from __future__ import annotations

from dataclasses import dataclass
from typing import Protocol


@dataclass(frozen=True)
class ModuleTx:
    frame: bytes
    label: str
    delay: float = 0.0


@dataclass(frozen=True)
class ModuleDecision:
    tx: tuple[ModuleTx, ...] = ()
    suppress_default_ack: bool = False
    reason: str = ""


class CcuModule(Protocol):
    name: str

    def on_rx(self, frame: bytes, label: str = "") -> ModuleDecision | None:
        """Inspect an RCP frame and optionally provide CCU response frames."""