woocommerce/includes/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		2.1.0
 * @package		WooCommerce/Classes
 * @category	Class
 * @author 		WooThemes
 */
class WC_Cart {

	/** @var array Contains an array of cart items. */
	public $cart_contents = array();

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

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

	/** @var array Contains an array of coupon usage counts after they have been applied. */
	public $coupon_applied_count = array();

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	/** @var array cart_session_data */
	public $cart_session_data = array();

	/** @var array An array of fees. */
	public $fees = array();

	/**
	 * Constructor for the cart class. Loads options and hooks in the init method.
	 *
	 * @access public
	 * @return void
	 */
	public function __construct() {
		$this->tax                   = new WC_Tax();
		$this->prices_include_tax    = get_option( 'woocommerce_prices_include_tax' ) == 'yes';
		$this->round_at_subtotal     = get_option('woocommerce_tax_round_at_subtotal') == 'yes';
		$this->tax_display_cart      = get_option( 'woocommerce_tax_display_cart' );
		$this->dp                    = absint( get_option( 'woocommerce_price_num_decimals' ) );
		$this->display_totals_ex_tax = $this->tax_display_cart == 'excl';
		$this->display_cart_ex_tax   = $this->tax_display_cart == 'excl';

		// Array of data the cart calculates and stores in the session with defaults
		$this->cart_session_data = array(
			'cart_contents_total'     => 0,
			'cart_contents_weight'    => 0,
			'cart_contents_count'     => 0,
			'cart_contents_tax'       => 0,
			'total'                   => 0,
			'subtotal'                => 0,
			'subtotal_ex_tax'         => 0,
			'tax_total'               => 0,
			'taxes'                   => array(),
			'shipping_taxes'          => array(),
			'discount_cart'           => 0,
			'discount_total'          => 0,
			'shipping_total'          => 0,
			'shipping_tax_total'      => 0,
			'coupon_discount_amounts' => array(),
		);

		add_action( 'init', array( $this, 'init' ), 5 ); // Get cart on init
		add_action( 'wp', array( $this, 'maybe_set_cart_cookies' ), 99 ); // Set cookies
		add_action( 'shutdown', array( $this, 'maybe_set_cart_cookies' ), 0 ); // Set cookies before shutdown and ob flushing
	}

    /**
	 * Loads the cart data from the PHP session during WordPress init and hooks in other methods.
     *
     * @access public
     * @return void
     */
    public 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 );
    }

    /**
     * Will set cart cookies if needed, once, during WP hook
     */
    public function maybe_set_cart_cookies() {
    	if ( ! headers_sent() ) {
	    	if ( sizeof( $this->cart_contents ) > 0 ) {
	    		$this->set_cart_cookies( true );
	    	} elseif ( isset( $_COOKIE['woocommerce_items_in_cart'] ) ) {
	    		$this->set_cart_cookies( false );
	    	}
	    }
    }

	/**
	 * Set cart hash cookie and items in cart.
	 *
	 * @access private
	 * @param bool $set (default: true)
	 * @return void
	 */
	private function set_cart_cookies( $set = true ) {
		if ( $set ) {
			wc_setcookie( 'woocommerce_items_in_cart', 1 );
			wc_setcookie( 'woocommerce_cart_hash', md5( json_encode( $this->get_cart() ) ) );
		} elseif ( isset( $_COOKIE['woocommerce_items_in_cart'] ) ) {
			wc_setcookie( 'woocommerce_items_in_cart', 0, time() - 3600 );
			wc_setcookie( 'woocommerce_cart_hash', '', time() - 3600 );
		}
		do_action( 'woocommerce_set_cart_cookies', $set );
	}

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

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

			// Load cart session data from session
			foreach ( $this->cart_session_data as $key => $default ) {
				$this->$key = WC()->session->get( $key, $default );
			}

			// Load coupons
			$this->applied_coupons = array_filter( WC()->session->get( 'applied_coupons', array() ) );

			// Load the cart
			$cart = WC()->session->get( 'cart', array() );

			$update_cart_session = false;

			if ( is_array( $cart ) ) {
				foreach ( $cart as $key => $values ) {
					$_product = wc_get_product( $values['variation_id'] ? $values['variation_id'] : $values['product_id'] );

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

						if ( ! $_product->is_purchasable() ) {

							// Flag to indicate the stored cart should be update
							$update_cart_session = true;
							wc_add_notice( sprintf( __( '%s has been removed from your cart because it can no longer be purchased. Please contact us if you need assistance.', 'woocommerce' ), $_product->get_title() ), 'error' );

						} else {

							// 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 ( $update_cart_session ) {
				WC()->session->cart = $this->get_cart_for_session();
			}

			// Trigger action
			do_action( 'woocommerce_cart_loaded_from_session', $this );

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

		/**
		 * Sets the php session data for the cart and coupons.
		 */
		public function set_session() {
			// Set cart and coupon session data
			$cart_session = $this->get_cart_for_session();

			WC()->session->set( 'cart', $cart_session );
			WC()->session->set( 'applied_coupons', $this->applied_coupons );
			WC()->session->set( 'coupon_discount_amounts', $this->coupon_discount_amounts );

			foreach ( $this->cart_session_data as $key => $default ) {
				WC()->session->set( $key, $this->$key );
			}

			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
		 */
		public function empty_cart( $clear_persistent_cart = true ) {
			$this->cart_contents = array();
			$this->reset();

			unset( WC()->session->order_awaiting_payment, WC()->session->applied_coupons, WC()->session->coupon_discount_amounts, WC()->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
		 */
		public function persistent_cart_update() {
			update_user_meta( get_current_user_id(), '_woocommerce_persistent_cart', array(
				'cart' => WC()->session->cart,
			) );
		}

