import os
from loguru import logger

class Config:
    OPTIONS = {
            'mqtt': [ 'login', 
                      'password', 
                      'ca', 
                      'cert', 
                      'key', 
                      'broker', 
                      'port', 
                      'meterPublishTopic', 
                      'meterPublishPeriod', 
                      'relaisSubscribeTopic' ],
            'modbus': [ 'gateway' ]
            }
    
    def __init__(self):
        self.values = {}
        for section, keys in Config.OPTIONS.items():
            self.values[section] = {}
            for key in keys:
                varname = f"{section}__{key}".upper()
                try:
                    self.values[section][key] = os.environ[varname]
                    logger.info(f"Config: {section} {key} -> {self.values[section][key]}")
                except KeyError:
                    pass

    def __getitem__(self, section):
        return self.values[section]