턴마다 붙는 두 가지 사실

from dataclasses import dataclass
from typing import Literal

InputModality = Literal["typed", "dictated"]
ReplyModality = Literal["written", "spoken"]


def normalize(value: object, allowed: set[str]) -> str | None:
    """Unknown or absent -> None. A bad value never fails the turn."""
    if isinstance(value, str) and value.strip().lower() in allowed:
        return value.strip().lower()
    return None


@dataclass
class Turn:
    text: str
    input_modality: InputModality = "typed"
    reply_modality: ReplyModality = "written"

    @classmethod
    def from_wire(cls, body: dict) -> "Turn":
        return cls(
            text=body["message"],
            input_modality=normalize(body.get("input_modality"), {"typed", "dictated"}) or "typed",
            reply_modality=normalize(body.get("reply_modality"), {"written", "spoken"}) or "written",
        )


def jsonl_voice(turn: Turn) -> dict | None:
    """The ground-truth log's voice object, built from the SAME values as the row."""
    voice = {}
    if turn.input_modality != "typed":
        voice["input_modality"] = turn.input_modality
    if turn.reply_modality != "written":
        voice["reply_modality"] = turn.reply_modality
    return voice or None


# An old client, a voice-mode client, and a typo, in one conversation:
for body in (
    {"message": "what's the weather"},
    {"message": "weather tomorrow?", "input_modality": "dictated", "reply_modality": "spoken"},
    {"message": "here's the link", "reply_modality": "SPOKEN "},
    {"message": "table please", "reply_modality": "sung"},
):
    turn = Turn.from_wire(body)
    print(turn.input_modality, turn.reply_modality, jsonl_voice(turn))