#!/bin/bash
#
#------------------------------------------------------------------------------
# Identify the files needed to support the NPP Polar Wander file
#  binary and ascii files needed for running the CSPP software. 
#  The script will first try to find the file locally and if it is 
#  not there,  try to download it from the JPSS_REMOTE_ANC_DIR (see below).
#  The files that it will identify  will be a pair of files converted 
#  from the original H5 - one Blob and one accompanying ascii file.
#
#  January 2012   Written by 
#  Kathleen Strabala  UW-Madison, SSEC, kathy.strabala@ssec.wisc.edu
#
#  Modified April 2012 because the polar wander files started 
#   appearing on Fridays, instead of Thursdays.  The script will now
#   check for a file each day.  KIS
#  
#  Fixed bug introduced by April update. Mistakenly took out part 
#   of script that checked if the file date was a date that one
#   of the files was issued.  If it is before 12UTC on that date,
#   you need to use the last file issued because this one is not
#   valid until 12 UTC.     KIS   6/8/2012
#
#  Added Option to only check local directory - no downloads.
#      KIS 3/15/2013
#
# Note that the following environment variables are needed in the
#  in the get_anc_jpss_tle.bash.  If they are not set, they will 
#  default to:
# $JPSS_LOCAL_ANC_DIR is the local ancillary data directory
#   e.g. ${PWD}/ancillary
# $JPSS_REMOTE_ANC_DIR is the remote FTP ancillary data directory (URL format) 
#   e.g. http://jpssdb.ssec.wisc.edu/cspp_v_2_0/ancillary/
#------------------------------------------------------------------------------

# Check number of arguments
if [ "$#" -lt 2 ] || [ "$#" -gt 3 ]; then
  echo "Usage: get_anc_jpss_polarwander.bash date time [search_flag]"
  echo "where"
  echo "  date is the required date (yyyyddd)"
  echo "    yyyy is the year "
  echo "    ddd is the day of the year "
  echo "  time is the required time (hhmm)"
  echo "    hh is the hour "
  echo "    mm is the minute "
  echo "  search_flag - Optional:"
  echo "    1 - Search locally only, 0 (default) - Search local and remotely"
  echo "The output is an echo of the blob filename and path, and the echo "
  echo "  of the matching ascii file and path with a space separating them."
  exit 1
fi

# Before we begin, make sure that wget is available
which wget > /dev/null
if [ $? != 0 ] ; then
    echo " "  > /dev/stderr
    echo "**** ERROR:  Could not find the wget utility. The ancillary" > /dev/stderr
    echo "**** data fetchers will not work without it. Please install" > /dev/stderr
    echo "**** and try again." > /dev/stderr
    echo " " > /dev/stderr
    exit 1
fi

# If the local ancillary directory variable is not set, then default to 
#  current directory

if [ -z "$JPSS_LOCAL_ANC_DIR" ] ; then
   export JPSS_LOCAL_ANC_DIR=${PWD}
fi

# If the remote ancillary directory variable is not set, then default to 
#  the 
if [ -z "$JPSS_REMOTE_ANC_DIR" ] ; then
  export JPSS_REMOTE_ANC_DIR=http://jpssdb.ssec.wisc.edu/cspp_v_2_0/ancillary
fi

# Set Polar Wander filename head and tail
file_head="off_USNO-PolarWander-UT1-ANC_Ser7_USNO_000f_"
file_tail="Internal"

# Set Polar Wander date range (window centered on current day)
#  The files are created on Thursday's
date_range=(0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 \
            -17 -18 -19 -20 -21 -22 -23 -24 -25 -26 -27 -28 -29 -30 )

#------------------------------------
# The rest of the script searches directories named yyyy/ddd in the 
# local and remote ancillary directories for files named 
# ${file_head}yymmdd${tail} within the search window defined by date_range

# Check local directory
if [ ! -d $JPSS_LOCAL_ANC_DIR ] ; then
  echo "Local ancillary data directory does not exist:JPSS_LOCAL_ANC_DIR " ${JPSS_LOCAL_ANC_DIR}
  exit 1
fi

# Get arguments
date=$1
if [[ $date -lt 2000001 || $date -gt 2100365 ]] ; then
  echo "Invalid beginning date string:" $date
  exit 4
fi
data_time=$2
data_time=$((10#$data_time))
if [[ $data_time -lt 0 || $data_time -gt 2359 ]] ; then
  echo "Invalid time entered " $data_time
  exit 5
fi
# Do you want to search for files locally only?
search_flag=${3:-0}
if [ "$search_flag" != "0" ] && [ "$search_flag" != "1" ]; then
    echo "Search flag must be set to either 0 or 1 " > /dev/stderr
    exit 1
fi