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

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

		/**
		 * Coupons enabled function. Filterable.
		 *
		 * @access public
		 * @return bool
		 */
		public function coupons_enabled() {
			return apply_filters( 'woocommerce_coupons_enabled', get_option( 'woocommerce_enable_coupons' ) == 'yes' );
		}

		/**
		 * Get number of items in the cart.
		 *
		 * @access public
		 * @return int
		 */
		public 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
		 */
		public function check_cart_items() {
			$result = $this->check_cart_item_validity();

			if ( is_wp_error( $result ) ) {
				wc_add_notice( $result->get_error_message(), 'error' );
			}

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

			if ( is_wp_error( $result ) ) {
				wc_add_notice( $result->get_error_message(), 'error' );
			}
		}

		/**
		 * Check cart coupons for errors.
		 *
		 * @access public
		 * @return void
		 */
		public function check_cart_coupons() {
			foreach ( $this->applied_coupons as $code ) {
				$coupon = new WC_Coupon( $code );

				if ( ! $coupon->is_valid() ) {
					// Error message
					$coupon->add_coupon_message( WC_Coupon::E_WC_COUPON_INVALID_REMOVED );

					// Remove the coupon
					$this->remove_coupon( $code );

					// Flag totals for refresh
					WC()->session->set( 'refresh_totals', true );
				}
			}
		}

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

			foreach ( $this->get_cart() as $cart_item_key => $values ) {
				$_product = $values['data'];

				if ( $_product->is_type( 'variation' ) && true === $_product->managing_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 {
					$quantities[ $values['product_id'] ] = isset( $quantities[ $values['product_id'] ] ) ? $quantities[ $values['product_id'] ] + $values['quantity'] : $values['quantity'];
				}
			}

			return $quantities;
		}

		/**
		 * Looks through cart items and checks the posts are not trashed or deleted.
		 * @return bool|WP_Error
		 */
		public function check_cart_item_validity() {
			foreach ( $this->get_cart() as $cart_item_key => $values ) {

				$_product = $values['data'];

				if ( ! $_product || ! $_product->exists() || $_product->post->post_status == 'trash' ) {
					$this->set_quantity( $cart_item_key, 0 );

					return new WP_Error( 'invalid', __( 'An item which is no longer available was removed from your cart.', 'woocommerce' ) );
				}
			}

			return true;
		}

		/**
		 * Looks through the cart to check each item is in stock. If not, add an error.
		 *
		 * @access public
		 * @return bool|WP_Error
		 */
		public function check_cart_item_stock() {
			global $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'];
				$key      = '_product_id';
				$value    = $values['product_id'];
				$in_cart  = $values['quantity'];

				/**
				 * Check stock based on stock-status
				 */
				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;
				}

				if ( ! $_product->managing_stock() ) {
					continue;
				}

				$check_qty = $_product->is_type( 'variation' ) && true === $_product->managing_stock() ? $product_qty_in_cart[ $values['variation_id'] ] : $product_qty_in_cart[ $values['product_id'] ];

				/**
				 * Check stock based on all items in the cart
				 */
				if ( ! $_product->has_enough_stock( $check_qty ) ) {
					$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->get_stock_quantity() ) );
					return $error;
				}

				/**
				 * Finally consider any held stock, from pending orders
				 */
				if ( get_option( 'woocommerce_hold_stock_minutes' ) > 0 && ! $_product->backorders_allowed() ) {
					$order_id   = isset( WC()->session->order_awaiting_payment ) ? absint( WC()->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
							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            IN ( '" . implode( "','", wc_get_order_types() ) . "' )
							AND 	posts.post_status          = 'wc-pending'
							AND		posts.ID                   != %d;",
							$_product->is_type( 'variation' ) && true === $_product->managing_stock() ? '_variation_id' : '_product_id',
							$_product->is_type( 'variation' ) && true === $_product->managing_stock() ? $values['variation_id'] : $values['product_id'],
							$order_id
						)
					);

					$not_enough_stock = false;

					if ( $_product->is_type( 'variation' ) && 'parent' === $_product->managing_stock() && $_product->parent->get_stock_quantity() < ( $held_stock + $check_qty ) ) {
						$not_enough_stock = true;
					} elseif ( $_product->get_stock_quantity() < ( $held_stock + $check_qty ) ) {
						$not_enough_stock = true;
					}
					if ( $not_enough_stock ) {
						$error->add( 'out-of-stock', sprintf(__( 'Sorry, we do not have enough "%s" in stock to fulfill 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;
					}
				}
			}

			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
		 */
		public function get_item_data( $cart_item, $flat = false ) {
			$item_data = array();

			// 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;

					$taxonomy = wc_attribute_taxonomy_name( str_replace( 'attribute_pa_', '', urldecode( $name ) ) );

					// If this is a term slug, get the term's nice name
		            if ( taxonomy_exists( $taxonomy ) ) {
		            	$term = get_term_by( 'slug', $value, $taxonomy );
		            	if ( ! is_wp_error( $term ) && $term && $term->name ) {
		            		$value = $term->name;
		            	}
		            	$label = wc_attribute_label( $taxonomy );

		            // If this is a custom option slug, get the options name
		            } else {
						$value              = apply_filters( 'woocommerce_variation_option_name', $value );
						$product_attributes = $cart_item['data']->get_attributes();
						if ( isset( $product_attributes[ str_replace( 'attribute_', '', $name ) ] ) ) {
							$label = wc_attribute_label( $product_attributes[ str_replace( 'attribute_', '', $name ) ]['name'] );
						} else {
							$label = $name;
						}
					}

					$item_data[] = array(
						'key'   => $label,
						'value' => $value
					);
				}
			}

			// 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 ) {

				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'];

						$item_data[] = array(
							'key'   => $data['name'],
							'value' => $display_value
						);
					}
				}
			}

