#!/usr/bin/env bash

postfix_main_cf="/etc/postfix/main.cf"

backup_date="$(date +%Y-%m-%d-%H%M)"
changed=false

log_file="$(mktemp)"

# -------------
# - Functions an Variable
# -------------
clean_up() {


   if [[ -f "$_backup_crontab_file" ]]; then

      echononl "(Re)Install previously saved crontab from '$_backup_crontab_file'.."

      crontab $_backup_crontab_file >> $log_file 2>&1

      if [[ $? -eq 0 ]]; then
         echo -e "$rc_done"
      else
         echo -e "$rc_failed"
         error "$(cat $log_file)"
      fi

   fi

   # Perform program exit housekeeping
   rm -f $log_file
   blank_line
   exit $1
}

fatal(){
   echo ""
   echo -e "\t[ \033[31m\033[1mFatal\033[m ]: \033[37m\033[1m$*\033[m"
   echo ""
   echo -e "\t\033[31m\033[1m           Skript wird abgebrochen\033[m\033[m\n"
   rm -f $log_file
   clean_up 1
}


echononl(){
   echo X\\c > /tmp/shprompt$$
   if [ `wc -c /tmp/shprompt$$ | awk '{print $1}'` -eq 1 ]; then
      echo -e "$*\\c" 1>&2
   else
       echo -en "$*" 1>&2
   fi
   rm /tmp/shprompt$$
}
error(){
   echo ""
   echo -e "\t[ \033[31m\033[1mError\033[m ]: $*"
   echo ""
}

warn(){
   echo ""
   echo -e "\t[ \033[33m\033[1mWarning\033[m ]: $*"
   echo ""
}

info(){
   echo ""
   echo -e "\t[ \033[32m\033[1mInfo\033[m ]: $*"
   echo ""
}

echo_done() {
   echo -e "\033[75G[ \033[32mdone\033[m ]"
}
echo_ok() {
   echo -e "\033[75G[ \033[32mok\033[m ]"
}
echo_warn() {
   echo -e "\033[75G[ \033[33mwarn\033[m ]"
}
echo_failed(){
   echo -e "\033[75G[ \033[1;31mfailed\033[m ]"
}
echo_skipped() {
   echo -e "\033[75G[ \033[90m\033[1mskipped\033[m ]"
}

blank_line() {
   if $terminal ; then
      echo ""
   fi
}


if [[ ! -f "$postfix_main_cf" ]] ; then
   fatal "Postfix configuration '${postfix_main_cf}' NOT found!"
fi

# ----------
# - Some checks ..
# ----------
# -Is systemd supported on this system?
# -
systemd_supported=false
systemd=$(which systemd)
systemctl=$(which systemctl)

if [[ -n "$systemd" ]] && [[ -n "$systemctl" ]] ; then
   systemd_supported=true
fi

blank_line

echononl "   Backup Postfix Cconfiguration file '${postfix_main_cf}'.."
if [[ ! -f "${postfix_main_cf}.${backup_date}" ]] ; then 
   cp -a "${postfix_main_cf}" "${postfix_main_cf}.${backup_date}" > $log_file 2>&1
   if [[ $? -eq 0 ]]; then
      echo_ok
   else
      echo_failed
      error "$(cat "$log_file")"
   fi
else
   echo_skipped
fi
   


blank_line

# - /etc/postfix/main.cf
# -
# - comment in:
# -    #virtual_transport = dovecot
# -    #dovecot_destination_recipient_limit = ..
# -
# - change:
# -    smtpd_sasl_auth_enable = yes
# -    smtpd_sasl_type = dovecot
# -    smtpd_sasl_path = private/dovecot-auth
# -    virtual_transport = lmtp:unix:private/dovecot-lmtp
var="smtpd_sasl_auth_enable"
val="yes"
echononl "   ${postfix_main_cf}: adjust '${var}'.."
if ! $(grep -E -q "^\s*${var}\s*=\s*${val}" ${postfix_main_cf} 2> /dev/null) ; then
   perl -i -n -p -e "s#^(\s*)(${var}\ *=.*)#${var} = ${val}#" \
      /etc/postfix/main.cf > $log_file 2>&1
   if [[ $? -eq 0 ]]; then
      echo_ok
      changed=true
   else
      echo_failed
      error "$(cat "$log_file")"
   fi
else
   echo_skipped
fi

