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

# Copyright (c) 2007 - 2011, 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

from VirtualMailManager.errors import DomainError as DomErr

from VirtualMailManager.pycompat import all, any

from VirtualMailManager.quotalimit import QuotaLimit

from VirtualMailManager.transport import Transport

MAILDIR_CHARS = '0123456789abcdefghijklmnopqrstuvwxyz'

RE_DOMAIN = re.compile(r"^(?:[a-z0-9-]{1,63}\.){1,}[a-z]{2,6}$")

_ = lambda msg: msg

class Domain(object):

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

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

                 '_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` : pyPgSQL.PgSQL.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._transport = None

        self._directory = 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, tid, domaindir, is_primary 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[4]:

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

                             self._name, DOMAIN_ALIAS_EXISTS)

            self._gid, self._directory = result[0], result[3]

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

            self._transport = Transport(self._dbh, tid=result[2])

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

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

                    'UNION SELECT count(gid) FROM relocated WHERE gid = '

                    '%(gid)u' % {'gid': self._gid})

        result = dbc.fetchall()

        dbc.close()

        result = [count[0] for count in result]

        if any(result):

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

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

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

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

                         ACCOUNT_AND_ALIAS_PRESENT)

    def _chk_state(self):

        """Throws a DomainError if the Domain is new - not saved in the

        database."""

        if self._new:

            raise DomErr(_(u"The domain '%s' doesn't exist.") % self._name,

                         NO_SUCH_DOMAIN)

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

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

        `True` also the corresponding column in the users table will be

        updated.

        Arguments:

        `column` : basestring

          Name of the table column. Currently: qid and tid

        `value` : long

          The referenced key

        `force` : bool

          enforce the new setting also for existing users. Default: `False`

        """

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

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

        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()

        if force:

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

                        (value, 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 transport(self):

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

        return self._transport

    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

        """

        if not self._new:

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

                         DOMAIN_EXISTS)

        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.

        """

        if not self._new:

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

                         DOMAIN_EXISTS)

        assert isinstance(quotalimit, QuotaLimit)

        self._qlimit = quotalimit

    def set_transport(self, transport):

        """Set the transport for the new Domain.

        Argument:

        `transport` : VirtualMailManager.Transport

          The transport of the new Domain

        """

        if not self._new:

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

                         DOMAIN_EXISTS)

        assert isinstance(transport, Transport)

        self._transport = transport

    def save(self):

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

        if not self._new:

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

                         DOMAIN_EXISTS)

        assert all((self._directory, self._qlimit, self._transport))

        dbc = self._dbh.cursor()

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

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

                    self._transport.tid, self._directory))

        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._new = True

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

        """Update the quota limit of the Domain.

        If *force* is `True` the new *quotalimit* will be applied to

        all existing accounts of the domain. Otherwise the *quotalimit*

        will be only applied to accounts created from now on.

        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 quotalimit == self._qlimit:

            return

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

        self._qlimit = quotalimit

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

        """Sets a new transport for the Domain.

        If *force* is `True` the new *transport* will be assigned to all

        existing accounts.  Otherwise the *transport* will be only used for

        accounts created from now on.

        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 transport == self._transport:

            return

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

        self._transport = transport

    def get_info(self):

        """Returns a dictionary with information about the domain."""

        self._chk_state()

        dbc = self._dbh.cursor()

        dbc.execute('SELECT gid, domainname, transport, domaindir, '

                    'aliasdomains, accounts, aliases, relocated, bytes, '

                    'messages FROM vmm_domain_info WHERE gid = %s',

                    (self._gid,))

        info = dbc.fetchone()

        dbc.close()

        keys = ('gid', 'domainname', 'transport', 'domaindir', 'aliasdomains',

                'accounts', 'aliases', 'relocated', 'bytes', 'messages')

        return dict(zip(keys, info))

    def get_accounts(self):

        """Returns a list with all accounts of the domain."""

        self._chk_state()

        dbc = self._dbh.cursor()

        dbc.execute('SELECT local_part from users where gid = %s ORDER BY '

                    'local_part', (self._gid,))

        users = dbc.fetchall()

        dbc.close()

        accounts = []

        if users:

            addr = u'@'.join

            _dom = self._name

            accounts = [addr((account[0], _dom)) for account in users]

        return accounts

    def get_aliases(self):

        """Returns a list with all aliases e-mail addresses of the domain."""

        self._chk_state()

        dbc = self._dbh.cursor()

        dbc.execute('SELECT DISTINCT address FROM alias WHERE gid = %s ORDER '

                    'BY address', (self._gid,))

        addresses = dbc.fetchall()

        dbc.close()

        aliases = []

        if addresses:

            addr = u'@'.join

            _dom = self._name

            aliases = [addr((alias[0], _dom)) for alias in addresses]

        return aliases

    def get_relocated(self):

        """Returns a list with all addresses of relocated users."""

        self._chk_state()

        dbc = self._dbh.cursor()

        dbc.execute('SELECT address FROM relocated WHERE gid = %s ORDER BY '

                    'address', (self._gid,))

        addresses = dbc.fetchall()

        dbc.close()

        relocated = []

        if addresses:

            addr = u'@'.join

            _dom = self._name

            relocated = [addr((address[0], _dom)) for address in addresses]

        return relocated

    def get_aliase_names(self):

        """Returns a list with all alias domain names of the domain."""

        self._chk_state()

        dbc = self._dbh.cursor()

        dbc.execute('SELECT domainname FROM domain_name WHERE gid = %s AND '

                    'NOT is_primary ORDER BY domainname', (self._gid,))

        anames = dbc.fetchall()

        dbc.close()

        aliasdomains = []

        if anames:

            aliasdomains = [aname[0] for aname in anames]

        return aliasdomains

def check_domainname(domainname):

    """Returns the validated domain name `domainname`.

    Throws an `DomainError`, if the domain name is too long or doesn't

    look like a valid domain name (label.label.label).

    """

    if not RE_DOMAIN.match(domainname):

        domainname = domainname.encode('idna')

    if len(domainname) > 255:

        raise DomErr(_(u'The domain name is too long'), DOMAIN_TOO_LONG)

    if not RE_DOMAIN.match(domainname):

        raise DomErr(_(u"The domain name '%s' is invalid") % domainname,

                     DOMAIN_INVALID)

    return domainname

def get_gid(dbh, domainname):

    """Returns the group id of the domain *domainname*.