			// Output flat or in list format
			if ( sizeof( $item_data ) > 0 ) {

				ob_start();

				if ( $flat ) {
					foreach ( $item_data as $data ) {
						echo esc_html( $data['key'] ) . ': ' . wp_kses_post( $data['value'] ) . "\n";
					}
				} else {
					wc_get_template( 'cart/cart-item-data.php', array( 'item_data' => $item_data ) );
				}

				return ob_get_clean();
			}

			return '';
		}

		/**
		 * Gets cross sells based on the items in the cart.
		 *
		 * @return array cross_sells (item ids)
		 */
		public function get_cross_sells() {
			$cross_sells = array();
			$in_cart = array();
			if ( sizeof( $this->get_cart() ) > 0 ) {
				foreach ( $this->get_cart() 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
		 */
		public function get_cart_url() {
			$cart_page_id = wc_get_page_id( 'cart' );
			return apply_filters( 'woocommerce_get_cart_url', $cart_page_id ? get_permalink( $cart_page_id ) : '' );
		}

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

		/**
		 * Gets the url to remove an item from the cart.
		 *
		 * @param string	cart_item_key	contains the id of the cart item
		 * @return string url to page
		 */
		public function get_remove_url( $cart_item_key ) {
			$cart_page_id = wc_get_page_id('cart');
			return apply_filters( 'woocommerce_get_remove_url', $cart_page_id ? wp_nonce_url( add_query_arg( 'remove_item', $cart_item_key, get_permalink( $cart_page_id ) ), 'woocommerce-cart' ) : '' );
		}

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

		/**
		 * Returns the contents of the cart in an array without the 'data' element.
		 *
		 * @return array contents of the cart
		 */
		private function get_cart_for_session() {

			$cart_session = array();

			if ( $this->get_cart() ) {
				foreach ( $this->get_cart() as $key => $values ) {
					$cart_session[ $key ] = $values;
					unset( $cart_session[ $key ]['data'] ); // Unset product object
				}
			}

			return $cart_session;
		}

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

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

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

		/**
		 * Get taxes, merged by code, formatted ready for output.
		 *
		 * @access public
		 * @return array
		 */
		public function get_tax_totals() {
			$taxes      = $this->get_taxes();
			$tax_totals = array();

			foreach ( $taxes as $key => $tax ) {

				$code = $this->tax->get_rate_code( $key );

				if ( $code ) {
					if ( ! isset( $tax_totals[ $code ] ) ) {
						$tax_totals[ $code ] = new stdClass();
						$tax_totals[ $code ]->amount = 0;
					}

	                $tax_totals[ $code ]->tax_rate_id       = $key;
					$tax_totals[ $code ]->is_compound       = $this->tax->is_compound( $key );
					$tax_totals[ $code ]->label             = $this->tax->get_rate_label( $key );
					$tax_totals[ $code ]->amount           += wc_round_tax_total( $tax );
					$tax_totals[ $code ]->formatted_amount  = wc_price( wc_round_tax_total( $tax_totals[ $code ]->amount ) );
				}
			}

			return apply_filters( 'woocommerce_cart_tax_totals', $tax_totals, $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
	     */
	    public function find_product_in_cart( $cart_id = false ) {
	        if ( $cart_id !== false ) {
	        	if ( is_array( $this->cart_contents ) ) {
	        		foreach ( $this->cart_contents as $cart_item_key => $cart_item ) {
	        			if ( $cart_item_key == $cart_id ) {
	        				return $cart_item_key;
	        			}
	        		}
	        	}
	        }
			return '';
		}

		/**
	     * 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
	     */
	    public function generate_cart_id( $product_id, $variation_id = 0, $variation = array(), $cart_item_data = array() ) {
	        $id_parts = array( $product_id );

	        if ( $variation_id && 0 != $variation_id )
	        	$id_parts[] = $variation_id;

	        if ( is_array( $variation ) && ! empty( $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 string $cart_item_key
		 */
		public function add_to_cart( $product_id, $quantity = 1, $variation_id = '', $variation = '', $cart_item_data = array() ) {

			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 );

			// Ensure we don't add a variation to the cart directly by variation ID
			if ( 'product_variation' == get_post_type( $product_id ) ) {
				$variation_id = $product_id;
				$product_id   = wp_get_post_parent_id( $variation_id );
			}

			// Get the product
			$product_data   = wc_get_product( $variation_id ? $variation_id : $product_id );

			if ( ! $product_data )
				return false;

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

			// Check product is_purchasable
			if ( ! $product_data->is_purchasable() ) {
				wc_add_notice( __( 'Sorry, this product cannot be purchased.', 'woocommerce' ), 'error' );
				return false;
			}

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

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

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

				wc_add_notice( 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() ), 'error' );

				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 it's greater than 0, it's already in the cart
				if ( $in_cart_quantity > 0 ) {
					wc_add_notice( sprintf(
						'<a href="%s" class="button wc-forward">%s</a> %s',
						$this->get_cart_url(),
						__( 'View Cart', 'woocommerce' ),
						sprintf( __( 'You cannot add another &quot;%s&quot; to your cart.', 'woocommerce' ), $product_data->get_title() )
					), 'error' );
					return false;
				}
			}

			// Stock check - this time accounting for whats already in-cart
			if ( $managing_stock = $product_data->managing_stock() ) {
				$products_qty_in_cart = $this->get_cart_item_quantities();

				if ( $product_data->is_type( 'variation' ) && true === $managing_stock ) {
					$check_qty = isset( $products_qty_in_cart[ $variation_id ] ) ? $products_qty_in_cart[ $variation_id ] : 0;
				} else {
					$check_qty = isset( $products_qty_in_cart[ $product_id ] ) ? $products_qty_in_cart[ $product_id ] : 0;
				}

