#!/bin/bash

read ICAO

if ! echo "$ICAO" | grep -Eq "^([A-Z]|[a-z]){4}$" ; then
  echo "error: invalid ICAO code!"
  exit 1
fi

ICAO="$(echo "$ICAO" | tr "a-z" "A-Z")"

# aviationweather.gov
result1="$(xmllint --xpath 'string(/response/data/METAR/raw_text)' <(curl -s "https://www.aviationweather.gov/adds/dataserver_current/httpparam?dataSource=metars&requestType=retrieve&format=xml&stationString=$ICAO&hoursBeforeNow=1") | head -n1)"

# metar-taf.com
result2="$(curl -s "https://metar-taf.com/history/$ICAO" | grep -E "METAR $ICAO [0-9]{6}Z" | head -n1 | sed "s/^\s*METAR // ; s|</td>|| ; s/\s*$//")"

if [[ "$result1" > "$result2" ]] ; then
  echo "$result1"
else
  echo "$result2"
fi