Sindbad~EG File Manager

#!/opt/alt/python37/bin/python3
import logging
import os
import json
from dataclasses import dataclass, asdict, field
from wmt.common.const import CONFIG_PATH
from wmt.common.exceptions import WmtConfigException
from wmt.common.url_parser import parse
from clcommon.cpapi import get_admin_email
from socket import gethostname
from typing import List


@dataclass
class Cfg:
    """
    Default values, in case config has not been specified yet
    """
    ping_interval: int = 30
    ping_timeout: int = 10
    report_email: str = None
    ignore_list: List[str] = field(default_factory=list)
    summary_notification_enabled: bool = True
    alert_notifications_enabled: bool = True


class ConfigManager:
    def __init__(self):
        self.allowed_params = Cfg.__dataclass_fields__.keys()
        self.from_email = f'web-monitoring-tool@{gethostname()}'
        self.default_report_email = get_admin_email()

        self.cfg = self._init_cfg()

        # self.ignored_domains is used as cache for checking domains if it is ignored or not
        self._ignored_domains = self.generate_ignored_domains()
        self.target_email = self._get_target_email()

    def _get_target_email(self):
        """
        This function checks to see which email address to use for TO: field of smtp.
        If report_email has been defined by user then report_email will be used.
        By default (in case not defined by user) default_report_email will be used
        """
        return self.cfg.report_email if self.cfg.report_email else self.default_report_email

    def to_dict(self):
        return asdict(self.cfg)

    def _init_cfg(self) -> Cfg:
        # if not present - use defaults
        if not self.is_present():
            return Cfg()

        data = self.read()

        cfg = Cfg()
        for key, value in data.items():
            if key not in self.allowed_params:
                logging.warning(
                    f'unsupported parameter "{key}", please ensure config contains'
                    f' only allowed parameters: {list(self.allowed_params)}'
                )
            else:
                setattr(cfg, key, value)

        return cfg

    @staticmethod
    def is_present():
        return os.path.isfile(CONFIG_PATH)

    def modify(self, new_json: str):
        """
        Changes configuration of wmt

        Returns:
            self.to_dict()

        Raises:
            WmtConfigException

        Example:
            wmt-api-solo --config-change {'key': 'val'}
        """
        try:
            new_config = json.loads(new_json)
        except json.JSONDecodeError as e:
            raise WmtConfigException(str(e))

        if not set(new_config.keys()).issubset(self.allowed_params):
            raise WmtConfigException(f'some of passed params are unsupported, '
                                     f'only allowed parameters: {list(self.allowed_params)}')

        config = {
            **self.to_dict(),
            **new_config
        }

        if config.get('ignore_list') and isinstance(config.get('ignore_list'), str):
            config['ignore_list'] = config['ignore_list'].split(',')

        # Write config to /etc/wmt/config.json file
        with open(CONFIG_PATH, 'w') as f:
            json.dump(config, f, indent=4)
        self.cfg = Cfg(**config)
        return self.to_dict()

    @staticmethod
    def read():
        try:
            with open(CONFIG_PATH) as f:
                data = json.load(f)
        except json.JSONDecodeError as e:
            raise WmtConfigException(str(e))
        return data

    def reload(self):
        self.cfg = self._init_cfg()

    def is_domain_ignored(self, domain) -> bool:
        """
        Check if domain is in ignored list.
        """
        return domain in self._ignored_domains

    def generate_ignored_domains(self) -> set:
        """
        Generates ignored domains from self.ignore_list and
        returns it for using as cache in self.ignored_domains set().

        Purpose of this function is to generate formatted url as "http://www.test.com"
        from user entered urls in self.ignore_list.
        It makes sense to check domains names with this cache before pings or reports
        """
        domains = set()
        for d in self.cfg.ignore_list:
            domain_from_ignore_list = parse(d)

            if 'https' in domain_from_ignore_list:
                domain_from_ignore_list = domain_from_ignore_list.replace('https', 'http')

            domains.add(domain_from_ignore_list)

        return domains