<?php
//****************************************************************************
// phpDBTree 1.4
//****************************************************************************
//      Author: Maxim Poltarak  <maxx at e dash taller dot net>
//         WWW: http://dev.e-taller.net/dbtree/
//    Category: Databases
// Description: PHP class implementing a Nested Sets approach to storing
//              tree-like structures in database tables. This technique was
//              introduced by Joe Celko <http://www.celko.com/> and has some
//              advantages over a widely used method called Adjacency Matrix.
//****************************************************************************
// The lib is FREEWARE. That means you may use it anywhere you want, you may
// do anything with it. The Author mentioned above is NOT responsible for any
// consequences of using this library.
// If you don't agree with this, you are NOT ALLOWED to use the lib!
//****************************************************************************
// You're welcome to send me all improvings, feature requests, bug reports...
//****************************************************************************
// SAMPLE DB TABLE STRUCTURE:
//
// CREATE TABLE categories (
//   cat_id		INT UNSIGNED NOT NULL AUTO_INCREMENT,
//   cat_left	INT UNSIGNED NOT NULL,
//   cat_right	INT UNSIGNED NOT NULL,
//   cat_level	INT UNSIGNED NOT NULL,
//   PRIMARY KEY(cat_id),
//   KEY(cat_left, cat_right, cat_level)
// );
//
// This is believed to be the optimal Nested Sets use case. Use `one-to-one`
// relations on `cat_id` field between this `structure` table and
// another `data` table in your database.
//
// Don't forget to make a single call to clear()
// to set up the Root node in an empty table.
//
//****************************************************************************
// NOTE: Although you may use this library to retrieve data from the table,
//		 it is recommended to write your own queries for doing that.
//		 The main purpose of the library is to provide a simpler way to
//		 create, update and delete records. Not to SELECT them.
//****************************************************************************
//
// IMPORTANT! DO NOT create either UNIQUE or PRIMARY keys on the set of
//            fields (`cat_left`, `cat_right` and `cat_level`)!
//            Unique keys will destroy the Nested Sets structure!
//
//****************************************************************************
// CHANGELOG:
// 16-Apr-2003 -=- 1.1
//			- Added moveAll() method
//			- Added fourth parameter to the constructor
//			- Renamed getElementInfo() to getNodeInfo() /keeping BC/
//			- Added "Sample Table Structure" comment
//			- Now it trigger_error()'s in case of any serious error, because if not you
//			  will lose the Nested Sets structure in your table
// 19-Feb-2004 -=- 1.2
//			- Fixed a bug in moveAll() method?
//			  Thanks to Maxim Matyukhin for the patch.
// 13-Jul-2004 -=- 1.3
//			- Changed all die()'s for a more standard trigger_error()
//			  Thanks to Dmitry Romakhin for pointing out an issue with
//			  incorrect error message call.
// 09-Nov-2004 -=- 1.4
//			- Added insertNear() method.
//			  Thanks to Michael Krenz who sent its implementation.
//			- Removed IGNORE keyword from UPDATE clauses in insert() methods.
//			  It was dumb to have it there all the time. Sorry. Anyway, you had
//			  to follow the important note mencioned above. If you hadn't, you're
//			  in problem.
//
//****************************************************************************
// Note: For best viewing of the code Tab size 4 is recommended
//****************************************************************************

function _case($c, $then, $else) {
    return " (CASE WHEN $c THEN $then ELSE $else END) ";
}

function _between($a, $x, $y) {
    return " " . $a . " BETWEEN " . $x . " AND " . $y;
}

function _inside($a, $x, $y) {
    return " " . $a . " > " . $x . " AND " . $a . " < " . $y;
}

class CDBTree
{
    var $db; // CDatabase class to plug to
    var $table; // Table with Nested Sets implemented
    var $id; // Name of the ID-auto_increment-field in the table.
    // These 3 variables are names of fields which are needed to implement
    // Nested Sets. All 3 fields should exist in your table!
    // However, you may want to change their names here to avoid name collisions.
    var $left = 'cat_left';
    var $right = 'cat_right';
    var $level = 'cat_level';
    var $qryParams = '';
    var $qryFields = '';
    var $qryTables = '';
    var $qryWhere = '';
    var $qryGroupBy = '';
    var $qryHaving = '';
    var $qryOrderBy = '';
    var $qryLimit = '';
    var $sqlNeedReset = true;
    var $sql; // Last SQL query

