srne-mqtt/srnemqtt/config.py

# -*- coding: utf-8 -*-
import importlib
import os
from time import sleep
from typing import Any, Dict, List, Optional, Type

import yaml

from .consumers import BaseConsumer
from .interfaces import BaseInterface
from .srne import Srne


def get_consumer(name: str) -> Optional[Type[BaseConsumer]]:
    mod_name, cls_name = name.rsplit(".", 1)

    mod = importlib.import_module(f".consumers.{mod_name}", package=__package__)

    # print(mod)
    # print(dir(mod))
    res = getattr(mod, cls_name)
    assert issubclass(res, BaseConsumer)

    return res


def get_config() -> Dict[str, Any]:
    with open("config.yaml", "r") as fh:
        conf: dict = yaml.safe_load(fh)
        conf.setdefault("consumers", {})

        return conf


def write_config(conf: Dict[str, Any]):
    with open(".config.yaml~writing", "w") as fh:
        yaml.safe_dump(conf, fh, indent=2, encoding="utf-8")
    os.rename(".config.yaml~writing", "config.yaml")


def get_consumers(
    srne: Srne, conf: Optional[Dict[str, Any]] = None
) -> List[BaseConsumer]:
    if conf is None:
        conf = get_config()

    consumers = []
    for name, consumer_config in conf["consumers"].items():
        # print(name, consumer_config)
        mod = get_consumer(name)
        if mod:
            # print(mod)
            consumers.append(mod(settings=consumer_config, srne=srne))

    write_config(conf)
    return consumers


def _get_interface(name: str) -> Type[BaseInterface]:
    mod_name, cls_name = name.rsplit(".", 1)

    mod = importlib.import_module(f".interfaces.{mod_name}", package=__package__)

    res = getattr(mod, cls_name)
    assert issubclass(res, BaseInterface)

    return res


def get_interface(conf: Optional[Dict[str, Any]] = None) -> BaseInterface:
    if conf is None:
        conf = get_config()

    name = conf["interface"]["name"]
    params = conf["interface"].get("params", {})

    mod = _get_interface(name)
    assert mod

    return mod(**params)


if __name__ == "__main__":
    conf = get_config()

    consumers = get_consumers(Srne(BaseInterface()), conf)

    try:
        while True:
            for consumer in consumers:
                consumer.poll()
                sleep(1)
    except (KeyboardInterrupt, SystemExit, Exception) as e:
        for consumer in consumers:
            consumer.exit()

        if type(e) is not KeyboardInterrupt:
            raise

        write_config(conf)