//————————————————————————————————————

/**
* Shopping Cart Class
*
* @package     CodeIgniter
* @subpackage   Libraries
* @category   Shopping Cart
* @author     ExpressionEngine Dev Team
* @link     http://codeigniter.com/user_guide/libraries/cart.html
*/
class CI_Cart {

  // These are the regular expression rules that we use to validate the product ID and product name
  var $product_id_rules   = ‘\.a-z0-9_-’; // alpha-numeric, dashes, underscores, or periods
  var $product_name_rules   = ‘\.\:\-_ a-z0-9’; // alpha-numeric, dashes, underscores, colons or periods
 
  // Private variables.  Do not change!
  var $CI;
  var $_cart_contents   = array();

  /**
    * Shopping Class Constructor
    *
    * The constructor loads the Session class, used to store the shopping cart contents.
    */     
  function CI_Cart($params = array())
  { 
      // Set the super object to a local variable for use later
      $this->CI =& get_instance();
     
      // Are any config settings being passed manually?  If so, set them
      $config = array();
      if (count($params) > 0)
      {
        foreach ($params as $key => $val)
        {
          $config[$key] = $val;
        }
      }
     
      // Load the Sessions class
      $this->CI->load->library(‘session’, $config);
       
      // Grab the shopping cart array from the session table, if it exists
      if ($this->CI->session->userdata(‘cart_contents’) !== FALSE)
      {
        $this->_cart_contents = $this->CI->session->userdata(‘cart_contents’);
      }
      else
      {
        // No cart exists so we’ll set some base values
        $this->_cart_contents[‘cart_total’] = 0;     
        $this->_cart_contents[‘total_items’] = 0;     
      }
 
      log_message(‘debug’, “Cart Class Initialized”);
  }

  //——————————————————————————————————
 
  /**
    * Insert items into the cart and save it to the session table
    *
    * @access   public
    * @param   array
    * @return   bool
    */
  function insert($items = array())
  {
      // Was any cart data passed? No? Bah…
      if ( ! is_array($items) OR count($items) == 0)
      {
        log_message(‘error’, ‘The insert method must be passed an array containing data.’);
        return FALSE;
      }
         
      // You can either insert a single product using a one-dimensional array,
      // or multiple products using a multi-dimensional one. The way we
      // determine the array type is by looking for a required array key named “id”
      // at the top level. If it’s not found, we will assume it’s a multi-dimensional array.
 
      $save_cart = FALSE;     
      if (isset($items[‘id’]))
      {       
        if ($this->_insert($items) == TRUE)
        {
          $save_cart = TRUE;
        }
      }
      else
      {
        foreach ($items as $val)
        {
          if (is_array($val) AND isset($val[‘id’]))
          {
              if ($this->_insert($val) == TRUE)
              {
                $save_cart = TRUE;
              }
          }       
        }
      }

      // Save the cart data if the insert was successful
      if ($save_cart == TRUE)
      {
        $this->_save_cart();
        return TRUE;
      }

      return FALSE;
  }

  //——————————————————————————————————
 
  /**
    * Insert
    *
    * @access   private
    * @param   array
    * @return   bool
    */
  function _insert($items = array())
  {
      // Was any cart data passed? No? Bah…
      if ( ! is_array($items) OR count($items) == 0)
      {
        log_message(‘error’, ‘The insert method must be passed an array containing data.’);
        return FALSE;
      }
     
      //——————————————————————————————————
 
      // Does the $items array contain an id, quantity, price, and name?  These are required
      if ( ! isset($items[‘id’]) OR ! isset($items[‘qty’]) OR ! isset($items[‘price’]) OR ! isset($items[‘name’]))
      {
        log_message(‘error’, ‘The cart array must contain a product ID, quantity, price, and name.’);
        return FALSE;
      }

      //——————————————————————————————————
 
      // Prep the quantity. It can only be a number.  Duh…
      $items[‘qty’] = trim(preg_replace(’/([^0-9])/i’, ‘’, $items[‘qty’]));
      // Trim any leading zeros
      $items[‘qty’] = trim(preg_replace(’/(^[0]+)/i’, ‘’, $items[‘qty’]));

      // If the quantity is zero or blank there’s nothing for us to do
      if ( ! is_numeric($items[‘qty’]) OR $items[‘qty’] == 0)
      {
        return FALSE;
      }
         
      //——————————————————————————————————
 
      // Validate the product ID. It can only be alpha-numeric, dashes, underscores or periods
      // Not totally sure we should impose this rule, but it seems prudent to standardize IDs.
      // Note: These can be user-specified by setting the $this->product_id_rules variable.
      if ( ! preg_match(”/^[”.$this->product_id_rules.”]+$/i”, $items[‘id’]))
      {
        log_message(‘error’, ‘Invalid product ID.  The product ID can only contain alpha-numeric characters, dashes, and underscores’);
        return FALSE;
      }

