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

# Copyright (c) 2007 - 2014, Pascal Volk

# See COPYING for distribution information.

"""

    VirtualMailManager.domain

    ~~~~~~~~~~~~~~~~~~~~~~~~~

    Virtual Mail Manager's Domain class to manage e-mail domains.

"""

import os

import re

from random import choice

from VirtualMailManager.constants import \

     ACCOUNT_AND_ALIAS_PRESENT, DOMAIN_ALIAS_EXISTS, DOMAIN_EXISTS, \

     DOMAIN_INVALID, DOMAIN_TOO_LONG, NO_SUCH_DOMAIN, VMM_ERROR

from VirtualMailManager.common import validate_transport

from VirtualMailManager.errors import VMMError, DomainError as DomErr

from VirtualMailManager.maillocation import MailLocation

from VirtualMailManager.quotalimit import QuotaLimit

from VirtualMailManager.serviceset import ServiceSet

from VirtualMailManager.transport import Transport

MAILDIR_CHARS = '0123456789abcdefghijklmnopqrstuvwxyz'

RE_DOMAIN = re.compile(r"""^(?:[a-z0-9-]{1,63}\.){1,}  # one or more labels

                            (?:[a-z]{2,}               # a ASCII TLD

                            |xn--[a-z0-9]{4,})$        # or a ACE TLD""", re.X)

_ = lambda msg: msg

cfg_dget = lambda option: None

class Domain(object):

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

    __slots__ = ('_directory', '_gid', '_name', '_qlimit', '_services',

                 '_transport', '_note', '_dbh', '_new')

    def __init__(self, dbh, domainname):

        """Creates a new Domain instance.

        Loads all relevant data from the database, if the domain could be

        found.  To create a new domain call the methods set_directory() and

        set_transport() before save().

        A DomainError will be thrown when the *domainname* is the name of

        an alias domain.

        Arguments:

        `dbh` : psycopg2._psycopg.connection

          a database connection for the database access

        `domainname` : basestring

          The name of the domain

        """

        self._name = check_domainname(domainname)

        self._dbh = dbh

        self._gid = 0

        self._qlimit = None

        self._services = None

        self._transport = None

        self._directory = None

        self._note = None

        self._new = True

        self._load()

    def _load(self):

        """Load information from the database and checks if the domain name

        is the primary one.

        Raises a DomainError if Domain._name isn't the primary name of the

        domain.

        """

        dbc = self._dbh.cursor()

        dbc.execute('SELECT dd.gid, qid, ssid, tid, domaindir, is_primary, '

                    'note '

                    'FROM domain_data dd, domain_name dn WHERE domainname = '

                    '%s AND dn.gid = dd.gid', (self._name,))

        result = dbc.fetchone()

        dbc.close()

        if result:

            if not result[5]:

                raise DomErr(_("The domain '%s' is an alias domain.") %

                             self._name, DOMAIN_ALIAS_EXISTS)

            self._gid, self._directory = result[0], result[4]

            self._qlimit = QuotaLimit(self._dbh, qid=result[1])

            self._services = ServiceSet(self._dbh, ssid=result[2])

            self._transport = Transport(self._dbh, tid=result[3])

            self._note = result[6]

            self._new = False

    def _set_gid(self):

        """Sets the ID of the domain - if not set yet."""

        assert self._gid == 0

        dbc = self._dbh.cursor()

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

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

        dbc.close()

    def _check_for_addresses(self):

        """Checks dependencies for deletion. Raises a DomainError if there

        are accounts, aliases and/or relocated users.

