woocommerce/classes/class-wc-cart.php

<?php
/**
 * WooCommerce cart
 *
 * The WooCommerce cart class stores cart data and active coupons as well as handling customer sessions and some cart related urls.
 * The cart class also has a price calculation function which calls upon other classes to calculate totals.
 *
 * @class 		WC_Cart
 * @version		2.0.0
 * @package		WooCommerce/Classes
 * @author 		WooThemes
 */
class WC_Cart {

	/** @var array Contains an array of cart items. */
	var $cart_contents;

	/** @var array Contains an array of coupon codes applied to the cart. */
	var $applied_coupons;

	/** @var array Contains an array of coupon code discounts after they have been applied. */
	var $coupon_discount_amounts;

	/** @var float The total cost of the cart items. */
	var $cart_contents_total;

	/** @var float The total weight of the cart items. */
	var $cart_contents_weight;

	/** @var float The total count of the cart items. */
	var $cart_contents_count;

	/** @var float The total tax for the cart items. */
	var $cart_contents_tax;

	/** @var float Cart grand total. */
	var $total;

	/** @var float Cart subtotal. */
	var $subtotal;

	/** @var float Cart subtotal without tax. */
	var $subtotal_ex_tax;

	/** @var float Total cart tax. */
	var $tax_total;

	/** @var array An array of taxes/tax rates for the cart. */
	var $taxes;

	/** @var array An array of taxes/tax rates for the shipping. */
	var $shipping_taxes;

	/** @var float Discounts before tax. */
	var $discount_cart;

	/** @var float Discounts after tax. */
	var $discount_total;

	/** @var float Total for additonal fees. */
	var $fee_total;

	/** @var float Shipping cost. */
	var $shipping_total;

	/** @var float Shipping tax. */
	var $shipping_tax_total;

	/** @var float Shipping title/label. */
	var $shipping_label;

	/** @var WC_Tax */
	var $tax;

	/** @var array An array of fees. */
	var $fees;

	/**
	 * Constructor for the cart class. Loads options and hooks in the init method.
	 *
	 * @access public
	 * @return void
	 */
	function __construct() {
		$this->tax = new WC_Tax();
		$this->prices_include_tax = ( get_option( 'woocommerce_prices_include_tax' ) == 'yes' ) ? true : false;
		$this->tax_display_cart = get_option( 'woocommerce_tax_display_cart' );
		$this->dp = (int) get_option( 'woocommerce_price_num_decimals' );

		$this->display_totals_ex_tax = $this->tax_display_cart == 'excl' ? true : false;
		$this->display_cart_ex_tax   = $this->tax_display_cart == 'excl' ? true : false;

		add_action( 'init', array( &$this, 'init' ), 5 ); // Get cart on init
	}


    /**
	 * Loads the cart data from the PHP session during WordPress init and hooks in other methods.
     *
     * @access public
     * @return void
     */
    function init() {
		$this->get_cart_from_session();

		add_action('woocommerce_check_cart_items', array( &$this, 'check_cart_items' ), 1 );
		add_action('woocommerce_check_cart_items', array( &$this, 'check_cart_coupons' ), 1 );
		add_action('woocommerce_after_checkout_validation', array( &$this, 'check_customer_coupons' ), 1 );
    }

 	/*-----------------------------------------------------------------------------------*/
	/* Cart Session Handling */
	/*-----------------------------------------------------------------------------------*/

		/**
		 * Get the cart data from the PHP session and store it in class variables.
		 *
		 * @access public
		 * @return void
		 */
		function get_cart_from_session() {
			global $woocommerce;

			// Load the coupons
			if ( get_option( 'woocommerce_enable_coupons' ) == 'yes' ) {
				$this->applied_coupons         = ( empty( $woocommerce->session->coupon_codes ) ) ? array() : array_filter( (array) $woocommerce->session->coupon_codes );
				$this->coupon_discount_amounts = ( empty( $woocommerce->session->coupon_amounts ) ) ? array() : array_filter( (array) $woocommerce->session->coupon_amounts );
			}

			// Load the cart
			if ( isset( $woocommerce->session->cart ) && is_array( $woocommerce->session->cart ) ) {
				$cart = $woocommerce->session->cart;

				foreach ( $cart as $key => $values ) {

					$_product = get_product( $values['variation_id'] ? $values['variation_id'] : $values['product_id'] );

					if ( $_product->exists() && $values['quantity'] > 0 ) {

						// Put session data into array. Run through filter so other plugins can load their own session data
						$this->cart_contents[ $key ] = apply_filters( 'woocommerce_get_cart_item_from_session', array(
							'product_id'	=> $values['product_id'],
							'variation_id'	=> $values['variation_id'],
							'variation' 	=> $values['variation'],
							'quantity' 		=> $values['quantity'],
							'data'			=> $_product
						), $values, $key );

					}
				}

				if ( ! is_array( $this->cart_contents ) )
					$this->cart_contents = array();

			} else {
				$this->cart_contents = array();
			}

			// Cookie
			if ( sizeof( $this->cart_contents ) > 0 )
				$woocommerce->cart_has_contents_cookie( true );
			else
				$woocommerce->cart_has_contents_cookie( false );

			// Load totals
			$this->cart_contents_total 	= isset( $woocommerce->session->cart_contents_total ) ? $woocommerce->session->cart_contents_total : 0;
			$this->cart_contents_weight = isset( $woocommerce->session->cart_contents_weight ) ? $woocommerce->session->cart_contents_weight : 0;
			$this->cart_contents_count 	= isset( $woocommerce->session->cart_contents_count ) ? $woocommerce->session->cart_contents_count : 0;
			$this->cart_contents_tax 	= isset( $woocommerce->session->cart_contents_tax ) ? $woocommerce->session->cart_contents_tax : 0;
			$this->total 				= isset( $woocommerce->session->total ) ? $woocommerce->session->total : 0;
			$this->subtotal 			= isset( $woocommerce->session->subtotal ) ? $woocommerce->session->subtotal : 0;
			$this->subtotal_ex_tax 		= isset( $woocommerce->session->subtotal_ex_tax ) ? $woocommerce->session->subtotal_ex_tax : 0;
			$this->tax_total 			= isset( $woocommerce->session->tax_total ) ? $woocommerce->session->tax_total : 0;
			$this->taxes 				= isset( $woocommerce->session->taxes ) ? $woocommerce->session->taxes : array();
			$this->shipping_taxes		= isset( $woocommerce->session->shipping_taxes ) ? $woocommerce->session->shipping_taxes : array();
			$this->discount_cart 		= isset( $woocommerce->session->discount_cart ) ? $woocommerce->session->discount_cart : 0;
			$this->discount_total 		= isset( $woocommerce->session->discount_total ) ? $woocommerce->session->discount_total : 0;
			$this->shipping_total 		= isset( $woocommerce->session->shipping_total ) ? $woocommerce->session->shipping_total : 0;
			$this->shipping_tax_total 	= isset( $woocommerce->session->shipping_tax_total ) ? $woocommerce->session->shipping_tax_total : 0;
			$this->shipping_label		= isset( $woocommerce->session->shipping_label ) ? $woocommerce->session->shipping_label : '';

			// Queue re-calc if subtotal is not set
			if ( ! $this->subtotal && sizeof( $this->cart_contents ) > 0 )
				$this->set_session();
		}


		/**
		 * Sets the php session data for the cart and coupons and re-calculates totals.
		 *
		 * @access public
		 * @return void
		 */
		function set_session() {
			global $woocommerce;

			// Re-calc totals
			$this->calculate_totals();

			// Set cart and coupon session data
			$cart_session = array();

			if ( $this->cart_contents ) {
				foreach ( $this->cart_contents as $key => $values ) {

					$cart_session[ $key ] = $values;

					// Unset product object
					unset( $cart_session[ $key ]['data'] );
				}
			}

			$woocommerce->session->cart           = $cart_session;
			$woocommerce->session->coupon_codes   = $this->applied_coupons;
			$woocommerce->session->coupon_amounts = $this->coupon_discount_amounts;

			// Store totals to avoid re-calc on page load
			$woocommerce->session->cart_contents_total  = $this->cart_contents_total;
			$woocommerce->session->cart_contents_weight = $this->cart_contents_weight;
			$woocommerce->session->cart_contents_count  = $this->cart_contents_count;
			$woocommerce->session->cart_contents_tax    = $this->cart_contents_tax;
			$woocommerce->session->total                = $this->total;
			$woocommerce->session->subtotal             = $this->subtotal;
			$woocommerce->session->subtotal_ex_tax      = $this->subtotal_ex_tax;
			$woocommerce->session->tax_total            = $this->tax_total;
			$woocommerce->session->shipping_taxes       = $this->shipping_taxes;
			$woocommerce->session->taxes                = $this->taxes;
			$woocommerce->session->discount_cart        = $this->discount_cart;
			$woocommerce->session->discount_total       = $this->discount_total;
			$woocommerce->session->shipping_total       = $this->shipping_total;
			$woocommerce->session->shipping_tax_total   = $this->shipping_tax_total;
			$woocommerce->session->shipping_label       = $this->shipping_label;

			if ( get_current_user_id() )
				$this->persistent_cart_update();

			do_action( 'woocommerce_cart_updated' );
		}

		/**
		 * Empties the cart and optionally the persistent cart too.
		 *
		 * @access public
		 * @param bool $clear_persistent_cart (default: true)
		 * @return void
		 */
		function empty_cart( $clear_persistent_cart = true ) {
			global $woocommerce;

