How to get order information on the checkout complete page?
I've managed to complete this task.
First, you must get the order id from session or database using query.
Second, you must create an $order object like this

$order = commerce_order_load($orderId);


Define a new order sdtClass

$myOrder = new stdClass();


Wrap the order

$orderWrapper = entity_metadata_wrapper('commerce_order', $order);


And then you can get various order info like this:

// Get order number
$orderNumber = $order-&gt;order_number;

// Get user's e-mail address and encode properly encode it
$orderMail = drupal_json_encode($user-&gt;mail);

// Prepare an array to store products
$orderPurchasedItems = array();
// Create a foreach to loop through all the products and get the products info
foreach ($items as $item) {
    // Checks if the value is equal to product
    if ($item-&gt;type-&gt;value() === 'product') {
        // Get the unit price value per product
        $commerceUnitPrice = $item-&gt;commerce_unit_price-&gt;value();
        $entity = $item-&gt;value();
        if ($entity) {
            $orderPurchasedItems[] = array(
                "id" =&gt; $entity-&gt;nid,
                "quantity" =&gt; $item-&gt;quantity-&gt;value(),
                "price" =&gt; commerce_currency_format(
                    $commerceUnitPrice['amount'],
                    $commerceUnitPrice['currency_code']
                ), // this will result in $10
            );
            // Store all the ordered products in a new variable so we can use it later
            $myOrderProducts = $orderPurchasedItems;
        }
    }
}