import base64
from typing import Any

import boto3
from fansifter_common.utils.functional import lazy_proxy

from app.config import settings


class KMSClient:
    def __init__(
        self, *, region_name: str, key_id: str, session: boto3.Session | None = None
    ) -> None:
        self.region_name = region_name
        self.key_id = key_id
        self._session = session
        self._client: Any | None = None

    @property
    def session(self) -> boto3.Session:
        if self._session is None:
            self._session = boto3.Session()
        return self._session

    @property
    def client(self) -> Any:
        if self._client is None:
            self._client = self.session.client("kms", region_name=self.region_name)
        return self._client

    def decrypt(self, value: str) -> str:
        response = self.client.decrypt(
            KeyId=self.key_id,
            CiphertextBlob=base64.b64decode(value),
        )
        return response["Plaintext"].decode()


def get_kms_client() -> KMSClient:
    return KMSClient(region_name=settings.aws_region_name, key_id=settings.kms_key_id)


kms_client = lazy_proxy(get_kms_client)