<?php
/*
#    This program is free software; you can redistribute it and/or
#    modify it under the terms of the GNU General Public License
#    as published by the Free Software Foundation; either version 2
#    of the License, or (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#    http://www.gnu.org/licenses/gpl.txt
#
*/

 /******
 *
 * class Positions - Get and set to table db position's records
 * 
 * @author	Vladimir S. Bredihin
 * @access	public
 * @version	1.0
 * @package	positions
 * @link	http://mycms.info
 *
 ******/
class Positions{
    var $table;
    var $parent;
    var $id;
    var $field = array ();
    var $_form = array (    'RU'	=>	array ( 'first'	=> 'First [Language = RU]',
    											'last'	=> 'Last [Language = RU]'),
    			     		'EN'	=>	array ( 'first' => 'First',
    			     							'last'	=> 'Last'));
    var $lang = 'EN';

    function Positions($table=null, $parent=null, $id=null, $fieldName='name', $fieldParent='parent')
    {
    	$this->table   = $table;
    	$this->parent  = $parent;
    	$this->id      = $id;
		$this->field['name'	] = $fieldName;
		$this->field['parent'	] = $fieldParent;
		$this->_constructor();
    }
    function _constructor()
    {
    	if ($this->table)
	    	if (!mysql_query ('SELECT position FROM '.$this->table.' LIMIT 0,1'))
	    	{
	    		mysql_query ('ALTER TABLE '.$this->table.' ADD COLUMN position int');
	    		mysql_query ('UPDATE '.$this->table.' SET position=id');
	    	}
    }
    /*
    This function list records table
    */
    function lst($table=null, $parent=null)
    {
        if (!$table) $table = $this->table;
        if (!$parent) $parent = $this->parent;
        $positions = array ('begin' => $this->_form [$this->lang]['first']);
    	$result = mysql_query ('SELECT id, '.$this->field['name'].' FROM '.$table." 
    	                        WHERE {$this->field['parent']}='{$parent}' ORDER BY position ") or die (__FILE__.' - '.__LINE__.' :'.mysql_error());
    	while ($row = mysql_fetch_assoc ($result))
    	{
    	   $positions [$row['id']] = $row [$this->field['name']];
    	}
    	$positions['end'] = $this->_form [$this->lang]['last'];
    	return $positions;
    }
    /*
    This function set position to table

    $set_position - is id record aftr which come set current record or constantes first|last
    if result success full (and not error) then return true else return false
    */
    function modify($set_position)
    {
        $table  = $this->table;
        $parent = $this->parent;
        $id     = $this->id;

        $break = false;
    	if ($set_position && $set_position != $id)
    	{
    	   if (is_numeric ($set_position))
    	   {
    	       $result = mysql_query ('SELECT position FROM '.$table." WHERE id='{$set_position}'");
               if ($row = mysql_fetch_row ($result))
               {
                    $position = $row[0]+1;
               }
    	   }
    	   elseif ($set_position == 'begin')
    	   {
    	       $position = 1;
    	   }
    	   elseif ($set_position=='end')
    	   {
    	       $result = mysql_query ('SELECT position FROM '.$table." WHERE {$this->field['parent']}='{$parent}' ORDER BY position DESC LIMIT 0,1");
    	       if ($row = mysql_fetch_row ($result))
    	           $position = $row[0]+1;
    	   }
    	   else 
    	   {
    	   		//error
    	   	   $break = true;
    	   }
    	   if (!$break)
    	   {
        	   mysql_query ('UPDATE '.$table." SET position='{$position}' WHERE id='{$id}'");
        	   $result = mysql_query ('SELECT id FROM '.$table." WHERE {$this->field['parent']}='{$parent}' AND position>={$position} AND id!='{$id}' ORDER BY position") or die (mysql_error());
        	   while ($row = mysql_fetch_row($result))
        	   {
        	       $position++;
        	       mysql_query ('UPDATE '.$table." SET position='{$position}' WHERE id='{$row[0]}'");
        	   }
    	   }
    	}
    	return !$break;
    }
}
?>