#!/bin/sh

set -Eeuo pipefail

source data/weather-schema
FIELD_COUNT=$(echo $SCHEMA  | grep -o ";" | wc -l)
URL=https://ssl.smn.gob.ar/dpd/zipopendata.php?dato=tiepre
TMPDIR=/tmp/weather
OUT=$HOME/.weather
CITY="La Plata"

print=false

help() {
  cat <<EOF

Usage: $(basename $0) [OPTION]

This script will fetch a zip file from datos.gob.ar and extract the .txt that
holds the latest info gathered from all the weather stations in Argentina.
After that, all lines except the one containing the city specified by the \$CITY
variable will be removed and the data will be formated and saved in the \$OUT file

More info: https://datos.gob.ar/dataset/smn-estado-tiempo-presente

Default \$CITY selected: $CITY
Default \$OUT file: $OUT

Options:
  -c       Set the \$CITY variable
  -C       Cleanup tmp directory
  -o       Set the \$OUT file
  -p       Print the output instead of saving it
  -h       Print this message
EOF
}

cleanup() {
  if [ -d $TMPDIR ]; then
    rm -rf $TMPDIR/*
  fi
}

# Parse args
while getopts "hCpc:" opt; do
  case $opt in
    h)
      help
      exit 0
      ;;
    C)
      cleanup
      exit 0
      ;;
    c)
      CITY=$OPTARG
      ;;
    o)
      OUT=$OPTARG
      ;;
    p)
      print=true
      ;;
    \?)
      echo "" >&2
      help
      exit 1
      ;;
  esac
done

# Create dir if not exists
if [ ! -d /tmp/weather ]; then
  mkdir -p $TMPDIR
fi

# Get the dataset
curl -s "$URL" --output $TMPDIR/weather.zip
unzip -q $TMPDIR/weather.zip -d $TMPDIR

# Sanitize
iconv -f latin1 -t utf8 $TMPDIR/*.txt | tr -d '
' > $TMPDIR/final.txt

# Cut city data
data=$(cat $TMPDIR/final.txt | grep -i "$CITY" || echo "notfound")

if [ "$data" = "notfound" ]; then
  echo "Error: City/Weather station not found"
  cleanup
  exit 1
fi

# Process string
processed=""
for (( i = 0; i <= $FIELD_COUNT; i++ )); do
  field_number=$(($i +1))
  field=$(echo $SCHEMA | cut -d ";" -f $field_number)
  value=$(echo $data | cut -d ";" -f $field_number)

  line="${field}=$(echo ${value/\//} | sed -e 's/^[ ]*//')"

  if [ ! $i = $FIELD_COUNT ]; then
    processed="${processed}${line}\n"
  else
    processed="${processed}${line}"
  fi
done

# Print or save?
if [ "$print" = true ]; then
  echo -e "$processed"
else
  if [ -f $OUT ]; then
    rm $OUT
  fi
  echo -e "$processed" > $OUT
fi

# Cleanup
cleanup