Viên ngọc phương Đông

<?PHP
/**
 * shopping cart object
 * may contain product objects
 */
class cart {

/**
	 * @var string $reference order reference
	 * @var float $cart_total values of goods in the cart
	 * @var int $num_items quantity of goods in the cart
	 * @var int $num_products number of distinct products in the cart
	 * @var array $products container for product objects
	 * @var array $customer contains customer details from checkout as array items or as an object 
	 * @var float $transaction_fee extra cost on order for transaction charges eg credit card, paypal, paymex
	 * @var int $ship_id db id of shipping category
	 * @var string $shipping_location text of shipping category
	 * @var float $shipping_cost
	 * @var string $discount_code
	 * @var string $discount_type
	 * @var string $discount_var
	 * @var float $discount_amount
	 * @var string $description
	 * @var bool $paid paid status
	 */
	var $reference
	, $cart_total
	, $num_items
	, $num_products
	, $products
	, $transaction_fee
	, $ship_id
	, $shipping_location
	, $shipping_cost
	, $discount_code
	, $discount_type
	, $discount_var
	, $discount_amount
	, $description
	, $paid
	;
	
	var $customer = array();
	
	/**
	 * object construction function
	 */
	function __construct()
	{
		$this->empty_cart();
		return;
	}
	
	/**
	 * generate the in-cart unique reference for a product
	 * this won't necessarily give the highest $i, if a product in the series has been deleted it will just give the first empty space 
	 * which is fine unless there is a need for the items to be ordered by when added
	 * @param $prod_id product id
	 * @return string
	 */
	function generate_product_reference($prod_id)
	{
		$i=0; //start at 0 because we're effectively shrinking a nested array
		while(isset($this->products["$prod_id:$i"]))
		{
			$i++;
		}
		
		return "$prod_id:$i";
	}
	
	/**
	 * split product id out of cart item reference
	 * @param string $ref starting with $prod_id
	 * @return int
	 */
	function split_reference($reference)
	{
		$parts = explode(':',$reference);
		return $parts[0];
	}
	
	/**
	 * modify cart contents
	 * @param string $reference unique reference to item in cart or product id of item not yet in cart
	 * @param int $qty quantity
	 * @param array $selected
	 * @param int $cat_id
	 * @return bool
	 */
	function product($reference,$qty=0,$selected=array(),$cat_id=0)
	{	
		/**
		 * get product ID from reference (may be entire string)
		 * @var int $prod_id product id
		 */
		$prod_id = $this->split_reference($reference);
		
		if($this->products["$reference"])
		{
			
			/**
			 * alter quantity of product in cart
			 * @var object $p short reference to manipulate cart item directly
			 * @todo options comparison
			 * @var int $instance position in the individual product quantiy and options arrays 
			 */
			
			$p = &$this->products["$reference"]; //alias to short reference
			
			$diff = $qty - $p->quantity;
			$p->quantity += $diff;
			
			if($p->quantity<=0)
			{
				/*
				 * remove product from cart
				 */
				$diff -= $p->quantity; //this makes sure we don't remove more items fron the cart than had been added by adding back any difference below 0
				unset($this->products["$reference"]); //can't just use $p here
				$this->num_products--;
			}
			elseif(!empty($selected))
			{
				/*
				 * update selected options
				 */
				 $p->selected = $options;
			}
			
			$this->cart_total += $p->price * $diff;
			$this->num_items += $diff;
		}
		elseif($qty>0) //can't add a nil quantity of a new product
		{
			/**
			 * add a new product to the cart
			 * prod_id is the naked $reference
			 * @uses object $customer
			 * @var object $p product object
			 */
			global $customer;
			$p = new product($reference);
			
			if(!$p->active){ return false; } //can't add products which are not active in the store (or don't exist)
			//else
			$p->quantity = $qty;
			$p->selected = $selected;
			$p->set_category($cat_id);
			
			if($customer->wholesale)
			{
				$p->price = $p->wholesale; 
			}
			
			if($customer->discount)
			{
				$p->price -= $p->set_discount('%',$customer->discount); 
			}
			
			/*
			 * get unique in-cart reference and store item
			 */
			$reference = $this->generate_product_reference($reference);
			
			$this->products["$reference"] = $p;
			$this->cart_total += $p->price * $qty;
			$this->num_items += $qty;
			$this->num_products++;
		}
		
		return true;
	}
	
	/**
	 * see if a product is in the cart and return reference
	 * @param string $prod_id
	 * @return array
	 */
	function contains_product($prod_id)
	{
		$instances = array();
		$references = array_keys($this->products);
		foreach($this->products as $ref => $p)
		{
			if($this->split_reference($ref)==$prod_id)
			{
				$instances[$ref] = $p;
			}
		}
		
		return $instances;
	}
	
	/**
	 * regenerate cart with latest price information
	 * @todo check for valid option sets
	 */
	function update_prices(){
		/**
		 * copy $this->products into local scope, empty cart, re-add each product with qty and options
		 * might be more efficient by some metric to iterate through $this->products and just pull out prod_id and qty.
		 * @var array $copy_products 
		 */
		$copy_products = $this->products;

$this->cart_total
		= $this->num_items 
		= $this->num_products 
		= 0;
		