				/**
				 * Check stock based on all items in the cart
				 */
				if ( ! $product_data->has_enough_stock( $check_qty + $quantity ) ) {
					wc_add_notice( sprintf(
						'<a href="%s" class="button wc-forward">%s</a> %s',
						$this->get_cart_url(),
						__( 'View Cart', 'woocommerce' ),
						sprintf( __( 'You cannot add that amount to the cart &mdash; we have %s in stock and you already have %s in your cart.', 'woocommerce' ), $product_data->get_stock_quantity(), $check_qty )
					), 'error' );
					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, false );

			} 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 );

			}

			if ( did_action( 'wp' ) ) {
    			$this->set_cart_cookies( sizeof( $this->cart_contents ) > 0 );
    		}

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

			$this->calculate_totals();

			return $cart_item_key;
		}

		/**
		 * 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
		 * @param boolean 	$refresh_totals	whether or not to calculate totals after setting the new qty
		 */
		public function set_quantity( $cart_item_key, $quantity = 1, $refresh_totals = true ) {
			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 );
			}

			if ( $refresh_totals ) {
				$this->calculate_totals();
			}
		}

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

		/**
		 * Reset cart totals and clear sessions.
		 *
		 * @access private
		 * @return void
		 */
		private function reset() {
			foreach ( $this->cart_session_data as $key => $default ) {
				$this->$key = $default;
				unset( WC()->session->$key );
			}
		}

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

			$this->reset();

			do_action( 'woocommerce_before_calculate_totals', $this );

			if ( sizeof( $this->get_cart() ) == 0 ) {
				$this->set_session();
				return;
			}

			$tax_rates      = array();
			$shop_tax_rates = array();

			/**
			 * Calculate subtotals for items. This is done first so that discount logic can use the values.
			 */
			foreach ( $this->get_cart() as $cart_item_key => $values ) {

				$_product = $values['data'];

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

				// Prices
				$base_price = $_product->get_price();
				$line_price = $_product->get_price() * $values['quantity'];

				$line_subtotal = 0;
				$line_subtotal_tax = 0;

				/**
				 * No tax to calculate
				 */
				if ( ! $_product->is_taxable() ) {

					// Subtotal is the undiscounted price
					$this->subtotal += $line_price;
					$this->subtotal_ex_tax += $line_price;

				/**
				 * 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
				 */
				} elseif ( $this->prices_include_tax ) {

					// Get base tax rates
					if ( empty( $shop_tax_rates[ $_product->tax_class ] ) )
						$shop_tax_rates[ $_product->tax_class ] = $this->tax->get_shop_base_rate( $_product->tax_class );

					// Get item tax rates
					if ( empty( $tax_rates[ $_product->get_tax_class() ] ) )
						$tax_rates[ $_product->get_tax_class() ] = $this->tax->get_rates( $_product->get_tax_class() );

					$base_tax_rates = $shop_tax_rates[ $_product->tax_class ];
					$item_tax_rates = $tax_rates[ $_product->get_tax_class() ];

					/**
					 * ADJUST TAX - Calculations when base tax is not equal to the item tax
					 */
					if ( $item_tax_rates !== $base_tax_rates ) {

						// Work out a new base price without the shop's base tax
						$taxes                 = $this->tax->calc_tax( $line_price, $base_tax_rates, true, true );

						// Now we have a new item price (excluding TAX)
						$line_subtotal         = $line_price - array_sum( $taxes );

						// Now add modifed taxes
						$tax_result            = $this->tax->calc_tax( $line_subtotal, $item_tax_rates );
						$line_subtotal_tax     = array_sum( $tax_result );

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

						// Calc tax normally
						$taxes                 = $this->tax->calc_tax( $line_price, $item_tax_rates, true );
						$line_subtotal_tax     = array_sum( $taxes );
						$line_subtotal         = $line_price - array_sum( $taxes );
					}

				/**
				 * Prices exclude tax
				 *
				 * This calculation is simpler - work with the base, untaxed price.
				 */
				} else {

					// Get item tax rates
					if ( empty( $tax_rates[ $_product->get_tax_class() ] ) )
						$tax_rates[ $_product->get_tax_class() ] = $this->tax->get_rates( $_product->get_tax_class() );

					$item_tax_rates        = $tax_rates[ $_product->get_tax_class() ];

					// Base tax for line before discount - we will store this in the order data
					$taxes                 = $this->tax->calc_tax( $line_price, $item_tax_rates );
					$line_subtotal_tax     = array_sum( $taxes );
					$line_subtotal         = $line_price;
				}

				// Add to main subtotal
				$this->subtotal        += $line_subtotal + $line_subtotal_tax;
				$this->subtotal_ex_tax += $line_subtotal;
			}

			/**
			 * Calculate totals for items
			 */
			foreach ( $this->get_cart() as $cart_item_key => $values ) {

				$_product = $values['data'];

				// Prices
				$base_price = $_product->get_price();
				$line_price = $_product->get_price() * $values['quantity'];

				// Tax data
				$taxes = array();
				$discounted_taxes = array();

				/**
				 * No tax to calculate
				 */
				if ( ! $_product->is_taxable() ) {

					// 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         = $line_price;
					$line_tax              = 0;
					$line_total            = $this->tax->round( $discounted_price * $values['quantity'] );

				/**
				 * Prices include tax
				 */
				} elseif ( $this->prices_include_tax ) {

					$base_tax_rates = $shop_tax_rates[ $_product->tax_class ];
					$item_tax_rates = $tax_rates[ $_product->get_tax_class() ];

					/**
					 * ADJUST TAX - Calculations when base tax is not equal to the item tax
					 */
					if ( $item_tax_rates !== $base_tax_rates ) {

						// Work out a new base price without the shop's base tax
						$taxes             = $this->tax->calc_tax( $line_price, $base_tax_rates, true, true );

						// Now we have a new item price (excluding TAX)
						$line_subtotal     = round( $line_price - array_sum( $taxes ), WC_ROUNDING_PRECISION );

