#!/bin/csh -f
#+
# observe_flux_standard -- acquire spectra for monthly DEIMOS throughput test
#
# Purpose:
#	Take a series of exposures required for the DEIMOS monthly
#	throughput check using the current grating.
#
# Usage:
#	observe_flux_standard   [-q | -v ]
# 
# Arguments:
#	-q = query mode (ask before running)
#                -v = verify the telescope setup (starname, pa, instrument) and
#                          do not execute data acquisiition and instr and tel moves. 
# Procedure:
#	- verifies that the telescope is pointed to a known DEIMOS 
#	  flux standard star by checking DCS keyword TARGNAME
#	- check the current grating and build appropriate exposure list
#	- save current DEIMOS configuration
#	- check that SKYPA is correct for this star
#	- set pointing origin to SLIT
#	- configure for slitless spectroscopy
#	- acquire exposures
#	- restore configuration
# 
# Restrictions:
#	- before starting the script, you must set the SKYPA to the
#	  correct value for the star you plan to observe.  See the following
#	  table
#	- a grating must be in place when the script is started
#
# Valid targets:
#	Starname	PA	RA           Dec          Equinox
#	--------	--	------------ ------------ -------
#	G191B2B		0	05:05:30.600 +52:49:54.00 2000.0
#	Feige34		90	10:39:36.700 +43:06:10.00 2000.0
#	HZ44		90	13:23:35.400 +36:08:00.00 2000.0
#	BD+33 2642      0       15:51:59.9   +32:56:55    2000
#	BD+28 4211	90	21:51:11.100 +28:51:52.00 2000.0
#	Feige110	90	23:19:58.400 -05:09:56.00 2000.0
#
#	Note: This information is in starlist 
#		/kroot/starlists/0000_Throughput_standards.list
#	
# Exit values:
#	 0 = normal completion
#	 1 = wrong number of arguments
#	 2 = current star is not a valid DEIMOS flux standard
#	 3 = no exposures defined for current grating
#	 4 = number of filters and wavelengths don't match
#	 5 = SKYPA is wrong
#
# Note:
#	SKYPA must currently be set manually prior to running the script,
#	since it is not possible currently to ensure that it can be set
#	automatically to a value not near the limits.
#
# Example:
#	1) To acquire exposures on the star G191B2B with the 1200G grating:
#		- point the telescope to G191B2B (any pointing origin)
#		- set the SKYPA to the 0 deg (see table above)
#		- move the 1200G grating into position
#		- execute the command:
#			observe_flux_standard
#	Assuming that the GG400, GG455, and OG550 filters are installed,
#	the script will acquire 3 60s exposures:
#		1200G/5000A + GG400
#		1200G/7000A + GG455
#		1200G/8000A + OG550
#-
# Modification history:
#	2003-Jul-31	GDW	Original version
#	2004-Jun-19	GDW	Changed all references to BAL12 -> GG400
#				(filter removed from service because of
#				scratching) 
#	2008-Dec-23	GDW	Added -q option
#	2009-Mar-30	GDW	Added new star BD+33 2642
#	2010-Feb-22	MK	Added verify flag and changed all 
#				WARNINGS to ERRORS so that the IDL
#				script will handle errors appropriately
#	2010-Mar-11	GDW	Changed verify logic
#       2010-Jun-12     MK      Changed Filter Error to a Warning because 
#                               the script skips filters if they are not
#                               installed in the instrument. 
#-----------------------------------------------------------------------

set buf = $0
set cmd = $buf:t
set usage = "Usage: $cmd"
set debug = 0
set do_verify = 0

if ( $debug ) then
    set cmd = echo
else
    set cmd = ""
endif

# parse flags...
while ( $#argv > 0 )

  # check for -no_init flag...
  if ( "$1" =~ -q* ) then
    set do_query = 1
    shift
    continue
  endif

  # check if verify flag is set
  if ( "$1" =~ -v* ) then
    set do_verify = 1
    shift
    continue
  endif

  # exit flag check if no flags remain...
  break

end

# verify args...
if ( $#argv > 0 ) then
  printf "$usage\n"
  exit 1
endif

cat <<EOF2
------------------------------------------------------------------------
	     Welcome to the OBSERVE_FLUX_STANDARD script
------------------------------------------------------------------------

This script will:
  - Save current DEIMOS settings
  - Configure DEIMOS for slitless spectroscopy
  - Acquire up to 3 DEIMOS slitless spectra of a standard star 
    at various central wavelengths
  - Restore original DEIMOS settings