# Compute Gregorian date (yyyymmdd)
# Find the last Thursday
jday1=`echo $date | cut -c5-7`
jday=`expr $jday1 - 1`
data_year=`echo $date | cut -c1-4`
greg_date=`date --date="$data_year-01-01 + $jday days" "+%y%m%d"`
greg_month=`date --date="$data_year-01-01 + $jday days" "+%m"`
greg_year=`date --date="$data_year-01-01 + $jday days" "+%y"`
greg_day=`date --date="$data_year-01-01 + $jday days" "+%d"`

try=1
# Search date range for an acceptable file
for delta in "${date_range[@]}"
  do

  if [[ $try -eq 1 && $data_time -lt 1200 ]] ; then

    # Compute Gregorian date adjusted by delta (yymmdd)
    file_date=`date --date="20$greg_year-$greg_month-$greg_day -1 days" "+%y%m%d"`

  else

     # Compute Gregorian date adjusted by delta (yymmdd)
     file_date=`date --date="20$greg_year-$greg_month-$greg_day $delta days" "+%y%m%d"`
  fi

  # Set binary file name
  file_name="*"$file_head"20"$file_date"*"$file_tail
  echo "Searching for file "$file_name > /dev/stderr
    
  # Get year, month, day and day of month for directory name
  year=`echo "20"$file_date | cut -c1-4`
  month=`echo $file_date | cut -c3-4`
  dd=`echo $file_date | cut -c5-6`
  day=`date --date="$year-$month-$dd" "+%j"`

  # Set local file path and name
  DAY_DIR=${year}_${month}_${dd}_${day}
  local_file=$JPSS_LOCAL_ANC_DIR/$DAY_DIR/$file_name
  
  # Check for file in local directory


#    echo "find -L $JPSS_LOCAL_ANC_DIR/$DAY_DIR  -nowarn -name $file_name" > /dev/stderr

  success=`find  -L $JPSS_LOCAL_ANC_DIR/$DAY_DIR -nowarn -name $file_name 2> /dev/null`

  if [ "${success}" != "" ] ; then
    ascii=`basename $success | cut -d. -f1` 
    ascii_file=${ascii}.asc
    local_ascii_filename=$JPSS_LOCAL_ANC_DIR/$DAY_DIR/$ascii_file
    success=`find -L $JPSS_LOCAL_ANC_DIR/$DAY_DIR -nowarn -name "$ascii_file" 2> /dev/null`
    if [ "${success}" != "" ] ; then
    
      # Files were found locally
      echo "Files were found on local disk" > /dev/stderr
      echo $local_file
      echo $local_ascii_filename
      exit 0
    fi
  
  elif [ $search_flag -eq 0 ] ; then
  
    # File was not found locally, so try to download it
#    echo "Trying to download file from "$JPSS_REMOTE_ANC_DIR/$DAY_DIR/$file_name > /dev/stderr


    wget -t 5 -T 15 -c -r -np -nH --cut-dirs=3 -q -N -A*off_USNO-PolarWander-UT1-ANC_Ser7_USNO_000f*Z_*_Internal $JPSS_REMOTE_ANC_DIR/$DAY_DIR/
     # Was it successful?
     blob=`find . -nowarn -name $file_name -print 2> /dev/null`
     if [ "$blob" != "" ] ; then
        tmpascii=`basename $file_name | cut -d. -f1` 
        ascii=${tmpascii}.asc
        wget -t 5 -T 15 -c -r -np -nH --cut-dirs=3 -q -N -A${ascii} $JPSS_REMOTE_ANC_DIR/$DAY_DIR/
        ascii_file=`find . -nowarn -name $ascii -print 2> /dev/null`

        if [ "$ascii_file" != "" ] ; then
          if [ ! -d $JPSS_LOCAL_ANC_DIR/$DAY_DIR ] ; then 
             mkdir $JPSS_LOCAL_ANC_DIR/$DAY_DIR
          fi
        else
          #If you are here, then you have a blob file but no matching ascii file
          echo "Error: Could not find Polar Wander ascii file to match blob for day $DAY_DIR"
          exit 2
        fi
        mv $blob $JPSS_LOCAL_ANC_DIR/$DAY_DIR/.
        mv $ascii_file  $JPSS_LOCAL_ANC_DIR/$DAY_DIR/.
        if [ $? -eq  0 ] ;  then
          echo "Files were downloaded successfully" > /dev/stderr
          echo $JPSS_LOCAL_ANC_DIR/$DAY_DIR/$blob
          echo $JPSS_LOCAL_ANC_DIR/$DAY_DIR/$ascii_file
          exit 0
        fi
     # Delete the file if it has zero length
     elif [ -z $file_name ] ; then
       rm $file_name
     fi

  fi

  try=$[ $try + 1 ]

done

# Ancillary file was not found
echo "ERROR: Ancillary JPSS Polar Wander blob file could not be found for day $date" > /dev/stderr
exit 1