<?php
/* SVN FILE: $Id$ */

/**
 * Object-relational mapper.
 *
 * DBO-backed object data model, for mapping database tables to Cake objects.
 *
 * PHP versions 4 and 5
 *
 * CakePHP :  Rapid Development Framework <http://www.cakephp.org/>
 * Copyright (c) 2005, Cake Software Foundation, Inc.
 *                     1785 E. Sahara Avenue, Suite 490-204
 *                     Las Vegas, Nevada 89104
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @filesource
 * @copyright    Copyright (c) 2005, Cake Software Foundation, Inc.
 * @link         http://www.cakefoundation.org/projects/info/cakephp CakePHP Project
 * @package      cake
 * @subpackage   cake.cake.libs.model
 * @since        CakePHP v 0.10.0.0
 * @version      $Revision$
 * @modifiedby   $LastChangedBy$
 * @lastmodified $Date$
 * @license      http://www.opensource.org/licenses/mit-license.php The MIT License
 */

/**
 * Included libs
 */
uses('class_registry', 'validators');


/**
 * Object-relational mapper.
 *
 * DBO-backed object data model.
 * Automatically selects a database table name based on a pluralized lowercase object class name
 * (i.e. class 'User' => table 'users'; class 'Man' => table 'men')
 * The table is required to have at least 'id auto_increment', 'created datetime',
 * and 'modified datetime' fields.
 *
 * @package    cake
 * @subpackage cake.cake.libs.model
 * @since      CakePHP v 0.2.9
 *
 */
class Model extends Object
{

/**
 * The name of the DataSource connection that this Model uses
 *
 * @var string
 * @access public
 */
   var $useDbConfig = 'default';

/**
 * The DataSource connection object that this Model uses
 *
 * @var unknown_type
 * @access public
 */
   var $db = null;

/**
 * Enter description here... Still used?
 *
 * @var unknown_type
 * @access public
 * @todo Is this still used? -OJ 22 nov 2005
 */
   var $parent = false;

/**
 * Custom database table name
 *
 * @var string
 * @access public
 */
   var $useTable = null;

/**
 * Custom display field name
 *
 * @var string
 * @access public
 */
   var $displayField = null;

/**
 *Value of the primary key ID of the record that this model is currently pointing to
 *
 * @var unknown_type
 * @access public
 */
   var $id = false;

/**
 * Container for the data that this model gets from persistent storage (the database).
 *
 * @var array
 * @access public
 */
   var $data = array();

/**
 * Table name for this Model.
 *
 * @var string
 * @access public
 */
   var $table = false;

/**
 * The name of the ID field for this Model.
 *
 * @var string
 * @access public
 */
   var $primaryKey = null;

/**
 * Table metadata
 *
 * @var array
 * @access private
 */
   var $_tableInfo = null;

/**
 * List of validation rules. Append entries for validation as ('field_name' => '/^perl_compat_regexp$/')
 * that have to match with preg_match(). Use these rules with Model::validate()
 *
 * @var array
 */
   var $validate = array();

/**
 * Errors in validation
 * @var array
 */
   var $validationErrors = null;

/**
 * Prefix for tables in model.
 *
 * @var string
 */
   var $tablePrefix = null;

/**
 * Name of the model.
 *
 * @var string
 */
   var $name = null;

/**
 * Name of the model.
 *
 * @var string
 */
   var $currentModel = null;

/**
 * List of table names included in the Model description. Used for associations.
 *
 * @var array
 */
   var $tableToModel = array();

/**
 * List of Model names by used tables. Used for associations.
 *
 * @var array
 */
   var $modelToTable = array();

/**
 * Alias table names for model, for use in SQL JOIN statements.
 *
 * @var array
 */
   var $alias = array();

/**
 * Whether or not transactions for this model should be logged
 *
 * @var boolean
 */
   var $logTransactions = false;

/**
 * Whether or not to enable transactions for this model (i.e. begin/commit/rollback)
 *
 * @var boolean
 */
   var $transactional = false;

/**
 * belongsTo association
 *
 * @var array
 */
   var $belongsTo = array();

