'''Config module handles the proxy configuration in the config.toml file'''

import shutil
import tomllib
import logging
from schema import Schema, And, Use, Optional


class Config():
    '''Static class Config is reads and sanitize the config.

    Read config.toml file and sanitize it with read().
    Get named parts of the config with get()'''

    config = {}
    conf_schema = Schema({
        'tsun': {
            'enabled': Use(bool),
            'host':    Use(str),
            'port':    And(Use(int), lambda n: 1024 <= n <= 65535)
            },
        'mqtt': {
            'host':    Use(str),
            'port':    And(Use(int), lambda n: 1024 <= n <= 65535),
            'user':    And(Use(str), Use(lambda s: s if len(s) > 0 else None)),
            'passwd':  And(Use(str), Use(lambda s: s if len(s) > 0 else None))
            },
        'ha': {
            'auto_conf_prefix': Use(str),
            'discovery_prefix': Use(str),
            'entity_prefix':    Use(str),
            'proxy_node_id':    Use(str),
            'proxy_unique_id':  Use(str)
            },
        'inverters': {
            'allow_all': Use(bool), And(Use(str), lambda s: len(s) == 16): {
                Optional('node_id', default=""): And(Use(str),
                                                     Use(lambda s: s + '/'
                                                         if len(s) > 0 and
                                                         s[-1] != '/' else s)),

                Optional('suggested_area',  default=""): Use(str)
                }}
            }, ignore_extra_keys=True
        )

    @classmethod
    def read(cls) -> None:
        '''Read config file, merge it with the default config
        and sanitize the result'''

        config = {}
        logger = logging.getLogger('data')

        try:
            # make the default config transparaent by copying it
            # in the config.example file
            shutil.copy2("default_config.toml", "config/config.example.toml")

            # read example config file as default configuration
            with open("default_config.toml", "rb") as f:
                def_config = tomllib.load(f)

            # overwrite the default values, with values from
            # the config.toml file
            with open("config/config.toml", "rb") as f:
                usr_config = tomllib.load(f)

            config['tsun'] = def_config['tsun'] | usr_config['tsun']
            config['mqtt'] = def_config['mqtt'] | usr_config['mqtt']
            config['ha'] = def_config['ha'] | usr_config['ha']
            config['inverters'] = def_config['inverters'] | \
                usr_config['inverters']

            cls.config = cls.conf_schema.validate(config)
            # logging.debug(f'Readed config: "{cls.config}" ')

        except Exception as error:
            logger.error(f'Config.read: {error}')
            cls.config = {}

    @classmethod
    def get(cls, member: str = None):
        '''Get a named attribute from the proxy config. If member ==
          None it returns the complete config dict'''

        if member:
            return cls.config.get(member, {})
        else:
            return cls.config