#!/bin/sh
#
# Unread E-mail screen status indicator
#
# Copyright (C) 2013 Mike Gerwitz
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# Unread e-mails will be displayed in the following format:
#   [X X X unread!X]
#
# This utility uses fetchmail in order to check for new messages. Please
# configure your ~/.fetchmailrc file appropriately.
##

pidfile=~/.screen/.mail.pid
curpid="$( cat "$pidfile" )"

# kill any existing instances and replace (to ensure that code changes take
# effect)
[ "$curpid" ] && kill "$curpid"
echo "$$" > "$pidfile"

# this will be displayed until the first time the mail is received
echo "\005{+ mw}(...)\005{-}"

# continue looping while parent (screen) process is still running
parent="$PPID"
while [ "$( ps | grep $parent)" ]; do
    fetchmail -t1 -c 2>/dev/null \
        | sed 's/^\([0-9]\+\).*(\([0-9]\+\) seen).*$/\1 \2/' \
        | awk '
            BEGIN {
                count=0
                total=0
                printf "%s", "\005{+ mw}[\005{+b}"
            }
            {
              total += total + ( $1 - $2 )
              count += $1
              printf "%d ", total
            }
            END {
              printf "%s", "\005{-}unread]\005{-}"

              if ( count > 100 )
                printf "%s%d%s", "\005{+ my}!", count, "\005{-}"

              printf "\n"

              if ( total > 0 )
                print "mail" > "/tmp/.keyind"
              else
                print "" > "/tmp/.keyind"
            }'

    sleep 30
done