import redis
from redis.lock import Lock

from auth0_block_users import config, constants

_redis_client = None


def get_redis_client() -> redis.StrictRedis:
    """Get redis client"""
    global _redis_client

    if not _redis_client:
        _redis_client = redis.StrictRedis(config.REDIS_HOST, config.REDIS_PORT)

    return _redis_client


def get_key(key: str) -> str:
    """Compose a Redis key.
    Args:
        key (str): Key.
    Returns:
        str: Complete key constructed by concatenated prefix + key.
    """
    return f'{constants.APP_NAME}/{key}'


def get_redis_lock() -> Lock:
    """Get redis lock"""
    redis_client = get_redis_client()
    return redis_client.lock(get_key('lock'), timeout=constants.REDIS_LOCK_TTL)