						// Now add modifed taxes
						$taxes             = $this->tax->calc_tax( $line_subtotal, $item_tax_rates );
						$line_subtotal_tax = array_sum( $taxes );

						// Adjusted price (this is the price including the new tax rate)
						$adjusted_price    = ( $line_subtotal + $line_subtotal_tax ) / $values['quantity'];

						// Apply discounts
						$discounted_price  = $this->get_discounted_price( $values, $adjusted_price, true );
						$discounted_taxes  = $this->tax->calc_tax( $discounted_price * $values['quantity'], $item_tax_rates, true );
						$line_tax          = array_sum( $discounted_taxes );
						$line_total        = ( $discounted_price * $values['quantity'] ) - $line_tax;

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

						// Work out a new base price without the shop's base tax
						$taxes             = $this->tax->calc_tax( $line_price, $item_tax_rates, true );

						// Now we have a new item price (excluding TAX)
						$line_subtotal     = $line_price - array_sum( $taxes );
						$line_subtotal_tax = array_sum( $taxes );

						// 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'], $item_tax_rates, true );
						$line_tax         = array_sum( $discounted_taxes );
						$line_total       = ( $discounted_price * $values['quantity'] ) - $line_tax;
					}

					// 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 );
					}

				/**
				 * Prices exclude tax
				 */
				} else {

					$item_tax_rates        = $tax_rates[ $_product->get_tax_class() ];

					// Work out a new base price without the shop's base tax
					$taxes                 = $this->tax->calc_tax( $line_price, $item_tax_rates );

					// Now we have the item price (excluding TAX)
					$line_subtotal         = $line_price;
					$line_subtotal_tax     = array_sum( $taxes );

					// Now calc product rates
					$discounted_price      = $this->get_discounted_price( $values, $base_price, true );
					$discounted_taxes      = $this->tax->calc_tax( $discounted_price * $values['quantity'], $item_tax_rates );
					$discounted_tax_amount = array_sum( $discounted_taxes );
					$line_tax              = $discounted_tax_amount;
					$line_total            = $discounted_price * $values['quantity'];

					// 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 );
					}
				}

				// 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 += $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;

				// Store rates ID and costs - Since 2.2
				$this->cart_contents[ $cart_item_key ]['line_tax_data']     = array( 'total' => $discounted_taxes, 'subtotal' => $taxes );
			}

			// Only calculate the grand total + shipping if on the cart/checkout
			if ( is_checkout() || is_cart() || defined('WOOCOMMERCE_CHECKOUT') || defined('WOOCOMMERCE_CART') ) {

				// Calculate the Shipping
				$this->calculate_shipping();

				// Trigger the fees API where developers can add fees to the cart
				$this->calculate_fees();

				// Total up/round taxes and shipping taxes
				if ( $this->round_at_subtotal ) {
					$this->tax_total          = $this->tax->get_tax_total( $this->taxes );
					$this->shipping_tax_total = $this->tax->get_tax_total( $this->shipping_taxes );
					$this->taxes              = array_map( array( $this->tax, 'round' ), $this->taxes );
					$this->shipping_taxes     = array_map( array( $this->tax, 'round' ), $this->shipping_taxes );
				} else {
					$this->tax_total          = array_sum( $this->taxes );
					$this->shipping_tax_total = array_sum( $this->shipping_taxes );
				}

				// VAT exemption done at this point - so all totals are correct before exemption
				if ( WC()->customer->is_vat_exempt() ) {
					$this->remove_taxes();
				}

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

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

				// Grand Total - Discounted product prices, discounted tax, shipping cost + tax, and any discounts to be added after tax (e.g. store credit)
				$this->total = max( 0, apply_filters( 'woocommerce_calculated_total', round( $this->cart_contents_total + $this->tax_total + $this->shipping_tax_total + $this->shipping_total - $this->discount_total + $this->fee_total, $this->dp ), $this ) );

			} else {

				// 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 ( WC()->customer->is_vat_exempt() ) {
					$this->remove_taxes();
				}

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

			$this->set_session();
		}

		/**
		 * remove_taxes function.
		 *
		 * @access public
		 * @return void
		 */
		public function remove_taxes() {
			$this->shipping_tax_total = $this->tax_total = 0;
			$this->subtotal           = $this->subtotal_ex_tax;

			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;
			}

			// If true, zero rate is applied so '0' tax is displayed on the frontend rather than nothing.
			if ( apply_filters( 'woocommerce_cart_remove_taxes_apply_zero_rate', true ) ) {
				$this->taxes = $this->shipping_taxes = array( apply_filters( 'woocommerce_cart_remove_taxes_zero_rate_id', 'zero-rated' ) => 0 );
			} else {
				$this->taxes = $this->shipping_taxes = array();
			}
		}

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

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

		/**
		 * Uses the shipping class to calculate shipping then gets the totals when its finished.
		 *
		 * @access public
		 * @return void
		 */
		public function calculate_shipping() {
			if ( $this->needs_shipping() && $this->show_shipping() ) {
				WC()->shipping->calculate_shipping( $this->get_shipping_packages() );
			} else {
				WC()->shipping->reset_shipping();
			}

			// Get totals for the chosen shipping method
			$this->shipping_total 		= WC()->shipping->shipping_total;	// Shipping Total
			$this->shipping_taxes		= WC()->shipping->shipping_taxes;	// Shipping Taxes
		}