        """

        dbc = self._dbh.cursor()

        dbc.execute('SELECT '

                    '(SELECT count(gid) FROM users WHERE gid = %(gid)u)'

                    '  as account_count, '

                    '(SELECT count(gid) FROM alias WHERE gid = %(gid)u)'

                    '  as alias_count, '

                    '(SELECT count(gid) FROM relocated WHERE gid = %(gid)u)'

                    '  as relocated_count'

                    % {'gid': self._gid})

        result = dbc.fetchall()

        dbc.close()

        result = result[0]

        if any(result):

            keys = ('account_count', 'alias_count', 'relocated_count')

            raise DomErr(_('There are %(account_count)u accounts, '

                           '%(alias_count)u aliases and %(relocated_count)u '

                           'relocated users.') % dict(list(zip(keys, result))),

                         ACCOUNT_AND_ALIAS_PRESENT)

    def _chk_state(self, must_exist=True):

        """Checks the state of the Domain instance and will raise a

        VirtualMailManager.errors.DomainError:

          - if *must_exist* is `True` and the domain doesn't exist

          - or *must_exist* is `False` and the domain exists

        """

        if must_exist and self._new:

            raise DomErr(_("The domain '%s' does not exist.") % self._name,

                         NO_SUCH_DOMAIN)

        elif not must_exist and not self._new:

            raise DomErr(_("The domain '%s' already exists.") % self._name,

                         DOMAIN_EXISTS)

    def _update_tables(self, column, value):

        """Update table columns in the domain_data table."""

        dbc = self._dbh.cursor()

        dbc.execute('UPDATE domain_data SET %s = %%s WHERE gid = %%s' % column,

                    (value, self._gid))

        if dbc.rowcount > 0:

            self._dbh.commit()

        dbc.close()

    def _update_tables_ref(self, column, value, force=False):

        """Update various columns in the domain_data table. When *force* is

        `True`, the corresponding column in the users table will be reset to

        NULL.

        Arguments:

        `column` : basestring

          Name of the table column. Currently: qid, ssid and tid

        `value` : int

          The referenced key

        `force` : bool

          reset existing users. Default: `False`

        """

        if column not in ('qid', 'ssid', 'tid'):

            raise ValueError('Unknown column: %r' % column)

        self._update_tables(column, value)

        if force:

            dbc = self._dbh.cursor()

            dbc.execute('UPDATE users SET %s = NULL WHERE gid = %%s' % column,

                        (self._gid,))

            if dbc.rowcount > 0:

                self._dbh.commit()

            dbc.close()

    @property

    def gid(self):

        """The GID of the Domain."""

        return self._gid

    @property

    def name(self):

        """The Domain's name."""

        return self._name

    @property

    def directory(self):

        """The Domain's directory."""

        return self._directory

    @property

    def quotalimit(self):

        """The Domain's quota limit."""

        return self._qlimit

    @property

    def serviceset(self):

        """The Domain's serviceset."""

        return self._services

    @property

    def transport(self):

        """The Domain's transport."""

        return self._transport

    @property

    def note(self):

        """The Domain's note."""

        return self._note

    def set_directory(self, basedir):

        """Set the path value of the Domain's directory, inside *basedir*.

        Argument:

        `basedir` : basestring

          The base directory of all domains

        """

        self._chk_state(False)

        assert self._directory is None

        self._set_gid()

        self._directory = os.path.join(basedir, choice(MAILDIR_CHARS),

                                       str(self._gid))

    def set_quotalimit(self, quotalimit):

        """Set the quota limit for the new Domain.

        Argument:

        `quotalimit` : VirtualMailManager.quotalimit.QuotaLimit

          The quota limit of the new Domain.

        """

        self._chk_state(False)

        assert isinstance(quotalimit, QuotaLimit)

        self._qlimit = quotalimit

    def set_serviceset(self, serviceset):

        """Set the services for the new Domain.

        Argument:

       `serviceset` : VirtualMailManager.serviceset.ServiceSet

         The service set for the new Domain.

        """

        self._chk_state(False)

        assert isinstance(serviceset, ServiceSet)

        self._services = serviceset

    def set_transport(self, transport):

        """Set the transport for the new Domain.

        Argument:

        `transport` : VirtualMailManager.Transport

          The transport of the new Domain

        """

        self._chk_state(False)

        assert isinstance(transport, Transport)

        validate_transport(transport,

                           MailLocation(self._dbh,

                                        mbfmt=cfg_dget('mailbox.format'),

                                        directory=cfg_dget('mailbox.root')))

        self._transport = transport

    def set_note(self, note):

        """Set the domain's (optional) note.