      //——————————————————————————————————
 
      // Validate the product name. It can only be alpha-numeric, dashes, underscores, colons or periods.
      // Note: These can be user-specified by setting the $this->product_name_rules variable.
      if ( ! preg_match(”/^[”.$this->product_name_rules.”]+$/i”, $items[‘name’]))
      {
        log_message(‘error’, ‘An invalid name was submitted as the product name: ‘.$items[‘name’].’ The name can only contain alpha-numeric characters, dashes, underscores, colons, and spaces’);
        return FALSE;
      }

      //——————————————————————————————————

      // Prep the price.  Remove anything that isn’t a number or decimal point.
      $items[‘price’] = trim(preg_replace(’/([^0-9\.])/i’, ‘’, $items[‘price’]));
      // Trim any leading zeros
      $items[‘price’] = trim(preg_replace(’/(^[0]+)/i’, ‘’, $items[‘price’]));
     
      // Is the price a valid number?
      if ( ! is_numeric($items[‘price’]))
      {
        log_message(‘error’, ‘An invalid price was submitted for product ID: ‘.$items[‘id’]);
        return FALSE;
      }

      //——————————————————————————————————
     
      // We now need to create a unique identifier for the item being inserted into the cart.
      // Every time something is added to the cart it is stored in the master cart array. 
      // Each row in the cart array, however, must have a unique index that identifies not only
      // a particular product, but makes it possible to store identical products with different options. 
      // For example, what if someone buys two identical t-shirts (same product ID), but in
      // different sizes?  The product ID (and other attributes, like the name) will be identical for
      // both sizes because it’s the same shirt. The only difference will be the size.
      // Internally, we need to treat identical submissions, but with different options, as a unique product.
      // Our solution is to convert the options array to a string and MD5 it along with the product ID.
      // This becomes the unique “row ID”
      if (isset($items[‘options’]) AND count($items[‘options’]) > 0)
      {
        $rowid = md5($items[‘id’].implode(’‘, $items[‘options’]));
      }
      else
      {
        // No options were submitted so we simply MD5 the product ID.
        // Technically, we don’t need to MD5 the ID in this case, but it makes
        // sense to standardize the format of array indexes for both conditions
        $rowid = md5($items[‘id’]);
      }     

      //——————————————————————————————————

      // Now that we have our unique “row ID”, we’ll add our cart items to the master array
     
      // let’s unset this first, just to make sure our index contains only the data from this submission
     
     
      if(isset($this->_cart_contents[$rowid][“rowid”]) && $this->_cart_contents[$rowid][“rowid”] == $rowid)
      {
        $items[“rowid”] = $rowid;
        $items[“qty”] = $this->_cart_contents[$rowid][‘qty’] + $items[‘qty’];
        if ($this->_update($items) == TRUE)
        {
          return TRUE;
        }
      }else
      {
        unset($this->_cart_contents[$rowid]);     
       
        // Create a new index with our new row ID
        $this->_cart_contents[$rowid][‘rowid’] = $rowid;
     
        // And add the new items to the cart array        
        foreach ($items as $key => $val)
        {
          $this->_cart_contents[$rowid][$key] = $val;
        }
      }
      // Woot!
      return TRUE;
  }

  //——————————————————————————————————
 
  /**
    * Update the cart
    *
    * This function permits the quantity of a given item to be changed.
    * Typically it is called from the “view cart” page if a user makes
    * changes to the quantity before checkout. That array must contain the
    * product ID and quantity for each item.
    *
    * @access   public
    * @param   array
    * @param   string
    * @return   bool
    */
  function update($items = array())
  {
      // Was any cart data passed?
      if ( ! is_array($items) OR count($items) == 0)
      {
        return FALSE;
      }
       
      // You can either update a single product using a one-dimensional array,
      // or multiple products using a multi-dimensional one.  The way we
      // determine the array type is by looking for a required array key named “id”.
      // If it’s not found we assume it’s a multi-dimensional array
      $save_cart = FALSE;
      if (isset($items[‘rowid’]) AND isset($items[‘qty’]))
      {
        if ($this->_update($items) == TRUE)
        {
          $save_cart = TRUE;
        }
      }
      else
      {
        foreach ($items as $val)
        {
          if (is_array($val) AND isset($val[‘rowid’]) AND isset($val[‘qty’]))
          {
              if ($this->_update($val) == TRUE)
              {
                $save_cart = TRUE;
              }
          }       
        }
      }

      // Save the cart data if the insert was successful
      if ($save_cart == TRUE)
      {
        $this->_save_cart();
        return TRUE;
      }

      return FALSE;
  }

  //——————————————————————————————————
 
  /**
    * Update the cart
    *
    * This function permits the quantity of a given item to be changed.
    * Typically it is called from the “view cart” page if a user makes
    * changes to the quantity before checkout. That array must contain the
    * product ID and quantity for each item.
    *
    * @access   private
    * @param   array
    * @return   bool
    */ 
  function _update($items = array())
  {
      // Without these array indexes there is nothing we can do
      if ( ! isset($items[‘qty’]) OR ! isset($items[‘rowid’]) OR ! isset($this->_cart_contents[$items[‘rowid’]]))
      {
        return FALSE;
      }
     