			$this->cart_contents = array();
			$this->reset();

			unset( $woocommerce->session->order_awaiting_payment, $woocommerce->session->coupon_codes, $woocommerce->session->coupon_amounts, $woocommerce->session->cart );

			if ( $clear_persistent_cart && get_current_user_id() )
				$this->persistent_cart_destroy();

			do_action( 'woocommerce_cart_emptied' );
		}

 	/*-----------------------------------------------------------------------------------*/
	/* Persistent cart handling */
	/*-----------------------------------------------------------------------------------*/

		/**
		 * Save the persistent cart when the cart is updated.
		 *
		 * @access public
		 * @return void
		 */
		function persistent_cart_update() {
			global $woocommerce;

			update_user_meta( get_current_user_id(), '_woocommerce_persistent_cart', array(
				'cart' => $woocommerce->session->cart,
			) );
		}


		/**
		 * Delete the persistent cart permanently.
		 *
		 * @access public
		 * @return void
		 */
		function persistent_cart_destroy() {
			delete_user_meta( get_current_user_id(), '_woocommerce_persistent_cart' );
		}

 	/*-----------------------------------------------------------------------------------*/
	/* Cart Data Functions */
	/*-----------------------------------------------------------------------------------*/

		/**
		 * Get number of items in the cart.
		 *
		 * @access public
		 * @return int
		 */
		function get_cart_contents_count() {
			return apply_filters( 'woocommerce_cart_contents_count', $this->cart_contents_count );
		}


		/**
		 * Check all cart items for errors.
		 *
		 * @access public
		 * @return void
		 */
		function check_cart_items() {
			global $woocommerce;

			// Check item stock
			$result = $this->check_cart_item_stock();

			if (is_wp_error($result))
				$woocommerce->add_error( $result->get_error_message() );
		}


		/**
		 * Check cart coupons for errors.
		 *
		 * @access public
		 * @return void
		 */
		function check_cart_coupons() {
			global $woocommerce;

			if ( ! empty( $this->applied_coupons ) ) {
				foreach ( $this->applied_coupons as $key => $code ) {
					$coupon = new WC_Coupon( $code );

					if ( is_wp_error( $coupon->is_valid() ) ) {

						$woocommerce->add_error( sprintf( __( 'Sorry, it seems the coupon "%s" is invalid - it has now been removed from your order.', 'woocommerce' ), $code ) );

						// Remove the coupon
						unset( $this->applied_coupons[ $key ] );

						$woocommerce->session->coupon_codes   = $this->applied_coupons;
						$woocommerce->session->refresh_totals     = true;
					}
				}
			}
		}

		/**
		 * Get cart items quantities - merged so we can do accurate stock checks on items across multiple lines.
		 *
		 * @access public
		 * @return array
		 */
		function get_cart_item_quantities() {
			$quantities = array();

			foreach ( $this->get_cart() as $cart_item_key => $values ) {

				if ( $values['data']->managing_stock() ) {

					if ( $values['variation_id'] > 0 ) {

						if ( $values['data']->variation_has_stock ) {

							// Variation has stock levels defined so its handled individually
							$quantities[ $values['variation_id'] ] = isset( $quantities[ $values['variation_id'] ] ) ? $quantities[ $values['variation_id'] ] + $values['quantity'] : $values['quantity'];

						} else {

							// Variation has no stock levels defined so use parents
							$quantities[ $values['product_id'] ] = isset( $quantities[ $values['product_id'] ] ) ? $quantities[ $values['product_id'] ] + $values['quantity'] : $values['quantity'];

						}

					} else {

						$quantities[ $values['product_id'] ] = isset( $quantities[ $values['product_id'] ] ) ? $quantities[ $values['product_id'] ] + $values['quantity'] : $values['quantity'];

					}

				}

			}
			return $quantities;
		}

		/**
		 * Check for user coupons (now that we have billing email). If a coupon is invalid, add an error.
		 *
		 * @access public
		 * @param array $posted
		 */
		function check_customer_coupons( $posted ) {
			global $woocommerce;

			if ( ! empty( $this->applied_coupons ) ) {
				foreach ( $this->applied_coupons as $key => $code ) {
					$coupon = new WC_Coupon( $code );

					if ( is_array( $coupon->customer_email ) && sizeof( $coupon->customer_email ) > 0 ) {

						$coupon->customer_email = array_map( 'sanitize_email', $coupon->customer_email );

						if ( is_user_logged_in() ) {
							$current_user = wp_get_current_user();
							$check_emails[] = $current_user->user_email;
						}
						$check_emails[] = $posted['billing_email'];

						$check_emails = array_map( 'sanitize_email', array_map( 'strtolower', $check_emails ) );

						if ( 0 == sizeof( array_intersect( $check_emails, $coupon->customer_email ) ) ) {
							$woocommerce->add_error( sprintf( __( 'Sorry, it seems the coupon "%s" is not yours - it has now been removed from your order.', 'woocommerce' ), $code ) );
							// Remove the coupon
							unset( $this->applied_coupons[ $key ] );

							$woocommerce->session->coupon_codes   = $this->applied_coupons;
							$woocommerce->session->refresh_totals     = true;
						}
					}
				}
			}
		}

		/**
		 * Looks through the cart to check each item is in stock. If not, add an error.
		 *
		 * @access public
		 * @return bool
		 */
		function check_cart_item_stock() {
			global $woocommerce, $wpdb;

			$error = new WP_Error();

			$product_qty_in_cart = $this->get_cart_item_quantities();

			// First stock check loop
			foreach ( $this->get_cart() as $cart_item_key => $values ) {

				$_product = $values['data'];

				/**
				 * Check stock based on inventory
				 */
				if ( $_product->managing_stock() ) {

					/**
					 * Check the stock for this item individually
					 */
					if ( ! $_product->is_in_stock() || ! $_product->has_enough_stock( $values['quantity'] ) ) {
						$error->add( 'out-of-stock', sprintf(__( 'Sorry, we do not have enough "%s" in stock to fulfill your order (%s in stock). Please edit your cart and try again. We apologise for any inconvenience caused.', 'woocommerce' ), $_product->get_title(), $_product->stock ) );
						return $error;
					}

					// For later on...
					$key     = '_product_id';
					$value   = $values['product_id'];
					$in_cart = $values['quantity'];

					/**
					 * Next check entire cart quantities
					 */
					if ( $values['variation_id'] && $_product->variation_has_stock && isset( $product_qty_in_cart[ $values['variation_id'] ] ) ) {

						$key     = '_variation_id';
						$value   = $values['variation_id'];
						$in_cart = $product_qty_in_cart[ $values['variation_id'] ];

						if ( ! $_product->has_enough_stock( $product_qty_in_cart[ $values['variation_id'] ] ) ) {
							$error->add( 'out-of-stock', sprintf(__( 'Sorry, we do not have enough "%s" in stock to fulfil your order (%s in stock). Please edit your cart and try again. We apologise for any inconvenience caused.', 'woocommerce' ), $_product->get_title(), $_product->stock ) );
							return $error;
						}

					} elseif ( isset( $product_qty_in_cart[ $values['product_id'] ] ) ) {

						$in_cart = $product_qty_in_cart[ $values['product_id'] ];

						if ( ! $_product->has_enough_stock( $product_qty_in_cart[ $values['product_id'] ] ) ) {
							$error->add( 'out-of-stock', sprintf(__( 'Sorry, we do not have enough "%s" in stock to fulfil your order (%s in stock). Please edit your cart and try again. We apologise for any inconvenience caused.', 'woocommerce' ), $_product->get_title(), $_product->stock ) );
							return $error;
						}

					}

					/**
					 * Finally consider any held stock, from pending orders
					 */
					if ( get_option( 'woocommerce_hold_stock_minutes' ) > 0 && ! $_product->backorders_allowed() ) {

						$order_id = isset( $woocommerce->session->order_awaiting_payment ) ? absint( $woocommerce->session->order_awaiting_payment ) : 0;

						$held_stock = $wpdb->get_var( $wpdb->prepare( "
							SELECT SUM( order_item_meta.meta_value ) AS held_qty

							FROM {$wpdb->posts} AS posts

							LEFT JOIN {$wpdb->prefix}woocommerce_order_items as order_items ON posts.ID = order_items.order_id
							LEFT JOIN {$wpdb->prefix}woocommerce_order_itemmeta as order_item_meta ON order_items.order_item_id = order_item_meta.order_item_id
							LEFT JOIN {$wpdb->prefix}woocommerce_order_itemmeta as order_item_meta2 ON order_items.order_item_id = order_item_meta2.order_item_id
							LEFT JOIN {$wpdb->term_relationships} AS rel ON posts.ID=rel.object_ID
							LEFT JOIN {$wpdb->term_taxonomy} AS tax USING( term_taxonomy_id )
							LEFT JOIN {$wpdb->terms} AS term USING( term_id )

