<?php
/**
 * Magento Commercial Edition
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Magento Commercial Edition License
 * that is available at: http://www.magentocommerce.com/license/commercial-edition
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@magentocommerce.com so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade Magento to newer
 * versions in the future. If you wish to customize Magento for your
 * needs please refer to http://www.magentocommerce.com for more information.
 *
 * @category    Mage
 * @package     Mage_Checkout
 * @copyright   Copyright (c) 2010 Magento Inc. (http://www.magentocommerce.com)
 * @license     http://www.magentocommerce.com/license/commercial-edition
 */

/**
 * Checkout observer model
 *
 * @category   Mage
 * @package    Mage_Checkout
 * @author      Magento Core Team <core@magentocommerce.com>
 */
class Mage_Checkout_Model_Observer
{
    public function unsetAll()
    {
        Mage::getSingleton('checkout/session')->unsetAll();
    }

    public function loadCustomerQuote()
    {
		// We do not want to merge items from last login into current cart. However, we want
		// to keep any items from the current session (before login) in the cart.
		try {
			$lastQid = Mage::getSingleton('checkout/session')->getQuoteId(); //quote id during session before login;
		
			if ($lastQid) { //cart before login has items
				$customerQuote = Mage::getModel('sales/quote')
					->loadByCustomer(Mage::getSingleton('customer/session')->getCustomerId()); //the cart from last login         
				//set it to the session before login and remove any old items from last login
				$customerQuote->setQuoteId($lastQid);
				$this->_removeAllItems($customerQuote);
				
			} else { //no session before login, so empty the cart (current cart is the old cart)
				$quote = Mage::getModel('checkout/session')->getQuote();                                
				$this->_removeAllItems($quote);
			} 
		}
		catch (Mage_Core_Exception $e) {
            Mage::getSingleton('checkout/session')->addError($e->getMessage());
        }
        catch (Exception $e) {
            Mage::getSingleton('checkout/session')->addException(
                $e,
                Mage::helper('checkout')->__('Load customer quote error')
            );
        }
    }

	 /**
     * iterate through quote and remove all items
     *           
     * @return nothing
     */
    protected function _removeAllItems($quote){
        //reset all custom attributes in the quote object here, eg:     
        // $quote->setDestinationCity('');
        
        foreach ($quote->getAllItems() as $item) {
            $item->isDeleted(true);
            if ($item->getHasChildren()) foreach ($item->getChildren() as $child) $child->isDeleted(true);
        }
        $quote->collectTotals()->save();        
    } //_removeAllItems
	
	
    public function salesQuoteSaveAfter($observer)
    {
        $quote = $observer->getEvent()->getQuote();
        /* @var $quote Mage_Sales_Model_Quote */
        if ($quote->getIsCheckoutCart()) {
            Mage::getSingleton('checkout/session')->getQuoteId($quote->getId());
        }
    }
}