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

# Copyright (c) 2008 - 2010, Pascal Volk

# See COPYING for distribution information.

"""Virtual Mail Manager's Transport class to manage the transport for

domains and accounts."""

import VirtualMailManager.constants.ERROR as ERR

from VirtualMailManager.errors import TransportError

class Transport(object):

    """A wrapper class that provides access to the transport table"""

    __slots__ = ('__id', '__transport', '_dbh')

    def __init__(self, dbh, tid=None, transport=None):

        """Creates a new Transport instance.

        Either tid or transport must be specified.

        Keyword arguments:

        dbh -- a pyPgSQL.PgSQL.connection

        tid -- the id of a transport (long)

        transport -- the value of the transport (str)

        """

        self._dbh = dbh

        if tid is None and transport is None:

            raise TransportError(

                _('Either tid or transport must be specified.'),

                ERR.TRANSPORT_INIT)

        elif tid is not None:

            try:

                self.__id = long(tid)

            except ValueError:

                raise TransportError(_('tid must be an int/long.'),

                    ERR.TRANSPORT_INIT)

            self._loadByID()

        else:

            self.__transport = transport

            self._loadByName()

    def __eq__(self, other):

        if isinstance(other, self.__class__):

            return self.__id == other.getID()

        return NotImplemented

    def __ne__(self, other):

        if isinstance(other, self.__class__):

            return self.__id != other.getID()

        return NotImplemented

    def __str__(self):

        return self.__transport

    def _loadByID(self):

        dbc = self._dbh.cursor()

        dbc.execute('SELECT transport FROM transport WHERE tid = %s', self.__id)

        result = dbc.fetchone()

        dbc.close()

        if result is not None:

            self.__transport = result[0]

        else:

            raise TransportError(_('Unknown tid specified.'),

                ERR.UNKNOWN_TRANSPORT_ID)

    def _loadByName(self):

        dbc = self._dbh.cursor()

        dbc.execute('SELECT tid FROM transport WHERE transport = %s',

                self.__transport)

        result = dbc.fetchone()

        dbc.close()

        if result is not None:

            self.__id = result[0]

        else:

            self._save()

    def _save(self):

        dbc = self._dbh.cursor()

        dbc.execute("SELECT nextval('transport_id')")

        self.__id = dbc.fetchone()[0]

        dbc.execute('INSERT INTO transport (tid, transport) VALUES (%s, %s)',

                self.__id, self.__transport)

        self._dbh.commit()

        dbc.close()

    def getID(self):

        """Returns the unique ID of the transport."""

        return self.__id

    def getTransport(self):

        """Returns the value of transport, ex: 'dovecot:'"""

        return self.__transport