    //************************************************************************
    // Constructor
    // $DB : CDatabase class instance to link to
    // $tableName : table in database where to implement nested sets
    // $itemId : name of the field which will uniquely identify every record
    // $fieldNames : optional configuration array to set field names. Example:
    //				 array(
    //					'left' => 'cat_left',
    //					'right' => 'cat_right',
    //					'level' => 'cat_level'
    //				 )    
    function CDBTree(&$DB, $tableName, $itemId, $seq, $fieldNames = array()) 
    {
        
        if (empty($tableName)) trigger_error("phpDbTree: Unknown table", E_USER_ERROR);
        
        if (empty($itemId)) trigger_error("phpDbTree: Unknown ID column", E_USER_ERROR);
        $this->seq = $seq;
        $this->db = $DB;
        $this->table = $tableName;
        $this->id = $itemId;
        
        if (is_array($fieldNames) && sizeof($fieldNames)) 
        foreach($fieldNames as $k => $v) $this->$k = $v;
    }

    //************************************************************************
    // Returns a Left and Right IDs and Level of an element or false on error
    // $ID : an ID of the element   
    function getElementInfo($ID) 
    {
        return $this->getNodeInfo($ID);
    }
    
    function getNodeInfo($ID) 
    {
        $this->sql = 'SELECT ' . $this->left . ',' . $this->right . ',' . $this->level . ' FROM ' . $this->table . ' WHERE ' . $this->id . '=\'' . $ID . '\'';
//        print_r($this->sql);
        
        if (($query = $this->db->query($this->sql)) && ($this->db->num_rows($query) == 1) && ($Data = $this->db->fetch_array($query))) return array(
            (int)$Data[$this->left],
            (int)$Data[$this->right],
            (int)$Data[$this->level]
        );
        else trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR); // throw new Exception();
    }

    //************************************************************************
    // Clears table and creates 'root' node
    // $data : optional argument with data for the root node    
    function clear($data = array()) 
    {
        // clearing table
        
        if ((!$this->db->query('TRUNCATE ' . $this->table)) && (!$this->db->query('DELETE FROM ' . $this->table))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        // preparing data to be inserted
        
        if (sizeof($data)) {
            $fld_names = implode(',', array_keys($data)) . ',';
            
            if (sizeof($data)) $fld_values = '\'' . implode('\',\'', array_values($data)) . '\',';
        }
        $fld_names.= $this->left . ',' . $this->right . ',' . $this->level;
        $fld_values.= '1,2,0';
        // inserting new record
        $this->sql = 'INSERT INTO ' . $this->table . '(' . $fld_names . ') VALUES(' . $fld_values . ')';
        
        if (!($this->db->query($this->sql))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        return $this->db->insert_id($this->seq);
    }

    //************************************************************************
    // Updates a record
    // $ID : element ID
    // $data : array with data to update: array(<field_name> => <fields_value>)   
    function update($ID, $data) 
    {
        $sql_set = '';
        
        foreach($data as $k => $v) $sql_set.= ',' . $k . '=\'' . addslashes($v) . '\'';
        return $this->db->query('UPDATE ' . $this->table . ' SET ' . substr($sql_set, 1) . ' WHERE ' . $this->id . '=\'' . $ID . '\'');
    }

