/** 照壁代理行为测试：头透传、SSE 流顺序、断线续传头、上游错误与不可达映射。 */
import http from "node:http";
import type { AddressInfo } from "node:net";
import { afterAll, beforeAll, describe, expect, it } from "vitest";
import { buildServer } from "../src/server.js";

let upstream: http.Server;
let upstreamUrl = "";
let upstreamCalls: Array<{ method: string; url: string; headers: http.IncomingHttpHeaders; body: string }> = [];

beforeAll(async () => {
  upstream = http.createServer((req, res) => {
    let body = "";
    req.on("data", (chunk) => (body += chunk));
    req.on("end", () => {
      upstreamCalls.push({ method: req.method ?? "", url: req.url ?? "", headers: req.headers, body });
      if (req.url === "/api/v1/echo") {
        res.writeHead(200, { "content-type": "application/json", "x-trace-id": String(req.headers["x-trace-id"] ?? "") });
        res.end(JSON.stringify({ ok: true, auth: req.headers.authorization ?? null, body }));
      } else if (req.url === "/api/v1/stream") {
        res.writeHead(200, { "content-type": "text/event-stream; charset=utf-8" });
        const frames = ["id: 1\nevent: run.started\n\n", "id: 2\nevent: llm.delta\n\n", "id: 3\nevent: run.finished\n\n"];
        frames.forEach((frame, i) => setTimeout(() => res.write(frame), i * 20));
        setTimeout(() => res.end(), frames.length * 20 + 10);
      } else if (req.url === "/api/v1/boom") {
        res.writeHead(404, { "content-type": "application/json" });
        res.end(JSON.stringify({ error: { code: "HJ-1002", message: "不存在" } }));
      } else {
        res.writeHead(200, { "content-type": "application/json" });
        res.end("{}");
      }
    });
  });
  await new Promise<void>((resolve) => upstream.listen(0, "127.0.0.1", resolve));
  upstreamUrl = `http://127.0.0.1:${(upstream.address() as AddressInfo).port}`;
});

afterAll(async () => {
  await new Promise<void>((resolve) => upstream.close(() => resolve()));
});

function app() {
  return buildServer({
    port: 0,
    backendUrl: upstreamUrl,
    bodyLimit: 1024 * 1024,
    logLevel: "silent",
  });
}

describe("照壁代理", () => {
  it("转发 Authorization 与 Idempotency-Key，透传响应体与 x-trace-id", async () => {
    const res = await app().inject({
      method: "POST",
      url: "/api/v1/echo",
      headers: { authorization: "Bearer tok", "idempotency-key": "idem-1", "x-trace-id": "trace-9" },
      payload: JSON.stringify({ a: 1 }),
    });
    expect(res.statusCode).toBe(200);
    const body = res.json();
    expect(body.ok).toBe(true);
    expect(body.auth).toBe("Bearer tok");
    expect(body.body).toBe(JSON.stringify({ a: 1 }));
    expect(res.headers["x-trace-id"]).toBe("trace-9");
    const call = upstreamCalls.at(-1)!;
    expect(call.headers["authorization"]).toBe("Bearer tok");
    expect(call.headers["idempotency-key"]).toBe("idem-1");
  });

  it("SSE 流式透传：帧序完整、禁缓冲头、Last-Event-ID 透传", async () => {
    const res = await app().inject({
      method: "GET",
      url: "/api/v1/stream",
      headers: { "last-event-id": "2", authorization: "Bearer tok" },
    });
    expect(res.statusCode).toBe(200);
    expect(res.headers["content-type"]).toContain("text/event-stream");
    expect(res.headers["x-accel-buffering"]).toBe("no");
    expect(res.body.indexOf("run.started")).toBeLessThan(res.body.indexOf("run.finished"));
    const call = upstreamCalls.at(-1)!;
    expect(call.headers["last-event-id"]).toBe("2");
  });

  it("上游错误状态与错误体原样透传", async () => {
    const res = await app().inject({ method: "GET", url: "/api/v1/boom" });
    expect(res.statusCode).toBe(404);
    expect(res.json().error.code).toBe("HJ-1002");
  });

  it("上游不可达映射 HJ-3001", async () => {
    const dead = buildServer({
      port: 0,
      backendUrl: "http://127.0.0.1:1",
      bodyLimit: 1024,
      logLevel: "silent",
    });
    const res = await dead.inject({ method: "GET", url: "/api/v1/echo" });
    expect(res.statusCode).toBe(502);
    expect(res.json().error.code).toBe("HJ-3001");
  });
});