# -*- coding: UTF-8 -*-
# Copyright (c) 2008 - 2010, Pascal Volk
# See COPYING for distribution information.

"""
    VirtualMailManager.Relocated

    Virtual Mail Manager's Relocated class to handle relocated users.
"""

from VirtualMailManager.Domain import get_gid
from VirtualMailManager.EmailAddress import EmailAddress
from VirtualMailManager.Exceptions import VMMRelocatedException as VMMRE
from VirtualMailManager.constants.ERROR import \
     NO_SUCH_RELOCATED, RELOCATED_ADDR_DEST_IDENTICAL, RELOCATED_EXISTS


_ = lambda msg: msg


class Relocated(object):
    """Class to handle e-mail addresses of relocated users."""
    __slots__ = ('_addr', '_dest', '_gid', '_dbh')

    def __init__(self, dbh, address):
        """Creates a new *Relocated* instance.  The ``address`` is the
        old e-mail address of the user.

        Use `setDestination()` to set/update the new address, where the
        user has moved to.

        """
        assert isinstance(address, EmailAddress)
        self._addr = address
        self._dbh = dbh
        self._gid = get_gid(self._dbh, self._addr.domainname)
        self._dest = None

        self.__load()

    def __load(self):
        """Loads the destination address from the database into the
        `_dest` attribute.

        """
        dbc = self._dbh.cursor()
        dbc.execute(
            'SELECT destination FROM relocated WHERE gid=%s AND address=%s',
                    self._gid, self._addr.localpart)
        destination = dbc.fetchone()
        dbc.close()
        if destination:
            self._dest = EmailAddress(destination[0])

    def set_destination(self, destination):
        """Sets/updates the new address of the relocated user."""
        update = False
        assert isinstance(destination, EmailAddress)
        if self._addr == destination:
            raise VMMRE(_(u'Address and destination are identical.'),
                        RELOCATED_ADDR_DEST_IDENTICAL)
        if self._dest:
            if self._dest == destination:
                raise VMMRE(_(u'The relocated user %r already exists.') %
                            self._addr, RELOCATED_EXISTS)
            else:
                self._dest = destination
                update = True
        else:
            self._dest = destination

        dbc = self._dbh.cursor()
        if not update:
            dbc.execute('INSERT INTO relocated VALUES (%s, %s, %s)',
                        self._gid, self._addr.localpart, str(self._dest))
        else:
            dbc.execute('UPDATE relocated SET destination=%s \
WHERE gid=%s AND address=%s',
                        str(self._dest), self._gid, self._addr.localpart)
        self._dbh.commit()
        dbc.close()

    def get_info(self):
        """Returns the address to which mails should be sent."""
        if not self._dest:
            raise VMMRE(_(u"The relocated user %r doesn't exist.") %
                        self._addr, NO_SUCH_RELOCATED)
        return self._dest

    def delete(self):
        """Deletes the relocated entry from the database."""
        if not self._dest:
            raise VMMRE(_(u"The relocated user %r doesn't exist.") %
                        self._addr, NO_SUCH_RELOCATED)
        dbc = self._dbh.cursor()
        dbc.execute("DELETE FROM relocated WHERE gid = %s AND address = %s",
                    self._gid, self._addr.localpart)
        if dbc.rowcount > 0:
            self._dbh.commit()
        dbc.close()
        self._dest = None


del _