							WHERE 	order_item_meta.meta_key   = '_qty'
							AND 	order_item_meta2.meta_key  = %s AND order_item_meta2.meta_value  = %d
							AND 	posts.post_type            = 'shop_order'
							AND 	posts.post_status          = 'publish'
							AND 	tax.taxonomy               = 'shop_order_status'
							AND		term.slug			       IN ('pending')
							AND		posts.ID                   != %d
						", $key, $value, $order_id ) );

						if ( $_product->stock < ( $held_stock + $in_cart ) ) {
							$error->add( 'out-of-stock', sprintf(__( 'Sorry, we do not have enough "%s" in stock to fulfil your order right now. Please try again in %d minutes or edit your cart and try again. We apologise for any inconvenience caused.', 'woocommerce' ), $_product->get_title(), get_option( 'woocommerce_hold_stock_minutes' ) ) );
							return $error;
						}
					}

				/**
				 * Check stock based on stock-status
				 */
				} else {
					if ( ! $_product->is_in_stock() ) {
						$error->add( 'out-of-stock', sprintf(__( 'Sorry, "%s" is not in stock. Please edit your cart and try again. We apologise for any inconvenience caused.', 'woocommerce' ), $_product->get_title() ) );
						return $error;
					}
				}
			}

			return true;
		}

		/**
		 * Gets and formats a list of cart item data + variations for display on the frontend.
		 *
		 * @access public
		 * @param array $cart_item
		 * @param bool $flat (default: false)
		 * @return string
		 */
		function get_item_data( $cart_item, $flat = false ) {
			global $woocommerce;

			$return = '';
			$has_data = false;

			if ( ! $flat ) $return .= '<dl class="variation">';

			// Variation data
			if ( ! empty( $cart_item['data']->variation_id ) && is_array( $cart_item['variation'] ) ) {

				$variation_list = array();

				foreach ( $cart_item['variation'] as $name => $value ) {

					if ( ! $value ) continue;

					// If this is a term slug, get the term's nice name
		            if ( taxonomy_exists( esc_attr( str_replace( 'attribute_', '', $name ) ) ) ) {
		            	$term = get_term_by( 'slug', $value, esc_attr( str_replace( 'attribute_', '', $name ) ) );
		            	if ( ! is_wp_error( $term ) && $term->name )
		            		$value = $term->name;
		            } else {
		            	$value = ucfirst( $value );
					}

					if ( $flat )
						$variation_list[] = $woocommerce->attribute_label( str_replace( 'attribute_', '', $name ) ) . ': ' . $value;
					else
						$variation_list[] = '<dt>' . $woocommerce->attribute_label( str_replace( 'attribute_', '', $name ) ) . ':</dt><dd>' . $value . '</dd>';

				}

				if ($flat)
					$return .= implode( ", \n", $variation_list );
				else
					$return .= implode( '', $variation_list );

				$has_data = true;

			}

			// Other data - returned as array with name/value values
			$other_data = apply_filters( 'woocommerce_get_item_data', array(), $cart_item );

			if ( $other_data && is_array( $other_data ) && sizeof( $other_data ) > 0 ) {

				$data_list = array();

				foreach ($other_data as $data ) {
					// Set hidden to true to not display meta on cart.
					if ( empty( $data['hidden'] ) ) {
						$display_value = !empty($data['display']) ? $data['display'] : $data['value'];

						if ($flat)
							$data_list[] = $data['name'].': '.$display_value;
						else
							$data_list[] = '<dt>'.$data['name'].':</dt><dd>'.$display_value.'</dd>';
					}
				}

				if ($flat)
					$return .= implode(', ', $data_list);
				else
					$return .= implode('', $data_list);

				$has_data = true;

			}

			if ( ! $flat )
				$return .= '</dl>';

			if ( $has_data )
				return $return;
		}

		/**
		 * Gets cross sells based on the items in the cart.
		 *
		 * @return array cross_sells (item ids)
		 */
		function get_cross_sells() {
			$cross_sells = array();
			$in_cart = array();
			if ( sizeof( $this->cart_contents) > 0 ) {
				foreach ( $this->cart_contents as $cart_item_key => $values ) {
					if ( $values['quantity'] > 0 ) {
						$cross_sells = array_merge( $values['data']->get_cross_sells(), $cross_sells );
						$in_cart[] = $values['product_id'];
					}
				}
			}
			$cross_sells = array_diff( $cross_sells, $in_cart );
			return $cross_sells;
		}

		/**
		 * Gets the url to the cart page.
		 *
		 * @return string url to page
		 */
		function get_cart_url() {
			$cart_page_id = woocommerce_get_page_id('cart');
			if ( $cart_page_id ) return apply_filters( 'woocommerce_get_cart_url', get_permalink( $cart_page_id ) );
		}

		/**
		 * Gets the url to the checkout page.
		 *
		 * @return string url to page
		 */
		function get_checkout_url() {
			$checkout_page_id = woocommerce_get_page_id('checkout');
			if ( $checkout_page_id ) {
				if ( is_ssl() )
					return str_replace( 'http:', 'https:', get_permalink($checkout_page_id) );
				else
					return apply_filters( 'woocommerce_get_checkout_url', get_permalink($checkout_page_id) );
			}
		}

		/**
		 * Gets the url to remove an item from the cart.
		 *
		 * @return string url to page
		 */
		function get_remove_url( $cart_item_key ) {
			global $woocommerce;
			$cart_page_id = woocommerce_get_page_id('cart');
			if ($cart_page_id)
				return apply_filters( 'woocommerce_get_remove_url', $woocommerce->nonce_url( 'cart', add_query_arg( 'remove_item', $cart_item_key, get_permalink($cart_page_id) ) ) );
		}

		/**
		 * Returns the contents of the cart in an array.
		 *
		 * @return array contents of the cart
		 */
		function get_cart() {
			return array_filter( (array) $this->cart_contents );
		}

		/**
		 * Returns the cart and shipping taxes, merged.
		 *
		 * @return array merged taxes
		 */
		function get_taxes() {
			$merged_taxes = array();

			// Merge
			foreach ( array_keys( $this->taxes + $this->shipping_taxes ) as $key ) {
				$merged_taxes[ $key ] = ( isset( $this->shipping_taxes[ $key ] ) ? $this->shipping_taxes[ $key ] : 0 ) + ( isset( $this->taxes[ $key ] ) ? $this->taxes[ $key ] : 0 );
			}

			return $merged_taxes;
		}

		/**
		 * Returns the cart and shipping taxes, merged & formatted.
		 *
		 * @return array merged taxes
		 */
		function get_formatted_taxes() {

			$taxes = $this->get_taxes();

			foreach ( $taxes as $key => $tax )
				if ( $tax > 0 )
					$taxes[ $key ] = woocommerce_price( $tax );

			return apply_filters( 'woocommerce_cart_formatted_taxes', $taxes, $this );
		}

	/*-----------------------------------------------------------------------------------*/
	/* Add to cart handling */
	/*-----------------------------------------------------------------------------------*/

		/**
	     * Check if product is in the cart and return cart item key.
	     *
	     * Cart item key will be unique based on the item and its properties, such as variations.
	     *
	     * @param mixed id of product to find in the cart
	     * @return string cart item key
	     */
	    function find_product_in_cart( $cart_id = false ) {
	        if ( $cart_id !== false )
	        	foreach ( $this->cart_contents as $cart_item_key => $cart_item )
	        		if ( $cart_item_key == $cart_id )
	        			return $cart_item_key;
	    }

		/**
	     * Generate a unique ID for the cart item being added.
	     *
	     * @param int $product_id - id of the product the key is being generated for
	     * @param int $variation_id of the product the key is being generated for
	     * @param array $variation data for the cart item
	     * @param array $cart_item_data other cart item data passed which affects this items uniqueness in the cart
	     * @return string cart item key
	     */
	    function generate_cart_id( $product_id, $variation_id = '', $variation = '', $cart_item_data = array() ) {

	        $id_parts = array( $product_id );

	        if ( $variation_id ) $id_parts[] = $variation_id;

	        if ( is_array( $variation ) ) {
	            $variation_key = '';
	            foreach ( $variation as $key => $value ) {
	                $variation_key .= trim( $key ) . trim( $value );
	            }
	            $id_parts[] = $variation_key;
	        }

	        if ( is_array( $cart_item_data ) && ! empty( $cart_item_data ) ) {
	            $cart_item_data_key = '';
	            foreach ( $cart_item_data as $key => $value ) {
	            	if ( is_array( $value ) ) $value = http_build_query( $value );
	                $cart_item_data_key .= trim($key) . trim($value);
	            }
	            $id_parts[] = $cart_item_data_key;
	        }

	        return md5( implode( '_', $id_parts ) );
	    }

		/**
		 * Add a product to the cart.
		 *
		 * @param string $product_id contains the id of the product to add to the cart
		 * @param string $quantity contains the quantity of the item to add
		 * @param int $variation_id
		 * @param array $variation attribute values
		 * @param array $cart_item_data extra cart item data we want to pass into the item
		 * @return bool
		 */
		function add_to_cart( $product_id, $quantity = 1, $variation_id = '', $variation = '', $cart_item_data = array() ) {
			global $woocommerce;

			if ( $quantity <= 0 ) return false;

			// Load cart item data - may be added by other plugins
			$cart_item_data = (array) apply_filters( 'woocommerce_add_cart_item_data', $cart_item_data, $product_id, $variation_id );

			// Generate a ID based on product ID, variation ID, variation data, and other cart item data
			$cart_id = $this->generate_cart_id( $product_id, $variation_id, $variation, $cart_item_data );

