"""Work-record flavor (STATE-WP-0092).

Flavor is a closed bucket on workplans and tasks, orthogonal to kind and
status. Unset flavor is not residual.
"""

from __future__ import annotations

from typing import Any

WORK_RECORD_FLAVORS: tuple[str, ...] = (
    "planning",
    "implementation",
    "refactoring",
    "extension",
    "residual",
)
RESIDUAL_FLAVOR = "residual"
FLAVOR_PROMOTION_REASONS: tuple[str, ...] = ("demand", "risk")

_EMPTY = {"", "~", "null", "none", "nil"}


def normalize_flavor(value: Any) -> str | None:
    if value is None:
        return None
    text = str(value).strip().lower()
    if text in _EMPTY:
        return None
    return text


def is_known_flavor(value: Any) -> bool:
    flavor = normalize_flavor(value)
    return flavor is None or flavor in WORK_RECORD_FLAVORS


def is_residual_flavor(value: Any) -> bool:
    return normalize_flavor(value) == RESIDUAL_FLAVOR


def normalize_promotion_reason(value: Any) -> str | None:
    if value is None:
        return None
    text = str(value).strip().lower()
    if text in _EMPTY:
        return None
    return text