<?php

/*
* MY_Cart extends the Cart library to allow for free ($0) prices and any product name you want
*/

class MY_Cart extends CI_Cart {
	function __construct ($config = array()) {
		parent::__construct($config);
	}

	/**
	 * 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']))
		{
			// price must be free
			$items['price'] = 0;
		}

		// --------------------------------------------------------------------
		
		// 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
		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;
	}
	
	/**
	* Extend update() so that it can update any part of the array...
	*/
	
	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']))
		{
			if ($this->_update($items) == TRUE)
			{
				$save_cart = TRUE;
			}
		}
		else
		{
			foreach ($items as $val)
			{
				if (is_array($val) AND isset($val['rowid']))
				{
					if ($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;
	}
	
	function _update($items = array())
	{
		// Without these array indexes there is nothing we can do
		if (!isset($items['rowid']) OR ! isset($this->_cart_contents[$items['rowid']]))
		{
			return FALSE;
		}
		
		foreach ($items as $key => $value) {		
			$this->_cart_contents[$items['rowid']][$key] = $value;
		}
		
		// 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 (isset($items['qty']) and $items['qty'] == 0)
		{
			unset($this->_cart_contents[$items['rowid']]);		
		}
		elseif (isset($items['qty']))
		{
			$this->_cart_contents[$items['rowid']]['qty'] = $items['qty'];
		}
		
		return TRUE;
	}
}