			// See if this product and its options is already in the cart
			$cart_item_key = $this->find_product_in_cart( $cart_id );

			$product_data = get_product( $variation_id ? $variation_id : $product_id );

			// Force quantity to 1 if sold individually
			if ( $product_data->is_sold_individually() )
				$quantity = 1;

			// Check product is_purchasable
			if ( ! $product_data->is_purchasable() ) {
				$woocommerce->add_error( sprintf( __( 'Sorry, &quot;%s&quot; cannot be purchased.', 'woocommerce' ), $product_data->get_title() ) );
				return false;
			}

			// Stock check - only check if we're managing stock and backorders are not allowed
			if ( ! $product_data->is_in_stock() ) {

				$woocommerce->add_error( sprintf( __( 'You cannot add &quot;%s&quot; to the cart because the product is out of stock.', 'woocommerce' ), $product_data->get_title() ) );

				return false;
			} elseif ( ! $product_data->has_enough_stock( $quantity ) ) {

				$woocommerce->add_error( sprintf(__( 'You cannot add that amount of &quot;%s&quot; to the cart because there is not enough stock (%s remaining).', 'woocommerce' ), $product_data->get_title(), $product_data->get_stock_quantity() ));

				return false;

			}

			// Downloadable/virtual qty check
			if ( $product_data->is_sold_individually() ) {
				$in_cart_quantity = $cart_item_key ? $this->cart_contents[$cart_item_key]['quantity'] : 0;

				// If its greater than 0, its already in the cart
				if ( $in_cart_quantity > 0 ) {
					$woocommerce->add_error( sprintf('<a href="%s" class="button">%s</a> %s', get_permalink(woocommerce_get_page_id('cart')), __( 'View Cart &rarr;', 'woocommerce' ), __( 'You already have this item in your cart.', 'woocommerce' ) ) );
					return false;
				}
			}

			// Stock check - this time accounting for whats already in-cart
			$product_qty_in_cart = $this->get_cart_item_quantities();

			if ( $product_data->managing_stock() ) {

				// Variations
				if ( $variation_id && $product_data->variation_has_stock ) {

					if ( isset( $product_qty_in_cart[ $variation_id ] ) && ! $product_data->has_enough_stock( $product_qty_in_cart[ $variation_id ] + $quantity ) ) {
						$woocommerce->add_error( sprintf(__( '<a href="%s" class="button">%s</a> You cannot add that amount to the cart &mdash; we have %s in stock and you already have %s in your cart.', 'woocommerce' ), get_permalink(woocommerce_get_page_id('cart')), __( 'View Cart &rarr;', 'woocommerce' ), $product_data->get_stock_quantity(), $product_qty_in_cart[ $variation_id ] ));
						return false;
					}

				// Products
				} else {

					if ( isset( $product_qty_in_cart[ $product_id ] ) && ! $product_data->has_enough_stock( $product_qty_in_cart[ $product_id ] + $quantity ) ) {
						$woocommerce->add_error( sprintf(__( '<a href="%s" class="button">%s</a> You cannot add that amount to the cart &mdash; we have %s in stock and you already have %s in your cart.', 'woocommerce' ), get_permalink(woocommerce_get_page_id('cart')), __( 'View Cart &rarr;', 'woocommerce' ), $product_data->get_stock_quantity(), $product_qty_in_cart[ $product_id ] ));
						return false;
					}

				}

			}

			// If cart_item_key is set, the item is already in the cart
			if ( $cart_item_key ) {

				$new_quantity = $quantity + $this->cart_contents[$cart_item_key]['quantity'];

				$this->set_quantity( $cart_item_key, $new_quantity );

			} else {

				$cart_item_key = $cart_id;

				// Add item after merging with $cart_item_data - hook to allow plugins to modify cart item
				$this->cart_contents[$cart_item_key] = apply_filters( 'woocommerce_add_cart_item', array_merge( $cart_item_data, array(
					'product_id'	=> $product_id,
					'variation_id'	=> $variation_id,
					'variation' 	=> $variation,
					'quantity' 		=> $quantity,
					'data'			=> $product_data
				) ), $cart_item_key );

			}

			do_action( 'woocommerce_add_to_cart', $cart_item_key, $product_id, $quantity, $variation_id, $variation, $cart_item_data );

			$woocommerce->cart_has_contents_cookie( true );

			$this->set_session();

			return true;
		}

		/**
		 * Set the quantity for an item in the cart.
		 *
		 * @param   string	cart_item_key	contains the id of the cart item
		 * @param   string	quantity	contains the quantity of the item
		 */
		function set_quantity( $cart_item_key, $quantity = 1 ) {

			if ( $quantity == 0 || $quantity < 0 ) {
				do_action( 'woocommerce_before_cart_item_quantity_zero', $cart_item_key );
				unset( $this->cart_contents[$cart_item_key] );
			} else {
				$this->cart_contents[$cart_item_key]['quantity'] = $quantity;
				do_action( 'woocommerce_after_cart_item_quantity_update', $cart_item_key, $quantity );
			}

			$this->set_session();
		}

    /*-----------------------------------------------------------------------------------*/
	/* Cart Calculation Functions */
	/*-----------------------------------------------------------------------------------*/

		/**
		 * Reset cart totals and clear sessions.
		 *
		 * @access private
		 * @return void
		 */
		private function reset() {
			global $woocommerce;

			$this->total = $this->cart_contents_total = $this->cart_contents_weight = $this->cart_contents_count = $this->cart_contents_tax = $this->tax_total = $this->shipping_tax_total = $this->subtotal = $this->subtotal_ex_tax = $this->discount_total = $this->discount_cart = $this->shipping_total = $this->fee_total = 0;
			$this->shipping_taxes = $this->taxes = array();

			unset( $woocommerce->session->cart_contents_total, $woocommerce->session->cart_contents_weight, $woocommerce->session->cart_contents_count, $woocommerce->session->cart_contents_tax, $woocommerce->session->total, $woocommerce->session->subtotal, $woocommerce->session->subtotal_ex_tax, $woocommerce->session->tax_total, $woocommerce->session->taxes, $woocommerce->session->shipping_taxes, $woocommerce->session->discount_cart, $woocommerce->session->discount_total, $woocommerce->session->shipping_total, $woocommerce->session->shipping_tax_total, $woocommerce->session->shipping_label );
		}

		/**
		 * Function to apply discounts to a product and get the discounted price (before tax is applied).
		 *
		 * @access public
		 * @param mixed $values
		 * @param mixed $price
		 * @param bool $add_totals (default: false)
		 * @return float price
		 */
		function get_discounted_price( $values, $price, $add_totals = false ) {

			if ( ! $price ) return $price;

			if ( ! empty( $this->applied_coupons ) ) {
				foreach ( $this->applied_coupons as $code ) {
					$coupon = new WC_Coupon( $code );

					if ( $coupon->apply_before_tax() && $coupon->is_valid() ) {

						switch ( $coupon->type ) {

							case "fixed_product" :
							case "percent_product" :

								$this_item_is_discounted = false;

								$product_cats = wp_get_post_terms( $values['product_id'], 'product_cat', array("fields" => "ids") );

								// Specific products get the discount
								if ( sizeof( $coupon->product_ids ) > 0 ) {

									if ( in_array( $values['product_id'], $coupon->product_ids ) || in_array( $values['variation_id'], $coupon->product_ids ) || in_array( $values['data']->get_parent(), $coupon->product_ids ) )
										$this_item_is_discounted = true;

								// Category discounts
								} elseif ( sizeof($coupon->product_categories ) > 0 ) {

									if ( sizeof( array_intersect( $product_cats, $coupon->product_categories ) ) > 0 )
										$this_item_is_discounted = true;

								} else {

									// No product ids - all items discounted
									$this_item_is_discounted = true;

								}

								// Specific product ID's excluded from the discount
								if ( sizeof( $coupon->exclude_product_ids ) > 0 )
									if ( in_array( $values['product_id'], $coupon->exclude_product_ids ) || in_array( $values['variation_id'], $coupon->exclude_product_ids ) || in_array( $values['data']->get_parent(), $coupon->exclude_product_ids ) )
										$this_item_is_discounted = false;

								// Specific categories excluded from the discount
								if ( sizeof( $coupon->exclude_product_categories ) > 0 )
									if ( sizeof( array_intersect( $product_cats, $coupon->exclude_product_categories ) ) > 0 )
										$this_item_is_discounted = false;

								// Apply filter
								$this_item_is_discounted = apply_filters( 'woocommerce_item_is_discounted', $this_item_is_discounted, $values, $before_tax = true );

								// Apply the discount
								if ( $this_item_is_discounted ) {
									if ( $coupon->type=='fixed_product' ) {

										if ( $price < $coupon->amount ) {
											$discount_amount = $price;
										} else {
											$discount_amount = $coupon->amount;
										}

										$price = $price - $coupon->amount;

										if ( $price < 0 ) $price = 0;

										if ( $add_totals ) {
											$this->discount_cart = $this->discount_cart + ( $discount_amount * $values['quantity'] );
											$this->coupon_discount_amounts[ $code ] = ( $discount_amount * $values['quantity'] );
										}

