# -*- coding: UTF-8 -*-
# Copyright (c) 2010 - 2014, 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 _