    //************************************************************************
    // Inserts a record into the table with nested sets
    // $ID : an ID of the parent element
    // $data : array with data to be inserted: array(<field_name> => <field_value>)
    // Returns : true on success, or false on error    
    function insert($ID, $data) 
    {
        
        if (!(list($leftId, $rightId, $level) = $this->getNodeInfo($ID))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        // preparing data to be inserted
        
        if (sizeof($data)) {
            $fld_names = implode(',', array_keys($data)) . ',';
            $fld_values = '\'' . implode('\',\'', array_values($data)) . '\',';
        }
        $fld_names.= $this->left . ',' . $this->right . ',' . $this->level;
        $fld_values.= ($rightId) . ',' . ($rightId+1) . ',' . ($level+1);
        // creating a place for the record being inserted
        
        if ($ID) {
            $this->sql = 'UPDATE ' . $this->table . ' SET ' . $this->left . '=' . _case($this->left . '>' . $rightId, $this->left . '+2', $this->left) . ',' . $this->right . '=' . _case($this->right . '>=' . $rightId, $this->right . '+2', $this->right) . 'WHERE ' . $this->right . '>=' . $rightId;
            
            if (!($this->db->query($this->sql))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        }
        // inserting new record
        $this->sql = 'INSERT INTO ' . $this->table . '(' . $fld_names . ') VALUES(' . $fld_values . ')';
        
        if (!($this->db->query($this->sql))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        return $this->db->insert_id($this->seq);
    }

    //************************************************************************
    // Inserts a record into the table with nested sets
    // $ID : ID of the element after which (i.e. at the same level) the new element
    //		 is to be inserted
    // $data : array with data to be inserted: array(<field_name> => <field_value>)
    // Returns : true on success, or false on error    
    function insertNear($ID, $data) 
    {
        
        if (!(list($leftId, $rightId, $level) = $this->getNodeInfo($ID))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        // preparing data to be inserted
        
        if (sizeof($data)) {
            $fld_names = implode(',', array_keys($data)) . ',';
            $fld_values = '\'' . implode('\',\'', array_values($data)) . '\',';
        }
        $fld_names.= $this->left . ',' . $this->right . ',' . $this->level;
        $fld_values.= ($rightId+1) . ',' . ($rightId+2) . ',' . ($level);
        // creating a place for the record being inserted
        
        if ($ID) {
            $this->sql = 'UPDATE ' . $this->table . ' SET ' . $this->left . '=' . _case($this->left . '>' . $rightId, $this->left . '+2', $this->left) . $this->right . '=' . _case($this->right . '>' . $rightId, $this->right . '+2', $this->right) . 'WHERE ' . $this->right . '>' . $rightId;
            
            if (!($this->db->query($this->sql))) trigger_error("phpDbTree error:" . $this->db->error() , E_USER_ERROR);
        }
        // inserting new record
        $this->sql = 'INSERT INTO ' . $this->table . '(' . $fld_names . ') VALUES(' . $fld_values . ')';
        
        if (!($this->db->query($this->sql))) trigger_error("phpDbTree error:" . $this->db->error() , E_USER_ERROR);
        return $this->db->insert_id($this->seq);
    }

    //************************************************************************
    // Assigns a node with all its children to another parent
    // $ID : node ID
    // $newParentID : ID of new parent node
    // Returns : false on error    
    function moveAll($ID, $newParentId) 
    {
        
        if (!(list($leftId, $rightId, $level) = $this->getNodeInfo($ID))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        
        if (!(list($leftIdP, $rightIdP, $levelP) = $this->getNodeInfo($newParentId))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        
        if ($ID == $newParentId || $leftId == $leftIdP || ($leftIdP >= $leftId && $leftIdP <= $rightId)) return false;
        // whether it is being moved upwards along the path
        