		/**
		 * Get packages to calculate shipping for.
		 *
		 * This lets us calculate costs for carts that are shipped to multiple locations.
		 *
		 * Shipping methods are responsible 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
		 */
		public function get_shipping_packages() {
			// 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;
			$packages[0]['user']['ID']               = get_current_user_id();
			$packages[0]['destination']['country']   = WC()->customer->get_shipping_country();
			$packages[0]['destination']['state']     = WC()->customer->get_shipping_state();
			$packages[0]['destination']['postcode']  = WC()->customer->get_shipping_postcode();
			$packages[0]['destination']['city']      = WC()->customer->get_shipping_city();
			$packages[0]['destination']['address']   = WC()->customer->get_shipping_address();
			$packages[0]['destination']['address_2'] = WC()->customer->get_shipping_address_2();

			foreach ( $this->get_cart() as $item )
				if ( $item['data']->needs_shipping() )
					if ( isset( $item['line_total'] ) )
						$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
		 */
		public function needs_shipping() {
			if ( get_option('woocommerce_calc_shipping') == 'no' )
				return false;

			$needs_shipping = false;

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

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

		/**
		 * Should the shipping address form be shown
		 *
		 * @return bool
		 */
		function needs_shipping_address() {

			$needs_shipping_address = false;

			if ( $this->needs_shipping() === true && ! $this->ship_to_billing_address_only() ) {
				$needs_shipping_address = true;
			}

			return apply_filters( 'woocommerce_cart_needs_shipping_address', $needs_shipping_address );
		}

		/**
		 * Sees if the customer has entered enough data to calc the shipping yet.
		 *
		 * @return bool
		 */
		public function show_shipping() {
			if ( get_option('woocommerce_calc_shipping') == 'no' || ! is_array( $this->cart_contents ) )
				return false;

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

			$show_shipping = true;

			return apply_filters( 'woocommerce_cart_ready_to_calc_shipping', $show_shipping );

		}

		/**
		 * Sees if we need a shipping address.
		 *
		 * @return bool
		 */
		public function ship_to_billing_address_only() {
			return wc_ship_to_billing_address_only();
		}

		/**
		 * Gets the shipping total (after calculation).
		 *
		 * @return string price or string for the shipping total
		 */
		public function get_cart_shipping_total() {
			if ( isset( $this->shipping_total ) ) {
				if ( $this->shipping_total > 0 ) {

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

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

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

						return $return;

					} else {

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

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

						return $return;

					}

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

			return '';
		}

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

		/**
		 * Check for user coupons (now that we have billing email). If a coupon is invalid, add an error.
		 *
		 * Checks two types of coupons:
		 *  1. Where a list of customer emails are set (limits coupon usage to those defined)
		 *  2. Where a usage_limit_per_user is set (limits coupon usage to a number based on user ID and email)
		 *
		 * @access public
		 * @param array $posted
		 */
		public function check_customer_coupons( $posted ) {
			if ( ! empty( $this->applied_coupons ) ) {
				foreach ( $this->applied_coupons as $code ) {
					$coupon = new WC_Coupon( $code );

					if ( $coupon->is_valid() ) {

						// Limit to defined email addresses
						if ( is_array( $coupon->customer_email ) && sizeof( $coupon->customer_email ) > 0 ) {
							$check_emails           = array();
							$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 ) ) ) {
								$coupon->add_coupon_message( WC_Coupon::E_WC_COUPON_NOT_YOURS_REMOVED );

								// Remove the coupon
								$this->remove_coupon( $code );

								// Flag totals for refresh
								WC()->session->set( 'refresh_totals', true );
							}
						}

						// Usage limits per user - check against billing and user email and user ID
						if ( $coupon->usage_limit_per_user > 0 ) {
							$check_emails = array();
							$used_by      = array_filter( (array) get_post_meta( $coupon->id, '_used_by' ) );

							if ( is_user_logged_in() ) {
								$current_user   = wp_get_current_user();
								$check_emails[] = sanitize_email( $current_user->user_email );
								$usage_count    = sizeof( array_keys( $used_by, get_current_user_id() ) );
							} else {
								$check_emails[] = sanitize_email( $posted['billing_email'] );
								$user           = get_user_by( 'email', $posted['billing_email'] );
								if ( $user ) {
									$usage_count = sizeof( array_keys( $used_by, $user->ID ) );
								} else {
									$usage_count = 0;
								}
							}

							foreach ( $check_emails as $check_email ) {
								$usage_count = $usage_count + sizeof( array_keys( $used_by, $check_email ) );
							}

							if ( $usage_count >= $coupon->usage_limit_per_user ) {
								$coupon->add_coupon_message( WC_Coupon::E_WC_COUPON_USAGE_LIMIT_REACHED );

								// Remove the coupon
								$this->remove_coupon( $code );

								// Flag totals for refresh
								WC()->session->set( 'refresh_totals', true );
							}
						}
					}
				}
			}
		}

		/**
		 * Returns whether or not a discount has been applied.
		 *
		 * @return bool
		 */
		public function has_discount( $coupon_code ) {
			return in_array( apply_filters( 'woocommerce_coupon_code', $coupon_code ), $this->applied_coupons );
		}

		/**
		 * 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
		 */
		public function add_discount( $coupon_code ) {
			// Coupons are globally disabled
			if ( ! $this->coupons_enabled() )
				return false;

			// Sanitize coupon code
			$coupon_code = apply_filters( 'woocommerce_coupon_code', $coupon_code );

			// Get the coupon
			$the_coupon = new WC_Coupon( $coupon_code );

			if ( $the_coupon->id ) {

				// Check it can be used with cart
				if ( ! $the_coupon->is_valid() ) {
					wc_add_notice( $the_coupon->get_error_message(), 'error' );
					return false;
				}

				// Check if applied
				if ( $this->has_discount( $coupon_code ) ) {
					$the_coupon->add_coupon_message( WC_Coupon::E_WC_COUPON_ALREADY_APPLIED );
					return false;
				}

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

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

						if ( $coupon->individual_use == 'yes' && false === apply_filters( 'woocommerce_apply_with_individual_use_coupon', false, $the_coupon, $coupon, $this->applied_coupons ) ) {

