import os
import pathlib
from functools import lru_cache


class BaseConfig:
    BASE_DIR: pathlib.Path = pathlib.Path(__file__).parent.parent

    DATABASE_URL: str = os.environ.get(
        "DATABASE_URL", f"sqlite:///{BASE_DIR}/db.sqlite3"
    )
    DATABASE_CONNECT_DICT: dict = {}

    CELERY_BROKER_URL: str = os.environ.get(
        "CELERY_BROKER_URL", "redis://127.0.0.1:6379/0"
    )
    CELERY_RESULT_BACKEND: str = os.environ.get(
        "CELERY_RESULT_BACKEND", "redis://127.0.0.1:6379/0"
    )
    # will be used for multi-process communication by FastAPI and the Celery Worker.
    WS_MESSAGE_QUEUE: str = os.environ.get("WS_MESSAGE_QUEUE", "redis://redis:6379/0")


class DevelopmentConfig(BaseConfig):
    pass


class ProductionConfig(BaseConfig):
    pass


class TestingConfig(BaseConfig):
    pass


@lru_cache()
def get_settings() -> BaseConfig:
    config_cls_dict = {
        "development": DevelopmentConfig,
        "production": ProductionConfig,
        "testing": TestingConfig,
    }

    config_name = os.environ.get("FASTAPI_CONFIG", "development")
    config_cls = config_cls_dict[config_name]
    return config_cls()


settings = get_settings()