SQL Server - Space Integrity Check

There was a requirement to allow  non -technical  users , to manage archiving
their databases on a SQL Server 2005 platform. They wanted to have the capacity to move the databases from a SAN drive to SATA drive, but they continued to have  a problem regarding space on the destination drive. In other words , having knowledge of the existing database and comparing to the space available on the destination drive.

The following code satisfied the requirement .

Firstly , create the following procedure (fnSpace_Integrity) , which has 2 input parameters .
@db  (which is the db name)
@intendedDrive   (the targe drive )
Secondly , call the procedure with code similar to the CODE 2 section. You can do whatever you want from the result

-------------------------------------CODE 1 START-------------------------------------
CREATE PROCEDURE [dbo].[fnSpace_Integrity]
@db VARCHAR(200) ,
@intendedDrive char(1),
@spResult int OUTPUT

AS

DECLARE @dbsize bigint,@logsize bigint,
@MB_Free int,
@reservedpages  bigint,
@database_size VARCHAR(100)

--establish db size in MB 
select   @database_size   = convert(int,
                                    case -- more than 2TB(maxint) worth of pages (by 8K each) can not fit an int...
                                    when convert(bigint, sum(s_mf.size)) >= 268435456
                                    then null
                                    else (sum(s_mf.size)*8)/1024 -- Convert from 8192 byte pages to Kb then to MB
                                    end)
from   sys.master_files s_mf
where
        s_mf.state = 0 and -- ONLINE
        has_dbaccess(db_name(s_mf.database_id)) = 1 -- Only look at databases to which we have access
        and db_name(s_mf.database_id) = @db
    group by s_mf.database_id
    order by 1

PRINT @database_size

create table #FreeSpace(
Drive char(1), 
MB_Free int)

insert into #FreeSpace exec xp_fixeddrives
select @MB_Free = MB_Free  from #FreeSpace WHERE drive = @intendedDrive
drop table #FreeSpace

--compare intended drive space with the database size  
if @MB_Free > @database_size 
begin
select  @spResult = 1 
end 
else 
begin
select  @spResult = 0
end 
--------------------------------CODE 1 END-----------------------------------------------------

--------------------------------CODE 2 START------------------------------------------------------

declare @spaceResult INT 
exec fnSpace_Integrity  @DB_NAME_EXISTING,@BackupDrive,@spaceResult OUT
select @spaceResult

if @spaceResult = 0 
begin
   
  PRINT 'There is not enough space on drive ' + @BackupDrive + ' to move the database : ' + 

@DB_NAME_EXISTING

end 

------------------------------CODE 2 END----------------------------------------------------------