"""AWS Secrets Manager client for fetching GitHub credentials."""

import boto3


class SecretsManagerClient:
    """Fetches GitHub credentials from AWS Secrets Manager."""

    def __init__(self) -> None:
        """Initialize with a boto3 Secrets Manager client."""
        self._client = boto3.client('secretsmanager')

    def get_github_token(self, secret_name: str) -> str:
        """Retrieve GitHub token from the given secret.

        :param secret_name: The name or ARN of the secret in AWS Secrets Manager.
        :return: The GitHub token string.
        :raises ValueError: If the secret contains neither SecretString nor SecretBinary.
        """
        response = self._client.get_secret_value(SecretId=secret_name)
        if 'SecretString' in response:
            return response['SecretString']
        if 'SecretBinary' in response:
            return response['SecretBinary'].decode('utf-8')
        raise ValueError(
            f'Secret {secret_name!r} contains neither SecretString nor SecretBinary'
        )