        if ($leftIdP < $leftId && $rightIdP > $rightId && $levelP < $level-1) {
            $this->sql = 'UPDATE ' . $this->table . ' SET ' 
                . $this->level . '=' . _case($this->left . ' BETWEEN ' . $leftId . ' AND ' . $rightId, $this->level . sprintf('%+d', -($level-1) +$levelP) , $this->level) . ","
                . $this->right . '=' . _case($this->right . ' BETWEEN ' . ($rightId+1) . ' AND ' . ($rightIdP-1) , $this->right . '-' . ($rightId-$leftId+1) 
                    , _case($this->left . ' BETWEEN ' . ($leftId) . ' AND ' . ($rightId) , $this->right . '+' . ((($rightIdP-$rightId-$level+$levelP) /2) *2+$level-$levelP-1) , $this->right)) . ","
                . $this->left . '=' . _case($this->left . ' BETWEEN ' . ($rightId+1) . ' AND ' . ($rightIdP-1) , $this->left . '-' . ($rightId-$leftId+1) , _case($this->left . ' BETWEEN ' . $leftId . ' AND ' . ($rightId) , $this->left . '+' . ((($rightIdP-$rightId-$level+$levelP) /2) *2+$level-$levelP-1) , $this->left)) . 'WHERE ' . $this->left . ' BETWEEN ' . ($leftIdP+1) . ' AND ' . ($rightIdP-1);

        } elseif ($leftIdP < $leftId) {
            $this->sql = 'UPDATE ' . $this->table . ' SET ' 
                . $this->level . '=' . _case($this->left . ' BETWEEN ' . $leftId . ' AND ' . $rightId, $this->level . sprintf('%+d', -($level-1) +$levelP) , $this->level) . ","
                . $this->left . '=' . _case($this->left . ' BETWEEN ' . $rightIdP . ' AND ' . ($leftId-1) , $this->left . '+' . ($rightId-$leftId+1) 
                    , _case($this->left . ' BETWEEN ' . $leftId . ' AND ' . $rightId, $this->left . '-' . ($leftId-$rightIdP) , $this->left)) . "," 
                . $this->right . '=' . _case($this->right . ' BETWEEN ' . $rightIdP . ' AND ' . $leftId, $this->right . '+' . ($rightId-$leftId+1) , _case($this->right . ' BETWEEN ' . $leftId . ' AND ' . $rightId, $this->right . '-' . ($leftId-$rightIdP) , $this->right)) . 'WHERE ' . $this->left . ' BETWEEN ' . $leftIdP . ' AND ' . $rightId
            // !!! added this line (Maxim Matyukhin)
             . ' OR ' . $this->right . ' BETWEEN ' . $leftIdP . ' AND ' . $rightId;
        } else {
            $this->sql = 'UPDATE ' . $this->table . ' SET ' 
                . $this->level . '=' . _case($this->left . ' BETWEEN ' . $leftId . ' AND ' . $rightId, $this->level . sprintf('%+d', -($level-1) +$levelP) , $this->level) . ","
                . $this->left . '=' . _case($this->left . ' BETWEEN ' . $rightId . ' AND ' . $rightIdP, $this->left . '-' . ($rightId-$leftId+1) 
                    , _case($this->left . ' BETWEEN ' . $leftId . ' AND ' . $rightId, $this->left . '+' . ($rightIdP-1-$rightId), $this->left)) . ", "
                . $this->right . '=' . _case($this->right . ' BETWEEN ' . ($rightId+1) . ' AND ' . ($rightIdP-1) , $this->right . '-' . ($rightId-$leftId+1) , _case($this->right . ' BETWEEN ' . $leftId . ' AND ' . $rightId, $this->right . '+' . ($rightIdP-1-$rightId) , $this->right)) . 'WHERE ' . $this->left . ' BETWEEN ' . $leftId . ' AND ' . $rightIdP
            // !!! added this line (Maxim Matyukhin)
             . ' OR ' . $this->right . ' BETWEEN ' . $leftId . ' AND ' . $rightIdP;
        }
        return $this->db->query($this->sql) or trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
    }

