"""Minimal serializable state for the first LangGraph slice."""

from dataclasses import dataclass, field
from typing import Any, Protocol, TypedDict


class AccidentGraphState(TypedDict, total=False):
    session_id: str
    input_text: str
    need_form_update: bool
    response_text: str
    stage_code: str
    form_update: dict[str, Any]
    turn_count: int


@dataclass(frozen=True)
class GeneratedTurn:
    content: str
    form_update: dict[str, Any] = field(default_factory=dict)


class ResponseGenerator(Protocol):
    async def generate(self, state: AccidentGraphState) -> GeneratedTurn:
        """Generate one state-prefixed response from graph state."""
        ...

    async def aclose(self) -> None:
        """Release any owned network resources."""
        ...