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

/**
 * Short description for file.
 *
 * Long description for file
 *
 * PHP versions 4 and 5
 *
 * CakePHP :  Rapid Development Framework <http://www.cakephp.org/>
 * Copyright (c) 2006, 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) 2006, 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.x.1402
 * @version      $Revision$
 * @modifiedby   $LastChangedBy$
 * @lastmodified $Date$
 * @license      http://www.opensource.org/licenses/mit-license.php The MIT License
 */

/**
 * Manages loaded instances of DataSource objects
 *
 * Long description for file
 *
 * @package    cake
 * @subpackage cake.cake.libs.model
 * @since      CakePHP v 0.10.x.1402
 *
 */

uses('model'.DS.'datasources'.DS.'datasource');
class ConnectionManager extends Object
{

/**
 * Holds a loaded instance of the Connections object
 *
 * @var class:Connections
 * @access public
 */
  var $config = null;

/**
 * Holds instances DataSource objects
 *
 * @var array
 * @access private
 */
  var $_dataSources = array();

/**
 * Contains a list of all file and class names used in Connection settings
 *
 * @var array
 * @access private
 */
  var $_connectionsEnum = array();

/**
 * Constructor.
 *
 */
  function __construct()
  {
      if(class_exists('DATABASE_CONFIG'))
      {
          $this->config = new DATABASE_CONFIG();
      }
  }

/**
 * Gets a reference to the ConnectionManger object instance
 *
 * @return object
 */
  function &getInstance()
  {
     static $instance = array();
     if(!isset($instance[0]) || !$instance[0])
     {
        $instance[0] =& new ConnectionManager();
     }
     return $instance[0];
  }

/**
 * Gets a reference to a DataSource object
 *
 * @param string $name The name of the DataSource, as defined in app/config/connections
 * @return object
 */
  function &getDataSource($name)
  {
     $_this =& ConnectionManager::getInstance();

     if(in_array($name, array_keys($_this->_dataSources)))
     {
        return $_this->_dataSources[$name];
     }

     $connections = $_this->enumConnectionObjects();
     if(in_array($name, array_keys($connections)))
     {
        $conn = $connections[$name];
        $class = $conn['classname'];
        $_this->loadDataSource($name);
        $_this->_dataSources[$name] =& new $class($_this->config->{$name});
        $_this->_dataSources[$name]->configKeyName = $name;
     }
     else
     {
        trigger_error("ConnectionManager::getDataSource - Non-existent data source {$name}", E_USER_ERROR);
        return null;
     }
     return $_this->_dataSources[$name];
  }


/**
 * Loads the DataSource class for the given connection name
 *
 * @param string $connName The name of the connection, as defined in Connections config
 * @return boolean True on success, false on failure or if the class is already loaded
 */
  function loadDataSource($connName)
  {
      $_this =& ConnectionManager::getInstance();

      $connections = $_this->enumConnectionObjects();
      $conn = $connections[$connName];

      if(class_exists($conn['classname']))
      {
          return false;
      }

      if (fileExistsInPath(LIBS.'model'.DS.$conn['filename'].'.php'))
      {
          require(LIBS.'model'.DS.$conn['filename'].'.php');
      }
      else if (file_exists(MODELS.$conn['filename'].'.php'))
      {
          require(MODELS.$conn['filename'].'.php');
      }
      else
      {
          trigger_error('Unable to load DataSource file ' . $filename . '.php', E_USER_ERROR);
          return null;
      }
  }

/**
 * Gets a list of class and file names associated with the user-defined DataSource connections
 *
 * @return array An associative array of elements where the key is the connection name
 *               (as defined in Connections), and the value is an array with keys 'filename' and 'classname'.
 */
  function enumConnectionObjects()
  {
      $_this =& ConnectionManager::getInstance();
      if (!empty($_this->_connectionsEnum))
      {
          return $_this->_connectionsEnum;
      }

      $connections = get_object_vars($_this->config);
      if($connections != null)
      {
          foreach ($connections as $name => $config)
          {
              if(isset($config['driver']) && $config['driver'] != null && $config['driver'] != '')
              {
                  $filename = 'dbo_'.$config['driver'];
                  $classname = Inflector::camelize(strtolower('DBO_'.$config['driver']));
              }
              else
              {
                  $filename = $config['datasource'].'_source';
                  $classname = Inflector::camelize(strtolower($config['datasource'].'_source'));
              }
              // TODO 2.0: Change 'dbo' to $config['datasource']
              $filename = 'dbo'.DS.$filename;
              $_this->_connectionsEnum[$name] = array('filename' => $filename, 'classname' => $classname);
          }
          return $this->_connectionsEnum;
      }
      else
      {
           $this->cakeError('missingConnection', array(array('className' => 'ConnectionManager')));
      }
  }
}
?>