    // Перемещение всех детей ветки в другую ветку
    function moveChildren($ID, $newParentId)
    {

        if (!(list($leftId, $rightId, $level) = $this->getNodeInfo($ID))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        
        if (!(list($leftIdP, $rightIdP, $levelP) = $this->getNodeInfo($newParentId))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        
        if ($ID == $newParentId || $leftId == $leftIdP || ($leftIdP >= $leftId && $leftIdP <= $rightId)) return false;
        // whether it is being moved upwards along the path
        
        if ($leftIdP < $leftId && $rightIdP > $rightId && $levelP < $level-1) {
            // _update($this->table, array(), )
            $this->sql = 'UPDATE ' . $this->table . ' SET '   
              // Меняем уровень
              . $this->level . '=' . 
                  _case(_between($this->left,  $leftId, $rightId), 
                        $this->level . sprintf('%+d', -($level-1) +$levelP) , $this->level) 
              // Меняем границы
              . $this->left . '=' . 
                  _case(_beetween($this->left, $rightId+1, $rightIdP-1), $this->left . '-' . $rightId-$leftId+1 , 
                        _case(_between($this->left, $leftId, $rightId), $this->left . '+' . ((($rightIdP-$rightId-$level+$levelP) /2) *2+$level-$levelP-1) , $this->left)) 
              . $this->right . '=' . 
                  _case(_between($this->right, $rightId+1, $rightIdP-1), $this->right . '-' . ($rightId-$leftId+1) , 
                        _case(_between($this->left, $leftId, $rightId), $this->right . '+' . ((($rightIdP-$rightId-$level+$levelP) /2) *2+$level-$levelP-1) , $this->right)) 
              . 'WHERE ' . _between($this->left, ($leftIdP+1), ($rightIdP-1));

        } elseif ($leftIdP < $leftId) {
            $this->sql = 'UPDATE ' . $this->table . ' SET ' 
              . $this->level . '=' . 
                  _case(_between($this->left, $leftId, $rightId), 
                        $this->level . sprintf('%+d', -($level-1) +$levelP) , $this->level) 
              . $this->left . '=' . 
                  _case(_between($this->left, $rightIdP, $leftId-1), $this->left . '+' . ($rightId-$leftId+1), 
                        _case(_between($this->left, $leftId, $rightId), $this->left . '-' . ($leftId-$rightIdP) , $this->left)) 
              . $this->right . '=' . 
                  _case(_between($this->right, $rightIdP, $leftId), $this->right . '+' . ($rightId-$leftId+1), 
                        _case(_between($this->right, $leftId, $rightId), $this->right . '-' . ($leftId-$rightIdP) , $this->right)) 
              . 'WHERE ' . _between($this->left, $leftIdP, $rightId)
              // !!! added this line (Maxim Matyukhin)
             . ' OR ' . _between($this->right, $leftIdP, $rightId);
        } else {
            $this->sql = 'UPDATE ' . $this->table . ' SET ' 
              . $this->level . '=' 
                  . _case(_between($this->left, $leftId, $rightId), 
                          $this->level . sprintf('%+d', -($level-1) +$levelP) , $this->level) 
              . $this->left . '=' . 
                    _case(_between($this->left, $rightId, $rightIdP), $this->left . '-' . ($rightId-$leftId+1), 
                          _case(_between($this->left, $leftId, $rightId), $this->left . '+' . ($rightIdP-1-$rightId), $this->left)) 
              . $this->right . '=' . 
                    _case(_between($this->right, $rightId+1, $rightIdP-1), $this->right . '-' . ($rightId-$leftId+1), 
                          _case(_between($this->right, $leftId, $rightId), $this->right . '+' . ($rightIdP-1-$rightId) , $this->right)) 
              . 'WHERE ' . _between($this->left, $leftId, $rightIdP)
              // !!! added this line (Maxim Matyukhin)
             . ' OR ' . _between($this->right, $leftId, $rightIdP);
        }
        return $this->db->query($this->sql) or trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);

