# -*- coding: UTF-8 -*-

# Copyright (c) 2007 - 2010, Pascal Volk

# See COPYING for distribution information.

"""Virtual Mail Manager's Alias class to manage e-mail aliases."""

import VirtualMailManager.constants.ERROR as ERR

from VirtualMailManager.Domain import Domain

from VirtualMailManager.EmailAddress import EmailAddress

from VirtualMailManager.Exceptions import VMMAliasException as VMMAE

import VirtualMailManager as VMM

class Alias(object):

    """Class to manage e-mail aliases."""

    __slots__ = ('_addr', '_dest', '_gid', '_isNew', '_dbh')

    def __init__(self, dbh, address, destination=None):

        if isinstance(address, EmailAddress):

            self._addr = address

        else:

            raise TypeError("Argument 'address' is not an EmailAddress")

        if destination is None:

            self._dest = None

        elif isinstance(destination, EmailAddress):

            self._dest = destination

        else:

            raise TypeError("Argument 'destination' is not an EmailAddress")

        if address == destination:

            raise VMMAE(_(u"Address and destination are identical."),

                ERR.ALIAS_ADDR_DEST_IDENTICAL)

        self._dbh = dbh

        self._gid = 0

        self._isNew = False

        self._setAddr()

        if not self._dest is None:

            self._exists()

        if VMM.VirtualMailManager.accountExists(self._dbh, self._addr):

            raise VMMAE(_(u"There is already an account with address “%s”.") %\

                    self._addr, ERR.ACCOUNT_EXISTS)

        if VMM.VirtualMailManager.relocatedExists(self._dbh, self._addr):

            raise VMMAE(

              _(u"There is already a relocated user with the address “%s”.") %\

                    self._addr, ERR.RELOCATED_EXISTS)

    def _exists(self):

        dbc = self._dbh.cursor()

        dbc.execute("SELECT gid FROM alias WHERE gid=%s AND address=%s\

 AND destination=%s", self._gid, self._addr._localpart, str(self._dest))

        gid = dbc.fetchone()

        dbc.close()

        if gid is None:

            self._isNew = True

    def _setAddr(self):

        dom = Domain(self._dbh, self._addr._domainname)

        self._gid = dom.getID()

        if self._gid == 0:

            raise VMMAE(_(u"The domain “%s” doesn't exist.") %\

                    self._addr._domainname, ERR.NO_SUCH_DOMAIN)

    def _checkExpansion(self, limit):

        dbc = self._dbh.cursor()

        dbc.execute('SELECT count(gid) FROM alias where gid=%s AND address=%s',

                self._gid, self._addr._localpart)

        curEx = dbc.fetchone()[0]

        dbc.close()

        if curEx == limit:

            errmsg = _(u"""Can't add new destination to alias “%(address)s”.

Currently this alias expands into %(count)i recipients.

One more destination will render this alias unusable.

Hint: Increase Postfix' virtual_alias_expansion_limit

""") % {'address': self._addr, 'count': curEx}

            raise VMMAE(errmsg, ERR.ALIAS_EXCEEDS_EXPANSION_LIMIT)

    def save(self, expansion_limit):

        if self._dest is None:

           raise VMMAE(_(u"No destination address specified for alias."),

               ERR.ALIAS_MISSING_DEST)

        if self._isNew:

            self._checkExpansion(expansion_limit)

            dbc = self._dbh.cursor()

            dbc.execute("INSERT INTO alias (gid, address, destination) VALUES\

 (%s, %s, %s)", self._gid, self._addr._localpart, str(self._dest))

            self._dbh.commit()

            dbc.close()

        else:

            raise VMMAE(

               _(u"The alias “%(a)s” with destination “%(d)s” already exists.")\

                       % {'a': self._addr, 'd': self._dest}, ERR.ALIAS_EXISTS)

    def getInfo(self):

        dbc = self._dbh.cursor()

        dbc.execute('SELECT destination FROM alias WHERE gid=%s AND address=%s',

                self._gid, self._addr._localpart)

        destinations = dbc.fetchall()

        dbc.close()

        if len(destinations) > 0:

            targets = [destination[0] for destination in destinations]

            return targets

        else:

            raise VMMAE(_(u"The alias “%s” doesn't exist.") % self._addr,

                    ERR.NO_SUCH_ALIAS)

    def delete(self):

        dbc = self._dbh.cursor()

        if self._dest is None:

            dbc.execute("DELETE FROM alias WHERE gid=%s AND address=%s",

                    self._gid, self._addr._localpart)

        else:

            dbc.execute("DELETE FROM alias WHERE gid=%s AND address=%s AND \

 destination=%s", self._gid, self._addr._localpart, str(self._dest))

        rowcount = dbc.rowcount

        dbc.close()

        if rowcount > 0:

            self._dbh.commit()

        else:

            if self._dest is None:

                msg = _(u"The alias “%s” doesn't exist.") % self._addr

            else:

                msg = _(u"The alias “%(a)s” with destination “%(d)s” doesn't\

 exist.") % {'a': self._addr, 'd': self._dest}

            raise VMMAE(msg, ERR.NO_SUCH_ALIAS)