# ------------------------------------------------------------
# Centralised enumeration definitions for the data‑model layer.
# Keeping them in one module avoids circular imports and makes
# type‑checking / IDE completion straightforward.
# ------------------------------------------------------------

from __future__ import annotations

from enum import StrEnum
from typing import Any, Iterable


class ScheduleStatus(StrEnum):
    """
    Canonical status values for a ``Schedule`` row.

    Using ``StrEnum`` means the enum members behave like regular strings
    (e.g. they can be written directly to SQLite) while still giving us
    the safety and autocomplete of an enum.
    """
    PENDING   = "pending"
    ACCEPTED  = "accepted"
    DECLINED  = "declined"

    @classmethod
    def from_raw(cls, value: Any) -> "ScheduleStatus":
        """
        Convert an arbitrary value (often a plain string coming from the DB)
        into a ``ScheduleStatus`` member.

        Raises
        ------
        ValueError
            If the value does not correspond to any defined member.
        """
        if isinstance(value, cls):
            return value
        try:
            # ``cls(value)`` works because ``StrEnum`` subclasses ``str``.
            return cls(value)
        except ValueError as exc:
            raise ValueError(f"Invalid ScheduleStatus: {value!r}") from exc