#!/bin/sh
#
# postinst -- clamsmtp post-installation configuration script
#
set -e

if [ ${DEBUG} ] ; then set -x ; fi

CUSER=clamsmtp
CGROUP=clamsmtp
CONFFILE=/etc/clamsmtpd.conf
DEFFILE=/etc/default/clamsmtp
RUNDIR=/var/run/clamsmtp
SPOOLDIR=/var/spool/clamsmtp

# If this is an upgrade, get current configuration
if [ -n "$2" ] ; then
    # Set up environment -- I know.  Hackery, but useful.
    if [ -f ${CONFFILE} ] ; then
        eval `sed -e '
# Delete comments
/^#.*/d

# Delete blank lines
/^[[:space:]]*$/d

# Replace first ": " with "=" and surround with quotes
s/^\([a-zA-Z]*\):[[:space:]]*\(.*\)$/\1\="\2";/
' < ${CONFFILE}` || true
    fi

    # Pull in config file settings if available
    # Set default variables
    RUNDIR=`dirname ${Pidfile:-"/var/run/clamsmtp/clamsmtpd.pid"}`
    SPOOLDIR=${TempDirectory}
    CUSER=${User}

    # Read the defaults file
    if [ -f ${DEFFILE} ] ; then
        . ${DEFFILE}
    fi
fi

#
# NOTE: I can't place the debconf source at the top of the file because I'm
# using sed to grab configuration information.  Weirdness happens otherwise and
# postinst hangs.
#
if [ -f /usr/share/debconf/confmodule ]; then
    . /usr/share/debconf/confmodule
fi

# Fix directory permissions
fixperms () {
    if (getent passwd ${CUSER}>/dev/null) && \
            (getent group ${CGROUP}>/dev/null) ; then
		    # Spool directory: Don't touch /tmp or /var/tmp
		    if [ "x${SPOOLDIR}" != "x/tmp" -a "x${SPOOLDIR}" != "x/var/tmp" ] ; then
			chown ${CUSER}':'${CGROUP} ${SPOOLDIR} || return 1
			chmod 750 ${SPOOLDIR} || return 1
		    fi
    fi

  return 0
}

# Create directories if new installation configure step
install_dirs() {
    # Build the spool directory if it doesn't exist
    if [ ! -d ${SPOOLDIR} ] ; then
        install -m 750 -d ${SPOOLDIR} || return 1
	fixperms
    fi

    # Build the run directory if it doesn't exist
    if [ ! -d ${RUNDIR} ] ; then
        install -o ${CUSER} -g ${CGROUP} -m 755 -d ${RUNDIR} || return 2
    fi

    return 0
}

# Add the clamsmtp user and group
add_user_group() {
    if (getent passwd ${CUSER}>/dev/null) && \
            (getent group ${CGROUP}>/dev/null) ; then
        return 1
    fi

    # Build the spool directory if it doesn't exist.
    if [ ! -d ${SPOOLDIR} ] ; then
        install -m 750 -d ${SPOOLDIR} || return 1
    fi

    adduser --system --group --no-create-home --quiet \
        --disabled-login --disabled-password \
        --shell /bin/false --home ${SPOOLDIR} ${CUSER} || return 2

    fixperms

    return 0
}

add_clamav2group() {
    # Add the clamav user to the clamsmtp group -- we can assume clamav exists
    # because of the dependency on clamav-daemon
    if ! (getent group ${CGROUP} | grep -q clamav>/dev/null) ; then
        adduser clamav ${CGROUP} || return $?

        # We need to restart the clamav-daemon process to use the new
        # permissions.  Although currently the restart functionality of
        # the clamav-daemon init script simply calls start/stop, we
        # cannot count on that for the future.
        invoke-rc.d clamav-daemon stop && \
            invoke-rc.d clamav-daemon start
   fi

    return 0
}

# Add CUSER to mail aliases if it isn't there
add_mail_alias () {
    AFILE=/etc/aliases
    # Add clamsmtp alias for root
    if [ ! -f ${AFILE} -o ! -L ${AFILE} ]; then
        return 1
    fi

    if ! grep -qi "^${CUSER}" ${AFILE}; then
        echo "${CUSER}: root" >> ${AFILE}
        newal=`which newaliases` || true
        if [ $newal ] && [ -x $newal ]; then
            newaliases || return 2
        fi
    fi

    return 0
}

# Update the configuration file with CUSER
update_config () {
    if (egrep -q "^User: ${CUSER}" ${CONFFILE}); then
        # config file is correct
        return 0
    fi

    TMP=`tempfile` || return 1
    cat ${CONFFILE} > ${TMP} || return 2
    sed -e "s/^\(User:\).*/\1 ${CUSER}/" < ${TMP} > ${CONFFILE} || return 3

    return 0
}

case $1 in
    configure)
        # Create new clamsmtp system user/group?
        db_get clamsmtp/addusergroup
        if [ "${RET}" = "true" ] ; then
            CUSER=clamsmtp
            CGROUP=clamsmtp

            # Add the clamsmtp user and group
            if (add_user_group) ; then
                # Make sure it only happens once
                db_set clamsmtp/addusergroup false || true
                # set do-fixperms true
                db_set clamsmtp/do-fixperms true
            else
                # We couldn't add clamsmtp for some reason
                db_set clamsmtp/do-fixperms false
            fi

            # Add clamav to group
            add_clamav2group
            
            # Add clamsmtp to aliases file
            add_mail_alias || true

            # Update configuration file
            update_config

        fi

        # New installation
        if [ -z "$2" ] ; then
            install_dirs
        # Upgrade
        else
            # Should we fix permissions?
            db_get clamsmtp/do-fixperms
            if [ "${RET}" = "true" ] ; then
                fixperms
                db_set clamsmtp/do-fixperms false
            fi # END do-fixperms
        fi
    ;;
esac

# Stop debconf before the init.d script starts -- uses sed again
db_stop

# Automatically added by dh_installinit
if [ -x "/etc/init.d/clamsmtp" ]; then
	update-rc.d clamsmtp defaults >/dev/null
	if [ -x "`which invoke-rc.d 2>/dev/null`" ]; then
		invoke-rc.d clamsmtp start || exit $?
	else
		/etc/init.d/clamsmtp start || exit $?
	fi
fi
# End automatically added section


exit 0