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

# Copyright (c) 2007 - 2010, 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 encodings.idna import ToASCII, ToUnicode

from random import choice

from VirtualMailManager.constants.ERROR import \

     ACCOUNT_AND_ALIAS_PRESENT, ACCOUNT_PRESENT, ALIAS_PRESENT, \

     DOMAIN_ALIAS_EXISTS, DOMAIN_EXISTS, DOMAIN_INVALID, DOMAIN_TOO_LONG, \

     NO_SUCH_DOMAIN

from VirtualMailManager.errors import DomainError as DomErr

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', '_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._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()

        result = dbc.fetchone()

        dbc.close()

        if result:

            if not result[3]:

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

                             self._name, DOMAIN_ALIAS_EXISTS)

            self._gid, self._directory = result[0], result[2]

            self._transport = Transport(self._dbh, tid=result[1])

            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 _has(self, what):

        """Checks if aliases or accounts are assigned to the domain.

        If there are assigned accounts or aliases True will be returned,

        otherwise False will be returned.

        Argument:

        `what` : basestring

            "alias" or "users"

        """

        assert what in ('alias', 'users')

        dbc = self._dbh.cursor()

        if what == 'users':

            dbc.execute("SELECT count(gid) FROM users WHERE gid=%s", self._gid)

        else:

            dbc.execute("SELECT count(gid) FROM alias WHERE gid=%s", self._gid)

        count = dbc.fetchone()

        dbc.close()

        return count[0] > 0

    def _chk_delete(self, deluser, delalias):

        """Checks dependencies for deletion.

        Arguments:

        deluser -- ignore available accounts (bool)

        delalias -- ignore available aliases (bool)

        """

        if not deluser:

            hasuser = self._has('users')

        else:

            hasuser = False

        if not delalias:

            hasalias = self._has('alias')

        else:

            hasalias = False

        if hasuser and hasalias:

            raise DomErr(_(u'There are accounts and aliases.'),

                         ACCOUNT_AND_ALIAS_PRESENT)

        elif hasuser:

            raise DomErr(_(u'There are accounts.'), ACCOUNT_PRESENT)

        elif hasalias:

            raise DomErr(_(u'There are aliases.'), 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)

    @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

    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

        """

        assert self._new and self._directory is None

        self._set_gid()

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

                                       str(self._gid))

    @property

    def transport(self):

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

        return self._transport

    def set_transport(self, transport):

        """Set the transport for the new Domain.

        Argument:

        `transport` : VirtualMailManager.Transport

          The transport of the new Domain

        """

        assert self._new and 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 self._directory is not None and self._transport is not None

        dbc = self._dbh.cursor()

        dbc.execute("INSERT INTO domain_data VALUES (%s, %s, %s)", self._gid,

                    self._transport.tid, self._directory)

        dbc.execute("INSERT INTO domain_name VALUES (%s, %s, %s)", self._name,

                    self._gid, True)

        self._dbh.commit()

        dbc.close()

        self._new = False

    def delete(self, deluser=False, delalias=False):

        """Deletes the domain.

        Arguments:

        `deluser` : bool

          force deletion of all available accounts, default `False`

        `delalias` : bool

          force deletion of all available aliases, default `False`

        """

        self._chk_state()

        self._chk_delete(deluser, delalias)

        dbc = self._dbh.cursor()

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

                    'domain_data'):

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

        self._dbh.commit()

        dbc.close()

        self._gid = 0

        self._directory = self._transport = None

        self._new = True

    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

        dbc = self._dbh.cursor()

        dbc.execute("UPDATE domain_data SET tid = %s WHERE gid = %s",

                    transport.tid, self._gid)

        if dbc.rowcount > 0:

            self._dbh.commit()

        if force:

            dbc.execute("UPDATE users SET tid = %s WHERE gid = %s",

                        transport.tid, self._gid)

            if dbc.rowcount > 0:

                self._dbh.commit()

        dbc.close()

        self._transport = transport

    def get_info(self):

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

        self._chk_state()

        dbc = self._dbh.cursor()

        info = dbc.fetchone()

        dbc.close()

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

                'accounts', 'aliases', 'relocated')

        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()

        users = dbc.fetchall()

        dbc.close()

        accounts = []

            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()

        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()

        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()

        anames = dbc.fetchall()

        dbc.close()

        aliasdomains = []

        if anames:

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

        return aliasdomains

def ace2idna(domainname):

    """Converts the domain name `domainname` from ACE according to IDNA."""

    return u'.'.join([ToUnicode(lbl) for lbl in domainname.split('.') if lbl])

def check_domainname(domainname):

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

    It also converts the name of the domain from IDN to ASCII, if

    necessary.

    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 = idn2ascii(domainname)

    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*.

    If the domain couldn't be found in the database 0 will be returned.

    """

    domainname = check_domainname(domainname)

    dbc = dbh.cursor()

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

    gid = dbc.fetchone()

    dbc.close()

    if gid:

        return gid[0]

    return 0

def idn2ascii(domainname):

    """Converts the idn domain name `domainname` into punycode."""

    return '.'.join([ToASCII(lbl) for lbl in domainname.split('.') if lbl])

def search(dbh, pattern=None, like=False):

    """'Search' for domains by *pattern* in the database.

    *pattern* may be a domain name or a partial domain name - starting

    and/or ending with a '%' sign.  When the *pattern* starts or ends with

    a '%' sign *like* has to be `True` to perform a wildcard search.

    To retrieve all available domains use the arguments' default values.

    This function returns a tuple with a list and a dict: (order, domains).

    The order list contains the domains' gid, alphabetical sorted by the

    primary domain name.  The domains dict's keys are the gids of the

    domains. The value of item is a list.  The first list element contains

    the primary domain name or `None`.  The elements [1:] contains the

    names of alias domains.

    Arguments:

    `pattern` : basestring

      a (partial) domain name (starting and/or ending with a "%" sign)

    `like` : bool

      should be `True` when *pattern* starts/ends with a "%" sign

    """

    if pattern and not like:

        pattern = check_domainname(pattern)

    sql = 'SELECT gid, domainname, is_primary FROM domain_name'

    if pattern:

        if like:

            sql += " WHERE domainname LIKE '%s'" % pattern