/**
 * hasOne association
 *
 * @var array
 */
   var $hasOne = array();

/**
 * hasMany association
 *
 * @var array
 */
   var $hasMany = array();

/**
 * hasAndBelongsToMany association
 *
 * @var array
 */
   var $hasAndBelongsToMany = array();


/**
 * Default association keys
 *
 * @var array
 */
   var $__associationKeys = array('belongsTo' 	=> array('className', 'conditions', 'order', 'foreignKey', 'counterCache'),
                                  'hasOne' 		=> array('className', 'conditions', 'order', 'foreignKey', 'dependent'),
                                  'hasMany' 	=> array('className', 'conditions', 'order', 'foreignKey', 'fields', 'dependent', 'exclusive', 'finder_query', 'counter_query'),
                                  'hasAndBelongsToMany' => array('className', 'joinTable', 'fields', 'foreignKey', 'associationForeignKey', 'conditions', 'order', 'uniq', 'finderQuery', 'deleteQuery', 'insertQuery')
                                 );

/**
 * Holds provided/generated association key names and other data for all associations
 *
 * @var array
 */
   var $__associations = array('belongsTo', 'hasOne', 'hasMany', 'hasAndBelongsToMany');

/**
 * The last inserted ID of the data that this model created
 *
 * @var int
 * @access private
 */
   var $__insertID = null;

/**
 * The number of records returned by the last query
 *
 * @access private
 * @var int
 */
   var $__numRows = null;

/**
 * The number of records affected by the last query
 *
 * @access private
 * @var int
 */
   var $__affectedRows = null;

/**
 * Constructor. Binds the Model's database table to the object.
 *
 * @param integer $id
 * @param string $table Database table to use.
 * @param unknown_type $ds DataSource connection object.
 */
    function __construct ($id=false, $table=null, $ds=null)
    {
        parent::__construct();

        if ($this->name === null)
        {
            $this->name = get_class($this);
        }
        if ($this->primaryKey === null)
        {
            $this->primaryKey = 'id';
        }

        $this->currentModel = Inflector::underscore($this->name);
        $this->setDataSource($ds);

        ClassRegistry::addObject($this->currentModel, $this);
        $this->id = $id;

        if($this->useTable !== false)
        {
           if ($table)
           {
               $tableName = $table;
           }
           else
           {
               if ($this->useTable)
               {
                   $tableName = $this->useTable;
               }
               else
               {
                   $tableName = Inflector::tableize($this->name);
               }
           }

           if (in_array('settableprefix', get_class_methods($this->name)))
           {
               $this->setTablePrefix();
           }

           if ($this->tablePrefix)
           {
               $this->setSource($this->tablePrefix.$tableName);
           }
           else
           {
               $this->setSource($tableName);
           }
           $this->__createLinks();
        }

        if ($this->displayField == null)
        {
            if ($this->hasField('title'))
            {
                $this->displayField = 'title';
            }
            if ($this->hasField('name'))
            {
                $this->displayField = 'name';
            }
            if ($this->displayField == null)
            {
                $this->displayField = $this->primaryKey;
            }
        }
    }

/**
 * Handles custom method calls, like findBy<field> for DB models,
 * and custom RPC calls for remote data sources.
 *
 * @access protected
 */
// --- PHP4 Only
    function __call($method, $params, &$return)
    {
       $return = $this->db->query($method, $params, $this);
       return true;
    }
// --- PHP4 Only

/**
 * Private helper method to create a set of associations.
 *
 * @access private
 */
    function __createLinks()
    {
        // Convert all string-based associations to array based
        foreach($this->__associations as $type)
        {
            if(!is_array($this->{$type}))
            {
                $this->{$type} = explode(',', $this->{$type});
                foreach ($this->{$type} as $i => $className)
                {
                    $className = trim($className);
                    unset($this->{$type}[$i]);
                    $this->{$type}[$className] = array();
                }
            }

            foreach ($this->{$type} as $assoc => $value)
            {
                $className = $assoc;
                if (isset($value['className']) && $value['className'] !== null)
                {
                    $className = $value['className'];
                }
                $this->__constructLinkedModel($assoc, $className, $type);
            }
        }

        foreach($this->__associations as $type)
        {
            foreach ($this->{$type} as $assoc => $value)
            {
                $this->__generateAssociation($type, $assoc);
            }
        }
    }

