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

# Copyright (c) 2010 - 2013, Pascal Volk

# See COPYING for distribution information.

"""

    VirtualMailManager.cli.config

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

    Adds some interactive stuff to the Config class.

"""

from configparser import RawConfigParser

from shutil import copy2

from string import Template

from VirtualMailManager import ENCODING

from VirtualMailManager.config import Config, ConfigValueError, LazyConfig

from VirtualMailManager.errors import ConfigError, VMMError

from VirtualMailManager.cli import w_err, w_std

from VirtualMailManager.constants import CONF_ERROR, VMM_TOO_MANY_FAILURES

_ = lambda msg: msg

class CliConfig(Config):

    """Adds the interactive ``configure`` method to the `Config` class

    and overwrites `LazyConfig.set(), in order to update a single option

    in the configuration file with a single command line command.

    """

    def configure(self, sections):

        """Interactive method for configuring all options of the given

        iterable ``sections`` object."""

        input_tpl = Template(_('Enter new value for option $option '

                               '[$current_value]: '))

        failures = 0

        w_std(_('Using configuration file: %s\n') % self._cfg_filename)

        for section in sections:

            w_std(_("* Configuration section: '%s'") % section)

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

                failures = 0

                while True:

                    if isinstance(val, str):

                        val = val.encode(ENCODING, 'replace').decode(ENCODING)

                    newval = input(input_tpl.substitute(option=opt,

                                                        current_value=val))

                    if newval and newval != val:

                        try:

                            LazyConfig.set(self, '%s.%s' % (section, opt),

                                           newval)

                            break

                        except (ValueError, ConfigValueError, VMMError) as err:

                            w_err(0, _('Warning: %s') % err)

                            failures += 1

                            if failures > 2:

                                raise ConfigError(_('Too many failures - try '

                                                    'again later.'),

                                                  VMM_TOO_MANY_FAILURES)

                    else:

                        break

            print()

        if self._modified:

            self._save_changes()

    def set(self, option, value):

        """Set the value of an option.

        If the new `value` has been set, the configuration file will be

        immediately updated.

        Throws a ``ConfigError`` if `value` couldn't be converted to

        ``LazyConfigOption.cls`` or ``LazyConfigOption.validate`` fails."""

        section, option_ = self._get_section_option(option)

        try:

            val = self._cfg[section][option_].cls(value)

            if self._cfg[section][option_].validate:

                val = self._cfg[section][option_].validate(val)

        except (ValueError, ConfigValueError) as err:

            raise ConfigError(str(err), CONF_ERROR)

        # Do not write default values also skip identical values

        if not self._cfg[section][option_].default is None:

            old_val = self.dget(option)

        else:

            old_val = self.pget(option)

        if val == old_val:

            return

        if not RawConfigParser.has_section(self, section):

            self.add_section(section)

        RawConfigParser.set(self, section, option_, val)

        self._save_changes()

    def _save_changes(self):

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

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

        with open(self._cfg_filename, 'w', encoding='utf-8') as self._cfg_file:

            self.write(self._cfg_file)

del _