#!/bin/sh
#
# Copyright 2011 Iordan Iordanov <iiordanov (AT) gmail.com>
#
#    This file is part of luci-pbx-voicemail.
#
#    luci-pbx-voicemail 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.
#
#    luci-pbx-voicemail 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 luci-pbx-voicemail.  If not, see <http://www.gnu.org/licenses/>.
#
#
# Thanks to http://www.zedwood.com for providing an excellent example of how to
# properly assemble an email message with a base64 encoded attachment.
#

LOGFILE=/tmp/voicemail/last_sent_voicemail.log

# Redirect standard error and standard output to a log file.
rm  -f "$LOGFILE"
exec 1>"$LOGFILE"
exec 2>&1

# Appends its second argument to a file named in the first argument.
append_to_file ()
{
    echo "$2">>$1;
}

# Grab the attachment name, which should be sent as the first argument, and
# exit with a warning if there is no voicemail to send.
ATTACHMENT="$1"
[ ! -f "$ATTACHMENT" ] && echo "WARNING: Found no voicemail recording to send." && exit

# Grab the callerID which should have been sent as an argument.
CALLERID="$2"
[ -z "$CALLERID" ]   && CALLERID="An unknown caller"

# Determine addresses we would like to send the voicemail to and exit if none are found.
TO="`uci -q get pbx-voicemail.global_voicemail.global_email_addresses | tr ' ' ','`"
[ -z "$TO" ] && echo "WARNING: Found no addresses to send voicemail to." && exit

# See whether we should retain a copy of the voicemail.
SAVEPATH="`uci -q get pbx-voicemail.global_voicemail.global_save_path`"

DATE="`date +%Y-%m-%d`"
TIME="`date +%H:%M:%S`"
FROM="voicemail@pbx"
REPLY="do-not-reply@pbx"
SUBJECT="Voicemail from $CALLERID, $DATE, $TIME"
MSGBODY="$CALLERID has left voicemail for you on $DATE at $TIME."
MIMETYPE="audio/wav"
TMP1="/tmp/voicemail/tmpemail1.$$";
TMP2="/tmp/voicemail/tmpemail2.$$";
BOUNDARY="`date +%s | md5sum | awk '{print $1}'`"
FILENAME="voicemail-$DATE-$TIME.WAV"

# Clean up just in case.
rm -f $TMP1 $TMP2

append_to_file $TMP1 "From: $FROM"
append_to_file $TMP1 "To: $TO"
append_to_file $TMP1 "Reply-To: $REPLY"
append_to_file $TMP1 "Subject: $SUBJECT"
append_to_file $TMP1 "Content-Type: multipart/mixed; boundary=\""$BOUNDARY"\""
append_to_file $TMP1 ""
append_to_file $TMP1 "This is a MIME formatted message.  If you see this text it means that your"
append_to_file $TMP1 "email software does not support MIME formatted messages."
append_to_file $TMP1 ""
append_to_file $TMP1 "--$BOUNDARY"
append_to_file $TMP1 "Content-Type: text/plain; charset=ISO-8859-1; format=flowed"
append_to_file $TMP1 "Content-Transfer-Encoding: 7bit"
append_to_file $TMP1 "Content-Disposition: inline"
append_to_file $TMP1 ""
append_to_file $TMP1 "$MSGBODY"
append_to_file $TMP1 ""
append_to_file $TMP1 ""
append_to_file $TMP1 "--$BOUNDARY"
append_to_file $TMP1 "Content-Type: $MIMETYPE; name=\"$FILENAME\""
append_to_file $TMP1 "Content-Transfer-Encoding: base64"
append_to_file $TMP1 "Content-Disposition: attachment; filename=\"$FILENAME\";"
append_to_file $TMP1 ""

append_to_file $TMP2 ""
append_to_file $TMP2 ""
append_to_file $TMP2 "--$BOUNDARY--"
append_to_file $TMP2 ""
append_to_file $TMP2 ""

# Cat everything together and pass to msmtprc to send out.
( cat $TMP1
  cat "$ATTACHMENT" | base64
  cat $TMP2 ) | msmtp -t -C /etc/pbx-msmtprc

# Clean up email temp files.
rm -f $TMP1 $TMP2

# Either delete or move the attachment based on the SAVEPATH variable.
if [ -z "$SAVEPATH" ]
then
    rm -f "$ATTACHMENT"
else
    mkdir -p "$SAVEPATH"
    mv --backup=t "$ATTACHMENT" "$SAVEPATH/$FILENAME"
fi