import json
import os
from functools import cache
from typing import Dict, Optional

from aidial_adapter_bedrock.utils.log_config import app_logger as log


def get_env(name: str, err_msg: Optional[str] = None) -> str:
    if (val := os.getenv(name)) is None:
        raise Exception(err_msg or f"{name} env variable is not set")
    return val


def get_str_dict(name: str) -> Dict[str, str]:
    if (val := os.getenv(name)) is None:
        return {}

    try:
        dct = json.loads(val)
        assert isinstance(dct, dict)
        assert all(
            isinstance(k, str) and isinstance(v, str) for k, v in dct.items()
        )
        return dct
    except Exception:
        raise ValueError(
            f"{name} env variable doesn't contain a valid string to string JSON dictionary"
        )


@cache
def get_aws_default_region() -> str:
    region = os.getenv("DEFAULT_REGION")
    if region is not None:
        log.warning(
            "DEFAULT_REGION env variable is deprecated. Use AWS_DEFAULT_REGION instead."
        )
        return region

    region = os.getenv("AWS_DEFAULT_REGION")
    if region is not None:
        return region

    raise ValueError("AWS_DEFAULT_REGION env variable is not set")