    }

    //************************************************************************
    // Deletes a record wihtout deleting its children
    // $ID : an ID of the element to be deleted
    // Returns : true on success, or false on error    
    function delete($ID) 
    {
        
        if (!(list($leftId, $rightId, $level) = $this->getNodeInfo($ID))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        // Deleting record
        $this->sql = 'DELETE FROM ' . $this->table . ' WHERE ' . $this->id . '=\'' . $ID . '\'';
        
        if (!$this->db->query($this->sql)) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        // Clearing blank spaces in a tree
        $this->sql = 'UPDATE ' . $this->table . ' SET ' 
          . $this->left . '=' . _case($this->left . ' BETWEEN ' . $leftId . ' AND ' . $rightId, $this->left . '-1', $this->left) . ", " 
          . $this->right . '=' . _case($this->right . ' BETWEEN ' . $leftId . ' AND ' . $rightId, $this->right . '-1', $this->right) . ", " 
          . $this->level . '=' . _case($this->left . ' BETWEEN ' . $leftId . ' AND ' . $rightId, $this->level . '-1', $this->level) . ", " 
          . $this->left . '=' . _case($this->left . '>' . $rightId, $this->left . '-2', $this->left) . ", " 
          . $this->right . '=' . _case($this->right . '>' . $rightId, $this->right . '-2', $this->right) 
          . ' WHERE ' . $this->right . '>' . $leftId;
        
        if (!$this->db->query($this->sql)) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        return true;
    }

    //************************************************************************
    // Deletes a record with all its children
    // $ID : an ID of the element to be deleted
    // Returns : true on success, or false on error    
    function deleteAll($ID) 
    {
        
        if (!(list($leftId, $rightId, $level) = $this->getNodeInfo($ID))) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        // Deleteing record(s)
        $this->sql = 'DELETE FROM ' . $this->table . ' WHERE ' . $this->left . ' BETWEEN ' . $leftId . ' AND ' . $rightId;
        
        if (!$this->db->query($this->sql)) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        // Clearing blank spaces in a tree
        $deltaId = ($rightId-$leftId) +1;
        $this->sql = 'UPDATE ' . $this->table . ' SET ' 
          . $this->left . '=' . _case($this->left . '>' . $leftId, $this->left . '-' . $deltaId, $this->left) . ", "
          . $this->right . '=' . _case($this->right . '>' . $leftId, $this->right . '-' . $deltaId, $this->right)   
          . ' WHERE ' . $this->right . '>' . $rightId;
       
        if (!$this->db->query($this->sql)) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        return true;
    }

    //************************************************************************
    // Enumerates children of an element
    // $ID : an ID of an element which children to be enumerated
    // $start_level : relative level from which start to enumerate children
    // $end_level : the last relative level at which enumerate children
    //   1. If $end_level isn't given, only children of
    //      $start_level levels are enumerated
    //   2. Level values should always be greater than zero.
    //      Level 1 means direct children of the element
    // Returns : a result id for using with other DB functions    
    function enumChildrenAll($ID) 
    {
        return $this->enumChildren($ID, 1, 0);
    }
    
    function enumChildren($ID, $start_level = 1, $end_level = 1) 
    {        
        if ($start_level < 0) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        // We could use sprintf() here, but it'd be too slow
        $whereSql1 = ' AND ' . $this->table . '.' . $this->level;
        $whereSql2 = '_' . $this->table . '.' . $this->level . '+';
        
        if (!$end_level) $whereSql = $whereSql1 . '>=' . $whereSql2 . (int)$start_level;
        else {
            $whereSql = ($end_level <= $start_level) ? $whereSql1 . '=' . $whereSql2 . (int)$start_level : ' AND ' . $this->table . '.' . $this->level . ' BETWEEN _' . $this->table . '.' . $this->level . '+' . (int)$start_level . ' AND _' . $this->table . '.' . $this->level . '+' . (int)$end_level;
        }
        $this->sql = $this->sqlComposeSelect(array(
            '', // Params
            '', // Fields
            $this->table . ' _' . $this->table . ', ' . $this->table, // Tables
            '_' . $this->table . '.' . $this->id . '=\'' . $ID . '\'' . ' AND ' . $this->table . '.' . $this->left . ' BETWEEN _' . $this->table . '.' . $this->left . ' AND _' . $this->table . '.' . $this->right . $whereSql
        ));
        return $this->db->query($this->sql);
    }

    function enumChildrenArray($ID, $start_level = 1, $end_level = 1)
    {
        return $this->db->result2array($this->enumChildren($ID, $start_level, $end_level));
    }