/**
 * Private helper method to create associated models of given class.
 * @param string $assoc
 * @param string $className Class name
 * @param string $type Type of assocation
 * @access private
 */
    function __constructLinkedModel($assoc, $className, $type)
    {
        $colKey = Inflector::underscore($className);
        if(ClassRegistry::isKeySet($colKey))
        {
            $this->{$className} = ClassRegistry::getObject($colKey);
        }
        else
        {
            $this->{$className} = new $className();
        }

        $this->alias[$assoc] = $this->{$className}->table;
        $this->tableToModel[$this->{$className}->table] = $className;
        $this->modelToTable[$className] = $this->{$className}->table;
    }

/**
 * Build array-based association from string
 *
 * @param string $type "Belongs", "One", "Many", "ManyTo"
 * @param string $assoc
 * @param string $model
 */
    function __generateAssociation ($type, $assoc)
    {
        foreach ($this->{$type} as $assocKey => $assocData)
        {
            $class = $assocKey;
            if (isset($this->{$type}[$assocKey]['className']) && $this->{$type}[$assocKey]['className'] !== null)
            {
                $class = $this->{$type}[$assocKey]['className'];
            }
            foreach($this->__associationKeys[$type] as $key)
            {
                if (!isset($this->{$type}[$assocKey][$key]) || $this->{$type}[$assocKey][$key] == null)
                {
                    $data = '';
                    switch($key)
                    {
                        case 'fields':
                            $data = '*';
                        break;
                        case 'foreignKey':
                            $data = Inflector::singularize($this->table).'_id';
                            if ($type == 'belongsTo')
                            {
                                $data = Inflector::singularize($this->{$class}->table).'_id';
                            }
                        break;
                        case 'associationForeignKey':
                            $data = Inflector::singularize($this->{$class}->table) . '_id';
                        break;
                        case 'joinTable':
                            $tables = array($this->table, $this->{$class}->table);
                            sort($tables);
                            $data = $tables[0].'_'.$tables[1];
                        break;
                        case 'className':
                            $data = $class;
                        break;
                    }
                    $this->{$type}[$assocKey][$key] = $data;
                }
            }
        }
    }

/**
 * Sets a custom table for your controller class. Used by your controller to select a database table.
 *
 * @param string $tableName Name of the custom table
 */
    function setSource($tableName)
    {
        if($this->db->isInterfaceSupported('listSources'))
        {
           if (!in_array(strtolower($tableName), $this->db->listSources()))
           {
               return $this->cakeError('missingTable',array(array('className' => $this->name,
                                                                  'table' => $tableName)));
           }
           else
           {
               $this->table = $tableName;
               $this->tableToModel[$this->table] = $this->name;
               $this->loadInfo();
           }
        }
        else
        {
           $this->table = $tableName;
           $this->tableToModel[$this->table] = $this->name;
           $this->loadInfo();
        }
    }


/**
 * This function does two things: 1) it scans the array $one for the primary key,
 * and if that's found, it sets the current id to the value of $one[id].
 * For all other keys than 'id' the keys and values of $one are copied to the 'data' property of this object.
 * 2) Returns an array with all of $one's keys and values.
 * (Alternative indata: two strings, which are mangled to
 * a one-item, two-dimensional array using $one for a key and $two as its value.)
 *
 * @param mixed $one Array or string of data
 * @param string $two Value string for the alternative indata method
 * @return unknown
 */
    function set ($one, $two=null)
    {
        $this->validationErrors = null;
        if (is_array($one))
        {
            $data = $one;
        }
        else
        {
            $data = array($one=>$two);
        }

        foreach ($data as $n => $v)
        {
            foreach ($v as $x => $y)
            {
                if($x == $this->primaryKey)
                {
                    $this->id = $y;
                }
                $this->data[$n][$x] = $y;
            }
        }
        return $data;
    }

