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

# Copyright (c) 2008 - 2014, Pascal Volk

# See COPYING for distribution information.

"""

    VirtualMailManager.maillocation

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

    Virtual Mail Manager's maillocation module to handle Dovecot's

    mail_location setting for accounts.

"""

from VirtualMailManager.constants import MAILLOCATION_INIT

from VirtualMailManager.errors import MailLocationError as MLErr

__all__ = ('MailLocation', 'known_format')

_ = lambda msg: msg

_format_info = {

    'maildir': dict(dovecot_version=0x10000f00, postfix=True),

    'mdbox': dict(dovecot_version=0x20000b05, postfix=False),

    'sdbox': dict(dovecot_version=0x20000c03, postfix=False),

}

class MailLocation(object):

    """Class to handle mail_location relevant information."""

    __slots__ = ('_directory', '_mbfmt', '_mid', '_dbh')

    _kwargs = ('mid', 'mbfmt', 'directory')

    def __init__(self, dbh, **kwargs):

        """Creates a new MailLocation instance.

        Either the mid keyword or the mbfmt and directory keywords must be

        specified.

        Arguments:

        `dbh` : psycopg2._psycopg.connection

          A database connection for the database access.

        Keyword arguments:

        `mid` : int

          the id of a mail_location

        `mbfmt` : str

          the mailbox format of the mail_location. One out of: ``maildir``,

          ``sdbox`` and ``mdbox``.

        `directory` : str

          name of the mailbox root directory.

        """

        self._dbh = dbh

        self._directory = None

        self._mbfmt = None

        self._mid = 0

        for key in kwargs.keys():

            if key not in self.__class__._kwargs:

                raise ValueError('unrecognized keyword: %r' % key)

        mid = kwargs.get('mid')

        if mid:

            assert isinstance(mid, int)

            self._load_by_mid(mid)

        else:

            args = kwargs.get('mbfmt'), kwargs.get('directory')

            assert all(isinstance(arg, str) for arg in args)

            if args[0].lower() not in _format_info:

                raise MLErr(_("Unsupported mailbox format: '%s'") % args[0],

                            MAILLOCATION_INIT)

            directory = args[1].strip()

            if not directory:

                raise MLErr(_("Empty directory name"), MAILLOCATION_INIT)

            if len(directory) > 20:

                raise MLErr(_("Directory name is too long: '%s'") % directory,

                            MAILLOCATION_INIT)

            self._load_by_names(args[0].lower(), directory)

    def __str__(self):

        return '%s:~/%s' % (self._mbfmt, self._directory)

    @property

    def directory(self):

        """The mail_location's directory name."""

        return self._directory

    @property

    def dovecot_version(self):

        """The required Dovecot version for this mailbox format."""

        return _format_info[self._mbfmt]['dovecot_version']

    @property

    def postfix(self):

        """`True` if Postfix supports this mailbox format, else `False`."""

        return _format_info[self._mbfmt]['postfix']

    @property

    def mbformat(self):

        """The mail_location's mailbox format."""

        return self._mbfmt

    @property

    def mail_location(self):

        """The mail_location, e.g. ``maildir:~/Maildir``"""

        return self.__str__()

    @property

    def mid(self):

        """The mail_location's unique ID."""

        return self._mid

    def _load_by_mid(self, mid):

        """Load mail_location relevant information by *mid*"""

        dbc = self._dbh.cursor()

        dbc.execute('SELECT format, directory FROM mailboxformat, '

                    'maillocation WHERE mid = %u AND '

                    'maillocation.fid = mailboxformat.fid' % mid)

        result = dbc.fetchone()

        dbc.close()

        if not result:

            raise ValueError('Unknown mail_location id specified: %r' % mid)

        self._mid = mid

        self._mbfmt, self._directory = result

    def _load_by_names(self, mbfmt, directory):

        """Try to load mail_location relevant information by *mbfmt* and

        *directory* name. If it fails goto _save()."""

        dbc = self._dbh.cursor()

        dbc.execute("SELECT mid FROM maillocation WHERE fid = (SELECT fid "

                    "FROM mailboxformat WHERE format = %s) AND directory = %s",

                    (mbfmt, directory))

        result = dbc.fetchone()

        dbc.close()

        if not result:

            self._save(mbfmt, directory)

        else:

            self._mid = result[0]

            self._mbfmt = mbfmt

            self._directory = directory

    def _save(self, mbfmt, directory):

        """Save a new mail_location in the database."""

        dbc = self._dbh.cursor()

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

        mid = dbc.fetchone()[0]

        dbc.execute("INSERT INTO maillocation (fid, mid, directory) VALUES ("

                    "(SELECT fid FROM mailboxformat WHERE format = %s), %s, "

                    "%s)",  (mbfmt, mid, directory))

        self._dbh.commit()

        dbc.close()

        self._mid = mid

        self._mbfmt = mbfmt

        self._directory = directory

def known_format(mbfmt):

    """Checks if the mailbox format *mbfmt* is known, returns bool."""

    return mbfmt.lower() in _format_info

del _