"""Cache helper functions."""

import logging
from typing import List, Tuple

logger = logging.getLogger(__name__)


DELIMITER_PREFIX = "@"
DELIMITER_ITEM = "|"
DELIMITER_KEY_VAL = "#"


def make_complicated_cache_key(
    prefix: str,
    key_vals: List[Tuple[str, str]],
) -> str:
    """Return a cache key delimiting multiple attribute/value pairs.

    For example:

    make_complicated_cache_key(
        prefix="tenant_hierarchy",
        key_vals=[
            ("tenant_id", "123"),
            ("tenant_type", "account"),
            ("tenant_uuid", "uuid1"),
        ],
    )
    returns:

    tenant_hierarchy@tenant_id#123|tenant_type#account|tenant_uuid#uuid1
    """
    if not key_vals:
        raise ValueError("key_vals cannot be empty")
    key_val_joined = [DELIMITER_KEY_VAL.join(kv) for kv in key_vals]
    return f"{prefix}{DELIMITER_PREFIX}{DELIMITER_ITEM.join(key_val_joined)}"