#!/bin/bash

# Script to mirror the JPSS ancillary data archive that contains
#  the files required to create the CSPP SDRs. At the point
#  of this writing, it includes the TLE and PolarWander files.
#  TLE files are available every day except weekends and American
#  holidays.  PolarWander files are issued once per week.
# 
# It is meant to by called by another script executed via cron 
#  whick checks to see if it is already running, in case one gets stuck
#  and they start to back up.  This script should be run at least once
#  per day.  It uses 'lftp' to mirror the LUT ancillary data directory
#  from http://jpssdb.ssec.wisc.edu/cspp_v_2_0/ancillary , and will only
#  grab any new files that have been updated or changed since the last
#  update.
#
#  Written by Kathleen Strabala UW/SSEC    January 2013
# 
#

# Before we do anything, check to see if lftp is installed on the 
#  local machine
which lftp > /dev/null
if [ $? != 0 ] ; then
    echo " "  > /dev/stderr
    echo "lftp not found locally.  Please install and try again. " > /dev/stderr
    echo " " > /dev/stderr
    exit 1
fi

echo ""
echo "Begin CSPP SDR Ancillary File update on " `date`
echo ""


# See if local and remote ancillary directories have been set
if [[ -z $CSPP_RT_ANC_CACHE_DIR ]]; then
    if [ -z "${CSPP_SDR_HOME}" ] ; then
       echo "Please set CSPP_SDR_HOME "
       exit 1
    else
       echo "Will download data to: ${CSPP_SDR_HOME}/anc/cache."
    fi
    echo "The CSPP_RT_ANC_CACHE_DIR directory has not been set. Defaulting to $CSPP_SDR_HOME/anc/cache"
    export CSPP_RT_ANC_CACHE_DIR=${CSPP_SDR_HOME}/anc/cache
fi

if [[ -z $JPSS_REMOTE_ANC_DIR ]]; then
   export JPSS_REMOTE_ANC_DIR=http://jpssdb.ssec.wisc.edu/cspp_v_2_0/ancillary/
fi

# Use lftp to download only the files that are new or updated 

date_range=(0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20)

# Get todays date in the right format
year=`date +%Y`
month=`date +%m`
dom=`date +%d`
doy=`date +%j`

jday=`expr $doy - 1`

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

 jday1=`expr $jday - $delta` 
 #  Get todays date in the right format
  data_year=`date --date="$year-01-01 + $jday1 days" "+%Y"`
  data_month=`date --date="$year-01-01 + $jday1 days" "+%m"`
  data_dom=`date --date="$year-01-01 + $jday1 days" "+%d"`
  data_doy=`date --date="$year-01-01 + $jday1 days" "+%j"`

  # Get directory
  day_of_interest=${data_year}_${data_month}_${data_dom}_${data_doy}


  # lftp command
  FILE_TYPE="-I *.TLE* -I *.asc -I *PolarWander*"
  lftp -c "mirror --verbose --no-empty-dirs --only-newer --parallel=2 $JPSS_REMOTE_ANC_DIR/${day_of_interest} ${FILE_TYPE}  ${CSPP_RT_ANC_CACHE_DIR}/"
  if [ $? -ne 0 ] ; then
    echo "CSPP Ancillary data update was not successful for day $day_of_interest ."   
    echo "The remote directory may not exist yet for this day."
    echo ""
  fi

done

echo " "
echo "CSPP SDR Ancillary data update completed."

exit 0