on every row on SELECT Query must lookup to other table

I'm working on Login/Logout System and I'm facing this problem regarding on SELECT Query. I have 2 tables namely dtr_tbl and shift_tbl. In dtr_tbl are the logs of the user(login/logout time details) and in shift_tbl are the list of shifts available for the users.

>> dtr_tbl

>> shift_tbl (please ignore dates on shifting_timeFr and shiftingtimeTo Columns, just focus on time )

What I wanted to do is compute the TotalHrs per day and per shifting_code . (see below my sample sql)

SELECT 
    user_id,
    CONVERT(varchar,log_date,101) AS [LogDate],
    MIN(d.login_time) AS [Login],
    MAX(d.logout_time) AS [Logout],
    d.shift_code,
    CASE WHEN MIN(d.login_time) <= -->> validate if `Login` time of user is valid within given `gracetime period` 
    CAST(
        CAST(CONVERT(DATE, -->> extract `Date` only from user's `login` time.
                        DATEADD( 
                                hh,
                                IIF(sh.shifting_LVtime=1,-15,0), -->> check if toggle for LVtime(just ignore this)
                                MIN(d.login_time) -->> current login time of user
                                )) AS DATETIME) + 
        CAST(CONVERT(TIME, -->> extract `Time` only from table `shift_tbl` on `shifting_timeFr` column
                        DATEADD( -->> add `15 minutes` for given `gracetime` period
                                MINUTE,
                                sh.shifting_gracetime, -->> 15 mins given `gracetime` period from shift_tbl
                                sh.shifting_timefr --> from `shift_tbl`
                                )) AS DATETIME) 
        AS DATETIME) THEN
    DATEDIFF(MINUTE,
                    CAST(CONVERT(
                                DATE,
                                MIN(d.login_time)
                                ) AS DATETIME) + 
                    CAST(CONVERT(
                                TIME,
                                sh.shifting_timefr
                                ) AS DATETIME)
            ,MAX(d.logout_time))/60.0
ELSE
    DATEDIFF(MINUTE,MIN(d.login_time),
                MAX(d.logout_time))/60.0 
END  AS [TotalHrs]
FROM tblDTR d
INNER JOIN tblShiftings sh
ON d.shift_code = sh.shifting_code
WHERE user_id = 'USER1' 
        AND d.log_date
            BETWEEN CAST('03/13/2015' AS datetime) 
                AND CAST('03/23/2015' AS datetime)
GROUP BY 
    d.user_id,
    d.shift_code,
    sh.shifting_gracetime,
    sh.shifting_timefr,
    sh.shifting_timeto,
    sh.shifting_LVtime,
    CONVERT(varchar,d.log_date,101)
ORDER BY LogDate ASC

My Sample code above is not working, it only work on shift_code with DS01, I also want to compute the other shift_code from dtr_tbl.

>> Result:

thanks.