from __future__ import absolute_import

import os
import platform


def _settings_root_XP():
	return os.path.join(os.environ['USERPROFILE'], 'Local Settings')

def _settings_root_Vista():
	return os.environ.get('LOCALAPPDATA', os.environ.get('ProgramData', '.'))

def _data_root_Windows():
	release, version, csd, ptype = platform.win32_ver()
	root = _settings_root_XP() if release == 'XP' else _settings_root_Vista()
	return os.path.join(root, 'Python Keyring')

def _data_root_Linux():
	"""
	Use freedesktop.org Base Dir Specfication to determine storage
	location.
	"""
	fallback = os.path.expanduser('~/.local/share')
	root = os.environ.get('XDG_DATA_HOME', None) or fallback
	return os.path.join(root, 'python_keyring')

_config_root_Windows = _data_root_Windows

def _check_old_config_root():
	"""
	Prior versions of keyring would search for the config
	in XDG_DATA_HOME, but should probably have been
	searching for config in XDG_CONFIG_HOME. If the
	config exists in the former but not in the latter,
	raise a RuntimeError to force the change.
	"""
	# disable the check - once is enough and avoids infinite loop
	globals()['_check_old_config_root'] = lambda: None
	config_file_new = os.path.join(_config_root_Linux(), 'keyringrc.cfg')
	config_file_old = os.path.join(_data_root_Linux(), 'keyringrc.cfg')
	if os.path.isfile(config_file_old) and not os.path.isfile(config_file_new):
		msg = ("Keyring config exists only in the old location "
			"{config_file_old} and should be moved to {config_file_new} "
			"to work with this version of keyring.")
		raise RuntimeError(msg)

def _config_root_Linux():
	"""
	Use freedesktop.org Base Dir Specfication to determine config
	location.
	"""
	_check_old_config_root()
	fallback = os.path.expanduser('~/.local/share')
	key = 'XDG_CONFIG_HOME'
	root = os.environ.get(key, None) or fallback
	return os.path.join(root, 'python_keyring')

# by default, use Unix convention
data_root = globals().get('_data_root_' + platform.system(), _data_root_Linux)
config_root = globals().get('_config_root' + platform.system(), _config_root_Linux)
