// 检验自己用的小 Jev 客户端（任务书 12 第四部分第 6 条）：不经 src/jev，也不改它。
// 请求格式参照 src/jev/jev.ts 和 RivalBits research-wiki/参考-Jev使用指南.md 第二部分：
// POST {model, state, questions}，回答里 answers.<问题名>.noul 是 0 到 1 的概率。
// 检验的问题都没有校准过阈值，一律以概率大于 0.5 判"是"，原始概率照存（任务书 12 第 5.2 节）。

const ENDPOINT = "https://api.typesafe.ai/v1/systemone";
/** 检验用的 Jev 模型名，和研究配置的 models.jev 同一个。 */
export const JEV_MODEL = "jev-latest";
export const THRESHOLD = 0.5;
export const THRESHOLD_NOTE = "阈值未校准：一律以概率大于 0.5 判\"是\"";

/** 一条是非题，写法照 src/jev/questions.ts：问题、关注点、判"是"判"否"的说明和反例。 */
export interface Noul {
  type: "noul";
  instructions: { question: string; focus: string };
  criteria: {
    true: { what: string; examples: string[] };
    false: { what: string; not_for: string; examples: string[] };
  };
}

export interface Answer {
  question: string;
  probability: number;
  yes: boolean;
  requestId: string;
}

/** 调不通时重试前等多久：只重试连不上、超时、429 和 5xx（原因在我们控制之外），一共最多 4 次。 */
const RETRY_WAITS_MS = [2_000, 10_000, 30_000];

/** 就一份材料问几问，一次请求。 */
export async function ask(state: Record<string, unknown>, questions: Record<string, Noul>): Promise<Answer[]> {
  const key = process.env["TYPESAFE_API_KEY"];
  if (key === undefined || key.trim() === "") throw new Error("环境变量 TYPESAFE_API_KEY 没有设置");
  const body = JSON.stringify({ model: JEV_MODEL, state, questions });
  const failures: string[] = [];
  for (let attempt = 0; attempt <= RETRY_WAITS_MS.length; attempt++) {
    if (attempt > 0) await new Promise((ok) => setTimeout(ok, RETRY_WAITS_MS[attempt - 1]));
    let response: Response;
    let text: string;
    try {
      response = await fetch(ENDPOINT, {
        method: "POST",
        headers: { "content-type": "application/json", authorization: `Bearer ${key}` },
        body,
        signal: AbortSignal.timeout(60_000),
      });
      text = await response.text();
    } catch (error) {
      failures.push((error as Error).message);
      continue;
    }
    const requestId = response.headers.get("x-typesafe-request-id") ?? "无";
    if (!response.ok) {
      const what = `HTTP ${response.status}（request-id: ${requestId}）：${text.slice(0, 300)}`;
      if (response.status !== 429 && response.status < 500) throw new Error(`Jev 拒绝了请求：${what}`);
      failures.push(what);
      continue;
    }
    const answers = (JSON.parse(text) as { answers?: Record<string, { noul?: unknown }> }).answers;
    return Object.keys(questions).map((question) => {
      const probability = answers?.[question]?.noul;
      if (typeof probability !== "number" || !(probability >= 0 && probability <= 1)) {
        throw new Error(`Jev 的回答里问题 ${question} 没有 0 到 1 之间的概率（request-id: ${requestId}）：${text.slice(0, 300)}`);
      }
      return { question, probability, yes: probability > THRESHOLD, requestId };
    });
  }
  throw new Error(`Jev 调不通，发了 ${failures.length} 次：${failures.join("；")}`);
}