// Copyright (c) 2001 Hursh Jain (http://www.mollypages.org) 
// The Molly framework is freely distributable under the terms of an
// MIT-style license. For details, see the molly pages web site at:
// http://www.mollypages.org/. Use, modify, have fun !

package fc.util;

import java.util.*;

/** 
Implements a simple table data structure. Like a 2D array
but uses nested hash tables to get (row, col) based on a 
(name, name) pair. The table grows automatically as needed.
<p>
Differs from a 2D Object[][] in that names can be used 
instead of indices.
<p>
All indexes are internally strings. When adding or retrieving
values, either numerical and string indices can be specified
for either row or col when retrieving a (row,col) value. <i>A
numerical index is converted into a string value</i> so if one puts
a value at (3, 5), that can later be retrieved as ("3", "5")
if desired.
<p>
Thread safety: This data structure is fully thread safe.

@author hursh jain
**/
public final class Table
{
private static final boolean dbg = false;

int row_default_size;
int col_default_size;

/*    
         A     B    C
rows  1:   x     y    z
      2:   a     e    n
      3:   c     d    m

rows(1) => hashtable (A->x, B->y, C->z)
rows(2) => hashtable (A->a, B->e, C->n)
..
*/
Map table;

/** 
Constructs a new table.
**/
public Table() {
  this(32, 32);
  }

/** 
Constructs a new table of the specified initial size.
**/
public Table(int rows, int cols) {
  this.row_default_size = rows;
  this.col_default_size = cols;
  this.table = new Hashtable(rows);
  }

/** 
Returns the object at row, col or <tt>null</tt> if the
specified row or col do not exist.
*/
public Object get(String row, String col) 
  {
  Object val = null;
  
  Map cols = (Map) table.get(row);
  
  if (cols != null) 
    val = cols.get(col);
    
  return val;
  }


/**
Returns the object at row, col or <tt>null</tt> if the
specified row or col do not exist.
*/
public Object get(int row, String col) 
  {
  return get(String.valueOf(row), col);
  }

/**
Returns the object at row, col or <tt>null</tt> if the
specified row or col do not exist.
*/
public Object get(String row, int col) 
  {
  return get(row, String.valueOf(col));
  }

/**
Returns the object at row, col or <tt>null</tt> if the
specified row or col do not exist.
*/
public Object get(int row, int col) 
  {
  return get(String.valueOf(row), String.valueOf(col));
  }

/**
Returns the object at row, col or <tt>null</tt> if the
specified row or col do not exist.

@return the old object at that (row, col) if it exists
*/
public Object put(String row, String col, Object obj) 
  {
  Object val = null;
  
  Map c = (Map) table.get(row);
  if (c == null) {
    c = new Hashtable(col_default_size);
    table.put(row, c);
    }
  
  val = c.put(col, obj);  
  return val;
  }


public Object put(int row, String col, Object obj) 
  {
  return put(String.valueOf(row), col, obj);
  }

public Object put(String row, int col, Object obj) 
  {
  return put(row, String.valueOf(col), obj);
  }

public Object put(int row, int col, Object obj) 
  {
  return put(String.valueOf(row), String.valueOf(col), obj);
  }


public String toString() {
  return "Table: [" + table.size() + " rows]";
  }
  
public static void main (String args[])
  {
  Table t = new Table();
  System.out.println("t.get(1,1)="+t.get(1,1));
  System.out.println("t.put(1,1,\"hello\")="+t.put(1,1, "hello"));
  System.out.println("t.get(\"1\",\"1\")="+t.get("1","1"));
  System.out.println("t.get(1,\"1\")="+t.get(1,"1"));
  System.out.println("t.get(1,0)="+t.get(1,0));
  System.out.println("t.put(1,1,\"hello\")="+t.put(1,1, "world"));
  System.out.println("t.get(\"1\",1)="+t.get("1",1));

  for (int n = 0; n < 10; n++) {
    t.put(n, n, n);
    }

  for (int n = 0; n < 10; n++) {
    System.out.println("table["+n+","+n+"]:"+t.get(n, n));
    }
  
  Watch w = new Watch().start();
  t.get(5,5);
  w.stop();
  System.out.println("time for one t.get() op: " + w.time() + " ms");
  }
}   //~class Table