"""Configuration handling

This module provides configuration information (loaded modules,
module parameters, etc.) to all other components
"""

import argparse
import textwrap
import importlib
import bumblebee.store

MODULE_HELP = "Specify a space-separated list of modules to load. The order of the list determines their order in the i3bar (from left to right). Use <module>:<alias> to provide an alias in case you want to load the same module multiple times, but specify different parameters."
THEME_HELP = "Specify the theme to use for drawing modules"
PARAMETER_HELP = "Provide configuration parameters in the form of <module>.<key>=<value>"
LIST_HELP = "Display a list of either available themes or available modules along with their parameters."

class print_usage(argparse.Action):
    def __init__(self, option_strings, dest, nargs=None, **kwargs):
        argparse.Action.__init__(self, option_strings, dest, nargs, **kwargs)
        self._indent = " "*2

    def __call__(self, parser, namespace, value, option_string=None):
        if value == "modules":
            self.print_modules()
        elif value == "themes":
            self.print_themes()
        else:
            parser.print_help()
        parser.exit()

    def print_themes(self):
        print(textwrap.fill(", ".join(bumblebee.theme.themes()),
            80, initial_indent = self._indent, subsequent_indent = self._indent
        ))

    def print_modules(self):
        for m in bumblebee.engine.all_modules():
            mod = importlib.import_module("bumblebee.modules.{}".format(m["name"]))
            print(textwrap.fill("{}:".format(m["name"]), 80,
                    initial_indent=self._indent*2, subsequent_indent=self._indent*2))
            for line in mod.__doc__.split("\n"):
                print(textwrap.fill(line, 80,
                    initial_indent=self._indent*3, subsequent_indent=self._indent*6))

def create_parser():
    """Create the argument parser"""
    parser = argparse.ArgumentParser(description="display system data in the i3bar")
    parser.add_argument("-m", "--modules", nargs="+", default=[],
        help=MODULE_HELP)
    parser.add_argument("-t", "--theme", default="default", help=THEME_HELP)
    parser.add_argument("-p", "--parameters", nargs="+", default=[],
        help=PARAMETER_HELP)
    parser.add_argument("-l", "--list", choices=["modules", "themes"], action=print_usage,
        help=LIST_HELP)
    return parser

class Config(bumblebee.store.Store):
    """Top-level configuration class

    Parses commandline arguments and provides non-module
    specific configuration information.
    """
    def __init__(self, args=None):
        super(Config, self).__init__()
        parser = create_parser()
        self._args = parser.parse_args(args if args else [])

        for param in self._args.parameters:
            key, value = param.split("=")
            self.set(key, value)

    def modules(self):
        """Return a list of all activated modules"""
        return [{
            "module": x.split(":")[0],
            "name": x if not ":" in x else x.split(":")[1],
        } for x in self._args.modules]

    def theme(self):
        """Return the name of the selected theme"""
        return self._args.theme

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