      // Prep the quantity
      $items[‘qty’] = preg_replace(’/([^0-9])/i’, ‘’, $items[‘qty’]);

      // Is the quantity a number?
      if ( ! is_numeric($items[‘qty’]))
      {
        return FALSE;
      }
     
      // Is the new quantity different than what is already saved in the cart?
      // If it’s the same there’s nothing to do
      if ($this->_cart_contents[$items[‘rowid’]][‘qty’] == $items[‘qty’])
      {
        return FALSE;
      }

      // Is the quantity zero?  If so we will remove the item from the cart.
      // If the quantity is greater than zero we are updating
      if ($items[‘qty’] == 0)
      {
        unset($this->_cart_contents[$items[‘rowid’]]);     
      }
      else
      {
        $this->_cart_contents[$items[‘rowid’]][‘qty’] = $items[‘qty’];
      }
     
      return TRUE;
  }

  //——————————————————————————————————
 
  /**
    * Save the cart array to the session DB
    *
    * @access   private
    * @return   bool
    */
  function _save_cart()
  {
      // Unset these so our total can be calculated correctly below
      unset($this->_cart_contents[‘total_items’]);
      unset($this->_cart_contents[‘cart_total’]);

      // Lets add up the individual prices and set the cart sub-total
      $total = 0;
      foreach ($this->_cart_contents as $key => $val)
      {
        // We make sure the array contains the proper indexes
        if ( ! is_array($val) OR ! isset($val[‘price’]) OR ! isset($val[‘qty’]))
        {
          continue;
        }

        $total += ($val[‘price’] * $val[‘qty’]);
       
        // Set the subtotal
        $this->_cart_contents[$key][‘subtotal’] = ($this->_cart_contents[$key][‘price’] * $this->_cart_contents[$key][‘qty’]);
      }

      // Set the cart total and total items.
      $this->_cart_contents[‘total_items’] = count($this->_cart_contents);       
      $this->_cart_contents[‘cart_total’] = $total;
 
      // Is our cart empty?  If so we delete it from the session
      if (count($this->_cart_contents) <= 2)
      {
        $this->CI->session->unset_userdata(‘cart_contents’);
       
        // Nothing more to do… coffee time!
        return FALSE;
      }

      // If we made it this far it means that our cart has data.
      // Let’s pass it to the Session class so it can be stored
      $this->CI->session->set_userdata(array(‘cart_contents’ => $this->_cart_contents));

      // Woot!
      return TRUE; 
  }

  //——————————————————————————————————
 
  /**
    * Cart Total
    *
    * @access   public
    * @return   integer
    */
  function total()
  {
      return $this->_cart_contents[‘cart_total’];
  }

  //——————————————————————————————————
 
  /**
    * Total Items
    *
    * Returns the total item count
    *
    * @access   public
    * @return   integer
    */
  function total_items()
  {
      return $this->_cart_contents[‘total_items’];
  }

  //——————————————————————————————————
 
  /**
    * Cart Contents
    *
    * Returns the entire cart array
    *
    * @access   public
    * @return   array
    */
  function contents()
  {
      $cart = $this->_cart_contents;
     
      // Remove these so they don’t create a problem when showing the cart table
      unset($cart[‘total_items’]);
      unset($cart[‘cart_total’]);
 
      return $cart;
  }

  //——————————————————————————————————
 
  /**
    * Has options
    *
    * Returns TRUE if the rowid passed to this function correlates to an item
    * that has options associated with it.
    *
    * @access   public
    * @return   array
    */
  function has_options($rowid = ‘’)
  {
      if ( ! isset($this->_cart_contents[$rowid][‘options’]) OR count($this->_cart_contents[$rowid][‘options’]) === 0)
      {
        return FALSE;
      }
     
      return TRUE;
  }

  //——————————————————————————————————
 
  /**
    * Product options
    *
    * Returns the an array of options, for a particular product row ID
    *
    * @access   public
    * @return   array
    */
  function product_options($rowid = ‘’)
  {
      if ( ! isset($this->_cart_contents[$rowid][‘options’]))
      {
        return array();
      }

      return $this->_cart_contents[$rowid][‘options’];
  }

  //——————————————————————————————————
 
  /**
    * Format Number
    *
    * Returns the supplied number with commas and a decimal point.
    *
    * @access   public
    * @return   integer
    */
  function format_number($n = ‘’)
  {
      if ($n == ‘’)
      {
        return ‘’;
      }
 
      // Remove anything that isn’t a number or decimal point.
      $n = trim(preg_replace(’/([^0-9\.])/i’, ‘’, $n));
 
      return number_format($n, 2, ‘.’, ‘,’);
  }
     
  //——————————————————————————————————
 
  /**
    * Destroy the cart
    *
    * Empties the cart and kills the session
    *
    * @access   public
    * @return   null
    */
  function destroy()
  {
      unset($this->_cart_contents);
 
      $this->_cart_contents[‘cart_total’] = 0;     
      $this->_cart_contents[‘total_items’] = 0;     

      $this->CI->session->unset_userdata(‘cart_contents’);
  }

}
// END Cart Class