/**
 * Returns an array of table metadata (column names and types) from the database.
 *
 * @return array Array of table metadata
 */
   function loadInfo ()
   {
      if (!is_object($this->_tableInfo) && $this->db->isInterfaceSupported('describe'))
      {
          $this->_tableInfo = new NeatArray($this->db->describe($this));
      }
      return $this->_tableInfo;
   }

/**
 * Returns true if given field name exists in this Model's database table.
 * Starts by loading the metadata into the private property table_info if that is not already set.
 *
 * @param string $name Name of table to look in
 * @return boolean
 */
    function hasField ($name)
    {
       if (empty($this->_tableInfo))
       {
          $this->loadInfo();
       }
       if($this->_tableInfo != null)
       {
          return $this->_tableInfo->findIn('name', $name);
       }
       return null;
    }

/**
 * Initializes the model for writing a new record
 *
 * @return boolean True on success
 */
   function create ()
   {
      $this->id = false;
      unset($this->data);
      $this->data = array();
      return true;
   }

/**
 * Deprecated
 *
 */
   function setId ($id)
   {
      $this->id = $id;
   }

/**
 * Deprecated
 *
 */
   function findBySql ($sql)
   {
      return $this->query($sql);
   }


/**
 * Returns a list of fields from the database
 *
 * @param mixed $id The ID of the record to read
 * @param mixed $fields String of single fieldname, or an array of fieldnames.
 * @return array Array of database fields
 */
    function read ($id = null, $fields = null)
    {
        $this->validationErrors = null;
        if ($id != null)
        {
            $this->id = $id;
        }

        $id = $this->id;
        if (is_array($this->id))
        {
            $id = $this->id[0];
        }

        if ($this->id)
        {
            $field = $this->db->name($this->name).'.'.$this->db->name($this->primaryKey);
            return $this->find($field . ' = ' . $this->db->value($id), $fields);
        }
        else
        {
            return false;
        }
    }

/**
 * Returns contents of a field in a query matching given conditions.
 *
 * @param string $name Name of field to get
 * @param string $conditions SQL conditions (defaults to NULL)
 * @return field contents
 */
    function field ($name, $conditions = null, $order = null)
    {
        if (isset($this->data[$this->name][$name]))
        {
            return $this->data[$this->name][$name];
        }

        if ($conditions)
        {
            $conditions = $this->db->conditions($conditions);
        }

        if ($data = $this->find($conditions, $name, $order))
        {
            if (isset($data[$this->name][$name]))
            {
                return $data[$this->name][$name];
            }
            else
            {
                return false;
            }
        }
        else
        {
            return false;
        }
    }

/**
 * Saves a single field to the database.
 *
 * @param string $name Name of the table field
 * @param mixed $value Value of the field
 * @param boolean $validate Whether or not this model should validate before saving (defaults to false)
 * @return boolean True on success save
 */
    function saveField($name, $value, $validate = false)
    {
        return $this->save(array($this->name => array($name => $value)), $validate);
    }

/**
 * Saves model data to the database.
 *
 * @param array $data Data to save.
 * @param boolean $validate
 * @param array $fields
 * @return boolean success
 * @todo Implement $fields param as a whitelist of allowable fields
 */
    function save ($data = null, $validate = true, $fields = null)
    {
        if ($data)
        {
            $this->set($data);
        }

        if ($validate && !$this->validates())
        {
            return false;
        }

        $fields = $values = array();

        $count = 0;
        if(count($this->data) > 1)
        {
            $weHaveMulti = true;
            $joined = false;
        }
        else
        {
            $weHaveMulti = false;
        }

        foreach ($this->data as $n => $v)
        {
            if(isset($weHaveMulti) && $count > 0 && count($this->hasAndBelongsToMany) > 0)
            {
                $joined[] = $v;
            }
            else
            {
                foreach ($v as $x => $y)
                {
                    if ($this->hasField($x))
                    {
                        $fields[] = $x;
                        $values[] = $y;

