Increase the performance of an inventory (FIFO) query - sql

Question

My goal is to get the price from item which goes into stock and put the price into out item by (FIFO order by TranDate), then calculate the total price of any line of production (" lineid ").
This is what I have done
-- temp table for result
declare #Test table ( stockID int , OriQty decimal(16,2) ,inuse decimal(16,2) , price decimal(16,2) , lineid int , Inid int )
declare #StockIn table (ID int , StockID int ,qty decimal(16,2),Price decimal(16,2), tranDate Date , running int)
insert into #StockIn(ID , StockID , qty , Price , tranDate , running) values
(1,1 , 15 , 430 , '2014-10-09' , 1),
(2,1 , 10 , 431, '2014-12-09' , 2),
(3,1 , 15 , 432, '2015-02-02' , 3),
(4,2 , 15 , 450, '2014-08-05' , 1),
(5,2 , 6 , 450, '2014-10-09' , 2),
(6,2 , 15 , 452, '2015-02-02' , 3)
-- lineid = line production
declare #StockOut table (ID int , StockID int ,qty decimal(16,2), lineid int, tranDate Date)
insert into #StockOut(ID , StockID ,qty , lineid, tranDate )
values
(1,1 , 20 , 2, '2014-10-10'),
(2,1 , 10 , 4, '2014-12-20'),
(3,2 , 12 , 8, '2014-10-01'),
(4,2 , 3 , 8, '2014-10-01') ;
DECLARE #intFlag INT
SET #intFlag = 1 -- initial of loop
WHILE (#intFlag <= (Select Max(ID) from #StockOut) )
BEGIN
declare #stockID int
declare #ids table (ID int , Inuse decimal(16,2))
declare #lineid int
declare #qtyToRemove decimal(16,2) -- get qty from #StockOut
--get data from #StockOut row by row
select #stockID = StockID , #qtyToRemove = qty , #lineid = lineid from #StockOut where ID = #intFlag;
with cte as (
select *, sum(qty) over (order by tranDate ASC , qty DESC , tranDate ASC Rows UNBOUNDED PRECEDING) - #qtyToRemove
as Total FROM #StockIn Where stockID = #stockID )
-- running FIFO from #StockIn and update QTy when stock is running out
, RunningFIFO as (
select cte.StockID , cte.qty AS OriginalQty , Case when
case when 0 > total then cte.qty else cte.qty-total End > 0 then case when 0 > total then cte.qty else cte.qty-total End else 0 End As Inuse
, cte.Price , #lineid AS lineid , id
from cte
)
-- insert result into result table
insert into #test (stockID , OriQty ,inuse , cte.Price , lineid ,Inid ) OUTPUT inserted.Inid , inserted.inuse into #ids select * from RunningFIFO Where Inuse > 0
UPDATE #StockIn set qty = qty - inuse from #ids A inner join #StockIn B on A.ID = b.ID
SET #intFlag = #intFlag + 1
END
Select sum(inuse * price) AS total , lineid from #Test group by lineid
But when data are more than a thousand, this query runs super slow.
How could I increase the performance of this query?