#!/bin/bash
set -euo pipefail

# ==== Variables ====
# Output warning if fewer than this number of seconds until expiry
WARNSECONDS=1209600 # Two weeks
# File containing a newline separated list of host:port combinations to be checked
DOMAINS="domains.txt"
# ==== Variables ====

# === Not variables ===
SUPPORTEDTLDS=(.co.uk .com .eu .info .je .net .org .ovh .uk)
# === Not variables ===


#for TLD in "${SUPPORTEDTLDS[@]}" ; do
#  echo "DEBUG: Supported TLD: $TLD."
#done

# Loop through all host:port combinations
while read -r DOMAIN ; do

  echo "DEBUG: DOMAIN: $DOMAIN."

  # Work out the TLD
  TLD=""
  DOTS=0
  for TLDTEST in "${SUPPORTEDTLDS[@]}" ; do
#    echo "DEBUG: Checking $DOMAIN against $TLDTEST."
    if echo "$DOMAIN" | grep -q "$TLDTEST$" ; then
#      echo "DEBUG: $DOMAIN may be a $TLDTEST domain..."
      DOTSTEST=$(echo "$TLDTEST" | grep -o "\." | wc -l)
#      echo "DEBUG: $TLDTEST has $DOTSTEST dots compared to the previous $DOTS."
      if [ "$DOTSTEST" -gt "$DOTS" ] ; then
#        echo "DEBUG: Yes, $TLDTEST is the current winner."
        TLD="$TLDTEST"
        DOTS="$DOTSTEST"
      fi
    fi
  done

  if [ "$TLD" == "" ] ; then
    echo "ERROR: Unknown TLD for $DOMAIN, ignoring."
    continue
  else
    echo "DEBUG: $DOMAIN is a $TLD domain."
  fi

  # Get the WHOIS data
  WHOIS="$(whois $DOMAIN)"

  # Do the appropriate WHOIS grepping magic based on what the TLD was
  case "$TLD" in
    .co.uk)
#      echo "DEBUG: Doing the .co.uk domain stuff"
      DATESTR=$(echo "$WHOIS" | grep -E '^\s*Expiry date:' | sed -r 's/^\s*Expiry date:\s*//')
#      echo "DEBUG: DATESTR: $DATESTR"
      EXPIRY=$(date --date "$DATESTR" +%s)
#      echo "DEBUG: $DOMAIN expires on $EXPIRY aka "$(date --date @"$EXPIRY")"."
      ;;
    .je)
#      echo "DEBUG: Doing the .je domain stuff"
      # .je WHOIS returns two dates, so pick the earlier one just in case
      # Strip out st/nd/rd/th (e.g. 30th -> 30) for parsing with `date`
      DATESTR=$(echo "$WHOIS" | grep -E '^\s*Registry fee due on' | sed -r 's/\s*Registry fee due on //; s/ each year//; s/(st |nd |rd |th )/ /')
      echo "DEBUG: DATESTR: $DATESTR"
      # Same again, plus the original registration year (e.g. 30th January 2011 -> 30 January)
      DATESTR2=$(echo "$WHOIS" | grep -E "^\s*Registered on" | sed -r 's/\s*Registered on //; s/ [0-9]+//; s/(st |nd |rd |th )/ /')
      echo "DEBUG: DATESTR2: $DATESTR2"
      # These date only strings will be assumed to be this year by `date`
      EXPIRY=$(date --date "$DATESTR" +%s)
      EXPIRY2=$(date --date "$DATESTR2" +%s)
      # Pick whichever is lower (i.e. sooner)
      if [ "$EXPIRY" -gt "$EXPIRY2" ] ; then
        EXPIRY="$EXPIRY2"
        # Keep the original chosen DATESTR for use later
        DATESTR="$DATESTR2"
      fi
      # If this date is in the past, assume it actually expires next year
      NOW=$(date +%s)
      if [ "$EXPIRY" -lt "$NOW" ] ; then
        YEAR=$(date +%Y)
        YEAR=$((YEAR+1))
        EXPIRY=$(date --date "$DATESTR $YEAR" +%s)
#        echo "DEBUG: Chosen DATESTR: $DATESTR $YEAR"
#      else
#        echo "DEBUG: Chosen DATESTR: $DATESTR"
      fi
#      echo "DEBUG: $DOMAIN expires on $EXPIRY aka "$(date --date @"$EXPIRY")"."
      ;;
    .uk)
      echo "DEBUG: Doing the .uk domain stuff"
      DATESTR=$(echo "$WHOIS" | grep -E '^\s*Expiry date:' | sed -r 's/^\s*Expiry date:\s*//')
#      echo "DEBUG: DATESTR: $DATESTR"
      EXPIRY=$(date --date "$DATESTR" +%s)
#      echo "DEBUG: $DOMAIN expires on $EXPIRY aka "$(date --date @"$EXPIRY")"."
      ;;
    *)
      echo "ERROR: Unknown TLD for $DOMAIN, I have no idea how we got here, exiting."
      exit
      ;;
  esac

  NOW=$(date +%s)
#  echo "DEBUG: NOW: $NOW."

  # Number of seconds left
  DIFFERENCE=$(("$EXPIRY" - "$NOW"))
#  echo "DEBUG: DIFFERENCE: $DIFFERENCE."

  # Warn if less than WARNSECONDS less
  if [ "$DIFFERENCE" -lt "$WARNSECONDS" ] ; then
    echo "Warning!  The domain $DOMAIN expires in $DIFFERENCE seconds (~$((DIFFERENCE / 60 / 60 / 24)) days)."
  else
    echo "DEBUG: The domain $DOMAIN expires in $DIFFERENCE seconds (~$((DIFFERENCE / 60 / 60 / 24)) days)."
  fi

done < "$DOMAINS"