#!/bin/bash

# Generate virtual file for postfix
#
# Each user should have space-separated hints like "mailname1@ mailname2@gid1 mailname3@gid2"
# stored in the "Other" field (using chfn).
#
# The user of each mailgroup should have hints like "@domain1 @domain2" for each hosted domain
# stored in the "Other" field (using chfn).

#TODO: reuse getent requests (drastically improves speed with multiple domains)

function get_fullname_field()	{ getent passwd $1 | awk -F: '{print $5}' | awk -F, '{print $1}'; }
function get_roomnumber_field()	{ getent passwd $1 | awk -F: '{print $5}' | awk -F, '{print $2}'; }
function get_other_field()	{ getent passwd $1 | awk -F: '{print $5}' | awk -F, '{print $5}'; }
function get_domain()		{ echo $1 | egrep "^@[\.[:alnum:]]+$" | sed -e 's/@//'; }
function get_account()		{ echo $1 | egrep "^[\.[:alnum:]]+@($gid)?$" | sed -e 's/@.*//'; }

loop=""
for gid in $@; do
	for maildomainchunk in `get_other_field $gid`; do
		for maildomain in `get_domain $maildomainchunk`; do
			if [ $loop ]; then
				echo
				echo "##################################################################"
				echo
			fi
			loop=true
			echo "$maildomain VIRTUAL"
			echo "postmaster@$maildomain root"
			echo
			mailusers=""
			for mailgroup in `get_roomnumber_field $gid`; do
				mailusers="$mailusers `members $mailgroup`"
			done
#			for uid in `members $gid | sort`; do
			for uid in `echo $mailusers | tsort | uniq | sort`; do
				echo "# `get_fullname_field $uid` (`get_roomnumber_field $uid`)"
				uid_seen=""
				for mailaccountchunk in `get_other_field $uid`; do
					for mailaccount in `get_account $mailaccountchunk`; do
						echo "$mailaccount@$maildomain $uid"
						uid_seen=true
					done
				done
				if [ ! $uid_seen ]; then
					echo "#WARNING: No addresses for $uid"
				fi
				echo
			done
		done
	done
done