"""Switchboard helpers."""
import time
from typing import Dict

import boto3
from ddex_ingester_common.constants.switchboard import JWT_EXPIRATION_VALUE
import jwt


def generate_switchboard_jwt(
        swb_role_arn: str, swb_secret_arn: str, application_name: str) -> str:
    """Generate a Switchboard JWT."""
    credentials = generate_switchboard_credentials(swb_role_arn,
                                                   application_name)
    secret = get_secrets_manager_value(swb_secret_arn, credentials)
    token_payload = {
        'systemName': 'ORCHARD',
        'exp': time.time() + JWT_EXPIRATION_VALUE,
        'iat': time.time(),
        'secretId': secret['VersionId'],
    }
    return jwt.encode(token_payload, secret['SecretString'])


def generate_switchboard_credentials(swb_role_arn: str,
                                     application_name: str) -> Dict:
    """Generate Switchboard AWS credentials."""
    sts = boto3.client('sts')
    assumed_role = sts.assume_role(
        RoleArn=swb_role_arn,
        RoleSessionName=f'{application_name}-session'
    )
    credentials = assumed_role['Credentials']
    return {
        'aws_access_key_id': credentials['AccessKeyId'],
        'aws_secret_access_key': credentials['SecretAccessKey'],
        'aws_session_token': credentials['SessionToken'],
    }


def get_secrets_manager_value(arn: str, credentials: Dict) -> Dict:
    """Get Amazon Secrets Manager secret value.

    Args:
        arn (str): The ARN/name of the secrets manager secret
        credentials (dict): AWS credentials to use
    Returns:
        Secrets manager value.
    """
    secretsmanager = boto3.client(
        'secretsmanager',
        **credentials
    )
    secret = secretsmanager.get_secret_value(
        SecretId=arn,
    )
    return secret