"""Hardware detection and heartbeat payload construction for the streamer."""

from __future__ import annotations

from ria_toolkit_oss.sdr import detect_available


def available_devices() -> list[str]:
    """Return a sorted list of device names whose driver modules import cleanly."""
    return sorted(detect_available().keys())


def heartbeat_payload(status: str = "idle", app_id: str | None = None) -> dict:
    """Build the JSON body of a periodic heartbeat frame."""
    payload: dict = {
        "type": "heartbeat",
        "hardware": available_devices(),
        "status": status,
    }
    if app_id:
        payload["app_id"] = app_id
    return payload