#!/bin/bash

# nearest Gaia star for given RA, DEC
# nsGaia [-v VERBOSITY] [-d DFS] [-g GaiaVersion] {-h} RAdeg DECdeg (or pipe)
# -r initial CONERADIUS in integer arcseconds [30]
# -d DFS is the field separator for output file
# -v VERBOSITY, [1],2,3
# -g Gaia verson, 1,2,[E]

# 1 February 2021
#-----------------------------------------------------------------------
RADIUS=30; DFS="\t";  VERBOSITY=1; GaiaVersion="E"
JSONFILE="nsGaia.json"
#-----------------------------------------------------------------------
TF="OUT_nsGaia" TFt=${TF}".tmp" TFj=${TF}".json" TFd=${TF}.dat
#-----------------------------------------------------------------------
:> $TFt; :> $TFj; :> $TFd
echo "nada">$TFt
#trap "rm $TFt" EXIT
#-----------------------------------------------------------------------

while getopts r:d:v:g:h optval
do 
   case $optval in
        r) RADIUS=$OPTARG;;
        d) DFS=$OPTARG;;
        v) VERBOSITY=$OPTARG;;
        g) GaiaVersion=$OPTARG;;
        h) HELP=1;;
        *) echo "nsGaia -h for help"; exit -1
   esac
done
shift $((OPTIND-1))

if [ $HELP ]; then
  echo "nsGaia [-r RADIUS][-d DFS] [-v VERBOSITY] [-g GaiaV] {-h} RAd DECd ..| pipe"
  echo "-r radius of cone search in arcseconds [30]"
  echo '-d DFS, the field separator for output ["\t"]'
  echo "-v VERBOSITY, [1],2,3 for increasing columns"
  echo "-g GaiaVersion, 1 for DR1 ,2,[E] for EDR3"
  exit
fi

#-----------------------------------------------------------------------
#input from pipe? if so, convert to positional parameters
#-----------------------------------------------------------------------

if [ $# -eq 0 ]; then 
  if [ -p /dev/stdin ]; then
    PIPE=$(cat -)
    set -- $PIPE
  else
    echo "mergeGaia: no inputs from pipe or command line"; exit -1
  fi
fi

if [ $# -lt 2 ];  then
   echo "csGia: need a minimum pair of RA, DEC"
   exit -1
fi

RA=$1; DEC=$2;shift 2 

while grep "^nada" $TFt > /dev/null 
do
   csGaia -r $RADIUS -d $DFS -v $VERBOSITY -g $GaiaVersion $RA $DEC > $TFt
   RADIUS=$((2*RADIUS))
done
RADIUS=$((RADIUS/2))

head -2 $TFt | dlm2json > $JSONFILE

#number of objects (recall, first line is header)

nobj=$(wc -l <$TFt)
nobj=$((nobj-1))
#printf "RADIUS %d arcsec; number of objects %d\n" $RADIUS $nobj

awk -F"$DFS" -v RA=$RA -v DEC=$DEC \
       'BEGIN{pi=3.141592653589793}
        NR==2 {ra=$3; dec=$4
	       dra=(ra-RA)*cos(dec*pi/180)*3600; ddec=(dec-DEC)*3600
               theta=sqrt(dra*dra+ddec*ddec)
               printf ("%0.7f %0.7f %0.1f\"\n", ra,dec, theta)}' $TFt