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

# Copyright (c) 2007 - 2011, Pascal Volk

# See COPYING for distribution information.

"""

    VirtualMailManager.account

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

    Virtual Mail Manager's Account class to manage e-mail accounts.

"""

from VirtualMailManager.common import version_str

from VirtualMailManager.constants import \

     ACCOUNT_EXISTS, ACCOUNT_MISSING_PASSWORD, ALIAS_PRESENT, \

     INVALID_ARGUMENT, INVALID_MAIL_LOCATION, NO_SUCH_ACCOUNT, \

     NO_SUCH_DOMAIN, VMM_ERROR

from VirtualMailManager.domain import Domain

from VirtualMailManager.emailaddress import EmailAddress

from VirtualMailManager.errors import VMMError, AccountError as AErr

from VirtualMailManager.maillocation import MailLocation

from VirtualMailManager.password import pwhash

from VirtualMailManager.quotalimit import QuotaLimit

from VirtualMailManager.transport import Transport

from VirtualMailManager.serviceset import ServiceSet

__all__ = ('Account', 'get_account_by_uid')

_ = lambda msg: msg

cfg_dget = lambda option: None

class Account(object):

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

    __slots__ = ('_addr', '_dbh', '_domain', '_mail', '_new', '_passwd',

                 '_qlimit', '_services', '_transport', '_uid')

    def __init__(self, dbh, address):

        """Creates a new Account instance.

        When an account with the given *address* could be found in the

        database all relevant data will be loaded.

        Arguments:

        `dbh` : pyPgSQL.PgSQL.Connection

          A database connection for the database access.

        `address` : VirtualMailManager.EmailAddress.EmailAddress

          The e-mail address of the (new) Account.

        """

        if not isinstance(address, EmailAddress):

            raise TypeError("Argument 'address' is not an EmailAddress")

        self._addr = address

        self._dbh = dbh

        self._domain = Domain(self._dbh, self._addr.domainname)

        if not self._domain.gid:

            # TP: Hm, what “quotation marks” should be used?

            # If you are unsure have a look at:

            # http://en.wikipedia.org/wiki/Quotation_mark,_non-English_usage

            raise AErr(_(u"The domain '%s' does not exist.") %

                       self._addr.domainname, NO_SUCH_DOMAIN)

        self._uid = 0

        self._mail = None

        self._passwd = None

        self._new = True

        self._load()

    def __nonzero__(self):

        """Returns `True` if the Account is known, `False` if it's new."""

        return not self._new

    def _load(self):

        """Load 'uid', 'mid', 'qid', 'ssid'  and 'tid' from the database and

        set _new to `False` - if the user could be found. """

        dbc = self._dbh.cursor()

        dbc.execute('SELECT uid, mid, qid, ssid, tid FROM users WHERE gid = '

                    '%s AND local_part = %s', (self._domain.gid,

                                               self._addr.localpart))

        result = dbc.fetchone()

        dbc.close()

        if result:

            self._uid, _mid, _qid, _ssid, _tid = result

            self._mail = MailLocation(self._dbh, mid=_mid)

            self._new = False

    def _set_uid(self):

        """Set the unique ID for the new Account."""

        assert self._uid == 0

        dbc = self._dbh.cursor()

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

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

        dbc.close()

    def _prepare(self, maillocation):

        """Check and set different attributes - before we store the

        information in the database.

        """

        if maillocation.dovecot_version > cfg_dget('misc.dovecot_version'):

            raise AErr(_(u"The mailbox format '%(mbfmt)s' requires Dovecot "

                         u">= v%(version)s.") % {

                       'mbfmt': maillocation.mbformat,

                       'version': version_str(maillocation.dovecot_version)},

                       INVALID_MAIL_LOCATION)

        if not maillocation.postfix and \

          self._transport.transport.lower() in ('virtual:', 'virtual'):

            raise AErr(_(u"Invalid transport '%(transport)s' for mailbox "

                         u"format '%(mbfmt)s'.") %

                       {'transport': self._transport,

                        'mbfmt': maillocation.mbformat}, INVALID_MAIL_LOCATION)

        self._mail = maillocation

        self._set_uid()

    def _update_tables(self, column, value):

        """Update various columns in the users table.

        Arguments:

        `column` : basestring

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

        `value` : long

          The referenced key

        """

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

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

        dbc = self._dbh.cursor()

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

                    (value, self._uid))

        if dbc.rowcount > 0:

            self._dbh.commit()

        dbc.close()

    def _count_aliases(self):

        """Count all alias addresses where the destination address is the

        address of the Account."""

        dbc = self._dbh.cursor()

        dbc.execute('SELECT COUNT(destination) FROM alias WHERE destination '

                    '= %s', (str(self._addr),))

        a_count = dbc.fetchone()[0]

        dbc.close()

        return a_count

    def _chk_state(self):

        """Raise an AccountError if the Account is new - not yet saved in the

        database."""

        if self._new:

            raise AErr(_(u"The account '%s' does not exist.") % self._addr,

                       NO_SUCH_ACCOUNT)

    @property

    def address(self):

        """The Account's EmailAddress instance."""

        return self._addr

    @property

    def domain(self):

        """The Domain to which the Account belongs to."""

        if self._domain:

            return self._domain

        return None

    @property

    def gid(self):

        """The Account's group ID."""

        if self._domain:

            return self._domain.gid

        return None

    @property

    def home(self):

        """The Account's home directory."""

        if not self._new:

            return '%s/%s' % (self._domain.directory, self._uid)

        return None

    @property

    def mail_location(self):

        """The Account's MailLocation."""

        return self._mail

    @property

    def uid(self):

        """The Account's unique ID."""

        return self._uid

    def set_password(self, password):

        """Set a password for the new Account.

