#!/usr/bin/env bash

script_name="$(basename $(realpath $0))"
working_dir="$(dirname $(realpath $0))"

conf_file="${working_dir}/conf/${script_name%%.*}.conf"


# ----------
# - Some variables
# ----------

host_name=`hostname -f`
from_address="postfix@$host_name"
content_type='Content-Type: text/plain;\n charset="utf-8"'

default_notification_addresses="argus@oopen.de"

postfix_queue_dir=/var/spool/postfix

declare -i count_warn
declare -i default_count_warn=80


# ----------
# Base Function(s)
# ----------

info (){
   if $terminal ; then
      echo ""
      echo -e "   [ \033[32m\033[1mInfo\033[m ]: $*"
      echo ""
   fi
}

warn (){
   if $terminal ; then
   	echo ""
      echo -e "   [ \033[33m\033[1mWarn\033[m ]  $*"
   	echo ""
   fi
}



# ----------
# - Some checks ..
# ----------

if [[ -t 1 ]] ; then
   terminal=true
else
   terminal=false
fi

# ----------
#  Read Configurations from $conf_file
# ----------


# - Give your default values here
# -

if [[ -f "$conf_file" ]]; then
   source "$conf_file"
else
   warn "No configuration file '$conf_file' present.\n
             Loading default values.."
fi

# - Commandline parameter overwrites those given at configuration file
# -
if [[ $1 =~ ^-?[0-9]+$ ]];then
   count_warn=$1
fi

[[ -n "$notification_addresses" ]] || notification_addresses="$default_notification_addresses"
[[ -n "$count_warn" ]] || count_warn=$default_count_warn




## - Get number of "deferred" mails in postfix queue
## -
## - Notice: Don't use mailq or postqueue command to examin
## -         the number of mails. Both will open every mail in
## -         the queue and this may take a (very) long time if
## -         many mails are there (and it will cost much resources).
## -
## -         I used a little perl script but its also posible to get
## -         the numbers of mail with:
## -            find ${postfix_queue_dir}/deferred -type f | wc -l
## -
declare -i count=$(

   perl -e '

   use strict;
   use warnings;
   use Symbol;
   sub count {
      my ($dir) = @_;
      my $dh = gensym();
      my $c = 0;
      opendir($dh, $dir) or die "$0: opendir: $dir: $!\n";
      while (my $f = readdir($dh)) {
         if ($f =~ m{^[A-F0-9]{5,}$}) {
               ++$c;
         } elsif ($f =~ m{^[A-F0-9]$}) {
               $c += count("$dir/$f");
         }
      }
      closedir($dh) or die "closedir: $dir: $!\n";
      return $c;
   }
   my $qdir = shift(@ARGV) or die "Usage: $0 queue-directory\n";
   chdir($qdir) or die "$0: chdir: $qdir: $!\n";
   printf count("deferred");
      ' $postfix_queue_dir 
)


if [[ $count -gt $count_warn ]]; then

   subject="[ WARN ] postfix deferred queue exceeds $count_warn Messages"

   msg="\n*${host_name}* - `date +\"%d.%m.%Y %H:%M h\"`\n\n[ Warning ]: $count messages in postfix deferred queue\n"
   msg+="\n\nRecipient domain and time (age in minutes):\n`qshape deferred`\n"
   msg+="\n\nSender domain and time (age in minutes):\n`qshape -s deferred`\n"
   msg+="\n\n\n** Output from script \"`basename $0`\" - Don't reply to this e-mail **"

   for email_to in $notification_addresses ; do

      echo -e "To:${email_to}\n${content_type}\nSubject:$subject\n\n${msg}" | \
         /usr/sbin/sendmail -F $from_address $email_to
      
  done
   
fi

info "$count messages in postfix deferred queue"

if $terminal ; then
   echo ""
   echo -e "   \033[1mRecipient domain and time (age in minutes)\033[m:"
   echo "$(qshape deferred)"
   echo ""
   echo ""
   echo -e "   \033[1mSender domain and time (age in minutes)\033[m:"
   echo "$(qshape -s deferred)"
   echo ""
fi

exit 0