<?php session_start();
//Define the products and cost
$products = array("product A", "product B", "product C");
$amounts = array("19.99", "10.99", "2.99");
//initialise sessions
if ( !isset($_SESSION["total"]) ) {
    $_SESSION["total"] = 0;
    for ($i=0; $i< count($products); $i++) {
        $_SESSION["qty"][$i] = 0;
        $_SESSION["amounts"][$i] = 0;
    }
}
//Reset
if ( isset($_GET['reset']) ) {
    if ($_GET["reset"] == 'true') {
        unset($_SESSION["qty"]);		//The quantity for each product
        unset($_SESSION["amounts"]);	//The amount from each product
        unset($_SESSION["total"]);		//The total cost
        unset($_SESSION["cart"]);		//Which item has been chosen
    }
}
//Add
if ( isset($_GET["add"]) ) {
    $i = $_GET["add"];
    $qty = $_SESSION["qty"][$i] + 1;
    $_SESSION["amounts"][$i] = $amounts[$i] * $qty;
    $_SESSION["cart"][$i] = $i;
    $_SESSION["qty"][$i] = $qty;
}
//Delete
if ( isset($_GET["delete"]) ) {
    $i = $_GET["delete"];
    $qty = $_SESSION["qty"][$i];
    $qty--;
    $_SESSION["qty"][$i] = $qty;
    //remove item if quantity is zero
    if ($qty == 0) {
        $_SESSION["amounts"][$i] = 0;
        unset($_SESSION["cart"][$i]);
    }
    else 
        $_SESSION["amounts"][$i] = $amounts[$i] * $qty;
}
?>
<h2>List of All Products</h2>
<table>
<tr>
	<th>Product</th>
	<th width="10px">&nbsp;</th>
	<th>Amount</th>
	<th width="10px">&nbsp;</th>
	<th>Action</th>         
</tr>
<?php
	for ($i=0; $i< count($products); $i++) {
		?>
		<tr>
			<td><?php echo($products[$i]); ?></td>
			<td width="10px">&nbsp;</td>
			<td><?php echo($amounts[$i]); ?></td>
			<td width="10px">&nbsp;</td>
			<td><a href="?add=<?php echo($i); ?>">Add to cart</a></td>	       
		</tr>
		<?php
	}
?>
<tr>
	<td colspan="5"></td>
</tr>   
<tr>
	<td colspan="5"><a href="?reset=true">Reset Cart</a></td>
</tr>    
</table>
<?php
if ( isset($_SESSION["cart"]) ) {
?>
<br/><br/><br/>
<h2>Cart</h2>
<table>    
	<tr>
	<th>Product</th>
	<th width="10px">&nbsp;</th>
	<th>Qty</th>
	<th width="10px">&nbsp;</th>
	<th>Amount</th>        
	<th width="10px">&nbsp;</th>
	<th>Action</th>         
</tr>
<?php
	$total = 0;
	foreach ( $_SESSION["cart"] as $i ) {
		?>
		<tr>
			<td><?php echo( $products[$_SESSION["cart"][$i]] ); ?></td>
			<td width="10px">&nbsp;</td>
			<td><?php echo( $_SESSION["qty"][$i] ); ?></td>
			<td width="10px">&nbsp;</td>
			<td><?php echo( $_SESSION["amounts"][$i] ); ?></td>
			<td width="10px">&nbsp;</td>
			<td><a href="?delete=<?php echo($i); ?>">Delete from cart</a></td>
		</tr>
		<?php
		$total = $total + $_SESSION["amounts"][$i];
	}
	$_SESSION["total"] = $total;
?>		
<tr>
	<td colspan="7">Total : <?php echo($total); ?></td>
</tr>    
</table>
<?php
}
?>