help on below output

create table Total_Points
(
id int primary key identity(1,1),
Code int Unique,
Points int
)
 
--insert into Total_Points values(1001,10)
--insert into Total_Points values(2001,20)
--insert into Total_Points values(3001,30)
--insert into Total_Points values(4001,40)
--insert into Total_Points values(5001,50)
 
--select * from Total_Points
--select * from Points_TRN
 
 
--create table Points_TRN
--(
--id int primary key identity(1,1),
--RefCode int ,
--EarnPoints int
--)
 
--insert into Points_TRN values(1001,1)
--insert into Points_TRN values(1001,2)
--insert into Points_TRN values(1001,3)
--insert into Points_TRN values(2001,2)
--insert into Points_TRN values(2001,2)
--insert into Points_TRN values(2001,2)
--insert into Points_TRN values(3001,7)
--insert into Points_TRN values(3001,5)
--insert into Points_TRN values(3001,4)
 
 
--Expected Output
-- id Code Totalpoint Earnpoint FinalPoint
 1   1001   10               6        4
 2   2001   20              6       14
 3   3001   30              16     14
 4   4001   40              0        0    
 5   5001   50              0        0