		$this->products = array();
		
		foreach($copy_products as $reference => $p)
		{
			$prod_id = $this->split_reference($reference);
			$this->product($p->prod_id,$p->quantity,$p->options,$p->cat_id);
		}
		
		return;
	}
	
	/**
	 * merge another cart with this one
	 * @param object $cart incoming cart
	 * @param bool $duplicates allow exact duplicates (not implemented)
	 * @todo duplicate checking and combining
	 */
	function merge($cart, $duplicates=true){
		
		foreach($cart->products as $reference => $p)
		{
			$this->product($p->prod_id,$p->quantity,$p->options,$p->cat_id);
		}
		
		return;
	}
	
	/**
	 * get shipping details from database based on ship_id
	 */
	function set_shipping()
	{
		if(!$this->ship_id)
		{
			$this->shipping_location = '';
			$this->shipping_cost = 0;
		}
		else
		{	
			$shipping = mysql_query("select * from shipping where ship_id ='".$this->ship_id ."'");
			if(!$shipping || mysql_num_rows($shipping)<1)
			{
				$this->shipping_location = ''.myslq_error();
				$this->shipping_cost = 0+$this->ship_id;
			}
			else
			{
				$s = mysql_fetch_assoc($shipping);
				$this->shipping_location = $s['location'];
				$this->shipping_cost = $s['shipping_cost'];
			} 
		}
		return;
	}
	
	/**
	 * calculate discount based on supplied %
	 * @param string $discount_type (ie '%', '$')
	 * @param float $discount (% or $ eg 12.5, 15, 25.50)
	 * @param string $discount_code
	 * @return float
	 */
	function set_discount($discount_type='%',$discount=0,$discount_code='')
	{
		$this->discount_code = $discount_code;
		$this->discount_type = $discount_type;
		$this->discount_var = $discount;
		switch($discount_type) //whitelist
		{
			case '$':
				$this->discount_amount = min($discount,$this->cart_total); //don't allow -ve values, excludes shipping
				break;
			case '%':
				$this->discount_amount = round(($this->cart_total/100)*$discount,2); //($this->cart_total/100)*$percent == $this->cart_total*($percent/100) but reduces the chance of floating point and rounding error
				break;
			default: //invalid value
				$this->discount_amount = 0;
				$this->discount_type = '';
				$this->discount_var = 0;
		}
		return $this->discount_amount;
	}
	
	/**
	 * format discount for display
	 * @return string
	 */
	function discount_format()
	{
		switch($this->discount_type)
		{
			case '$':
				return format_price($this->discount_var,2);
			case '%':
				return $this->discount_var.'%';
			default:
				return '';
		}
	}
	
	/**
	 * return order total - always calculate this so we don;t have to worry about updating it every time
	 * we change one of the components
	 */
	function order_total()
	{
		return $this->cart_total - $this->discount_amount + $this->shipping_cost + $this->transaction_fee;
	}
	
	function empty_cart()
	{
		$this->products = array(); 
		$this->customer = array();
		$this->reference = $this->discount_code = $this->description = '';
		// $this->shipping_location = '';
		
		$this->cart_total 
		// = $this->ship_id 
		= $this->shipping_cost
		= $this->discount_amount 
		= $this->transaction_fee
		= $this->num_items 
		= $this->num_products 
		= $this->paid
		= 0;
		
		return;
	}
	
	/**
	 * recreate 
	 * @param int $order_id
	 */
	function recreate_from_order($order_id)
	{
		$order = mysql_query("select * from orders where order_id = '$order_id'");
		if(!$order || mysql_num_rows($order)<1)
		{
			//die(mysql_error()); //debugging
			return;
		}
		//else
		$products = mysql_query("select * from order_products where order_id = '$order_id'");
		$temp = mysql_query("select * from order_temp where order_id = '$order_id'");
		
		$o = mysql_fetch_assoc($order);
		$this->reference = $o['order_ref'];
		$this->description = $o['order_description'];
		$this->ship_id = select_one('shipping','ship_id','location',$o['shipping_location']);
		$this->shipping_location = $o['shipping_location'];
		$this->shipping_cost = $o['shipping_cost'];
		$this->discount_code = $o['discount_code'];
		$this->discount_amount = $o['discount_amount'];
		$this->paid = $o['paid'];
		
		$o['customer_name'] = html_entity_decode($o['customer_name'],ENT_QUOTES);
		$names = explode(' ',$o['customer_name'],2);
		$this->customer['name'] = $o['customer_name'];
		$this->customer['first_name'] = $names[0];
		$this->customer['last_name'] = $names[1];
		$this->customer['phone'] = html_entity_decode($o['customer_phone'],ENT_QUOTES);
		$this->customer['email'] = $o['customer_email'];
		$this->customer['delivery_address'] = html_entity_decode($o['delivery_address'],ENT_QUOTES);
		$this->customer['delivery_instructions'] = html_entity_decode($o['delivery_instructions'],ENT_QUOTES);
		$this->customer['payment_method'] = $o['payment_method'];
		$this->transaction_fee = $o['transaction_fee'];
		
		if($temp && mysql_num_rows($temp)>0)
		{
			$t = mysql_fetch_assoc($temp);
			$this->customer['json'] = html_entity_decode($t['json'],ENT_QUOTES);
			$this->customer['email_text'] = html_entity_decode($t['email_text'],ENT_QUOTES);
		}
		
		if($products && mysql_num_rows($products)>0)
		{
			$i = 0;
			while($pr = mysql_fetch_assoc($products))
			{
				$p = new product;
				$p->prod_id = $prod_id = $this->split_reference($pr['product_id']);
				$p->name = $pr['product_name'];
				$p->price = $price = $pr['price'];
				$p->quantity = $qty = $pr['quantity'];
				$p->qDesc = $pr['quantity_description'];
				$p->selected = json_decode($pr['options']);
				$p->set_category($pr['category_id'],true);
				
				/*
				 * get unique in-cart reference and store item
				 */
				$reference = $this->generate_product_reference($prod_id);
				
				$this->products["$reference"] = $p;
				$this->cart_total += $price * $qty;
				$this->num_items += $qty;
				$this->num_products++;
			}
		}
		
		return;
	}
}
?>