    //************************************************************************
    // Enumerates the PATH from an element to its top level parent
    // $ID : an ID of an element
    // $showRoot : whether to show root node in a path
    // Returns : a result id for using with other DB functions    
    function enumPath($ID, $showRoot = false) 
    {
        $this->sql = $this->sqlComposeSelect(array(
            '', // Params
            '', // Fields
            $this->table . ' _' . $this->table . ', ' . $this->table, // Tables
            '_' . $this->table . '.' . $this->id . '=\'' . $ID . '\'' . ' AND _' . $this->table . '.' . $this->left . ' BETWEEN ' . $this->table . '.' . $this->left . ' AND ' . $this->table . '.' . $this->right . (($showRoot) ? '' : ' AND ' . $this->table . '.' . $this->level . '>0') , // Where
            '', // GroupBy
            '', // Having
            $this->table . '.' . $this->left // OrderBy
            
        ));
        return $this->db->query($this->sql);
    }

    function enumPathArray($ID, $showRoot = false)
    {
        return $this->db->result2array($this->enumPath($ID, $showRoot));
    }

    //************************************************************************
    // Returns query result to fetch data of the element's parent
    // $ID : an ID of an element which parent to be retrieved
    // $level : Relative level of parent
    // Returns : a result id for using with other DB functions    
    function getParent($ID, $level = 1) 
    {
        
        if ($level < 1) trigger_error("phpDbTree error: " . $this->db->error() , E_USER_ERROR);
        $this->sql = $this->sqlComposeSelect(array(
            '', // Params
            '', // Fields
            $this->table . ' _' . $this->table . ', ' . $this->table, // Tables
            '_' . $this->table . '.' . $this->id . '=\'' . $ID . '\'' . ' AND _' . $this->table . '.' . $this->left . ' BETWEEN ' . $this->table . '.' . $this->left . ' AND ' . $this->table . '.' . $this->right . ' AND ' . $this->table . '.' . $this->level . '=_' . $this->table . '.' . $this->level . '-' . (int)$level // Where
            
        ));
        $result = $this->db->result2array($this->db->query($this->sql));
        return (int)$result[0][$this->id];
    }
    //************************************************************************
    
    function sqlReset() 
    {
        $this->qryParams = '';
        $this->qryFields = '';
        $this->qryTables = '';
        $this->qryWhere = '';
        $this->qryGroupBy = '';
        $this->qryHaving = '';
        $this->qryOrderBy = '';
        $this->qryLimit = '';
        return true;
    }

    //************************************************************************    
    function sqlSetReset($resetMode) 
    {
        $this->sqlNeedReset = ($resetMode) ? true : false;
    }

    //************************************************************************    
    function sqlParams($param = '') 
    {
        return (empty($param)) ? $this->qryParams : $this->qryParams = $param;
    }
    
    function sqlFields($param = '') 
    {
        return (empty($param)) ? $this->qryFields : $this->qryFields = $param;
    }
    
    function sqlSelect($param = '') 
    {
        return $this->sqlFields($param);
    }
    
    function sqlTables($param = '') 
    {
        return (empty($param)) ? $this->qryTables : $this->qryTables = $param;
    }
    
    function sqlFrom($param = '') 
    {
        return $this->sqlTables($param);
    }
    
    function sqlWhere($param = '') 
    {
        return (empty($param)) ? $this->qryWhere : $this->qryWhere = $param;
    }
    