									} elseif ( $coupon->type == 'percent_product' ) {

										$percent_discount = ( $values['data']->get_price_excluding_tax() / 100 ) * $coupon->amount;

										if ( $add_totals ) {
											$this->discount_cart = $this->discount_cart + ( $percent_discount * $values['quantity'] );
											$this->coupon_discount_amounts[ $code ] = ( $percent_discount * $values['quantity'] );
										}

										$price = $price - $percent_discount;

									}
								}

							break;

							case "fixed_cart" :

								/**
								 * This is the most complex discount - we need to divide the discount between rows based on their price in
								 * proportion to the subtotal. This is so rows with different tax rates get a fair discount, and so rows
								 * with no price (free) don't get discount too.
								 */

								// Get item discount by dividing item cost by subtotal to get a %
								if ( $this->subtotal_ex_tax )
									$discount_percent = ( $values['data']->get_price_excluding_tax()*$values['quantity'] ) / $this->subtotal_ex_tax;
								else
									$discount_percent = 0;

								// Use pence to help prevent rounding errors
								$coupon_amount_pence = $coupon->amount * 100;

								// Work out the discount for the row
								$item_discount = $coupon_amount_pence * $discount_percent;

								// Work out discount per item
								$item_discount = $item_discount / $values['quantity'];

								// Pence
								$price = ( $price * 100 );

								// Check if discount is more than price
								if ( $price < $item_discount )
									$discount_amount = $price;
								else
									$discount_amount = $item_discount;

								// Take discount off of price (in pence)
								$price = $price - $discount_amount;

								// Back to pounds
								$price = $price / 100;

								// Cannot be below 0
								if ( $price < 0 ) $price = 0;

								// Add coupon to discount total (once, since this is a fixed cart discount and we don't want rounding issues)
								if ( $add_totals ) {
									$this->discount_cart = $this->discount_cart + ( ( $discount_amount * $values['quantity'] ) / 100 );
									$this->coupon_discount_amounts[ $code ] = ( ( $discount_amount * $values['quantity'] ) / 100 );
								}

							break;

							case "percent" :

								$percent_discount = round( ( $values['data']->get_price() / 100 ) * $coupon->amount, $this->dp );

								if ( $add_totals ) {
									$this->discount_cart = $this->discount_cart + ( $percent_discount * $values['quantity'] );
									$this->coupon_discount_amounts[ $code ] = ( $percent_discount * $values['quantity'] );
								}

								$price = $price - $percent_discount;

							break;

						}
					}
				}
			}

			return apply_filters( 'woocommerce_get_discounted_price', $price, $values, $this );
		}

		/**
		 * Function to apply product discounts after tax.
		 *
		 * @access public
		 * @param mixed $values
		 * @param mixed $price
		 */
		function apply_product_discounts_after_tax( $values, $price ) {

			if ( ! empty( $this->applied_coupons) ) {
				foreach ( $this->applied_coupons as $code ) {
					$coupon = new WC_Coupon( $code );

					do_action( 'woocommerce_product_discount_after_tax_' . $coupon->type, $coupon, $values, $price );

					if ( $coupon->type != 'fixed_product' && $coupon->type != 'percent_product' ) continue;

					if ( !$coupon->apply_before_tax() && $coupon->is_valid() ) {

						$product_cats = wp_get_post_terms( $values['product_id'], 'product_cat', array("fields" => "ids") );

						$this_item_is_discounted = false;

						// Specific products get the discount
						if ( sizeof( $coupon->product_ids ) > 0 ) {

							if (in_array($values['product_id'], $coupon->product_ids) || in_array($values['variation_id'], $coupon->product_ids) || in_array($values['data']->get_parent(), $coupon->product_ids))
								$this_item_is_discounted = true;

						// Category discounts
						} elseif ( sizeof( $coupon->product_categories ) > 0 ) {

							if ( sizeof( array_intersect( $product_cats, $coupon->product_categories ) ) > 0 )
								$this_item_is_discounted = true;

						} else {

							// No product ids - all items discounted
							$this_item_is_discounted = true;

						}

						// Specific product ID's excluded from the discount
						if ( sizeof( $coupon->exclude_product_ids ) > 0 )
							if ( in_array( $values['product_id'], $coupon->exclude_product_ids ) || in_array( $values['variation_id'], $coupon->exclude_product_ids ) || in_array( $values['data']->get_parent(), $coupon->exclude_product_ids ) )
								$this_item_is_discounted = false;

						// Specific categories excluded from the discount
						if ( sizeof( $coupon->exclude_product_categories ) > 0 )
							if ( sizeof( array_intersect( $product_cats, $coupon->exclude_product_categories ) ) > 0 )
								$this_item_is_discounted = false;

						// Apply filter
						$this_item_is_discounted = apply_filters( 'woocommerce_item_is_discounted', $this_item_is_discounted, $values, $before_tax = false );

						// Apply the discount
						if ( $this_item_is_discounted ) {
							if ( $coupon->type == 'fixed_product' ) {

								if ( $price < $coupon->amount )
									$discount_amount = $price;
								else
									$discount_amount = $coupon->amount;

								$this->discount_total = $this->discount_total + ( $discount_amount * $values['quantity'] );

								$this->coupon_discount_amounts[ $code ] = ( $discount_amount * $values['quantity'] );

							} elseif ( $coupon->type == 'percent_product' ) {
								$this->discount_total = $this->discount_total + round( ( $price / 100 ) * $coupon->amount, $this->dp );
								$this->coupon_discount_amounts[ $code ] = round( ( $price / 100 ) * $coupon->amount, $this->dp );
							}
						}
					}
				}
			}

		}

		/**
		 * Function to apply cart discounts after tax.
		 *
		 * @access public
		 */
		function apply_cart_discounts_after_tax() {

			if ( $this->applied_coupons ) {
				foreach ( $this->applied_coupons as $code ) {
					$coupon = new WC_Coupon( $code );

					do_action( 'woocommerce_cart_discount_after_tax_' . $coupon->type, $coupon );

					if ( !$coupon->apply_before_tax() && $coupon->is_valid() ) {

						switch ( $coupon->type ) {

							case "fixed_cart" :

								$this->discount_total = $this->discount_total + $coupon->amount;

								$this->coupon_discount_amounts[ $code ] = $coupon->amount;

							break;

							case "percent" :

								$percent_discount = ( round( $this->cart_contents_total + $this->tax_total, $this->dp ) / 100 ) * $coupon->amount;

								$this->discount_total = $this->discount_total + round( $percent_discount, $this->dp );

								$this->coupon_discount_amounts[ $code ] = round( $percent_discount, $this->dp );

							break;

						}

					}
				}
			}
		}

		/**
		 * Calculate totals for the items in the cart.
		 *
		 * @access public
		 */
		function calculate_totals() {
			global $woocommerce;

			$this->reset();

			do_action( 'woocommerce_before_calculate_totals', $this );

			// Get count of all items + weights + subtotal (we may need this for discounts)
			if ( sizeof( $this->cart_contents ) > 0 ) {
				foreach ( $this->cart_contents as $cart_item_key => $values ) {

					$_product = $values['data'];

					$this->cart_contents_weight = $this->cart_contents_weight + ( $_product->get_weight() * $values['quantity'] );
					$this->cart_contents_count 	= $this->cart_contents_count + $values['quantity'];

					// Base Price (inclusive of tax for now)
					$row_base_price 		= $_product->get_price() * $values['quantity'];
					$base_tax_rates 		= $this->tax->get_shop_base_rate( $_product->tax_class );
					$tax_amount				= 0;

					if ( $this->prices_include_tax ) {

						if ( $_product->is_taxable() ) {

							$tax_rates			 	= $this->tax->get_rates( $_product->get_tax_class() );

							// ADJUST BASE if tax rate is different (different region or modified tax class)
							if ( $tax_rates !== $base_tax_rates ) {
								$base_taxes			= $this->tax->calc_tax( $row_base_price, $base_tax_rates, true, true );
								$modded_taxes		= $this->tax->calc_tax( $row_base_price - array_sum( $base_taxes ), $tax_rates, false );
								$row_base_price 	= ( $row_base_price - array_sum( $base_taxes ) ) + array_sum( $modded_taxes );
							}

							$taxes 					= $this->tax->calc_tax( $row_base_price, $tax_rates, true );
							$tax_amount				= $this->tax->get_tax_total( $taxes );
						}

						// Sub total is based on base prices (without discounts)
						$this->subtotal 			= $this->subtotal + $row_base_price;
						$this->subtotal_ex_tax 		= $this->subtotal_ex_tax + ( $row_base_price - $tax_amount);

					} else {

						if ( $_product->is_taxable() ) {
							$tax_rates			 	= $this->tax->get_rates( $_product->get_tax_class() );
							$taxes 					= $this->tax->calc_tax( $row_base_price, $tax_rates, false );
							$tax_amount				= $this->tax->get_tax_total( $taxes );
						}

						// Sub total is based on base prices (without discounts)
						$this->subtotal 			= $this->subtotal + $row_base_price + $tax_amount;
						$this->subtotal_ex_tax 		= $this->subtotal_ex_tax + $row_base_price;

					}
				}
			}

			// Now calc the main totals, including discounts
			if ( $this->prices_include_tax ) {

				/**
				 * Calculate totals for items
				 */
				if ( sizeof($this->cart_contents) > 0 ) {
					foreach ($this->cart_contents as $cart_item_key => $values ) {