							// Reject new coupon
							$coupon->add_coupon_message( WC_Coupon::E_WC_COUPON_ALREADY_APPLIED_INDIV_USE_ONLY );

							return false;
						}
					}
				}

				$this->applied_coupons[] = $coupon_code;

				// Choose free shipping
				if ( $the_coupon->enable_free_shipping() ) {
					$packages = WC()->shipping->get_packages();
					$chosen_shipping_methods = WC()->session->get( 'chosen_shipping_methods' );

					foreach ( $packages as $i => $package ) {
						$chosen_shipping_methods[ $i ] = 'free_shipping';
					}

					WC()->session->set( 'chosen_shipping_methods', $chosen_shipping_methods );
				}

				$this->calculate_totals();

				$the_coupon->add_coupon_message( WC_Coupon::WC_COUPON_SUCCESS );

				do_action( 'woocommerce_applied_coupon', $coupon_code );

				return true;

			} else {
				$the_coupon->add_coupon_message( WC_Coupon::E_WC_COUPON_NOT_EXIST );
				return false;
			}
			return false;
		}

		/**
		 * Get array of applied coupon objects and codes.
		 * @param  string Type of coupons to get. Can be 'cart' or 'order' which are before and after tax respectively.
		 * @return array of applied coupons
		 */
		public function get_coupons( $type = null ) {
			$coupons = array();

			if ( 'cart' == $type || is_null( $type ) ) {
				if ( $this->applied_coupons ) {
					foreach ( $this->applied_coupons as $code ) {
						$coupon = new WC_Coupon( $code );

						if ( $coupon->apply_before_tax() )
							$coupons[ $code ] = $coupon;
					}
				}
			}

			if ( 'order' == $type || is_null( $type ) ) {
				if ( $this->applied_coupons ) {
					foreach ( $this->applied_coupons as $code ) {
						$coupon = new WC_Coupon( $code );

						if ( ! $coupon->apply_before_tax() )
							$coupons[ $code ] = $coupon;
					}
				}
			}

			return $coupons;
		}

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

		/**
		 * Get the discount amount for a used coupon
		 * @param  string $code coupon code
		 * @return float discount amount
		 */
		public function get_coupon_discount_amount( $code ) {
			return isset( $this->coupon_discount_amounts[ $code ] ) ? $this->coupon_discount_amounts[ $code ] : 0;
		}

		/**
		 * Remove coupons from the cart of a defined type. Type 1 is before tax, type 2 is after tax.
		 *
		 * @params string type - cart for before tax, order for after tax
		 */
		public function remove_coupons( $type = null ) {

			if ( 'cart' == $type || 1 == $type ) {
				if ( $this->applied_coupons ) {
					foreach ( $this->applied_coupons as $code ) {
						$coupon = new WC_Coupon( $code );

						if ( $coupon->apply_before_tax() )
							$this->remove_coupon( $code );
					}
				}
			} elseif ( 'order' == $type || 2 == $type ) {
				if ( $this->applied_coupons ) {
					foreach ( $this->applied_coupons as $code ) {
						$coupon = new WC_Coupon( $code );

						if ( ! $coupon->apply_before_tax() )
							$this->remove_coupon( $code );
					}
				}
			} else {
				$this->applied_coupons = $this->coupon_discount_amounts = $this->coupon_applied_count = array();
				WC()->session->set( 'applied_coupons', array() );
				WC()->session->set( 'coupon_discount_amounts', array() );
			}
		}

		/**
		 * Remove a single coupon by code
		 * @param  string $coupon_code Code of the coupon to remove
		 * @return bool
		 */
		public function remove_coupon( $coupon_code ) {
			// Coupons are globally disabled
			if ( ! $this->coupons_enabled() )
				return false;

			// Get the coupon
			$coupon_code  = apply_filters( 'woocommerce_coupon_code', $coupon_code );
			$position     = array_search( $coupon_code, $this->applied_coupons );

			if ( $position !== false )
				unset( $this->applied_coupons[ $position ] );

			WC()->session->set( 'applied_coupons', $this->applied_coupons );

			return true;
		}

		/**
		 * 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
		 */
		public 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() ) {
						if ( $coupon->is_valid_for_product( $values['data'] ) || $coupon->is_valid_for_cart() ) {

							$discount_amount       = $coupon->get_discount_amount( $price, $values, $single = true );
							$price                 = max( $price - $discount_amount, 0 );

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

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

		/**
		 * Function to apply cart discounts after tax.
		 *
		 * @access public
		 */
		public function apply_cart_discounts_after_tax() {
			$pre_discount_total = round( $this->cart_contents_total + $this->tax_total + $this->shipping_tax_total + $this->shipping_total + $this->fee_total, $this->dp );

			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->is_valid() && ! $coupon->apply_before_tax() && $coupon->is_valid_for_cart() ) {
						$discount_amount       = $coupon->get_discount_amount( $pre_discount_total );
						$pre_discount_total    = $pre_discount_total - $discount_amount;
						$this->discount_total += $discount_amount;
						$this->increase_coupon_discount_amount( $code, $discount_amount );
						$this->increase_coupon_applied_count( $code );
					}
				}
			}
		}

		/**
		 * Function to apply product discounts after tax.
		 *
		 * @access public
		 * @param mixed $values
		 * @param mixed $price
		 */
		public 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->is_valid() && ! $coupon->apply_before_tax() && $coupon->is_valid_for_product( $values['data'] ) ) {
						$discount_amount       = $coupon->get_discount_amount( $price, $values );
						$this->discount_total += $discount_amount;
						$this->increase_coupon_discount_amount( $code, $discount_amount );
						$this->increase_coupon_applied_count( $code, $values['quantity'] );
					}
				}
			}
		}

