Select highest aggregated group

I’m having trouble with selecting the highest aggregated group.

I have data in a table like this: Sales table:

ID	GroupDescription	Sales
1	Group1	2
1	Group1	15
1	Group2	3
1	Group3	2
1	Group3	2
1	Group3	2
2	Group1	2
2	Group2	5
2	Group3	3
2	Group4	12
2	Group4	2
2	Group4	2

I want to return 1 record for each ID. I also want to include the Group that had the most sales and the total sales for that group and ID.

Expected output:

ID	GroupDescription	SumSales
1	Group1	17
2	Group4	16

I have code working but I feel like it can be written much better:

SELECT * FROM
(
    SELECT ROW_NUMBER() OVER(PARTITION BY ID ORDER BY ID, SumSales DESC) as RowNum, * FROM
    (
        SELECT
        ID 
        ,GroupDescription
        ,SUM(Sales) OVER(PARTITION BY ID,GroupDescription) as SumSales 
        FROM Sales
        ) t1
    ) t2
WHERE RowNum = 1

Answer

Aggregate by ID and GroupDescription and use window functions FIRST_VALUE() and MAX() to get the top group and its total:

SELECT DISTINCT ID,
       FIRST_VALUE(GroupDescription) OVER (PARTITION BY ID ORDER BY SUM(Sales) DESC) GroupDescription,
       MAX(SUM(Sales)) OVER (PARTITION BY ID) SumSales
FROM Sales
GROUP BY ID, GroupDescription;

See the demo.