                        if($x == $this->primaryKey && !is_numeric($y))
                        {
                            $newID = $y;
                        }
                    }
                }
                $count++;
            }
        }

        if (empty($this->id) && $this->hasField('created') && !in_array('created', $fields))
        {
            $fields[] = 'created';
            $values[] = date('Y-m-d H:i:s');
        }
        if ($this->hasField('modified') && !in_array('modified', $fields))
        {
            $fields[] = 'modified';
            $values[] = date('Y-m-d H:i:s');
        }
        if ($this->hasField('updated') && !in_array('updated', $fields))
        {
            $fields[] = 'updated';
            $values[] = date('Y-m-d H:i:s');
        }

        if(!$this->exists())
        {
            $this->id = false;
        }

        if(count($fields))
        {
            if(!empty($this->id))
            {
                if ($this->db->update($this, $fields, $values))
                {
                    if(!empty($joined))
                    {
                        $this->__saveMulti($joined, $this->id);
                    }
                    $this->data = false;
                    return true;
                }
                else
                {
                    return $this->hasAny($this->escapeField($this->primaryKey).' = '.$this->db->value($this->id));
                }
            }
            else
            {
                if($this->db->create($this, $fields, $values))
                {
                    $this->__insertID = $this->db->lastInsertId($this->table, $this->primaryKey);
                    $this->id = $this->__insertID;
                    if(!empty($joined))
                    {
                        if(!$this->id > 0 && isset($newID))
                        {
                            $this->id = $newID;
                        }
                        $this->__saveMulti($joined, $this->id);
                    }
                    return true;
                }
                else
                {
                    return false;
                }
            }
        }
        else
        {
            return false;
        }
    }

/**
 * Saves model hasAndBelongsToMany data to the database.
 *
 * @param array $joined Data to save.
 * @param string $id
 * @return
 * @access private
 */
    function __saveMulti ($joined, $id)
    {
        foreach ($joined as $x => $y)
        {
            foreach ($y as $assoc => $value)
            {
                $joinTable[] = $this->hasAndBelongsToMany[$assoc]['joinTable'];
                $mainKey = $this->hasAndBelongsToMany[$assoc]['foreignKey'];
                $keys[] = $mainKey;
                $keys[] = $this->hasAndBelongsToMany[$assoc]['associationForeignKey'];
                $fields[] = join(',', $keys);
                unset($keys);

                foreach ($value as $update)
                {
                    if(!empty($update))
                    {
                        $values[] = $this->db->value($id);
                        $values[] = $this->db->value($update);
                        $values = join(',', $values);
                        $newValues[] = "({$values})";
                        unset($values);
                    }
                }
                if(!empty($newValues))
                {
                    $newValue[] = join(',', $newValues);
                    unset($newValues);
                }
            }
        }

        $total = count($joinTable);
        for ($count = 0; $count < $total; $count++)
        {
            $this->db->execute("DELETE FROM {$joinTable[$count]} WHERE $mainKey = '{$id}'");
            if(!empty($newValue[$count]))
            {
                $this->db->execute("INSERT INTO {$joinTable[$count]} ({$fields[$count]}) VALUES {$newValue[$count]}");
            }
        }
    }

/**
 * Synonym for del().
 *
 * @param mixed $id
 * @see function del
 * @return boolean True on success
 */
    function remove ($id=null)
    {
        return $this->del($id);
    }

/**
 * Removes record for given id. If no id is given, the current id is used. Returns true on success.
 *
 * @param mixed $id Id of database record to delete
 * @return boolean True on success
 */
    function del ($id = null)
    {
        if ($id)
        {
            $this->id = $id;
        }

        if($this->beforeDelete())
        {
            if ($this->id && $this->db->delete($this))
            {
                $this->afterDelete();
                $this->id = false;
                return true;
            }
        }

        return false;
    }

/**
 * Returns true if a record with set id exists.
 *
 * @return boolean True if such a record exists
 */
    function exists ()
    {
        if ($this->id)
        {
            $id = $this->id;
            if (is_array($id))
            {
                $id = $id[0];
            }
            return $this->db->hasAny($this->table,$this->primaryKey.'='.$this->db->value($id));
        }
        return false;
    }

