#!/bin/bash
#
# configuration
#
VERSION=0.1
#
VERBOSE=1
# send an email, setting default subject... 
EMAIL_SUBJ="MailCow cert for $DOMAIN"
#
EMAIL=dave@davelane.nz
# Mailcow stuff
DOMAIN=moe.lane.net.nz
MCDIR=/home/docker/mailcow
SSLDIR=data/assets/ssl
MCCA=$MCDIR/$SSLDIR/cert.pem
MCPRIV=$MCDIR/$SSLDIR/key.pem
# Let's Encrypt stuff
LEDIR=/etc/letsencrypt/live/$DOMAIN
LECA=$LEDIR/fullchain.pem
LEPRIV=$LEDIR/privkey.pem
# 
# Defaults
LOG=/var/log/$0.log
#
# Automated defaults
#
LS=`which ls`
DATE=`date '+%Y-%m-%d'`
# email program
MAIL=`which mail`
# docker-compose
DC=`which docker-compose`
# temporary holding point for email
TMP_EMAIL=/tmp/tmp_email.$0.$DATE_$TIME
#
# Functions
#
# get the file date in seconds since 1970
getfiledate() {
    local DATE=`$LS -l --time-style=+"%s" $@ | cut -d " " -sf 6`
    echo $DATE
}
#
# put a message in the log
message() {
    #
    # a timestamp for logging purposes
    local TIMESTAMP=`date  '+%Y-%m-%d %H:%M.%S'`
    if test $VERBOSE = 1 ; then
	echo "$@"
    else
        echo "$0: $TIMESTAMP $@" >> $LOG
        if test -f $TMP_EMAIL ; then
            echo "$0: $TIMESTAMP $@" >> $TMP_EMAIL
        fi
    fi
}
#
# create the temporary email file
create_tmp_email() {
  touch $TMP_EMAIL
  if test -f $TMP_EMAIL ; then
    message "created temporary email  $TMP_EMAIL"
  else
    message "failed to create temporary email  $TMP_EMAIL"
  fi
}
#
# send the contents of the temporary file to the
# designated report recipient
send_email_report() {
     if test -f $TMP_EMAIL ; then
        message "sending email report to $EMAIL"
        $MAIL -s "$EMAIL_SUBJ" $EMAIL < $TMP_EMAIL
        rm $TMP_EMAIL
        if test -f $TMP_EMAIL ; then
            message "failed to remove temporary email  $TMP_EMAIL"
        else
            message "successfully removed temporary email  $TMP_EMAIL"
        fi
        message "email report successfully sent"
    fi
}

restart_mailcow() {
    CWD=`pwd`
    cd $MCDIR
    # restart the mailcow app
    $DC stop && $DC up -d
    cd $CWD
}

# get the dates for the files... 
MCCA_DATE=$(getfiledate $MCCA)
MCPRIV_DATE=$(getfiledate $MCPRIV_DATE)
LECA_DATE=$(getfiledate $LECA)
LEPRIV_DATE=$(getfiledate $LEPRIV_DATE)

# is the Let's Encrypt CA more recent than that used by Mailcow?
# If so - update the Mailcow ones, reload Mailcow, and alert the webmaster
EX=0
if (( "$LECA_DATE" > "$MCCA_DATE" )) ; then
    create_tmp_email
    message "Need to update MailCow certs for $DOMAIN!"
    # backup the current files
    cp $MCCA $MCCA.${DATE}
    cp $MCPRIV $MCPRIV.${DATE}
    # now copy over the updated files, dereferencing the Let's Encrypt links 
    cp -L $LECA $MCCA
    cp -L $LEPRIV $MCPRIV
    # get the dates for the MailCow certs again:
    TIMESTAMP=`date  '+%Y-%m-%d %H:%M.%S'`
    MCCA_DATE=$(getfiledate $MCCA)
    MCPRIV_DATE=$(getfiledate $MCPRIV_DATE)
    if (( "$MCCA_DATE" < "$LECA_DATE" && "$MCPRIV_DATE" < "$LECAPRIV_DATE" )) ; then 
	restart_mailcow
        msg="Updated $MCCA and $MCPRIV at $TIMESTAMP"
	EMAIL_SUBJ='Success! '${EMAIL_SUBJ}
    else
	msg="Failed to update $MCCA and $MCPRIV at $TIMESTAMP"
	EMAIL_SUBJ='Failed! '${EMAIL_SUBJ}	
	EX=0
    fi
    message $msg
    send_email_report
else
    message "MailCow certs for $DOMAIN still current..."
fi

exit $EX