        Argument:

        `note` : basestring or None

          The note, or None to remove

        """

        self._chk_state(False)

        assert note is None or isinstance(note, str)

        self._note = note

    def save(self):

        """Stores the new domain in the database."""

        self._chk_state(False)

        assert all((self._directory, self._qlimit, self._services,

                    self._transport))

        dbc = self._dbh.cursor()

        dbc.execute('INSERT INTO domain_data (gid, qid, ssid, tid, domaindir, '

                    'note) '

                    'VALUES (%s, %s, %s, %s, %s, %s)', (self._gid,

                    self._qlimit.qid, self._services.ssid, self._transport.tid,

                    self._directory, self._note))

        dbc.execute('INSERT INTO domain_name (domainname, gid, is_primary) '

                    'VALUES (%s, %s, TRUE)', (self._name, self._gid))

        self._dbh.commit()

        dbc.close()

        self._new = False

    def delete(self, force=False):

        """Deletes the domain.

        Arguments:

        `force` : bool

          force the deletion of all available accounts, aliases and

          relocated users.  When *force* is `False` and there are accounts,

          aliases and/or relocated users a DomainError will be raised.

          Default `False`

        """

        if not isinstance(force, bool):

            raise TypeError('force must be a bool')

        self._chk_state()

        if not force:

            self._check_for_addresses()

        dbc = self._dbh.cursor()

        for tbl in ('alias', 'users', 'relocated', 'domain_name',

                    'domain_data'):

            dbc.execute("DELETE FROM %s WHERE gid = %u" % (tbl, self._gid))

        self._dbh.commit()

        dbc.close()

        self._gid = 0

        self._directory = self._qlimit = self._transport = None

        self._services = None

        self._new = True

    def update_quotalimit(self, quotalimit, force=False):

        """Update the quota limit of the Domain.

        If *force* is `True`, accounts-specific overrides will be reset

        for all existing accounts of the domain. Otherwise, the limit

        will only affect accounts that use the default.

        Arguments:

        `quotalimit` : VirtualMailManager.quotalimit.QuotaLimit

          the new quota limit of the domain.

        `force` : bool

          enforce new quota limit for all accounts, default `False`

        """

        self._chk_state()

        assert isinstance(quotalimit, QuotaLimit)

        if not force and quotalimit == self._qlimit:

            return

        self._update_tables_ref('qid', quotalimit.qid, force)

        self._qlimit = quotalimit

    def update_serviceset(self, serviceset, force=False):

        """Assign a different set of services to the Domain,

        If *force* is `True`, accounts-specific overrides will be reset

        for all existing accounts of the domain. Otherwise, the service

        set will only affect accounts that use the default.

        Arguments:

        `serviceset` : VirtualMailManager.serviceset.ServiceSet

          the new set of services

        `force`

          enforce the serviceset for all accounts, default `False`

        """

        self._chk_state()

        assert isinstance(serviceset, ServiceSet)

        if not force and serviceset == self._services:

            return

        self._update_tables_ref('ssid', serviceset.ssid, force)

        self._services = serviceset

    def update_transport(self, transport, force=False):

        """Sets a new transport for the Domain.

        If *force* is `True`, accounts-specific overrides will be reset

        for all existing accounts of the domain. Otherwise, the transport

        setting will only affect accounts that use the default.

        Arguments:

        `transport` : VirtualMailManager.Transport

          the new transport

        `force` : bool

          enforce new transport setting for all accounts, default `False`

        """

        self._chk_state()

        assert isinstance(transport, Transport)

        if not force and transport == self._transport:

            return

        validate_transport(transport,

                           MailLocation(self._dbh,

                                        mbfmt=cfg_dget('mailbox.format'),

                                        directory=cfg_dget('mailbox.root')))

        self._update_tables_ref('tid', transport.tid, force)

        self._transport = transport

    def update_note(self, note):

        """Sets a new note for the Domain.

        Arguments:

        `transport` : basestring or None

          the new note

        """

        self._chk_state()

        assert note is None or isinstance(note, str)

        if note == self._note:

            return

        self._update_tables('note', note)

        self._note = note