var="smtpd_sasl_type"
val="dovecot"
echononl "   ${postfix_main_cf}: adjust '${var}'.."
if ! $(grep -E -q "^\s*${var}\s*=\s*${val}" ${postfix_main_cf} 2> /dev/null) ; then
   perl -i -n -p -e "s#^(\s*)(${var}\ *=.*)#${var} = ${val}#" \
      /etc/postfix/main.cf > $log_file 2>&1
   if [[ $? -eq 0 ]]; then
      echo_ok
      changed=true
   else
      echo_failed
      error "$(cat "$log_file")"
   fi
else
   echo_skipped
fi

var="smtpd_sasl_path"
val="private/dovecot-auth"
echononl "   ${postfix_main_cf}: adjust '${var}'.."
if ! $(grep -E -q "^\s*${var}\s*=\s*${val}" ${postfix_main_cf} 2> /dev/null) ; then
   perl -i -n -p -e "s#^(\s*)(${var}\ *=.*)#${var} = ${val}#" \
      /etc/postfix/main.cf > $log_file 2>&1
   if [[ $? -eq 0 ]]; then
      echo_ok
      changed=true
   else
      echo_failed
      error "$(cat "$log_file")"
   fi
else
   echo_skipped
fi

var="virtual_transport"
val="lmtp:unix:private/dovecot-lmtp"
echononl "   ${postfix_main_cf}: adjust '${var}'.."
if ! $(grep -E -q "^\s*${var}\s*=\s*${val}" ${postfix_main_cf} 2> /dev/null) ; then
   perl -i -n -p -e "s#^(\s*)(${var}\ *=.*)#${var} = ${val}#" \
      /etc/postfix/main.cf > $log_file 2>&1
   if [[ $? -eq 0 ]]; then
      echo_ok
   else
      echo_failed
      changed=true
      error "$(cat "$log_file")"
   fi
else
   echo_skipped
fi


echononl "   Comment variable 'dovecot_destination_recipient_limit'.."
if $(grep -E -q "^\s*dovecot_destination_recipient_limit" ${postfix_main_cf} 2> /dev/null) ; then
   perl -i-n -p -e "s/^(\s*)(dovecot_destination_recipient_limit.*)/\1\#\2/" /etc/postfix/main.cf > $log_file 2>&1
   if [[ $? -eq 0 ]]; then
      echo_ok
      changed=true
   else
      echo_failed
      error "$(cat "$log_file")"
   fi
else
   echo_skipped
fi

blank_line

# - restart postfix
# -
echononl "   Restart Postfix Service..."
if $changed ; then
   if $systemd_supported ; then
      systemctl restart postfix > /dev/null 2>&1
      if [[ $? -eq 0 ]] ; then
         echo_ok
      else
         echo_failed
      fi
   else
      /etc/init.d/postfix restart > /dev/null 2>&1
      if [[ $? -eq 0 ]] ; then
         echo_ok
      else
         echo_failed
      fi
   fi
else
   echo_skipped
fi


diff "${postfix_main_cf}" "${postfix_main_cf}.${backup_date}"  > /dev/null 2>&1
if [[ $? -eq 0 ]]; then

   info "File \033[1m${postfix_main_cf}\033[m has not changed.
                  \033[32mGoing to remove previos created backup\033[m.."

   echononl "   Remove file \033[1m${postfix_main_cf}.${backup_date}\033[m .."
   rm "${postfix_main_cf}.${backup_date}" > $log_file 2>&1
   if [[ $? -eq 0 ]]; then
      echo_ok
   else
      echo_failed
      error "$(cat "$log_file")"
   fi
fi


clean_up 0