    function sqlGroupBy($param = '') 
    {
        return (empty($param)) ? $this->qryGroupBy : $this->qryGroupBy = $param;
    }
    
    function sqlHaving($param = '') 
    {
        return (empty($param)) ? $this->qryHaving : $this->qryHaving = $param;
    }
    
    function sqlOrderBy($param = '') 
    {
        return (empty($param)) ? $this->qryOrderBy : $this->qryOrderBy = $param;
    }
    
    function sqlLimit($param = '') 
    {
        return (empty($param)) ? $this->qryLimit : $this->qryLimit = $param;
    }

    //************************************************************************    
    function sqlComposeSelect($arSql) 
    {
        $joinTypes = array(
            'join' => 1,
            'cross' => 1,
            'inner' => 1,
            'straight' => 1,
            'left' => 1,
            'natural' => 1,
            'right' => 1
        );
        $this->sql = 'SELECT ' . $arSql[0] . ' ';
        
        if (!empty($this->qryParams)) $this->sql.= $this->sqlParams . ' ';
        
        if (empty($arSql[1]) && empty($this->qryFields)) $this->sql.= $this->table . '.' . $this->id;
        else {
            
            if (!empty($arSql[1])) $this->sql.= $arSql[1];
            
            if (!empty($this->qryFields)) $this->sql.= ((empty($arSql[1])) ? '' : ',') . $this->qryFields;
        }
        $this->sql.= ' FROM ';
//        $tblAr = array(0 => 'join');
        $isJoin = ($tblAr = explode(' ', trim($this->qryTables))) 
          && /*($joinTypes[strtolower($tblAr[0]) ])*/ 1;
        
        if (empty($arSql[2]) && empty($this->qryTables)) $this->sql.= $this->table;
        else {
            
            if (!empty($arSql[2])) $this->sql.= $arSql[2];
            
            if (!empty($this->qryTables)) {
                
                if (!empty($arSql[2])) $this->sql.= (($isJoin) ? ' ' : ',');
                elseif ($isJoin) $this->sql.= $this->table . ' ';
                $this->sql.= $this->qryTables;
            }
        }
        
        if ((!empty($arSql[3])) || (!empty($this->qryWhere))) {
            $this->sql.= ' WHERE ' . $arSql[3] . ' ';
            
            if (!empty($this->qryWhere)) $this->sql.= (empty($arSql[3])) ? $this->qryWhere : 'AND(' . $this->qryWhere . ')';
        }
        
        if ((!empty($arSql[4])) || (!empty($this->qryGroupBy))) {
            $this->sql.= ' GROUP BY ' . $arSql[4] . ' ';
            
            if (!empty($this->qryGroupBy)) $this->sql.= (empty($arSql[4])) ? $this->qryGroupBy : ',' . $this->qryGroupBy;
        }
        
        if ((!empty($arSql[5])) || (!empty($this->qryHaving))) {
            $this->sql.= ' HAVING ' . $arSql[5] . ' ';
            
            if (!empty($this->qryHaving)) $this->sql.= (empty($arSql[5])) ? $this->qryHaving : 'AND(' . $this->qryHaving . ')';
        }
        
        if ((!empty($arSql[6])) || (!empty($this->qryOrderBy))) {
            $this->sql.= ' ORDER BY ' . (isset($arSql[6]) ? $arSql[6] : '') . ' ';
            
            if (!empty($this->qryOrderBy)) $this->sql.= (empty($arSql[6])) ? $this->qryOrderBy : ',' . $this->qryOrderBy;
        }
        
        if (!empty($arSql[7])) $this->sql.= ' LIMIT ' . $arSql[7];
        elseif (!empty($this->qryLimit)) $this->sql.= ' LIMIT ' . $this->qryLimit;
        
        if ($this->sqlNeedReset) $this->sqlReset();
        return $this->sql;
    }
    //************************************************************************
    
}