export type PairingAccessState =
  | "available"
  | "request_pending"
  | "gated"
  | "inactive"
  | "full";

export type BetaOnboardingState =
  | "request_needed"
  | "request_pending"
  | "ready"
  | "full";

export type BetaOnboarding = {
  state: BetaOnboardingState;
  pairingAccessState: PairingAccessState;
  primaryHref: string;
  primaryLabel: string;
  tone: "good" | "warn" | "neutral" | "info";
  title: string;
  detail: string;
};

export function deriveBetaOnboarding(input: {
  entitlement: {
    mode: "public_beta" | "grant" | "none";
    publicBetaState: "open" | "gated" | "inactive";
    unlimited: boolean;
    availableSlots: number | null;
  };
  hasPendingRequest: boolean;
}): BetaOnboarding {
  const { entitlement } = input;
  if (entitlement.mode === "none") {
    if (input.hasPendingRequest) {
      return {
        state: "request_pending",
        pairingAccessState: "request_pending",
        primaryHref: "/dashboard/billing",
        primaryLabel: "查看申请进度",
        tone: "warn",
        title: "免费闭测申请正在审核",
        detail: "处理结果会显示在公测权益页；审核期间不需要重复申请。",
      };
    }
    const gated = entitlement.publicBetaState === "gated";
    return {
      state: "request_needed",
      pairingAccessState: gated ? "gated" : "inactive",
      primaryHref: "/dashboard/billing",
      primaryLabel: "申请免费闭测",
      tone: gated ? "warn" : "neutral",
      title: gated ? "公开接入尚未开放" : "当前没有免费测试资格",
      detail: gated
        ? "安全门禁仍在核对，可以先申请小范围免费闭测。"
        : "可以提交免费闭测申请；不会绑定支付方式或自动转为付费。",
    };
  }

  if (!entitlement.unlimited && (entitlement.availableSlots ?? 0) < 1) {
    return {
      state: "full",
      pairingAccessState: "full",
      primaryHref: "/dashboard/hosts",
      primaryLabel: "管理已接入主机",
      tone: "neutral",
      title: "当前免费主机名额已用完",
      detail: "可以取消等待中的配对、撤销不再使用的主机，或等待管理员调整闭测名额。",
    };
  }

  return {
    state: "ready",
    pairingAccessState: "available",
    primaryHref: "/dashboard/hosts/new",
    primaryLabel: "连接主机",
    tone: "good",
    title: entitlement.mode === "grant" ? "闭测资格已生效" : "免费公测资格已生效",
    detail: entitlement.unlimited
      ? "当前策略不按主机槽位限额，可以开始连接主机。"
      : `还可以连接 ${entitlement.availableSlots ?? 0} 台主机。`,
  };
}