#!/usr/bin/awk -f
function usage(){
  print "purpose: convert geographical/projected coordinates from NMEA input"
  print "default: parses GGA and transforms coordinates from WGS84 to UTM 32 N"
  print "options [-v OPT=value]:"
  print "EPSGFROM=4326 (epsg code to convert from)"
  print "EPSGTO=25832 (epsg code to convert to)"
  print "MYFS=\",\" (field separator)"
  print "CNV=false (convert to pseudo NMEA message with converted coordinates)"
  print "NFN=3 (input field latitude)"
  print "EFN=5 (input field longitude)"
  print "ECHO=false (echo NMEA messages)"
  print "PRINT2FILE=false (set to false in order not to write to file)"
  print "OUTPUTFILE=ggacs2cs (filename of the output file)"
  
}
#Windows command: gawk -f ggacs2cs.awk -v ECHO=true PRINT2FILE=true OUTPUTFILE=utm_row4_adana EPSGTO=32636 ggaLog.log
#Windows command: gawk -f ggacs2cs.awk -v PRINT2FILE=true OUTPUTFILE=gga_l_u EPSGTO=32636 GGAlinksoben.log
#EPSG:32636: WGS 84 / UTM zone 36N

# TODO: feed all coordinates to cs2cs in one large chunk, not line per line
# TODO: use optarg: http://snap.nlc.dcccd.edu/reference/awkref/gawk_17.html
BEGIN{
<<<<<<< .mine
CONVFMT="%.12f"
=======
CONVFMT="%.10f"
>>>>>>> .r1275
#     while ((c = getopt(ARGC, ARGV, "h")) != -1) {
#         if (c == "h") {
#             usage()
#         }# else if (c == "c") { # TODO implement other options here
        #}

if(MYFS==""){
  FS=","
}
  OFS=FS
  if (EPSGTO==""){
    EPSGTO="25832" # 25832: # ETRS89 / UTM zone 32N <25832> +proj=utm +zone=32 +ellps=GRS80 +units=m +no_defs  <>
  }
  if (EPSGFROM==""){
    EPSGFROM="4326"
  }
  if (CNV==""){ # if CNV="true" then a fake string is created with the transformed coordinates
    CNV="false" 
  }
  if(NFN==""){NFN=3}
  if(EFN==""){EFN=5}
  if(HFN==""){HFN=10}
  if(ECHO==""){ECHO="false"} # echo NMEA as seen? set with -v ECHO=true
  if(PRINT2FILE==""){PRINT2FILE="false"}
  if(OUTPUTFILE==""){OUTPUTFILE="ggacs2cs"}
}

function nmea2dd(nmeacoord){
  dn=int(nmeacoord/100);
  return dn+((nmeacoord-(dn*100.0))/60)
}
function cs2cs(coordarray){
  CMD="echo "coordarray[2]" "coordarray[1]" "coordarray[3]" | cs2cs -f \"%.6f\" +init=epsg:"coordarray[4]" +to +init=epsg:"coordarray[5]
   #print CMD
  gkarray[0]=""
  CMD | getline TRANSFCOORD
#   printf "begin"TRANSFCOORD"end"
  split(TRANSFCOORD, gkarray, "\t")
  split(gkarray[2],D," ")
  # print  C[0]
  # GKR=C[1]
  # GKH=D[1]
  coordarray[7]=gkarray[1]
  coordarray[6] = D[1] #northing
  coordarray[8] = D[2] #easting
#   print "\\debug wgs2gk3: " coordarray[1] FS coordarray[2] FS coordarray[3]  FS coordarray[4] FS coordarray[5] FS coordarray[6]
#   return gkarray
}

# function wgs84toepsg(coord_n_e_h_to){
#   CMD="echo "coord_n_e_h_to[1]" "coord_n_e_h_to[2]" "coord_n_e_h_to[3]" | cs2cs -f \"%.3f\" +proj=latlong +datum=WGS84 +to +EPSG:"coord_n_e_h_to[4]" "
#   # print CMD
#   resarray[0]=""
#   CMD | getline TRANSFCOORD
# #   printf "begin"TRANSFCOORD"end"
#   split(TRANSFCOORD, splitarray, "\t")
#   split(splitarray[2],D," ")
#   # print  C[0]
#   # GKR=C[1]
#   # GKH=D[1]
#   resarray[1]=splitarray[1]
#   resarray[2] = D[1]
#   resarray[3] = D[2]
#    print "\\debug wgs84toepsg: " resarray[1] FS resarray[2] FS resarray[3]
#   return resarray
# }
{if (ECHO!="false"){print;}
#if (true){
#	for (i=1;i<=NF;i++){
#		print i"\t"$i
#	}
#}
}
/GGA/{
#   $GPGGA,131329.00,4842.71443089,N,00912.27614062,E,4,07,1.3,437.834,M,0.000,M,0.0,0000*70
  transarray[0]=""
  transarray[1]=nmea2dd($NFN) # ddlat
  transarray[2]=nmea2dd($EFN) # ddlon
  transarray[3]=$HFN		# wgsheight
  transarray[4]=EPSGFROM
  transarray[5]=EPSGTO
#   transarray[4]=EPSGCODE
  cs2cs(transarray)
  if(CNV!="false"){ # print pseudo string with transformed coordinates
    $1="$CCONV"
    $NFN=transarray[6]
    $EFN=transarray[7]
    $HFN=transarray[8]
    print $0
  }else
  print transarray[6] FS transarray[7] FS transarray[8]
  #write to file: works in windows
  if(PRINT2FILE=="true"){
	#{print transarray[6] FS transarray[7] FS transarray[8] > OUTPUTFILE".log"}
	#northing,easting
	{print transarray[1] FS transarray[2] FS transarray[3] > OUTPUTFILE".log"}
	
  }
}