;+
; NAME:
;	smei_frm_mask
; PURPOSE:
;	Check whether camera 3 mask is active at specified time
; CATEGORY:
;	camera/idl/frm
; CALLING SEQUENCE:
	FUNCTION smei_frm_mask, tframe, mask=mask
; INPUTS:
;	tframe		character*(*)	SMEI frame time in format YYYY_DOY_hhmmss
; OUTPUTS:
;	smei_frm_mask_active
;				logical			.TRUE. : bad pixel mask in use for specified time
;								.FALSE.: no bad pixel mask in use for specified time
;	cmask		character*(*)	mask time in format YYYY_DOY
;								This is used in the construction of the file
;								name for the mask.
; PROCEDURE:
;	A bad pixel mask is in effect during time periods hardcoded in this routine.
;	If the specified frame time tframe is inside one of these time periods then
;	the appropriate mask is returned. If not inside any one of the time periods
;	then a mask containing only the value 1 is returned.
; MODIFICATION HISTORY:
;	MAR-2007, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
;-

;	  Start time        End time           Mask name
tmask = [	$
	['2006_033_000000','2006_033_235959', '2005_342']	, $ ; Test period
    ['2006_053_234500','2006_124_235959', '2005_342']	, $ ; Ends when DHU-B comes online
    ['2006_261_195846','2006_333_235959', '2006_215']	, $
    ['2006_334_000000','2050_000_000000', '2006_334']	]


CASE 1 OF
IsTime(tframe): tt = TimeSet(tframe,format='YYYY_DOY_hhmmss')
ELSE		  : tt = tframe
ENDCASE

; Loop over the time periods where a "bad pixel" mask was in effect.

n = (size(tmask,/dim))[1]

name   = ''
SyncArgs, tframe, name, active

FOR i=0,n-1 DO BEGIN
	j = where( tmask[0,i] LE tt AND tt LE tmask[1,i] )
	IF j[0] NE -1 THEN name[j] = tmask[2,i]
ENDFOR

IF arg_present(mask) THEN BEGIN

	CASE n_elements(name) NE 1 OF
	0: message, 'specify single time only to retrieve mask array'
	1: BEGIN
		f = filepath(root=getenv('SMEIDB'),subdir='c3mask','ff_mask_'+name+'.txt')
		IF txt_read(f,n) THEN mask = byte(n)-48B
	END
	ENDCASE

ENDIF

RETURN, name  &  END