#! /usr/bin/env python

import os, string

USERPREFIX="usr"
EXIMCONFDIR="etc/exim/"
VIRTUALDOMDIR=EXIMCONFDIR+"virtual/"

# if [ -n $USERPREFIX ]; then
# 	USERPREFIX="usr"
# fi

# if [ $1 == "" ]; then
# 	echo "give <UserNumber>p<pop3Account> as parameter"
# 	exit
# fi

# NEWUSER="$USERPREFIX$1"
# NEWHOME="/home/mail/$NEWUSER"
# NEWPASS=$(apg -n 1 -a 1 -CL -m 8 -x 12)
# echo $NEWHOME

# adduser --home "$NEWHOME" --shell /bin/true --no-create-home --firstuid 20000 --ingroup poponly --disabled-password --disabled-login --gecos "Popuser $NEWUSER" $NEWUSER

# mkdir -p "$NEWHOME"
# chown -Rc $NEWUSER.poponly "$NEWHOME"
# echo "${NEWUSER}:${NEWPASS}" | chpasswd

# echo "Herzlich willkommen auf dem GNU-Viech" | mail -s "Willkommen auf dem GNU-Viech" ${NEWUSER}
# echo added new pop3 user $NEWUSER with password $NEWPASS

def readaliasfile(domainname):
    """reads the aliasfile for the given domain and returns a dictionary
    object with the aliases
    """
    aliases={}
    if (os.access(VIRTUALDOMDIR, os.R_OK)):
        try:
            aliasfile=open(VIRTUALDOMDIR+domainname, 'r')
            for line in aliasfile.readlines():
                keyvals = string.split(line,":",1)
                aliases[keyvals[0]]=keyvals[1].strip()
            aliasfile.close()
        except IOError:
            print "couldn't read the aliasfile for "+domainname+"."
    else:
        print "couldn't read from "+VIRTUALDOMDIR+"."
    return aliases

def writealiasfile(domainname, aliases):
    """writes the aliasfile for the given domain with the aliases defined
    in the dictionary object aliases
    """
    if (os.access(VIRTUALDOMDIR, os.W_OK)):
        try:
            aliasfile=open(VIRTUALDOMDIR+domainname, 'w')
            for key in aliases.keys():
                aliasfile.write(key+":"+aliases[key]+"\n")
            aliasfile.close()
        except IOError:
            print "writing to aliasfile failed."
    else:
        print "no write access to directory "+VIRTUALDOMDIR+"."

def createpopaccount(domainname, sysuser):
    """Creates a pop3/imap account for given domain and system user"""
    "addpopuser sysusrp<num>"

def setmailalias(domainname, alias, target):
    """sets a mail alias for given domain which directs the MTA to the
    given target
    """
    aliases=readaliasfile(domainname)
    aliases[alias]=target
    writealiasfile(domainname, aliases)

createpopaccount("test.de", "usr03")
setmailalias("test.de", "doedel", "horst@dittberner.info")