import type { Worker } from "./types";
import { workerAgeText } from "./client";

// CHV 可用性纯逻辑：不发请求、不拼 URL，只从 ctx 已有的
// /workers 数据推断。非管理员的 /workers 只返回聚合数
// （workers_total/online/offline），没有按执行器的分项，
// 此时 CHV 在线数是未知，绝不能把未知写成 0，也绝不能
// 把聚合在线数当成 CHV 在线数。
export function isWorkerAlive(w: Worker): boolean {
  if (w.alive !== undefined && w.alive !== null) return !!w.alive;
  const info = workerAgeText(w);
  return info.age !== null && info.age <= 120;
}

export function countChvWorkers(workers: Worker[]): { online: number; total: number } {
  const chv = workers.filter((w) => w.executor === "cloud-hypervisor");
  return { online: chv.filter(isWorkerAlive).length, total: chv.length };
}

export type ChvAvailability =
  | { state: "known"; online: number; total: number }
  | { state: "unknown"; reason: "not-loaded" | "aggregate-only" | "load-failed" };

export function chvAvailability(
  workers: Worker[] | null,
  workersSummary: string,
  workersError: string,
): ChvAvailability {
  if (workers) return { state: "known", ...countChvWorkers(workers) };
  if (workersError) return { state: "unknown", reason: "load-failed" };
  if (workersSummary.includes("无 worker 注册")) return { state: "known", online: 0, total: 0 };
  if (workersSummary.includes("完整 worker 清单仅全局管理员可见")) {
    return { state: "unknown", reason: "aggregate-only" };
  }
  return { state: "unknown", reason: "not-loaded" };
}

// 排队原因提示：只在“已知零 CHV worker 在线 + CHV 任务排队”时
// 给出，文案明确写“可能原因”，且不编造后端未返回的
// VM 状态/IP/快照。未知时返回空串（不提示、不猜测）。
export function chvQueueHint(
  executor: string | undefined | null,
  status: string | undefined | null,
  availability: ChvAvailability,
): string {
  if (executor !== "cloud-hypervisor" || status !== "queued") return "";
  if (availability.state === "known" && availability.online === 0) {
    return "可能原因：当前无 cloud-hypervisor worker 在线，任务在排队（基于 /workers 推断；VM 状态/IP/快照等后端未返回字段不展示）。请先确认 KVM 宿主上的 CHV worker 已起，worker 上线后可认领。";
  }
  return "";
}