#!/usr/bin/env python

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

# Copyright 2007-2008 VEB IT

# See COPYING for distribution information.

# $Id$

"""Configurtion class for read, modify and write the

configuration from Virtual Mail Manager.

"""

from constants.VERSION import VERSION

__author__ = 'Pascal Volk <p.volk@veb-it.de>'

__version__ = VERSION

__revision__ = 'rev '+'$Rev$'.split()[1]

__date__ = '$Date$'.split()[1]

import sys

from shutil import copy2

from ConfigParser import ConfigParser

from cStringIO import StringIO

from Exceptions import VMMConfigException

import constants.ERROR as ERR

class VMMConfig(ConfigParser):

    """This class is for configure the Virtual Mail Manager.

    You can specify settings for the database connection

    and maildirectories.

    """

    def __init__(self, filename):

        """Creates a new VMMConfig instance

        Keyword arguments:

        filename -- name of the configuration file

        """

        ConfigParser.__init__(self)

        self.__cfgFileName = filename

        self.__cfgFile = None

        self.__VMMsections = ['database', 'maildir', 'domdir', 'bin', 'misc',

                'config']

        self.__changes = False

        self.__missing = {}

        self.__dbopts = [

                ['host', 'localhot'],

                ['user', 'vmm'],

                ['pass', 'your secret password'],

                ['name', 'mailsys']

                ]

        self.__mdopts = [

                ['base', '/home/mail'],

                ['folder', 'Maildir'],

                ['mode', 448],

                ['diskusage', 'false'],

                ['delete', 'false']

                ]

        self.__domdopts = [

                ['mode', 504],

                ['delete', 'false']

                ]

        self.__binopts = [

                ['dovecotpw', '/usr/sbin/dovecotpw'],

                ['du', '/usr/bin/du']

                ]

        self.__miscopts = [

                ['passwdscheme', 'CRAM-MD5'],

                ['gid_mail', 8],

                ]

    def load(self):

        """Loads the configuration, r/o"""

        try:

            self.__cfgFile = file(self.__cfgFileName, 'r')

        except:

            raise

        self.readfp(self.__cfgFile)

        self.__cfgFile.close()

    def check(self):

        if not self.__chkSections():

            errmsg = StringIO()

            for k,v in self.__missing.items():

                if v[0] is True:

                    errmsg.write("missing section: %s\n" % k)

                else:

                    errmsg.write("missing options in section %s:\n" % k)

                    for o in v:

                        errmsg.write(" * %s\n" % o)

            raise VMMConfigException((errmsg.getvalue(), ERR.CONF_ERROR))

    def getsections(self):

        """Return a list with all configurable sections."""

        return self.__VMMsections[:-1]

    def configure(self, sections):

        """Interactive method for configuring all options in the given section

        Keyword arguments:

        sections -- list of strings

        """

        if not isinstance(sections, list):

            raise TypeError("Argument 'sections' is not a list.")

        # if [config] done = false (default at 1st run),

        # then set changes true

        try:

            if not self.getboolean('config', 'done'):

                self.__changes = True

        except ValueError:

            self.set('config', 'done', 'False')

            self.__changes = True

        for s in sections:

            if s == 'config':

                pass

            else:

                print '* Config section: %s' % s

            for opt, val in self.items(s):

                newval = raw_input('Enter new value for %s [%s]: ' %(opt, val))

                if newval and newval != val:

                    self.set(s, opt, newval)

                    self.__changes = True

            print

        if self.__changes:

            self.__saveChanges()

    def __saveChanges(self):

        """Writes changes to the configuration file."""

        self.set('config', 'done', 'true')

        copy2(self.__cfgFileName, self.__cfgFileName+'.bak')

        self.__cfgFile = file(self.__cfgFileName, 'w')

        self.write(self.__cfgFile)

        self.__cfgFile.close()

    def __chkSections(self):

        """Checks if all configuration sections are existing."""

        errors = False

        for s in self.__VMMsections:

            if not self.has_section(s):

                self.__missing[s] = [True]

            elif not self.__chkOptions(s):

                errors = True

        return not errors

    def __chkOptions(self, section):

        """Checks if all configuration options in section are existing.

        Keyword arguments:

        section -- the section to be checked

        """

        retval = True

        missing = []

        if section == 'database':

            opts = self.__dbopts

        elif section == 'maildir':

            opts = self.__mdopts

        elif section == 'domdir':

            opts = self.__domdopts

        elif section == 'bin':

            opts = self.__binopts

        elif section == 'misc':

            opts = self.__miscopts

        elif section == 'config':

            opts = [['done', 'false']]

        for o, v in opts:

            if not self.has_option(section, o):

                missing.append(o)

                retval = False

        if len(missing):

            self.__missing[section] = missing

        return retval