<%@ page import="java.text.*,Puzzle" %>
<%


    // process page



    String action = request.getParameter("action");
    String nString = null;

    Puzzle puzzle = null;

    int n = -1;



    boolean hasError = false;

    String message = null;



    if (action == null)

    {

    }

    else

    {

        if (action.equals("New Puzzle"))
        {
            nString = request.getParameter("n");

            try
            {
                n = Integer.valueOf(nString).intValue();
            }
            catch (NumberFormatException nfe)
            {
                hasError = true;
                message = "Enter an integer >= 3 for <i>n</i>!";
            }

            if (n < 3)
            {
                hasError = true;
                message = "Enter an integer >= 3 for <i>n</i>!";
            }
        }
        else
        {
            puzzle = (Puzzle)session.getAttribute("puzzle");
            n = puzzle.getSize();
            nString = n+"";
        }




    }



    // print page

%>

<html>

<head><title>Puzzle</title></head>

<body bgcolor="white">

<font size=3>

Enter <i>n</i> and click <i>New Puzzle</i> below to generate an (n^2 - 1)
puzzle.  Click the cells to arrange them in the natural order.
<p>

<form method=POST action=Puzzle.jsp>

<%


    if (nString == null || nString.equals(""))
    {

%>

<i>n</i> <input text=text name=n size=2 maxlength=2>
<%


    }

    else

    {

%>

<i>n</i> <input text=text name=n value=<%= nString %> size=2 maxlength=2>
<%


    }

%>

<p>

<i>

<input type=submit name=action value="New Puzzle">
</i>

<p>

<%


    if (action == null)

    {

    }

    else if (hasError)

    {

%>

<%= message %>

<%


    }

    else

    {

        if (action.equals("New Puzzle"))
        {
            puzzle = new Puzzle(n);
            puzzle.startTimer();
        }
        else
        {
            puzzle = (Puzzle)session.getAttribute("puzzle");
            n = puzzle.getSize();
            int index = ((Integer)session.getAttribute(action)).intValue();

            if (puzzle.isCellMovable(index))
                puzzle.move(index);
        }

        if (puzzle.isDone())
        {




%>

Congrats!  You finished the puzzle in <%= puzzle.getMoves() %> moves and <%= puzzle.getElapseTime() %>.
<%

        }
        else
        {
            if (action.equals("New Puzzle"))
            {




%>

You used 0 moves and spent 0' 0'' so far.
<%

            }
            else
            {




%>

You used <%= puzzle.getMoves() %> moves and spent <%= puzzle.getElapseTime() %> so far.
<%


            }

%>

<p>

<i>

<table border=1 cellspacing=0 cellpadding=0>
<%

            for (int row=0; row<n; row++)
            {




%>

<tr align=center>

<%

               for (int col=0; col<n; col++)
               {
                   if (puzzle.getMissingCellRow()==row
                       && puzzle.getMissingCellCol()==col)
                   {




%>

<td>&nbsp;

<%

                   }
                   else
                   {
                       NumberFormat nf = NumberFormat.getInstance();
                       nf.setMinimumIntegerDigits(4);
                       nf.setGroupingUsed(false);
                       String valueString = nf.format(puzzle.getCell(row, col));




%>

<td><input type=submit name=action value="<%= valueString %>">
<%

                       session.setAttribute(valueString, new Integer(row*n+col));
                   }
               }
            }




%>

</table>

</i>

<%

            session.setAttribute("puzzle", puzzle);
        }




    }

%>

</form>

</font>

<hr>

<a href="http://www.computing-wisdom.com"><i>Computing Wisdom Inc. Home Page</i></a>
</body>

</html>