		/**
		 * Store how much discount each coupon grants.
		 *
		 * @access private
		 * @param mixed $code
		 * @param mixed $amount
		 */
		private function increase_coupon_discount_amount( $code, $amount ) {
			if ( empty( $this->coupon_discount_amounts[ $code ] ) )
				$this->coupon_discount_amounts[ $code ] = 0;

			$this->coupon_discount_amounts[ $code ] += $amount;
		}

		/**
		 * Store how many times each coupon is applied to cart/items
		 *
		 * @access private
		 * @param mixed $code
		 * @param mixed $amount
		 */
		private function increase_coupon_applied_count( $code, $count = 1 ) {
			if ( empty( $this->coupon_applied_count[ $code ] ) )
				$this->coupon_applied_count[ $code ] = 0;

			$this->coupon_applied_count[ $code ] += $count;
		}

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

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

			$new_fee_id = sanitize_title( $name );

			// Only add each fee once
			foreach ( $this->fees as $fee ) {
				if ( $fee->id == $new_fee_id ) {
					return;
				}
			}

			$new_fee            = new stdClass();
			$new_fee->id        = $new_fee_id;
			$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;
			$new_fee->tax_data  = array();
			$this->fees[]       = $new_fee;
		}

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

		/**
		 * Calculate fees
		 */
		public function calculate_fees() {

			// Fire an action where developers can add their fees
			do_action( 'woocommerce_cart_calculate_fees', $this );

			// If fees were added, total them and calculate tax
			if ( ! empty( $this->fees ) ) {
				foreach ( $this->fees as $fee_key => $fee ) {
					$this->fee_total += $fee->amount;

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

						if ( ! empty( $fee_taxes ) ) {
							// Set the tax total for this fee
							$this->fees[ $fee_key ]->tax = array_sum( $fee_taxes );

							// Set tax data - Since 2.2
							$this->fees[ $fee_key ]->tax_data = $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 );
							}
						}
					}
				}
			}
		}

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

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

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

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

		/**
		 * Gets the total excluding taxes.
		 *
		 * @return string formatted price
		 */
		public 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', wc_price( $total ) );
		}

		/**
		 * Gets the cart contents total (after calculation).
		 *
		 * @return string formatted price
		 */
		public function get_cart_total() {
			if ( ! $this->prices_include_tax ) {
				$cart_contents_total = wc_price( $this->cart_contents_total );
			} else {
				$cart_contents_total = wc_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
		 */
		public function get_cart_subtotal( $compound = false ) {

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

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

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

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

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

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

				} else {

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

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

				}
			}

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

		/**
		 * Get the product row price per item.
		 *
		 * @param WC_Product $_product
		 * @return string formatted price
		 */
		public function get_product_price( $_product ) {
			if ( $this->tax_display_cart == 'excl' )
				$product_price = $_product->get_price_excluding_tax();
			else
				$product_price = $_product->get_price_including_tax();

			return apply_filters( 'woocommerce_cart_product_price', wc_price( $product_price ), $_product );
		}

		/**
		 * 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
		 *
		 * @param WC_Product $_product
		 * @param int quantity
		 * @return string formatted price
		 */
		public function get_product_subtotal( $_product, $quantity ) {

			$price 			= $_product->get_price();
			$taxable 		= $_product->is_taxable();

			// Taxable
			if ( $taxable ) {

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

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

					if ( $this->prices_include_tax && $this->tax_total > 0 ) {
						$product_subtotal .= ' <small class="tax_label">' . WC()->countries->ex_tax_or_vat() . '</small>';
					}

				} else {

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

					if ( ! $this->prices_include_tax && $this->tax_total > 0 ) {
						$product_subtotal .= ' <small class="tax_label">' . WC()->countries->inc_tax_or_vat() . '</small>';
					}

				}

			// Non-taxable
			} else {

				$row_price        = $price * $quantity;
				$product_subtotal = wc_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
		 */
		public function get_cart_tax() {
			$cart_total_tax = wc_round_tax_total( $this->tax_total + $this->shipping_tax_total );

			return apply_filters( 'woocommerce_get_cart_tax', $cart_total_tax ? wc_price( $cart_total_tax ) : '' );
		}

		/**
		 * Get a tax amount
		 * @param  string $tax_rate_id
		 * @return float amount
		 */
		public function get_tax_amount( $tax_rate_id ) {
			return isset( $this->taxes[ $tax_rate_id ] ) ? $this->taxes[ $tax_rate_id ] : 0;
		}

		/**
		 * Get a tax amount
		 * @param  string $tax_rate_id
		 * @return float amount
		 */
		public function get_shipping_tax_amount( $tax_rate_id ) {
			return isset( $this->shipping_taxes[ $tax_rate_id ] ) ? $this->shipping_taxes[ $tax_rate_id ] : 0;
		}

		/**
		 * Get tax row amounts with or without compound taxes includes.
		 *
		 * @param  boolean $compound True if getting compound taxes
		 * @param  boolean $display  True if getting total to display
		 * @return float price
		 */
		public function get_taxes_total( $compound = true, $display = 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;
			}
			if ( $display ) {
				$total = wc_round_tax_total( $total );
			}
			return apply_filters( 'woocommerce_cart_taxes_total', $total, $compound, $display, $this );
		}

		/**
		 * Gets the total (product) discount amount - these are applied before tax.
		 *
		 * @return mixed formatted price or false if there are none
		 */
		public function get_discounts_before_tax() {
			if ( $this->discount_cart ) {
				$discounts_before_tax = wc_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
		 */
		public function get_discounts_after_tax() {
			if ( $this->discount_total ) {
				$discounts_after_tax = wc_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
		 */
		public function get_total_discount() {
			if ( $this->discount_total || $this->discount_cart ) {
				$total_discount = wc_price( $this->discount_total + $this->discount_cart );
			} else {
				$total_discount = false;
			}
			return apply_filters( 'woocommerce_cart_total_discount', $total_discount, $this );
		}
}