# Copyright (C) 2005-2012 Aaron Bentley <abentley@panoramicfeedback.com>
#                         Chris Ball <cjb@laptop.org>
#                         Gianluca Montecchi <gian@grys.it>
#                         W. Trevor King <wking@tremily.us>
#
# This file is part of Bugs Everywhere.
#
# Bugs Everywhere is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation, either version 2 of the License, or (at your option) any
# later version.
#
# Bugs Everywhere is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
# more details.
#
# You should have received a copy of the GNU General Public License along with
# Bugs Everywhere.  If not, see <http://www.gnu.org/licenses/>.

"""Create, save, and load the per-user config file at :py:func:`path`.
"""

import configparser
import codecs
import os
import os.path

import libbe
import libbe.util.encoding
if libbe.TESTING == True:
    import doctest


default_encoding = libbe.util.encoding.get_text_file_encoding()
"""Default filesystem encoding.

Initialized with :py:func:`libbe.util.encoding.get_text_file_encoding`.
"""

def path():
    """Return the path to the per-user config file.

    Defaults to :file:`~/.config/bugs-everywhere`, but you can
    override the directory with ``XDG_CONFIG_HOME`` from the `XDG Base
    Directory Specification`_.  You can also override the entire path
    by setting the ``BE_CONFIG_PATH`` environment variable.

    .. _XDG Base Directory Specification:
      http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
    """
    default_dir = os.path.join('~', '.config')
    dirname = os.path.expanduser(
        os.environ.get('XDG_CONFIG_HOME', default_dir))
    default = os.path.join(dirname, 'bugs-everywhere')
    return os.path.expanduser(os.environ.get('BE_CONFIG_PATH', default))

def set_val(name, value, section="DEFAULT", encoding=None):
    """Set a value in the per-user config file.

    Parameters
    ----------
    name : str
      The name of the value to set.
    value : str or None
      The new value to set (or None to delete the value).
    section : str
      The section to store the name/value in.
    encoding : str
      The config file's encoding, defaults to :py:data:`default_encoding`.
    """
    if encoding == None:
        encoding = default_encoding
    config = configparser.ConfigParser()
    if os.path.exists(path()) == False: # touch file or config
        open(path(), 'w').close()       # read chokes on missing file
    f = codecs.open(path(), 'r', encoding)
    config.readfp(f, path())
    f.close()
    if value is not None:
        config.set(section, name, value)
    else:
        config.remove_option(section, name)
    f = codecs.open(path(), 'w', encoding)
    config.write(f)
    f.close()

def get_val(name, section="DEFAULT", default=None, encoding=None):
    """Get a value from the per-user config file

    Parameters
    ----------
    name : str
      The name of the value to set.
    section : str
      The section to store the name/value in.
    default :
      The value to return if `name` is not set.
    encoding : str
      The config file's encoding, defaults to :py:data:`default_encoding`.

    Examples
    --------

    >>> get_val("junk") is None
    True
    >>> set_val("junk", "random")
    >>> get_val("junk")
    u'random'
    >>> set_val("junk", None)
    >>> get_val("junk") is None
    True
    """
    if os.path.exists(path()):
        if encoding == None:
            encoding = default_encoding
        config = configparser.ConfigParser()
        f = codecs.open(path(), 'r', encoding)
        config.readfp(f, path())
        f.close()
        try:
            return config.get(section, name)
        except configparser.NoOptionError:
            return default
    else:
        return default

if libbe.TESTING == True:
    suite = doctest.DocTestSuite()