import os
import collections

from .p3 import configparser

# constant stuff (DFT = DEFAULT)

MAIN_SECTION = 'papers'
DFT_CONFIG_PATH = os.path.expanduser('~/.papersrc')
try:
    DFT_EDIT_CMD = os.environ['EDITOR']
except KeyError:
    DFT_EDIT_CMD = 'vi'

DFT_PLUGINS = ''

DFT_CONFIG = collections.OrderedDict([
              ('pubsdir',         os.path.expanduser('~/.papers')),
              ('docsdir',         ''),
              ('import_copy',     True),
              ('import_move',     False),
              ('color',           True),
              ('version',         4),
              ('version_warning', True),
              ('open_cmd',       'open'),
              ('edit_cmd',        DFT_EDIT_CMD),
              ('plugins',         DFT_PLUGINS)
             ])

BOOLEANS = {'import_copy', 'import_move', 'color', 'version_warning'}


# package-shared config that can be accessed using :
# from configs import config
_config = None


def config(section=MAIN_SECTION):
    if _config is None:
        raise ValueError('not config instanciated yet')
    _config._section = section
    return _config


class Config(object):

    def __init__(self, **kwargs):
        object.__setattr__(self, '_section', MAIN_SECTION)  # active section
        object.__setattr__(self, '_cfg', configparser.SafeConfigParser())

        self._cfg.add_section(self._section)
        for name, value in DFT_CONFIG.items():
            self._cfg.set(self._section, name, str(value))

        for name, value in kwargs.items():
            self.__setattr__(name, value)

    def as_global(self):
        global _config
        _config = self

    def load(self, path=DFT_CONFIG_PATH):
        self._cfg.read(path)
        return self

    def save(self, path=DFT_CONFIG_PATH):
        with open(path, 'w') as f:
            self._cfg.write(f)

    def __setattr__(self, name, value):
        if name in ('_cfg', '_section'):
            object.__setattr__(self, name, value)
        else:
            if type(value) is bool:
                BOOLEANS.add(name)
            self._cfg.set(self._section, name, str(value))

    def __getattr__(self, name):
        value = self._cfg.get(self._section, name)
        if name in BOOLEANS:
            value = str2bool(value)
        return value

    def get(self, name, default=None):
        try:
            return self.__getattr__(name)
        except (configparser.NoOptionError, configparser.NoSectionError):
            return default

    def items(self):
        for name, value in self._cfg.items(self._section):
            if name in BOOLEANS:
                value = str2bool(value)
            yield name, value


def str2bool(s):
    return str(s).lower() in ('yes', 'true', 't', 'y', '1')