<?php
/**
 * SocialEngine
 *
 * @category   Application_Core
 * @package    Storage
 * @copyright  Copyright 2006-2010 Webligo Developments
 * @license    http://www.socialengine.net/license/
 * @version    $Id: RoundRobin.php 8427 2011-02-09 23:11:24Z john $
 * @author     John Boehr <j@webligo.com>
 */

/**
 * @category   Application_Core
 * @package    Storage
 * @copyright  Copyright 2006-2010 Webligo Developments
 * @license    http://www.socialengine.net/license/
 */
class Storage_Service_RoundRobin extends Storage_Service_Abstract
{
  protected $_type = 'round-robin';

  protected $_services;
  
  public function  __construct(array $config = array())
  {
    // Get services
    if( !empty($config['services']) ) {
      $this->_services = $config['services'];
    } else {
      $serviceTable = Engine_Api::_()->getDbtable('services', 'storage');
      $this->_services = $serviceTable->select()
        ->from($serviceTable, 'service_id')
        ->where('enabled = ?', true)
        ->query()
        ->fetchAll(Zend_Db::FETCH_COLUMN);
    }
    // Do not allow self
    $this->_services = array_diff($this->_services, (array) $config['service_id']);
    // Whoops, no services
    if( empty($this->_services) ) {
      throw new Storage_Service_Exception('No services available.');
    }
    
    parent::__construct($config);
  }

  public function getType()
  {
    return $this->_type;
  }




  /**
   * Returns a url that allows for external access to the file. May point to some
   * adapter which then retrieves the file and outputs it, if desirable
   *
   * @param Storage_Model_DbRow_File The file for operation
   * @return string
   */
  public function map(Storage_Model_File $model)
  {
    $path = $model->storage_path;
    list($service_id, $path) = explode('-|-', $path, 2);

    // Get the other serice
    $serviceTable = Engine_Api::_()->getDbtable('services', 'storage');
    $otherService = $serviceTable->getService($service_id);

    // Blegh
    $tmpModel = clone $model;
    $tmpModel->storage_path = $path;

    return $otherService->map($tmpModel);
  }

  /**
   * Stores a local file in the storage service
   *
   * @param Zend_Form_Element_File|array|string $file Temporary local file to store
   * @param array $params Contains iden
   * @return string Storage type specific path (internal use only)
   */
  public function store(Storage_Model_File $model, $file)
  {
    if( count($this->_services) <= 0 ) {
      throw new Storage_Service_Exception('Unable to get storage service.');
    }
    do {
      $index = $this->_getCounter() % count($this->_services);
    } while( !isset($this->_services[$index]) );
    $service_id = $this->_services[$index];

    // Get the other serice
    $serviceTable = Engine_Api::_()->getDbtable('services', 'storage');
    $otherService = $serviceTable->getService($service_id);

    $path = $otherService->store($model, $file);

    // Add nasty prefix
    $path = $service_id . '-|-' . $path;

    return $path;
  }

  /**
   * Returns the content of the file
   *
   * @param Storage_Model_DbRow_File $model The file for operation
   * @param array $params
   */
  public function read(Storage_Model_File $model)
  {
    $path = $model->storage_path;
    list($service_id, $path) = explode('-|-', $path, 2);

    // Get the other serice
    $serviceTable = Engine_Api::_()->getDbtable('services', 'storage');
    $otherService = $serviceTable->getService($service_id);

    // Blegh
    $tmpModel = clone $model;
    $tmpModel->storage_path = $path;

    return $otherService->read($tmpModel);
  }

  /**
   * Creates a new file from data rather than an existing file
   *
   * @param Storage_Model_DbRow_File $model The file for operation
   * @param string $data
   */
  public function write(Storage_Model_File $model, $data)
  {
    if( count($this->_services) <= 0 ) {
      throw new Storage_Service_Exception('Unable to get storage service.');
    }
    do {
      $index = $this->_getCounter() % count($this->_services);
    } while( !isset($this->_services[$index]) );
    $service_id = $this->_services[$index];

    // Get the other serice
    $serviceTable = Engine_Api::_()->getDbtable('services', 'storage');
    $otherService = $serviceTable->getService($service_id);

    $path = $otherService->write($model, $data);

    // Add nasty prefix
    $path = $service_id . '-|-' . $path;

    return $path;
  }

  /**
   * Removes the file
   *
   * @param Storage_Model_DbRow_File $model The file for operation
   */
  public function remove(Storage_Model_File $model)
  {
    if( !empty($model->storage_path) ) {
      $path = $model->storage_path;
      list($service_id, $path) = explode('-|-', $path, 2);

      // Get the other serice
      $serviceTable = Engine_Api::_()->getDbtable('services', 'storage');
      $otherService = $serviceTable->getService($service_id);

      // Blegh
      $tmpModel = clone $model;
      $tmpModel->storage_path = $path;

      $otherService->remove($tmpModel);
    }
  }

  /**
   * Creates a local temporary local copy of the file
   *
   * @param Storage_Model_DbRow_File $model The file for operation
   */
  public function temporary(Storage_Model_File $model)
  {
    $path = $model->storage_path;
    list($service_id, $path) = explode('-|-', $path, 2);

    // Get the other serice
    $serviceTable = Engine_Api::_()->getDbtable('services', 'storage');
    $otherService = $serviceTable->getService($service_id);

    // Blegh
    $tmpModel = clone $model;
    $tmpModel->storage_path = $path;

    return $otherService->temporary($tmpModel);
  }

  public function removeFile($path)
  {
    // Whoops, can't do this one
  }




  // Utility

  protected function _getCounter($increment = true)
  {
    $settings = Engine_Api::_()->getApi('settings', 'core');
    $counter = $settings->getSetting('storage.service.roundrobin.counter', 0);
    if( $increment ) {
      $counter++;
      $settings->setSetting('storage.service.roundrobin.counter', $counter);
    }
    return $counter;
  }
}