#!/bin/sh
set -eu

ME="${0##*/}"

about()
{
  echo "$ME -- list postponed messages which have expired"
  echo "Copyright © martin f. krafft <madduck@madduck.net>"
  echo "Released under the terms of the Artistic Licence 2.0"
}   
    
usage()
{
  echo "Usage: $ME [options] <Maildir> [<Maildir> ...]"
  echo
  echo "Valid options are:"
  cat <<-_eof | column -s\& -t
	-V|--version & show version information.
	-h|--help & show this output.
	-a|--all & list all postponed messages, not only expired ones
	-s|--stamp & include the time stamp *before* the filename
	_eof
}

SHORTOPTS=Vhas
LONGOPTS=version,help,all,stamp

maildirs=
listall=0
timestamp=0

for opt in $(getopt -n $ME -o $SHORTOPTS -l $LONGOPTS -u -- "$@"); do
  case "$opt" in
    -V|--version) about; exit 0;;
    -h|--help) about; echo; usage; exit 0;;
    -a|--all) listall=1;;
    -s|--stamp) timestamp=1;;
    --) :;;
    *)
      if [ -d "$opt/cur" ] && [ -d "$opt/new" ] && [ -d "$opt/tmp" ]; then
        maildirs="$maildirs $opt"
      else
        echo "E: unknown argument: $opt" >&2
        exit 1
      fi
      ;;
  esac
done

if [ -z "$maildirs" ]; then
  echo "E: no Maildirs specified." >&2
  exit 2
fi

NOW=$(date +%s)

for i in $maildirs; do
  d="${i%/}"
  echo "$d/new/"
  echo "$d/cur/"
done \
  | xargs -I {} find {} -type f \
  | xargs grep --with-filename --text --max-count=150 '^X-Postponed:' \
  | while read i; do
      f="${i%:X-Postponed:*}"
      ts="${i#*:X-Postponed: }"; ts="${ts%% *}"

      if [ $listall -eq 1 ] || [ $ts -le $NOW ]; then
        [ $timestamp -eq 1 ] && echo -n "$ts "
        echo "$f"
      fi
  done