// 不自动运行（需要 npm install 后执行 node --test app.test.ts）
import assert from "node:assert/strict";
import type { AddressInfo } from "node:net";
import { after, before, test } from "node:test";
import { createApp } from "./app.ts";

let base = "";
let close: () => void = () => {};

before(async () => {
  const app = createApp({
    async *askLLM(q) {
      if (q === "boom") throw new Error("upstream down");
      yield "你好";
      yield q;
    },
    findOrder: async (id) => (id === "A001" ? { id, status: "paid" } : null),
  });
  const server = app.listen(0);
  await new Promise((r) => server.once("listening", r));
  base = `http://127.0.0.1:${(server.address() as AddressInfo).port}`;
  close = () => server.close();
});
after(() => close());

test("查询订单：正常 / 格式错误 / 不存在", async () => {
  assert.deepEqual(await (await fetch(`${base}/orders/A001`)).json(), { id: "A001", status: "paid" });
  const bad = await fetch(`${base}/orders/xx`);
  assert.equal(bad.status, 400);
  assert.equal((await bad.json()).code, "BAD_ORDER_ID");
  const missing = await fetch(`${base}/orders/A999`);
  assert.equal(missing.status, 404);
  assert.ok(missing.headers.get("x-request-id"));
});

test("请求体不是合法 JSON 时返回 400 而不是 500", async () => {
  const r = await fetch(`${base}/chat`, { method: "POST", headers: { "content-type": "application/json" }, body: "{bad" });
  assert.equal(r.status, 400);
});

test("流式对话：逐条 SSE 事件，最后是 done", async () => {
  const r = await fetch(`${base}/chat`, { method: "POST", headers: { "content-type": "application/json" }, body: JSON.stringify({ question: "退货" }) });
  assert.match(r.headers.get("content-type") ?? "", /^text\/event-stream/);   // express 会追加 charset
  const text = await r.text();
  assert.match(text, /data: \{"token":"你好"\}/);
  assert.match(text, /data: \{"token":"退货"\}/);
  assert.match(text, /event: done/);
});

test("上游失败：用 error 事件通知，而不是挂起连接", async () => {
  const r = await fetch(`${base}/chat`, { method: "POST", headers: { "content-type": "application/json" }, body: JSON.stringify({ question: "boom" }) });
  assert.match(await r.text(), /event: error/);
});