/**
 * Returns true if a record that meets given conditions exists
 *
 * @return boolean True if such a record exists
 */
    function hasAny ($conditions = null)
    {
        return ($this->findCount($conditions) !== false);
    }

/**
 * Return a single row as a resultset array.
 *
 * @param string $conditions SQL conditions
 * @param mixed $fields Either a single string of a field name, or an array of field names
 * @param string $order SQL ORDER BY conditions (e.g. "price DESC" or "name ASC")
 * @param int $recursize The number of levels deep to fetch associated records
 * @return array Array of records
 */
    function find ($conditions = null, $fields = null, $order = null, $recursive = 1)
    {
        $data = $this->findAll($conditions, $fields, $order, 1, $recursive);
        if (empty($data[0]))
        {
            return false;
        }
        return $data[0];
    }

/**
 * Returns a resultset array with specified fields from database matching given conditions.
 *
 * @param mixed $conditions SQL conditions as a string or as an array('field'=>'value',...)
 * @param mixed $fields Either a single string of a field name, or an array of field names
 * @param string $order SQL ORDER BY conditions (e.g. "price DESC" or "name ASC")
 * @param int $limit SQL LIMIT clause, for calculating items per page
 * @param int $page Page number
 * @param int $recursize The number of levels deep to fetch associated records
 * @return array Array of records
 */
    function findAll ($conditions = null, $fields = null, $order = null, $limit = 50, $page = 1, $recursive = 1)
    {
        if (!$this->beforeFind($conditions))
        {
            return null;
        }

        $this->id = $this->getID();
        $offset = 0;
        if ($page > 1)
        {
            $offset = ($page - 1) * $limit;
        }
        $limit_str = '';
        if ($limit)
        {
            $limit_str = $this->db->limit($limit, $offset);
        }

        $queryData = array(
            'conditions' 	=> $conditions,
            'fields'		=> $fields,
            'joins'			=> array(),
            'limit'			=> $limit_str,
            'order'			=> $order
        );
        return $this->afterFind($this->db->read($this, $queryData, $recursive));
    }


//////////////

/*        $joins[] = $join;

        if (count($joins))
        {
            $joins = join(' ', $joins);
        }
        else
        {
            $joins = null;
        }

        if (count($whers))
        {
            $whers = '(' . join(' AND ', $whers) . ')';
        }
        else
        {
            $whers = null;
        }

        if ($conditions && $whers)
        {
            $conditions .= ' AND ';
        }
        $conditions .= $whers;

////////// conditions & order

        $sql .= $limit_str;

        $data = $this->db->fetchAll($sql);

        return $data;
    }*/

/**
 * Runs a direct query against the bound DataSource, and returns the result
 *
 * @param string $data Query data
 * @return array
 */
   function execute ($data)
   {
       $data = $this->db->fetchAll($data);
       foreach ($data as $key => $value)
       {
           foreach ($this->tableToModel as $key1 => $value1)
           {
               if (isset($data[$key][$key1]))
               {
                   $newData[$key][$value1] = $data[$key][$key1];
               }
           }
       }
       if (!empty($newData))
       {
           return $newData;
       }
       return $data;
   }

/**
 * Returns number of rows matching given SQL condition.
 *
 * @param string $conditions SQL conditions (WHERE clause conditions)
 * @return int Number of matching rows
 */
   function findCount ($conditions = null)
   {
      list($data) = $this->findAll($conditions, 'COUNT(*) AS count', null, null, 1, 0);
      if (isset($data[0]['count']))
      {
          return $data[0]['count'];
      }
      return false;
   }

