#!/usr/bin/env python3
# encoding: utf-8
#

"""
cfgfile.py

Created by Marcus Stoegbauer on 2013-01-12.
"""
import configparser
import os
import re


class Conf(object):
    confobj = configparser.RawConfigParser()
    cfgfile = ''
    debug = None

    def __init__(self, filename=None):
        """if filename is set, open config file and initialize the ConfigParser
        """
        self.confobj = configparser.RawConfigParser()
        if filename:
            self.setfilename(filename)

    def setdebug(self, debug):
        """docstring for setdebug"""
        self.debug = debug

    def setfilename(self, filename):
        """initialize the ConfigParser
        """
        ret = self.confobj.read(filename)
        if len(ret) == 0 or ret[0] != filename:
            raise Exception('Cannot read config file ' + filename)
        self.cfgfile = filename
        if self.debug:
            self.debug.debug("Read config file %s" % filename, 2)
            self.debug.debug("Replacing environment variables in %s." % filename, 3)

        for s in self.confobj.sections():
            for (i, val) in self.confobj.items(s):
                tempre = re.search(r"\$([A-Z]+)[^A-Z]*", val)
                if tempre:
                    varname = tempre.group(1)
                    if self.debug:
                        self.debug.debug("Found variable %s in %s." % (varname, i), 3)
                    if varname in os.environ:
                        if self.debug:
                            self.debug.debug("%s exists in environment, replacing with %s." %
                                             (varname, os.environ[varname]), 3)
                        self.set(s, i, val.replace("$"+varname, os.environ[varname]))

    def get(self, section, option):
        """returns the value of option in section
        """
        if not self.cfgfile:
            raise Exception('No config file set')
        return self.confobj.get(section, option)

    def set(self, section, option, value):
        """docstring for update"""
        self.confobj.set(section, option, value)

    def getitems(self, section):
        """returns all items in section
        """
        if not self.cfgfile:
            raise Exception('No config file set')
        return self.confobj.items(section)

    def check(self, section, option):
        """checks for option in section"""
        return self.confobj.has_option(section, option)