#!/bin/csh -f
#+
# skypa -- set rotator celestial position angle in position angle mode
#
# Purpose:
#	With no arguments, show the current rotator position angle as
#	it would appear on FACSUM.  With one numeric argument, set the
#	rotator to the specified sky position angle.
#
# Usage:
#	skypa [-relative]  [angle]
# 
# Arguments:
#	angle = rotator position angle [degrees]
# 
# Options:
#       -relative = apply a delta move; default is absolute move
#
# Output:
#	Current or new position angle [degrees]
# 
# Restrictions:
#	- DEIMOS must be the selected instrument
# 
# Exit values:
#	 0 = normal completion
#	 1 = wrong number of arguments
#
# Example:
#
#-
# Modification history:
#	2002-Aug-12	GDW	Original version
#       2012-May-30     GDW     Add -relative option
#-----------------------------------------------------------------------

set buf = $0
set cmd = $buf:t
set usage = "Usage: $cmd [angle]"
set mode = absolute

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

  # check for -debug flag...
  if ( "$1" =~ \-d* ) then
    set debug = 1
    printf "DEBUG MODE enabled\n\a"
    shift
    continue
  endif

  # check for -relative flag...
  if ( "$1" =~ \-r* ) then
    set mode = relative
    shift
    continue
  endif

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

end

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

# check the instrument...
set instrume = `show -s dcs -terse instrume`
if ( $instrume != "DEIMOS" ) then
    printf "ERROR -- current instrument is not DEIMOS\n"
    exit 2
endif

# take appropriate action...
if ( $#argv == 0 ) then
    set rotposn = `show -s dcs2 -terse rotposn`
    set skypa = `calc "$rotposn+90"`
    printf "%g\n" $skypa
else

    # validate argument...
    set skypa = $1
    is_float $skypa > /dev/null
    if ( $status != 0 ) then
	printf "$usage\n"
	exit 1
    endif

    # set rotator angle...
    if ( "$mode" == "relative" ) then
        set rotdest = `show -s dcs2 -terse rotdest`
        set rotdest = `calc $rotdest + $skypa`
    else
	set rotdest = `calc "$skypa-90"`
    endif

    # make the move...
    if ( $?debug ) then 
        echo modify -s dcs ROTDEST=$rotdest ROTMODE=1
        echo sleep 3
        echo waitfor -s dcs ROTSTAT=8
        exit
    endif

    modify -s dcs ROTDEST=$rotdest ROTMODE=1
    sleep 3
    waitfor -s dcs ROTSTAT=8
endif