/**
 * Special findAll variation for tables joined to themselves.
 * The table needs fields id and parent_id to work.
 *
 * @todo Perhaps create a Component with this logic, according to a thought from Michal, its author. -OJ 22 nov 2005
 * @param array $conditions Conditions for the findAll() call
 * @param array $fields Fields for the findAll() call
 * @param string $sort SQL ORDER BY statement
 * @return unknown
 */
   function findAllThreaded ($conditions=null, $fields=null, $sort=null)
   {
      return $this->__doThread(Model::findAll($conditions, $fields, $sort), null);
   }

/**
 * Private, recursive helper method for findAllThreaded.
 *
 * @param array $data
 * @param string $root NULL or id for root node of operation
 * @return array
 * @access private
 */
   function __doThread ($data, $root)
   {
      $out = array();

      for ($ii=0; $ii<sizeof($data); $ii++)
      {
         if ($data[$ii]['parent_id'] == $root)
         {
            $tmp = $data[$ii];
            if (isset($data[$ii]['id']))
            {
                $tmp['children'] = $this->__doThread($data, $data[$ii]['id']);
            }
            else
            {
                $tmp['children'] = null;
            }
            $out[] = $tmp;
         }
      }

      return $out;
   }

/**
 * Returns an array with keys "prev" and "next" that holds the id's of neighbouring data,
 * which is useful when creating paged lists.
 *
 * @param string $conditions SQL conditions for matching rows
 * @param unknown_type $field
 * @param unknown_type $value
 * @return array Array with keys "prev" and "next" that holds the id's
 */
    function findNeighbours ($conditions, $field, $value)
    {
        @list($prev) = Model::findAll($conditions . ' AND ' . $field . ' < ' . $this->db->value($value), $field, $field . ' DESC', 1);
        @list($next) = Model::findAll($conditions . ' AND ' . $field . ' > ' . $this->db->value($value), $field, $field . ' ASC', 1);

        if (!isset($prev))
        {
            $prev = null;
        }
        if (!isset($next))
        {
            $next = null;
        }
        return array('prev' => $prev, 'next' => $next);
    }

/**
 * Returns a resultset for given SQL statement.
 *
 * @param string $sql SQL statement
 * @return array Resultset
 */
   function query ()
   {
      $params = func_get_args();
      return call_user_func_array(array(&$this->db, 'query'), $params);
   }

/**
 * Returns true if all fields pass validation.
 *
 * @param array $data POST data
 * @return boolean True if there are no errors
 */
   function validates ($data = null)
   {
      if ($data == null)
      {
          $data = $this->data;
      }
      $errors = $this->invalidFields($data);
      return count($errors) == 0;
   }

/**
 * Returns an array of invalid fields.
 *
 * @param array $data
 * @return array Array of invalid fields
 */
   function invalidFields ($data=null)
   {
      if (!isset($this->validate) || is_array($this->validationErrors))
      {
         if (!isset($this->validate))
         {
             return true;
         }
         else
         {
             return $this->validationErrors;
         }
      }

      if ($data == null)
      {
          if (isset($this->data))
          {
              $data = $this->data;
          }
          else
          {
              $data = array();
          }
      }

      $errors = array();
      foreach ($data as $table => $field)
      {
         foreach ($this->validate as $field_name => $validator)
         {
           if (isset($data[$table][$field_name]) && !preg_match($validator, $data[$table][$field_name]))
            {
                $errors[$field_name] = 1;
            }
         }
         $this->validationErrors = $errors;
         return $errors;
      }
   }

/**
 * This function determines whether or not a string is a foreign key
 *
 * @param string $field Returns true if the input string ends in "_id"
 * @return True if the field is a foreign key listed in the belongsTo array.
 */
    function isForeignKey($field)
    {
       $foreignKeys = array();
       if(count($this->belongsTo))
       {
         foreach ($this->belongsTo as $assoc => $data)
         {
            $foreignKeys[] = $data['foreignKey'];
         }
       }

       return (bool)(in_array($field, $foreignKeys));
    }

/**
 * Gets the display field for this model
 *
 * @return string The name of the display field for this Model (i.e. 'name', 'title').
 */
    function getDisplayField()
    {
        return $this->displayField;
    }

