How to find the distinct elements in XML using XSLT

Question

input code:

<?xml-stylesheet type="text/xsl" href="result.xml"?>
    <productCatalog>
        <product>
            <name>bread</name>
            <quantity>5</quantity> 
            <price>20</price>   
        </product>
        <product>
            <name>milk</name>
            <quantity>12</quantity>
            <price>40</price>   
        </product>
        <product>
            <name>sugar</name>
            <quantity>10</quantity>
            <price>22</price>   
        </product>
        <product>
            <name>tea powder</name>
            <quantity>3</quantity>
            <price>10</price>   
        </product>
        <product>
            <name>flour</name>
            <quantity>20</quantity>
            <price>25</price>   
        </product>
        <product>
            <name>bread</name>
            <quantity>6</quantity>  
            <price>20</price>        
        </product>
        <product>
            <name>flour</name>
            <quantity>3</quantity>
            <price>25</price>   
        </product>
    </productCatalog>

output code should be:

    <?xml version="1.0" encoding="utf-8"?>
<product name="bread" Price="20" TotalPrice="220">
</product>
<product name="milk" Price="40" TotalPrice="480">
</product>
<product name="sugar" Price="22" TotalPrice="220">
</product>
<product name="tea powder" Price="10" TotalPrice="30">
</product>
<product name="flour" Price="25" TotalPrice="575">
</product>

because Bread and flour node is repeated we should add that value and should produce the output. It should produce the consolidate code which is stored in the attribute.