						/**
						 * Prices include tax
						 *
						 * To prevent rounding issues we need to work with the inclusive price where possible
						 * otherwise we'll see errors such as when working with a 9.99 inc price, 20% VAT which would
						 * be 8.325 leading to totals being 1p off
						 *
						 * Pre tax coupons come off the price the customer thinks they are paying - tax is calculated
						 * afterwards.
						 *
						 * e.g. $100 bike with $10 coupon = customer pays $90 and tax worked backwards from that
						 *
						 * Used this excellent article for reference:
						 *	http://developer.practicalecommerce.com/articles/1473-Coding-for-Tax-Calculations-Everything-You-Never-Wanted-to-Know-Part-2
						 */
						$_product = $values['data'];

						// Base Price (inlusive of tax for now)
						$base_price 			= $_product->get_price();

						// Base Price Adjustment
						if ( $_product->is_taxable() ) {

							// Get rates
							$tax_rates			 	= $this->tax->get_rates( $_product->get_tax_class() );

							/**
							 * ADJUST TAX - Calculations when customer is OUTSIDE the shop base country/state and prices INCLUDE tax
							 * 	OR
							 * ADJUST TAX - Calculations when a tax class is modified
							 */
							if ( ( $woocommerce->customer->is_customer_outside_base() && ( defined('WOOCOMMERCE_CHECKOUT') || $woocommerce->customer->has_calculated_shipping() ) ) || ( $_product->get_tax_class() !== $_product->tax_class ) ) {

								// Get tax rate for the store base, ensuring we use the unmodified tax_class for the product
								$base_tax_rates 		= $this->tax->get_shop_base_rate( $_product->tax_class );

								// Work out new price based on region
								$row_base_price 		= $base_price * $values['quantity'];
								$base_taxes				= $this->tax->calc_tax( $row_base_price, $base_tax_rates, true, true ); // Unrounded
								$taxes					= $this->tax->calc_tax( $row_base_price - array_sum($base_taxes), $tax_rates, false );

								// Tax amount
								$tax_amount				= array_sum( $taxes );

								// Line subtotal + tax
								$line_subtotal_tax 		= get_option('woocommerce_tax_round_at_subtotal') == 'no' ? round( $tax_amount, $this->dp ) : $tax_amount;
								$line_subtotal			= $row_base_price - $this->tax->get_tax_total( $base_taxes );

								// Adjusted price
								$adjusted_price 		= ( $row_base_price - array_sum( $base_taxes ) + array_sum( $taxes ) ) / $values['quantity'];

								// Apply discounts
								$discounted_price 		= $this->get_discounted_price( $values, $adjusted_price, true );

								$discounted_taxes		= $this->tax->calc_tax( $discounted_price * $values['quantity'], $tax_rates, true );
								$discounted_tax_amount	= array_sum( $discounted_taxes ); // Sum taxes

							/**
							 * Regular tax calculation (customer inside base and the tax class is unmodified
							 */
							} else {

								// Base tax for line before discount - we will store this in the order data
								$tax_amount				= array_sum( $this->tax->calc_tax( $base_price * $values['quantity'], $tax_rates, true ) );

								// Line subtotal + tax
								$line_subtotal_tax 		= get_option('woocommerce_tax_round_at_subtotal') == 'no' ? round( $tax_amount, $this->dp ) : $tax_amount;
								$line_subtotal			= ( $base_price * $values['quantity'] ) - round( $line_subtotal_tax, $this->dp );

								// Calc prices and tax (discounted)
								$discounted_price 		= $this->get_discounted_price( $values, $base_price, true );
								$discounted_taxes		= $this->tax->calc_tax( $discounted_price * $values['quantity'], $tax_rates, true );
								$discounted_tax_amount	= array_sum( $discounted_taxes ); // Sum taxes

							}

							// Tax rows - merge the totals we just got
							foreach ( array_keys( $this->taxes + $discounted_taxes ) as $key ) {
							    $this->taxes[ $key ] = ( isset( $discounted_taxes[ $key ] ) ? $discounted_taxes[ $key ] : 0 ) + ( isset( $this->taxes[ $key ] ) ? $this->taxes[ $key ] : 0 );
							}

						} else {

							// Discounted Price (price with any pre-tax discounts applied)
							$discounted_price 		= $this->get_discounted_price( $values, $base_price, true );
							$discounted_tax_amount 	= 0;
							$tax_amount 			= 0;
							$line_subtotal_tax		= 0;
							$line_subtotal			= $base_price * $values['quantity'];

						}

						// Line prices
						$line_tax 		= get_option('woocommerce_tax_round_at_subtotal') == 'no' ? round( $discounted_tax_amount, $this->dp ) : $discounted_tax_amount;
						$line_total 	= round( ( $discounted_price * $values['quantity'] ) - round( $line_tax, $this->dp ), $this->dp );

						// Add any product discounts (after tax)
						$this->apply_product_discounts_after_tax( $values, $line_total + $discounted_tax_amount );

						// Cart contents total is based on discounted prices and is used for the final total calculation
						$this->cart_contents_total 	= $this->cart_contents_total + $line_total;

						// Store costs + taxes for lines
						$this->cart_contents[ $cart_item_key ]['line_total'] 		= $line_total;
						$this->cart_contents[ $cart_item_key ]['line_tax'] 			= $line_tax;
						$this->cart_contents[ $cart_item_key ]['line_subtotal'] 	= $line_subtotal;
						$this->cart_contents[ $cart_item_key ]['line_subtotal_tax'] = $line_subtotal_tax;

					}
				}

			} else {

				if ( sizeof( $this->cart_contents ) > 0 ) {
					foreach ( $this->cart_contents as $cart_item_key => $values ) {

						/**
						 * Prices exclude tax
						 *
						 * This calculation is simpler - work with the base, untaxed price.
						 */
						$_product = $values['data'];

						// Base Price (i.e. no tax, regardless of region)
						$base_price 				= $_product->get_price();

						// Discounted Price (base price with any pre-tax discounts applied
						$discounted_price 			= $this->get_discounted_price( $values, $base_price, true );

						// Tax Amount (For the line, based on discounted, ex.tax price)
						if ( $_product->is_taxable() ) {

							// Get tax rates
							$tax_rates 				= $this->tax->get_rates( $_product->get_tax_class() );

							// Base tax for line before discount - we will store this in the order data
							$tax_amount				= array_sum( $this->tax->calc_tax( $base_price * $values['quantity'], $tax_rates, false ) );

							// Now calc product rates
							$discounted_taxes		= $this->tax->calc_tax( $discounted_price * $values['quantity'], $tax_rates, false );
							$discounted_tax_amount	= array_sum( $discounted_taxes );

							// Tax rows - merge the totals we just got
							foreach ( array_keys( $this->taxes + $discounted_taxes ) as $key ) {
							    $this->taxes[ $key ] = ( isset( $discounted_taxes[ $key ] ) ? $discounted_taxes[ $key ] : 0 ) + ( isset( $this->taxes[ $key ] ) ? $this->taxes[ $key ] : 0 );
							}

						} else {
							$discounted_tax_amount 	= 0;
							$tax_amount 			= 0;
						}

						// Line prices
						$line_subtotal_tax	= $tax_amount;
						$line_tax			= $discounted_tax_amount;
						$line_subtotal		= $base_price * $values['quantity'];
						$line_total 		= $discounted_price * $values['quantity'];

						// Add any product discounts (after tax)
						$this->apply_product_discounts_after_tax( $values, $line_total + $line_tax );

						// Cart contents total is based on discounted prices and is used for the final total calculation
						$this->cart_contents_total 	= $this->cart_contents_total + $line_total;

						// Store costs + taxes for lines
						$this->cart_contents[ $cart_item_key ]['line_total'] 		= $line_total;
						$this->cart_contents[ $cart_item_key ]['line_tax'] 			= $line_tax;
						$this->cart_contents[ $cart_item_key ]['line_subtotal'] 	= $line_subtotal;
						$this->cart_contents[ $cart_item_key ]['line_subtotal_tax'] = $line_subtotal_tax;
					}
				}
			}

			// Add fees
			foreach ( $this->get_fees() as $fee ) {
				$this->fee_total += $fee->amount;

				if ( $fee->taxable ) {
					// Get tax rates
					$tax_rates 				= $this->tax->get_rates();
					$fee_taxes				= $this->tax->calc_tax( $fee->amount, $tax_rates, false );

					// Store
					$fee->tax 				= array_sum( $fee_taxes );

					// Tax rows - merge the totals we just got
					foreach ( array_keys( $this->taxes + $fee_taxes ) as $key ) {
					    $this->taxes[ $key ] = ( isset( $fee_taxes[ $key ] ) ? $fee_taxes[ $key ] : 0 ) + ( isset( $this->taxes[ $key ] ) ? $this->taxes[ $key ] : 0 );
					}
				}
			}

			// Set tax total to sum of all tax rows
			$this->tax_total = $this->tax->get_tax_total( $this->taxes );

			// VAT exemption done at this point - so all totals are correct before exemption
			if ( $woocommerce->customer->is_vat_exempt() ) {
				$this->shipping_tax_total = $this->tax_total = 0;
				$this->taxes = $this->shipping_taxes = array();

				foreach ( $this->cart_contents as $cart_item_key => $item )
					$this->cart_contents[ $cart_item_key ]['line_subtotal_tax'] = $this->cart_contents[ $cart_item_key ]['line_tax'] = 0;
			}