/**
 * Returns a resultset array with specified fields from database matching given conditions.
 *
 * @param mixed $conditions SQL conditions as a string or as an array('field'=>'value',...)
 * @param mixed $fields Either a single string of a field name, or an array of field names
 * @param string $order SQL ORDER BY conditions (e.g. "price DESC" or "name ASC")
 * @param int $limit SQL LIMIT clause, for calculating items per page
 * @param string $keyPath A string path to the key, i.e. "{n}.Post.id"
 * @param string $valuePath A string path to the value, i.e. "{n}.Post.title"
 * @return array An associative array of records, where the id is the key, and the display field is the value
 */
    function generateList ($conditions = null, $order = null, $limit = null, $keyPath = null, $valuePath = null)
    {
        $fields = array($this->primaryKey, $this->displayField);
        $result = $this->findAll($conditions, $fields, $order, $limit, 1, 0);

        if ($keyPath == null)
        {
            $keyPath = '{n}.'.$this->name.'.'.$this->primaryKey;
        }
        if ($valuePath == null)
        {
            $valuePath = '{n}.'.$this->name.'.'.$this->displayField;
        }
        $keys = $this->db->getFieldValue($result, $keyPath);
        $vals = $this->db->getFieldValue($result, $valuePath);
        return array_combine($keys, $vals);
    }

/**
 * Escapes the field name and prepends the model name
 *
 * @return string The name of the escaped field for this Model (i.e. id becomes `Post`.`id`).
 */
    function escapeField($field)
    {
        return $this->db->name($this->name).'.'.$this->db->name($field);
    }
/**
 * Returns the current record's ID
 *
 * @return mixed The ID of the current record
 */
    function getID($list = 0)
    {
        if (!is_array($this->id))
        {
            return $this->id;
        }
        if (count($this->id) == 0)
        {
            return false;
        }
        if (isset($this->id[$list]))
        {
            return $this->id[$list];
        }
        foreach ($this->id as $id)
        {
            return $id;
        }
        return false;
    }

/**
 * Gets the ID of the last record this Model inserted
 *
 * @return mixed
 */
    function getLastInsertID ()
    {
      return $this->getInsertID();
    }

/**
 * Gets the ID of the last record this Model inserted
 *
 * @return mixed
 */
    function getInsertID ()
    {
      return $this->__insertID;
    }

/**
 * Gets the number of rows returned from the last query
 *
 * @return int
 */
    function getNumRows ()
    {
      return $this->__numRows;
    }

/**
 * Gets the number of rows affected by the last query
 *
 * @return int
 */
    function getAffectedRows ()
    {
      return $this->__affectedRows;
    }

/**
 * Sets the DataSource to which this model is bound
 *
 * @param string $dataSource The name of the DataSource, as defined in Connections.php
 * @return boolean True on success
 */
    function setDataSource($dataSource = null)
    {
        if ($dataSource == null)
        {
            $dataSource = $this->useDbConfig;
        }
        $this->db =& ConnectionManager::getDataSource($dataSource);
        if(empty($this->db) || $this->db == null || !is_object($this->db))
        {
            return $this->cakeError('missingConnection',array(array('className' => $this->name)));
        }
    }

/**
 * Before find callback
 *
 * @return boolean True if the operation should continue, false if it should abort
 */
    function beforeFind($conditions)
    {
        return true;
    }

/**
 * After find callback
 *
 * @param mixed $results The results of the find operation
 * @return mixed Result of the find operation
 */
    function afterFind($results)
    {
        return $results;
    }

/**
 * Before save callback
 *
 * @return boolean True if the operation should continue, false if it should abort
 */
    function beforeSave()
    {
        return true;
    }

/**
 * After save callback
 *
 * @return void
 */
    function afterSave()
    {
    }

/**
 * Before delete callback
 *
 * @return boolean True if the operation should continue, false if it should abort
 */
    function beforeDelete()
    {
        return true;
    }

/**
 * After save callback
 *
 * @return void
 */
    function afterDelete()
    {
    }
}

// --- PHP4 Only
overload('Model');
// --- PHP4 Only

?>