 
	    	new Coordinate(1, 1), new Coordinate(-1, 1) };
 
    /**
     * Maze constructor.  This takes the name of a file containing a maze and reads it into 
     * the internal represenation.
     * @param fileName the name of the file containing the maze
     * @throws FileNotFoundException
     * @throws ImproperMazeException
     */
    public Maze(String fileName) throws FileNotFoundException, ImproperMazeException
    {
	// first read the file into an array list to get the dimensions of the maze
	ArrayList<String> tmaz = new ArrayList<>();
	Scanner fscanner = new Scanner(new File(fileName));
	int wid=-1;
	while (fscanner.hasNextLine())
	{
	    String lin = fscanner.nextLine();
	    if (wid>0 && lin.length()!=wid)
	    {
		fscanner.close();
		throw new ImproperMazeException("Maze must be a rectangle current width="+wid+" new line width="+lin.length());
	    }
	    if (wid<0)
		wid=lin.length();
	    tmaz.add(lin);
	}
	fscanner.close();
	
	// with the file read complete, fill in the internal representation
	mazeRep = new char[tmaz.size()][wid];
	for (int i=0; i<tmaz.size(); i++)
	{
	    String s = tmaz.get(i);
	    for (int j=0; j<s.length(); j++)
	    {
		if (s.charAt(j)==WALL ||
			s.charAt(j)==START ||
			s.charAt(j)==FINISH ||
			s.charAt(j)==PATH)
		{
		    mazeRep[i][j] = s.charAt(j);
		}
		else
		{
		    throw new ImproperMazeException("Maze contains an unknown character ||" + s.charAt(j) + "||");
		}
	    }
	}
    }
    
    public static void main(String[] args)
    {
	String fn = "/home/gtowell/Public206/a6/maze1.txt";
	if (args.length>0)
	    fn = args[0];
	Maze m;
	try
	{
	    m = new Maze(fn);
	}
	catch (FileNotFoundException fnf)
	{
	    System.err.println(fnf + " " + fn); 
	    return;
	}
	catch (ImproperMazeException ime)
	{
	    System.err.println(ime);
	    return;
	}

    }
        
}