			// Cart Discounts (after tax)
			$this->apply_cart_discounts_after_tax();

			// Only go beyond this point if on the cart/checkout
			if ( ! is_checkout() && ! is_cart() && ! defined('WOOCOMMERCE_CHECKOUT') && ! defined('WOOCOMMERCE_CART') ) return;

			// Cart Shipping
			$this->calculate_shipping();

			// VAT exemption for shipping
			if ( $woocommerce->customer->is_vat_exempt() ) {
				$this->shipping_tax_total = 0;
				$this->shipping_taxes = array();
			}

			// Round cart/shipping tax rows
			$this->taxes = array_map( array( &$this->tax, 'round' ), $this->taxes );
			$this->shipping_taxes = array_map( array( &$this->tax, 'round' ), $this->shipping_taxes );

			// Allow plugins to hook and alter totals before final total is calculated
			do_action( 'woocommerce_calculate_totals', $this );

			/**
			 * Grand Total
			 *
			 * Based on discounted product prices, discounted tax, shipping cost + tax, and any discounts to be added after tax (e.g. store credit)
			 */
			$this->total = apply_filters( 'woocommerce_calculated_total', number_format( $this->cart_contents_total + $this->tax_total + $this->shipping_tax_total + $this->shipping_total - $this->discount_total + $this->fee_total, $this->dp, '.', '' ), $this );

			if ( $this->total < 0 )
				$this->total = 0;
		}

		/**
		 * looks at the totals to see if payment is actually required.
		 *
		 * @return bool
		 */
		function needs_payment() {
			$needs_payment = ( $this->total > 0 ) ? true : false;
			return apply_filters( 'woocommerce_cart_needs_payment', $needs_payment, $this );
		}

    /*-----------------------------------------------------------------------------------*/
	/* Shipping related functions */
	/*-----------------------------------------------------------------------------------*/

		/**
		 * Uses the shipping class to calculate shipping then gets the totals when its finished.
		 *
		 * @access public
		 * @return void
		 */
		function calculate_shipping() {
			global $woocommerce;

			if ( $this->needs_shipping() && $this->show_shipping() ) {
				$woocommerce->shipping->calculate_shipping( $this->get_shipping_packages() );
			} else {
				$woocommerce->shipping->reset_shipping();
			}

			// Get totals for the chosen shipping method
			$this->shipping_total 		= $woocommerce->shipping->shipping_total;	// Shipping Total
			$this->shipping_label 		= $woocommerce->shipping->shipping_label;	// Shipping Label
			$this->shipping_taxes		= $woocommerce->shipping->shipping_taxes;	// Shipping Taxes
			$this->shipping_tax_total 	= $this->tax->get_tax_total( $this->shipping_taxes );	// Shipping tax amount
		}

		/**
		 * Get packages to calculate shipping for.
		 *
		 * This lets us calculate costs for carts that are shipped to multiple locations.
		 *
		 * Shipping methods are responsble for looping through these packages.
		 *
		 * By default we pass the cart itself as a package - plugins can change this
		 * through the filter and break it up.
		 *
		 * @since 1.5.4
		 * @access public
		 * @return array of cart items
		 */
		function get_shipping_packages() {
			global $woocommerce;

			// Packages array for storing 'carts'
			$packages = array();

			$packages[0]['contents'] 				= $this->get_cart();		// Items in the package
			$packages[0]['contents_cost'] 			= 0;						// Cost of items in the package, set below
			$packages[0]['applied_coupons']			= $this->applied_coupons; 	// Applied coupons - some, like free shipping, affect costs
			$packages[0]['destination']['country'] 	= $woocommerce->customer->get_shipping_country();
			$packages[0]['destination']['state'] 	= $woocommerce->customer->get_shipping_state();
			$packages[0]['destination']['postcode'] = $woocommerce->customer->get_shipping_postcode();
			$packages[0]['destination']['city'] 	= $woocommerce->customer->get_shipping_city();

			foreach ( $this->get_cart() as $item )
				if ( $item['data']->needs_shipping() )
					$packages[0]['contents_cost'] += $item['line_total'];

			return apply_filters( 'woocommerce_cart_shipping_packages', $packages );
		}

		/**
		 * Looks through the cart to see if shipping is actually required.
		 *
		 * @return bool whether or not the cart needs shipping
		 */
		function needs_shipping() {
			if ( get_option('woocommerce_calc_shipping')=='no' ) return false;
			if ( ! is_array( $this->cart_contents ) ) return false;

			$needs_shipping = false;

			foreach ( $this->cart_contents as $cart_item_key => $values ) {
				$_product = $values['data'];
				if ( $_product->needs_shipping() ) {
					$needs_shipping = true;
				}
			}

			return apply_filters( 'woocomerce_cart_needs_shipping', $needs_shipping );
		}

		/**
		 * Sees if the customer has entered enough data to calc the shipping yet.
		 *
		 * @return bool
		 */
		function show_shipping() {
			global $woocommerce;

			if ( get_option('woocommerce_calc_shipping')=='no' ) return false;
			if ( ! is_array( $this->cart_contents ) ) return false;

			if ( get_option( 'woocommerce_shipping_cost_requires_address' ) == 'yes' ) {
				if ( ! $woocommerce->customer->has_calculated_shipping() ) {
					if ( ! $woocommerce->customer->get_shipping_country() || ( ! $woocommerce->customer->get_shipping_state() && ! $woocommerce->customer->get_shipping_postcode() ) ) return false;
				}
			}

			$show_shipping = true;

			return apply_filters( 'woocomerce_cart_ready_to_calc_shipping', $show_shipping );

		}

		/**
		 * Sees if we need a shipping address.
		 *
		 * @return bool
		 */
		function ship_to_billing_address_only() {
			if ( get_option('woocommerce_ship_to_billing_address_only') == 'yes' ) return true; else return false;
		}

		/**
		 * Gets the shipping total (after calculation).
		 *
		 * @return mixed price or string for the shipping total
		 */
		function get_cart_shipping_total() {
			global $woocommerce;

			if ( isset( $this->shipping_label ) ) {
				if ( $this->shipping_total > 0 ) {

					// Display varies depending on settings
					if ( $this->tax_display_cart == 'excl' ) {

						$return = woocommerce_price( $this->shipping_total );

						if ( $this->shipping_tax_total > 0 && $this->prices_include_tax ) {
							$return .= ' <small>' . $woocommerce->countries->ex_tax_or_vat() . '</small>';
						}

						return $return;

					} else {

						$return = woocommerce_price( $this->shipping_total + $this->shipping_tax_total );

						if ( $this->shipping_tax_total > 0 && ! $this->prices_include_tax ) {
							$return .= ' <small>' . $woocommerce->countries->inc_tax_or_vat() . '</small>';
						}

						return $return;

					}

				} else {
					return __( 'Free!', 'woocommerce' );
				}
			}
		}

		/**
		 * Gets title of the chosen shipping method.
		 *
		 * @return string shipping method title
		 */
		function get_cart_shipping_title() {
			if ( isset( $this->shipping_label ) ) {
				return __( 'via', 'woocommerce' ) . ' ' . $this->shipping_label;
			}
			return false;
		}

    /*-----------------------------------------------------------------------------------*/
	/* Coupons/Discount related functions */
	/*-----------------------------------------------------------------------------------*/

		/**
		 * Returns whether or not a discount has been applied.
		 *
		 * @return bool
		 */
		function has_discount( $code ) {
			if ( in_array( $code, $this->applied_coupons ) ) return true;
			return false;
		}

		/**
		 * Applies a coupon code passed to the method.
		 *
		 * @param string $coupon_code - The code to apply
		 * @return bool	True if the coupon is applied, false if it does not exist or cannot be applied
		 */
		function add_discount( $coupon_code ) {
			global $woocommerce;

			// Coupons are globally disabled
			if ( get_option('woocommerce_enable_coupons') == 'no' ) return false;

			$the_coupon = new WC_Coupon( $coupon_code );

			if ( $the_coupon->id ) {

				// Check it can be used with cart
				$return = $the_coupon->is_valid();
				if ( ! $return || is_wp_error( $return ) ) {
					$woocommerce->add_error( is_wp_error( $return ) ? $return->get_error_message() : __( 'Invalid coupon.', 'woocommerce' ) );
					return false;
				}

				// Check if applied
				if ( $woocommerce->cart->has_discount( $coupon_code ) ) {
					$woocommerce->add_error( __( 'Discount code already applied!', 'woocommerce' ) );
					return false;
				}

				// If its individual use then remove other coupons
				if ( $the_coupon->individual_use == 'yes' ) {
					$this->applied_coupons = array();
				}

				foreach ( $this->applied_coupons as $code ) {
					$coupon = new WC_Coupon($code);
					if ( $coupon->individual_use == 'yes' ) {
						$this->applied_coupons = array();
					}
				}

				$this->applied_coupons[] = $coupon_code;

				// Choose free shipping
				if ( $the_coupon->enable_free_shipping() ) {
					$woocommerce->session->chosen_shipping_method = 'free_shipping';
				}

				$this->set_session();

				$woocommerce->add_message( __( 'Discount code applied successfully.', 'woocommerce' ) );

				do_action( 'woocommerce_applied_coupon', $coupon_code );

				return true;

