async function jsonOrThrow(response, fallbackMessage) {
  if (response.ok) {
    if (response.status === 204) return null;
    return response.json();
  }
  let detail = "";
  try {
    const body = await response.json();
    detail = body?.message || body?.err_msg || JSON.stringify(body);
  } catch {
    detail = await response.text();
  }
  throw new Error(`${fallbackMessage}: ${response.status} ${detail || response.statusText}`);
}

export async function fetchOverview() {
  const response = await fetch("/api/runtime/overview");
  return jsonOrThrow(response, "加载段运行态失败");
}

async function postControl(path, label) {
  const response = await fetch(path, { method: "POST" });
  return jsonOrThrow(response, label);
}

export const segmentControl = {
  startAuto: (id) => postControl(`/api/control/segment/${id}/start-auto`, "启动自动控制失败"),
  stopAuto: (id) => postControl(`/api/control/segment/${id}/stop-auto`, "停止自动控制失败"),
  ackFault: (id) => postControl(`/api/control/segment/${id}/ack-fault`, "故障确认失败"),
  reset: (id) => postControl(`/api/control/segment/${id}/reset`, "复位失败"),
  batchStart: () => postControl(`/api/control/segment/batch-start-auto`, "批量启动失败"),
  batchStop: () => postControl(`/api/control/segment/batch-stop-auto`, "批量停止失败"),
};