EOF2

# query if requested...
if ( $?do_query ) then
    printf "Do you want to continue? (y/n) [y]: "
    set ans = $<
    if ( "$ans" == "" || "$ans" == "y" ) then
	printf "Continuing...\n"
    else
	printf "Aborting!\n\a"
	exit 1
    endif
endif

# define known targets...
set target_list = ( G191B2B HZ44 BD+284211 Feige34 Feige110 BD+332642)
set pa_list     = ( 0 90 90 90 90 0)

# check the current target...
show -s dcs -terse targname
set targname = ( `show -s dcs -terse targname` )
## echo targname is $targname
if ( $debug ) set targname = "HZ 44"
set targname2 = `echo $targname | sed "s/ //g"`	# whitespace removed

# verify that the current target is a known one...
set found = 0
@ i=1
while ( $i <= $#target_list )
    if ( "$targname2" == "$target_list[$i]" ) then
	set found = 1
	set pa = $pa_list[$i]
	break
    endif
    @ i++
end
if ( $found == 0 ) then
    printf "ERROR -- current target '$targname' is not a known DEIMOS flux standard.\n\a"
    printf "Known flux standards are:\n"
    foreach item ( $target_list )
	printf "$item\n"
    end
    exit 2
endif

# set appropriate telescope parameters...
set thresh = 5
set skypa = `skypa`
set diff = `calc "int(abs($skypa-$pa)%180)"`
if ( $diff > $thresh ) then
    printf "ERROR: current SKYPA of $skypa is too far off of desired value $pa -- abort!\n\a"
    exit 6
endif


# check the current grating...
set grating = `grating`
if ( $grating == "600ZD" ) then
    set desired_wavelengths = (5500 6500 7500)
    set desired_filters = (GG400 GG455 OG550)
    set ttime = 30
else if ( $grating == "830G" ) then
    set desired_wavelengths = (5000 7000 8000)
    set desired_filters = (GG400 GG455 OG550)
    set ttime = 45
else if ( $grating == "900ZD" ) then
    set desired_wavelengths = (5000 7000 8000)
    set desired_filters = (GG400 GG455 OG550)
    set ttime = 45
else if ( $grating == "1200G" ) then
    set desired_wavelengths = (5000 7000 8000)
    set desired_filters = (GG400 GG455 OG550)
    set ttime = 60
else
    printf "ERROR -- can't take data with grating $grating!\n\a"
    exit 3
endif

# exclude unavailable filters...
set filter_list = ( `consort -fn` )
set wavelengths = ()
set filters = ()
@ i=1
while ( $i <= $#desired_filters )

    # add the requested filter to the list of to-be-observed filters
    # only if it is loaded...
    set found = 0
    foreach filter ( $filter_list )
	if ( "$desired_filters[$i]" == "$filter" ) then
	    set filters     = ( $filters     $desired_filters[$i])
	    set wavelengths = ( $wavelengths $desired_wavelengths[$i])
	    set found = 1
	    break
	endif
    end

    # warn if not available...
    if ( ! $found ) then
	printf "WARNING: desired filter %s not available; skipping...\n\a" \
	    "$desired_filters[$i]"
    endif

    @ i++
end

# verify that the number of filters and wavelengths matches...
if ( $#wavelengths != $#filters ) then
    printf "ERROR -- number of filters and wavelengths don't match!\n\a"
    exit 4
endif

# if the verify flag is set, then do not execute any moves.
if ( $do_verify ) then 
    exit 
endif

# save current configuration...
$cmd save_state
$cmd poname Slit

# configure instrument for slitless spectroscopy...
$cmd modify -s deimot hatchpos=open
$cmd lamps off
$cmd slitmask None
$cmd modify -s deiccd obstype=Object
$cmd spectral
$cmd tint $ttime

# ensure shutter is working...
cycle_shutter -10
if ( $status != 0 ) then
  printf "ERROR: couldn't open shutter -- abort\n\a"
  exit 1
endif

# loop over configurations...
@ i=1
while ( $i <= $#wavelengths )
$cmd     filter $filters[$i]
$cmd     wavelen $wavelengths[$i]
$cmd     object DEIMOS flux standard $targname $grating/$wavelengths[$i]A + $filters[$i]
$cmd     goi
    @ i++
end

# restore original configuration...
$cmd restore_state

exit