#!/bin/bash

verwendung() {
  >&2 echo 'sendmailadvanced [-h|--hook param-for-hooks] [-i|--inline file] [-e|--encrypt] [-s|--stamp] [-t] [--no-hooks]'
  exit 1
}

datei=""
encrypt=false
stamp=false
applyHooks=true

if [ -x /etc/sendmailadvanced.conf ]
then
  . /etc/sendmailadvanced.conf
else
  for konfig in $(readlink -f "$0").conf $(find . -name sendmailadvanced.conf 2> /dev/null)
  do
    [ -x "${konfig}" ] || continue
    . "${konfig}"
    break
  done
fi


eval set -- "$(getopt -o eh:i:st --long encrypt,hook:,inline:,no-hooks,stamp -n "$(basename "$0")" -- "$@")"

while true
do
  case "$1" in
    -h|--hook)
      shift
      hooks[${#hooks[@]}]="$1"
    ;;
    -i|--inline)
      echo "inline erkannt"
      shift
      datei="$1"
    ;;
    -e|--encrypt)
      encrypt=true
    ;;
    -s|--stamp)
      stamp=true
    ;;
    --no-hooks)
      applyHooks=false
    ;;
    -t)
      encrypt=true
      stamp=true
    ;;
    --)
      shift
      break
    ;;
    *)
      >&2 echo "FEHLER: Verstehe Option \"$1\" doch nicht! Ich beende."
      verwendung
    ;;
  esac
  shift
done

[ $# -ne 0 ] && verwendung

MAILER="cantfind"
for executable in sendmail msmtp
do
  for prefix in /usr/bin /usr/sbin /bin /sbin
  do
    [ "${MAILER}" == "cantfind" ] && [ -x ${prefix}/${executable} ] && MAILER="${prefix}/${executable}"
  done
done

if [ -z "${datei}" ] && [ "${MAILER}" == "cantfind" ]
then
  >&2 echo "ERROR: Can't find suitable mailer."
  exit 1
fi

(
  [ -z "${datei}" ] && cat || cat "${datei}"
) | \
(
  IFS=''
  adressatenString=""
  adressatenSammeln=false
  while read -r zeile
  do
    echo "${zeile}" | grep -q "\S" || break
    s="${zeile}"
    if [ "${s:0:3}" == "To:" ] || [ "${s:0:3}" == "Cc:" ]
    then
      adressatenSammeln=true
      s=" ,${s:4}"
    fi
    [ "${s:0:1}" == " " ] || adressatenSammeln=false
    ${adressatenSammeln} && adressatenString="${adressatenString}${s}"
    echo "${zeile}"
  done

  if ${stamp}
  then
    IFS=','
    for adressat in ${adressatenString}
    do
      if [[ "${adressat}" == *"<"*">"* ]]
      then
        adressat="${adressat#*<}"
        adressat="${adressat%>*}"
      fi
      adressat="$(
        echo "${adressat}" | \
          tr -d "[:space:]"
      )"
      echo "${adressat}" | grep -q "\S" || continue
      hashcash -b ${hashcash_bits} -Xm "${adressat}"
    done
  fi
  echo "${zeile}"

  (
    ${applyHooks} && body_header_hook "${hooks[@]}"
    cat
    ${applyHooks} && body_footer_hook "${hooks[@]}"
  ) | \
  (
    ${encrypt} && gpg -e -a -s -r ${gpg_recipient} || cat
  )
) | \
(
  if [ -z "${datei}" ]
  then
    ${MAILER} -t
  else
    tmpFile="$(mktemp)"
    cat > "${tmpFile}"
    cat "${tmpFile}" > "${datei}"
    rm -f "${tmpFile}"
  fi
)