        If you want to update the password of an existing Account use

        Account.modify().

        Argument:

        `password` : basestring

          The password for the new Account.

        """

        if not self._new:

            raise AErr(_(u"The account '%s' already exists.") % self._addr,

                       ACCOUNT_EXISTS)

        if not isinstance(password, basestring) or not password:

            raise AErr(_(u"Could not accept password: '%s'") % password,

                       ACCOUNT_MISSING_PASSWORD)

        self._passwd = password

    def save(self):

        """Save the new Account in the database."""

        if not self._new:

            raise AErr(_(u"The account '%s' already exists.") % self._addr,

                       ACCOUNT_EXISTS)

        if not self._passwd:

            raise AErr(_(u"No password set for account: '%s'") % self._addr,

                       ACCOUNT_MISSING_PASSWORD)

        self._prepare(MailLocation(self._dbh, mbfmt=cfg_dget('mailbox.format'),

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

        dbc = self._dbh.cursor()

        dbc.execute('INSERT INTO users (local_part, passwd, uid, gid, mid, '

                    'qid, ssid, tid) VALUES (%s, %s, %s, %s, %s, %s, %s, %s)',

                    (self._addr.localpart,

                     pwhash(self._passwd, user=self._addr), self._uid,

        self._dbh.commit()

        dbc.close()

        self._new = False

    def modify(self, field, value):

        """Update the Account's *field* to the new *value*.

        Possible values for *field* are: 'name', 'password'.

        Arguments:

        `field` : basestring

          The attribute name: 'name' or 'password'

        `value` : basestring

          The new value of the attribute.

        """

        if field not in ('name', 'password'):

            raise AErr(_(u"Unknown field: '%s'") % field, INVALID_ARGUMENT)

        self._chk_state()

        dbc = self._dbh.cursor()

        if field == 'password':

            dbc.execute('UPDATE users SET passwd = %s WHERE uid = %s',

                        (pwhash(value, user=self._addr), self._uid))

        else:

            dbc.execute('UPDATE users SET name = %s WHERE uid = %s',

                        (value, self._uid))

        if dbc.rowcount > 0:

            self._dbh.commit()

        dbc.close()

    def update_quotalimit(self, quotalimit):

        """Update the user's quota limit.

        Arguments:

        `quotalimit` : VirtualMailManager.quotalimit.QuotaLimit

          the new quota limit of the domain.

        """

        if cfg_dget('misc.dovecot_version') < 0x10102f00:

            raise VMMError(_(u'PostgreSQL-based dictionary quota requires '

                             u'Dovecot >= v1.1.2.'), VMM_ERROR)

        self._chk_state()

        if quotalimit == self._qlimit:

            return

        self._qlimit = quotalimit

    def update_serviceset(self, serviceset):

        """Assign a different set of services to the Account.

        Argument:

        `serviceset` : VirtualMailManager.serviceset.ServiceSet

          the new service set.

        """

        self._chk_state()

        if serviceset == self._services:

            return

        self._services = serviceset

    def update_transport(self, transport):

        """Sets a new transport for the Account.

        Arguments:

        `transport` : VirtualMailManager.transport.Transport

          the new transport

        """

        self._chk_state()

        if transport == self._transport:

            return

        self._transport = transport

    def get_info(self):

        """Returns a dict with some information about the Account.

        The keys of the dict are: 'address', 'gid', 'home', 'imap'

        'mail_location', 'name', 'pop3', 'sieve', 'smtp', transport', 'uid',

        'uq_bytes', 'uq_messages', 'ql_bytes', and 'ql_messages'.

        """

        self._chk_state()

        dbc = self._dbh.cursor()

        dbc.execute('SELECT name, CASE WHEN bytes IS NULL THEN 0 ELSE bytes '

                    'END, CASE WHEN messages IS NULL THEN 0 ELSE messages END '

                    'FROM users LEFT JOIN userquota USING (uid) WHERE '

                    'users.uid = %s', (self._uid,))

        info = dbc.fetchone()

        dbc.close()

        if info:

            info = dict(zip(('name', 'uq_bytes', 'uq_messages'), info))

            info['address'] = self._addr

            info['gid'] = self._domain.gid

            info['home'] = '%s/%s' % (self._domain.directory, self._uid)

            info['mail_location'] = self._mail.mail_location

            info['ql_bytes'] = self._qlimit.bytes

            info['ql_messages'] = self._qlimit.messages

            info['transport'] = self._transport.transport

            info['uid'] = self._uid

            return info

        # nearly impossible‽

        raise AErr(_(u"Could not fetch information for account: '%s'") %

                   self._addr, NO_SUCH_ACCOUNT)