			} else {
				$woocommerce->add_error( __( 'Coupon does not exist!', 'woocommerce' ) );
				return false;
			}
			return false;
		}

		/**
		 * Gets the array of applied coupon codes.
		 *
		 * @return array of applied coupons
		 */
		function get_applied_coupons() {
			return (array) $this->applied_coupons;
		}

		/**
		 * Remove coupons from the cart of a defined type. Type 1 is before tax, type 2 is after tax.
		 *
		 * @params int type - 0 for all, 1 for before tax, 2 for after tax
		 */
		function remove_coupons( $type = 0 ) {
			global $woocommerce;

			if ( 1 == $type ) {
				if ( $this->applied_coupons ) {
					foreach ( $this->applied_coupons as $index => $code ) {
						$coupon = new WC_Coupon( $code );
						if ( $coupon->apply_before_tax() ) unset( $this->applied_coupons[ $index ] );
					}
				}

				$woocommerce->session->coupon_codes   = $this->applied_coupons;
			} elseif ( $type == 2 ) {
				if ( $this->applied_coupons ) {
					foreach ( $this->applied_coupons as $index => $code ) {
						$coupon = new WC_Coupon( $code );
						if ( ! $coupon->apply_before_tax() ) unset( $this->applied_coupons[ $index ] );
					}
				}

				$woocommerce->session->coupon_codes   = $this->applied_coupons;
			} else {
				unset( $woocommerce->session->coupon_codes, $woocommerce->session->coupon_amounts );
				$this->applied_coupons = array();
			}
		}

 	/*-----------------------------------------------------------------------------------*/
	/* Fees API to add additonal costs to orders */
	/*-----------------------------------------------------------------------------------*/

		/**
		 * add_fee function.
		 *
		 * @access public
		 * @param mixed $name
		 * @param mixed $amount
		 * @param bool $taxable (default: false)
		 * @param string $tax_class (default: '')
		 * @return void
		 */
		function add_fee( $name, $amount, $taxable = false, $tax_class = '' ) {

			if ( empty( $this->fees ) )
				$this->fees = array();

			$new_fee 			= new stdClass();
			$new_fee->id 		= sanitize_title( $name );
			$new_fee->name 		= esc_attr( $name );
			$new_fee->amount	= (float) esc_attr( $amount );
			$new_fee->tax_class	= $tax_class;
			$new_fee->taxable	= $taxable ? true : false;
			$new_fee->tax		= 0;

			$this->fees[] 		= $new_fee;
		}

		/**
		 * get_fees function.
		 *
		 * @access public
		 * @return void
		 */
		function get_fees() {
			return (array) $this->fees;
		}

    /*-----------------------------------------------------------------------------------*/
	/* Get Formatted Totals */
	/*-----------------------------------------------------------------------------------*/

		/**
		 * Get the total of all order discounts (after tax discounts).
		 *
		 * @return float
		 */
		function get_order_discount_total() {
			return $this->discount_total;
		}

		/**
		 * Get the total of all cart discounts (before tax discounts).
		 *
		 * @return float
		 */
		function get_cart_discount_total() {
			return $this->discount_cart;
		}

		/**
		 * Gets the order total (after calculation).
		 *
		 * @return string formatted price
		 */
		function get_total() {
			return apply_filters( 'woocommerce_cart_total', woocommerce_price( $this->total ) );
		}

		/**
		 * Gets the total excluding taxes.
		 *
		 * @return string formatted price
		 */
		function get_total_ex_tax() {
			$total = $this->total - $this->tax_total - $this->shipping_tax_total;
			if ( $total < 0 ) $total = 0;
			return apply_filters( 'woocommerce_cart_total_ex_tax', woocommerce_price( $total ) );
		}

		/**
		 * Gets the cart contents total (after calculation).
		 *
		 * @return string formatted price
		 */
		function get_cart_total() {
			if ( ! $this->prices_include_tax ) {
				$cart_contents_total = woocommerce_price( $this->cart_contents_total );
			} else {
				$cart_contents_total = woocommerce_price( $this->cart_contents_total + $this->tax_total );
			}

			return apply_filters( 'woocommerce_cart_contents_total', $cart_contents_total );
		}

		/**
		 * Gets the sub total (after calculation).
		 *
		 * @params bool whether to include compound taxes
		 * @return string formatted price
		 */
		function get_cart_subtotal( $compound = false ) {
			global $woocommerce;

			// If the cart has compound tax, we want to show the subtotal as
			// cart + shipping + non-compound taxes (after discount)
			if ( $compound ) {

				$cart_subtotal = woocommerce_price( $this->cart_contents_total + $this->shipping_total + $this->get_taxes_total( false ) );

			// Otherwise we show cart items totals only (before discount)
			} else {

				// Display varies depending on settings
				if ( $this->tax_display_cart == 'excl' ) {

					$cart_subtotal = woocommerce_price( $this->subtotal_ex_tax );

					if ( $this->tax_total > 0 && $this->prices_include_tax ) {
						$cart_subtotal .= ' <small>' . $woocommerce->countries->ex_tax_or_vat() . '</small>';
					}

				} else {

					$cart_subtotal = woocommerce_price( $this->subtotal );

					if ( $this->tax_total > 0 && !$this->prices_include_tax ) {
						$cart_subtotal .= ' <small>' . $woocommerce->countries->inc_tax_or_vat() . '</small>';
					}

				}
			}

			return apply_filters( 'woocommerce_cart_subtotal', $cart_subtotal, $compound, $this );
		}

		/**
		 * Get the product row subtotal.
		 *
		 * Gets the tax etc to avoid rounding issues.
		 *
		 * When on the checkout (review order), this will get the subtotal based on the customer's tax rate rather than the base rate
		 *
		 * @params object product
		 * @params int quantity
		 * @return string formatted price
		 */
		function get_product_subtotal( $_product, $quantity ) {
			global $woocommerce;

			$price 			= $_product->get_price();
			$taxable 		= $_product->is_taxable();
			$base_tax_rates = $this->tax->get_shop_base_rate( $_product->tax_class );
			$tax_rates 		= $this->tax->get_rates( $_product->get_tax_class() ); // This will get the base rate unless we're on the checkout page

			// Taxable
			if ( $taxable ) {

				if ( $this->tax_display_cart == 'excl' ) {

					$row_price        = $_product->get_price_excluding_tax( $quantity );
					$product_subtotal = woocommerce_price( $row_price );

					if ( $this->prices_include_tax )
						$product_subtotal .= ' <small class="tax_label">' . $woocommerce->countries->ex_tax_or_vat() . '</small>';

				} else {

					$row_price        = $_product->get_price_including_tax( $quantity );
					$product_subtotal = woocommerce_price( $row_price );

					if ( ! $this->prices_include_tax )
						$product_subtotal .= ' <small class="tax_label">' . $woocommerce->countries->inc_tax_or_vat() . '</small>';

				}

			// Non-taxable
			} else {

				$row_price        = $price * $quantity;
				$product_subtotal = woocommerce_price( $row_price );

			}

			return apply_filters( 'woocommerce_cart_product_subtotal', $product_subtotal, $_product, $quantity, $this );
		}

		/**
		 * Gets the cart tax (after calculation).
		 *
		 * @return string formatted price
		 */
		function get_cart_tax() {
			$return = false;
			$cart_total_tax = $this->tax_total + $this->shipping_tax_total;
			if ( $cart_total_tax > 0 ) $return = woocommerce_price( $cart_total_tax );
			return apply_filters( 'woocommerce_get_cart_tax', $return );
		}

		/**
		 * Get tax row amounts with or without compound taxes includes.
		 *
		 * @return float price
		 */
		function get_taxes_total( $compound = true ) {
			$total = 0;
			foreach ( $this->taxes as $key => $tax ) {
				if ( ! $compound && $this->tax->is_compound( $key ) ) continue;
				$total += $tax;
			}
			foreach ( $this->shipping_taxes as $key => $tax ) {
				if ( ! $compound && $this->tax->is_compound( $key ) ) continue;
				$total += $tax;
			}
			return $total;
		}

		/**
		 * Gets the total (product) discount amount - these are applied before tax.
		 *
		 * @return mixed formatted price or false if there are none
		 */
		function get_discounts_before_tax() {
			if ( $this->discount_cart ) {
				$discounts_before_tax = woocommerce_price( $this->discount_cart );
			} else {
				$discounts_before_tax = false;
			}
			return apply_filters( 'woocommerce_cart_discounts_before_tax', $discounts_before_tax, $this );
		}

		/**
		 * Gets the order discount amount - these are applied after tax.
		 *
		 * @return mixed formatted price or false if there are none
		 */
		function get_discounts_after_tax() {
			if ( $this->discount_total ) {
				$discounts_after_tax = woocommerce_price( $this->discount_total );
			} else {
				$discounts_after_tax = false;
			}
			return apply_filters( 'woocommerce_cart_discounts_after_tax', $discounts_after_tax, $this );
		}

		/**
		 * Gets the total discount amount - both kinds.
		 *
		 * @return mixed formatted price or false if there are none
		 */
		function get_total_discount() {
			if ( $this->discount_total || $this->discount_cart ) {
				$total_discount = woocommerce_price( $this->discount_total + $this->discount_cart );
			} else {
				$total_discount = false;
			}
			return apply_filters( 'woocommerce_cart_total_discount', $total_discount, $this );
		}
}