path: root/src/config.py

# Copyright 2010-2011 Florent Le Coz <louiz@louiz.org>
#
# This file is part of Poezio.
#
# Poezio is free software: you can redistribute it and/or modify
# it under the terms of the zlib license. See the COPYING file.

"""
Defines the global config instance, used to get or set (and save) values
from/to the config file.

This module has the particularity that some imports and global variables
are delayed because it would mean doing an incomplete setup of the python
loggers.
"""

DEFSECTION = "Poezio"

import logging.config
import os
import sys
from gettext import gettext as _

from configparser import RawConfigParser, NoOptionError, NoSectionError
from os import environ, makedirs, path, remove
from shutil import copy2
from args import parse_args


class Config(RawConfigParser):
    """
    load/save the config to a file
    """
    def __init__(self, file_name):
        RawConfigParser.__init__(self, None)
        # make the options case sensitive
        self.optionxform = str
        self.read_file(file_name)

    def read_file(self, file_name):
        self.file_name = file_name
        try:
            RawConfigParser.read(self, file_name, encoding='utf-8')
        except TypeError: # python < 3.2 sucks
            RawConfigParser.read(self, file_name)
        # Check config integrity and fix it if it’s wrong
        for section in ('bindings', 'var'):
            if not self.has_section(section):
                self.add_section(section)

    def get(self, option, default, section=DEFSECTION):
        """
        get a value from the config but return
        a default value if it is not found
        The type of default defines the type
        returned
        """
        try:
            if type(default) == int:
                res = self.getint(option, section)
            elif type(default) == float:
                res = self.getfloat(option, section)
            elif type(default) == bool:
                res = self.getboolean(option, section)
            else:
                res = self.getstr(option, section)
        except (NoOptionError, NoSectionError, ValueError, AttributeError):
            return default
        if res is None:
            return default
        return res

    def get_by_tabname(self, option, default, tabname, fallback=True, fallback_server=True):
        """
        Try to get the value for the option. First we look in
        a section named `tabname`, if the option is not present
        in the section, we search for the global option if fallback is
        True. And we return `default` as a fallback as a last resort.
        """
        if tabname in self.sections():
            if option in self.options(tabname):
                # We go the tab-specific option
                return self.get(option, default, tabname)
        if fallback_server:
            return self.get_by_servname(tabname, option, default, fallback)
        if fallback:
            # We fallback to the global option
            return self.get(option, default)
        return default

    def get_by_servname(self, jid, option, default, fallback=True):
        """
        Try to get the value of an option for a server
        """
        server = safeJID(jid).server
        if server:
            server = '@' + server
            if server in self.sections() and option in self.options(server):
                return self.get(option, default, server)
        if fallback:
            return self.get(option, default)
        return default


    def __get(self, option, section=DEFSECTION, **kwargs):
        """
        facility for RawConfigParser.get
        """
        return RawConfigParser.get(self, section, option, **kwargs)

    def _get(self, section, conv, option, **kwargs):
        """
        Redirects RawConfigParser._get
        """
        return conv(self.__get(option, section, **kwargs))

    def getstr(self, option, section=DEFSECTION):
        """
        get a value and returns it as a string
        """
        return self.__get(option, section)

    def getint(self, option, section=DEFSECTION):
        """
        get a value and returns it as an int
        """
        return RawConfigParser.getint(self, section, option)

    def getfloat(self, option, section=DEFSECTION):
        """
        get a value and returns it as a float
        """
        return RawConfigParser.getfloat(self, section, option)

    def getboolean(self, option, section=DEFSECTION):
        """
        get a value and returns it as a boolean
        """
        return RawConfigParser.getboolean(self, section, option)

    def write_in_file(self, section, option, value):
        """
        Our own way to save write the value in the file
        Just find the right section, and then find the
        right option, and edit it.
        """
        if file_ok(self.file_name):
            try:
                with open(self.file_name, 'r', encoding='utf-8') as df:
                    lines_before = (line.strip() for line in df.readlines())
            except:
                log.error('Unable to read the config file %s',
                        self.file_name,
                        exc_info=True)
                return False
        else:
            lines_before = []
        result_lines = []
        we_are_in_the_right_section = False
        written = False
        section_found = False
        for line in lines_before:
            if line.startswith('['): # check the section
                if we_are_in_the_right_section and not written:
                    result_lines.append('%s = %s' % (option, value))
                    written = True
                if line == '[%s]' % section:
                    we_are_in_the_right_section = True
                    section_found = True
                else:
                    we_are_in_the_right_section = False
            if (line.startswith('%s ' % (option,)) or
                line.startswith('%s=' % (option,)) or
                line.startswith('%s = ' % (option,))) and we_are_in_the_right_section:
                line = '%s = %s' % (option, value)
                written = True
            result_lines.append(line)

        if not section_found:
            result_lines.append('[%s]' % section)
            result_lines.append('%s = %s' % (option, value))
        elif not written:
            result_lines.append('%s = %s' % (option, value))

        try:
            prefix, file = path.split(self.file_name)
            filename = path.join(prefix, '.%s.tmp' % file)
            fd = os.fdopen(
                    os.open(
                        filename,
                        os.O_WRONLY | os.O_CREAT,
                        0o600),
                    'w')
            for line in result_lines:
                fd.write('%s\n' % line)
            fd.close()
            copy2(filename, self.file_name)
            remove(filename)
        except:
            success = False
            log.error('Unable to save the config file.', exc_info=True)
        else:
            success = True
        return success

