import os.path

import tomli
import tomli_w

from metar_navigate.utils import DirectoryManager

from threading import Lock

class SingletonMeta(type):
    _instances = {}
    _lock: Lock = Lock()

    def __call__(cls, *args, **kwargs):
        with cls._lock:
            if cls not in cls._instances:
                instance = super().__call__(*args, **kwargs)
                cls._instances[cls] = instance
        return cls._instances[cls]


class ConfigManager(metaclass=SingletonMeta):
    def __init__(self):
        self.config_dir = DirectoryManager.get_config_directory()
        self.__data = None

    def read_config(self):
        if os.path.exists(f"{self.config_dir}/config.toml"):
            try:
                with open(f"{self.config_dir}/config.toml", "rb") as f:
                    data = tomli.load(f)
            except tomli.TOMLDecodeError as e:
                raise ValueError(f"Invalid TOML file; {e}")
            except Exception as e:
                raise ValueError(f"Error reading config file; {e}")

            self.__data = data
            return self.__data

        else:
            return None
    def set_data_dict(self,data):
        self.__data.update(data)


    def write_config(self):
        default = {
            "checkwx_api_key": "",
            "always_show_detailed": False,
            "wind_speed_unit": "Keep",
            "temp_unit": "Keep",
            "visibility_unit": "Keep",
            "pressure_unit": "Keep"

        }