# -*- 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.domain import Domain

from VirtualMailManager.emailaddress import EmailAddress

from VirtualMailManager.transport import Transport

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, UNKNOWN_SERVICE

from VirtualMailManager.errors import AccountError as AErr

from VirtualMailManager.maillocation import MailLocation

from VirtualMailManager.password import pwhash

__all__ = ('SERVICES', 'Account', 'get_account_by_uid')

SERVICES = ('imap', 'pop3', 'smtp', 'sieve')

_ = lambda msg: msg

cfg_dget = lambda option: None

class Account(object):

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

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

                 '_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' doesn't exist.") %

                       self._addr.domainname, NO_SUCH_DOMAIN)

        self._uid = 0

        self._mail = None

        self._transport = self._domain.transport

        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' 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, 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, _tid = result

            if _tid != self._transport.tid:

                self._transport = Transport(self._dbh, tid=_tid)

            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_services(self, activate, *services):

        """Activate or deactivate the Account's services.

        Arguments:

        `activate`: bool

          When `True` the Account's user will be able to login to the

          services, otherwise the login will fail.

        `*services`

          No or one or more of the services: imap, pop3, smtp and sieve

        """

        self._chk_state()

        if services:

            services = set(services)

            for service in services:

                if service not in SERVICES:

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

                               UNKNOWN_SERVICE)

        else:

            services = SERVICES

        state = ('FALSE', 'TRUE')[activate]

        sql = 'UPDATE users SET %s WHERE uid = %u' % (

                    (' = %(s)s, '.join(services) + ' = %(s)s') % {'s': state},

                    self._uid)

        if 'sieve' in services and \

           cfg_dget('misc.dovecot_version') < 0x10200b02:

            sql = sql.replace('sieve', 'managesieve')

        dbc = self._dbh.cursor()

        dbc.execute(sql)

        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' doesn't 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 isinstance(password, basestring) or not password:

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

                       ACCOUNT_MISSING_PASSWORD)

        self._passwd = password

    def set_transport(self, transport):

        """Set the transport for the new Account.

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

        Account.modify().

        Argument:

        `transport` : basestring

          The string representation of the transport, e.g.: 'dovecot:'

        """

        self._transport = Transport(self._dbh, transport=transport)

    def enable(self, *services):

        """Enable all or the given service/s for the Account.

        Possible *services* are: 'imap', 'pop3', 'sieve' and 'smtp'.

        When all services should be enabled, give no service name.

        Arguments:

        `*services` : basestring

          No or one or more of the services 'imap', 'pop3', 'smtp', and

          'sieve'.

        """

        self._update_services(True, *services)

    def disable(self, *services):

        """Disable all or the given service/s for the Account.

        For more information see: Account.enable()."""

        self._update_services(False, *services)

    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 '%s'.") % self._addr,

                       ACCOUNT_MISSING_PASSWORD)

        if cfg_dget('misc.dovecot_version') >= 0x10200b02:

            sieve_col = 'sieve'

        else:

            sieve_col = 'managesieve'

        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, '

                    'tid, smtp, pop3, imap, %s) VALUES' % (sieve_col,) + \

                    '(%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)',

                    (self._addr.localpart,

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

                     self._domain.gid, self._mail.mid, self._transport.tid,

                     cfg_dget('account.smtp'), cfg_dget('account.pop3'),

                     cfg_dget('account.imap'), cfg_dget('account.sieve')))

        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' and

        'transport'.  *value* is the *field*'s new value.

        Arguments:

        `field` : basestring

          The attribute name: 'name', 'password' or 'transport'

        `value` : basestring

          The new value of the attribute.

        """

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

            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))

        elif field == 'transport':

            if value != self._transport.transport:

                self._transport = Transport(self._dbh, transport=value)

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

                            (self._transport.tid, 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 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' and

        'uid'.

        """

        self._chk_state()

        if cfg_dget('misc.dovecot_version') >= 0x10200b02:

            sieve_col = 'sieve'

        else:

            sieve_col = 'managesieve'

        sql = 'SELECT name, smtp, pop3, imap, %s FROM users WHERE uid = %d' % \

            (sieve_col, self._uid)

        dbc = self._dbh.cursor()

        dbc.execute(sql)

        info = dbc.fetchone()

        dbc.close()

        if info:

            keys = ('name', 'smtp', 'pop3', 'imap', sieve_col)

            info = dict(zip(keys, info))

            for service in keys[1:]:

                if info[service]:

                    # TP: A service (pop3/imap) is enabled/usable for a user

                    info[service] = _('enabled')

                else:

                    # TP: A service (pop3/imap) isn't enabled/usable for a user

                    info[service] = _('disabled')

            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['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)

    def get_aliases(self):

        """Return a list with all alias e-mail addresses, whose destination

        is the address of the Account."""

        self._chk_state()

        dbc = self._dbh.cursor()

        dbc.execute("SELECT address ||'@'|| domainname FROM alias, "

                    "domain_name WHERE destination = %s AND domain_name.gid = "

                    "alias.gid AND domain_name.is_primary ORDER BY address",

                    (str(self._addr),))

        addresses = dbc.fetchall()

        dbc.close()

        aliases = []

        if addresses:

            aliases = [alias[0] for alias in addresses]

        return aliases

    def delete(self, force=False):

        """Delete the Account from the database.

        Argument:

        `force` : bool

          if *force* is `True`, all aliases, which points to the Account,

          will be also deleted.  If there are aliases and *force* is

          `False`, an AccountError will be raised.

        """

        if not isinstance(force, bool):

            raise TypeError('force must be a bool')

        self._chk_state()

        dbc = self._dbh.cursor()

        if force:

            dbc.execute('DELETE FROM users WHERE uid = %s', (self._uid),)

            # delete also all aliases where the destination address is the same

            # as for this account.

            dbc.execute("DELETE FROM alias WHERE destination = %s",

                        (str(self._addr),))