    def set_and_save(self, option, value, section=DEFSECTION):
        """
        set the value in the configuration then save it
        to the file
        """
        # Special case for a 'toggle' value. We take the current value
        # and set the opposite. Warning if the no current value exists
        # or it is not a bool.
        if value == "toggle":
            current = self.get(option, "", section)
            if isinstance(current, bool):
                value = str(not current)
            else:
                if current.lower() == "false":
                    value = "true"
                elif current.lower() == "true":
                    value = "false"
                else:
                    return (_("Could not toggle option: %s. Current value is %s.") % (option, current or _("empty")), 'Warning')
        if self.has_section(section):
            RawConfigParser.set(self, section, option, value)
        else:
            self.add_section(section)
            RawConfigParser.set(self, section, option, value)
        if not self.write_in_file(section, option, value):
            return (_('Unable to write in the config file'), 'Error')
        return ("%s=%s" % (option, value), 'Info')

    def silent_set(self, option, value, section=DEFSECTION):
        """
        Set a value, save, and return True on success and False on failure
        """
        if self.has_section(section):
            RawConfigParser.set(self, section, option, value)
        else:
            self.add_section(section)
            RawConfigParser.set(self, section, option, value)
        return self.write_in_file(section, option, value)

    def set(self, option, value, section=DEFSECTION):
        """
        Set the value of an option temporarily
        """
        try:
            RawConfigParser.set(self, section, option, value)
        except NoSectionError:
            pass

    def to_dict(self):
        """
        Returns a dict of the form {section: {option: value, option: value}, …}
        """
        res = {}
        for section in self.sections():
            res[section] = {}
            for option in self.options(section):
                res[section][option] = self.get(option, "", section)
        return res


def file_ok(filepath):
    """
    Returns True if the file exists and is readable and writeable,
    False otherwise.
    """
    val = path.exists(filepath)
    val &= os.access(filepath, os.R_OK | os.W_OK)
    return bool(val)

def check_create_config_dir():
    """
    create the configuration directory if it doesn't exist
    and copy the default config in it
    """
    CONFIG_HOME = environ.get("XDG_CONFIG_HOME")
    if not CONFIG_HOME:
        CONFIG_HOME = path.join(environ.get('HOME'), '.config')
    CONFIG_PATH = path.join(CONFIG_HOME, 'poezio')

    try:
        makedirs(CONFIG_PATH)
    except OSError:
        pass
    return CONFIG_PATH

def run_cmdline_args(CONFIG_PATH):
    "Parse the command line arguments"
    global options
    options = parse_args(CONFIG_PATH)

    # Copy a default file if none exists
    if not path.isfile(options.filename):
        default = path.join(path.dirname(__file__), '../data/default_config.cfg')
        other = path.join(path.dirname(__file__), 'default_config.cfg')
        if path.isfile(default):
            copy2(default, options.filename)
        elif path.isfile(other):
            copy2(other, options.filename)
        global firstrun
        firstrun = True

def create_global_config():
    "Create the global config object, or crash"
    try:
        global config
        config = Config(options.filename)
    except:
        import traceback
        sys.stderr.write('Poezio was unable to read or'
                         ' parse the config file.\n')
        traceback.print_exc(limit=0)
        sys.exit(1)

def check_create_log_dir():
    "Create the poezio logging directory if it doesn’t exist"
    global LOG_DIR
    LOG_DIR = config.get('log_dir', '')

    if not LOG_DIR:

        data_dir = environ.get('XDG_DATA_HOME')
        if not data_dir:
            home = environ.get('HOME')
            data_dir = path.join(home, '.local', 'share')

        LOG_DIR = path.join(data_dir, 'poezio')

    LOG_DIR = path.expanduser(LOG_DIR)

    try:
        makedirs(LOG_DIR)
    except:
        pass

def setup_logging():
    "Change the logging config according to the cmdline options and config"
    if config.get('log_errors', True):
        LOGGING_CONFIG['root']['handlers'].append('error')
        LOGGING_CONFIG['handlers']['error'] = {
                'level': 'ERROR',
                'class': 'logging.FileHandler',
                'filename': path.join(LOG_DIR, 'errors.log'),
                'formatter': 'simple',
            }

    if options.debug:
        LOGGING_CONFIG['root']['handlers'].append('debug')
        LOGGING_CONFIG['handlers']['debug'] = {
                'level':'DEBUG',
                'class':'logging.FileHandler',
                'filename': options.debug,
                'formatter': 'simple',
            }


    if LOGGING_CONFIG['root']['handlers']:
        logging.config.dictConfig(LOGGING_CONFIG)
    else:
        logging.basicConfig(level=logging.CRITICAL)

    global log
    log = logging.getLogger(__name__)

def post_logging_setup():
    # common imports sleekxmpp, which creates then its loggers, so
    # it needs to be after logger configuration
    from common import safeJID as JID
    global safeJID
    safeJID = JID

LOGGING_CONFIG = {
    'version': 1,
    'disable_existing_loggers': True,
    'formatters': {
        'simple': {
            'format': '%(asctime)s %(levelname)s:%(module)s:%(message)s'
        }
    },
    'handlers': {
    },
    'root': {
            'handlers': [],
            'propagate': True,
            'level': 'DEBUG',
    }
}

# True if this is the first run, in this case we will display
# some help in the info buffer
firstrun = False

# Global config object. Is setup in poezio.py
config = None

# The logger object for this module
log = None

# The command-line options
options = None

# delayed import from common.py
safeJID = None

# the global log dir
LOG_DIR = ''