import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
import { Transport } from "../src/transport";
import { mergeConfig } from "../src/config";
import { SDK_VERSION, SCHEMA_VERSION, BUILD_ID } from "../src/types";
import { getVisitorId, getSessionId } from "../src/identity";

// 快照信封验证（T8）：identity 包一层 spy（委托真实实现，其余用例行为不变），
// 断言"全队列带归属字段的 flush 不再读身份"（信封归属=事件顶层快照）。
vi.mock("../src/identity", async (importOriginal) => {
  const actual = await importOriginal<typeof import("../src/identity")>();
  return {
    ...actual,
    getVisitorId: vi.fn(actual.getVisitorId),
    getSessionId: vi.fn(actual.getSessionId),
  };
});

// uuid v4 格式（crypto.randomUUID 或 Math.random 兜底均为该形状）
const UUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/;

/** 可选 data：成功响应的 T3 契约体 {accepted,duplicated,rejected,request_id,server_time} */
const res = (status: number, data?: unknown) =>
  ({ ok: status < 400, status, json: () => Promise.resolve(data ?? null) }) as unknown as Response;

// 与 mergeConfig 默认值无关的测试专用 cfg（各用例按需覆盖）
function mkCfg(over: Record<string, unknown> = {}) {
  return {
    siteId: "site1",
    endpoint: "/api/v1/collect",
    batchSize: 3,
    flushMs: 15000,
    maxRetry: 3,
    queueMax: 50,
    ...over,
  };
}

let fetchMock: ReturnType<typeof vi.fn>;

describe("transport", () => {
  beforeEach(() => {
    localStorage.clear(); // identity 持久化隔离
    vi.useFakeTimers(); // 默认连 Date 一起 fake
    fetchMock = vi.fn().mockResolvedValue(res(200));
    vi.stubGlobal("fetch", fetchMock);
    vi.mocked(getVisitorId).mockClear(); // identity spy 调用记录按用例隔离
    vi.mocked(getSessionId).mockClear();
  });
  afterEach(() => {
    vi.unstubAllGlobals(); // 还原 fetch / navigator 桩
    vi.useRealTimers();
    delete (globalThis as { __ctk_ctx?: unknown }).__ctk_ctx;
  });

  it("满 batchSize 即发：body 含 batch_id/site_id/visitor_id/session_id/sent_at/events", () => {
    const t = new Transport(mkCfg({ batchSize: 3 }));
    t.push({ event_id: "e1" });
    t.push({ event_id: "e2" });
    expect(fetchMock).not.toHaveBeenCalled();
    t.push({ event_id: "e3" });
    expect(fetchMock).toHaveBeenCalledTimes(1);

    const [url, init] = fetchMock.mock.calls[0];
    expect(url).toBe("/api/v1/collect");
    expect(init.method).toBe("POST");
    expect(init.keepalive).toBe(true);
    const body = JSON.parse(init.body);
    expect(body.batch_id).toMatch(UUID_RE);
    expect(body.site_id).toBe("site1");
    expect(body.visitor_id).toMatch(UUID_RE);
    expect(body.session_id).toMatch(UUID_RE);
    expect(body.sent_at).toBe(new Date().toISOString()); // fake Date 下两处取值一致
    expect(body.sent_at).toMatch(/^\d{4}-\d{2}-\d{2}T/);
    expect(body.events.map((e: { event_id: string }) => e.event_id)).toEqual([
      "e1",
      "e2",
      "e3",
    ]);
    expect("context" in body).toBe(false); // __ctk_ctx 未注入时序列化后无 context 键
  });

  it("不足 batchSize 时由 flushMs 定时器触发", async () => {
    const t = new Transport(mkCfg({ batchSize: 10 }));
    t.push({ event_id: "e1" });
    expect(fetchMock).not.toHaveBeenCalled();
    await vi.advanceTimersByTimeAsync(14999);
    expect(fetchMock).not.toHaveBeenCalled();
    await vi.advanceTimersByTimeAsync(1);
    expect(fetchMock).toHaveBeenCalledTimes(1);
    expect(JSON.parse(fetchMock.mock.calls[0][1].body).events).toHaveLength(1);
  });

  it("context 透传：__ctk_ctx 原样进 body.context", () => {
    const t = new Transport(mkCfg({ batchSize: 1 }));
    (globalThis as { __ctk_ctx?: unknown }).__ctk_ctx = { device_type: "PC" };
    t.push({ event_id: "e1" });
    const body = JSON.parse(fetchMock.mock.calls[0][1].body);
    expect(body.context).toEqual({ device_type: "PC" }); // 引用透传而非拷贝拼接
  });

  it("500 失败退避重试后成功：body 逐字节不变（同 event_id 重放）", async () => {
    fetchMock.mockResolvedValueOnce(res(500)).mockResolvedValueOnce(res(200));
    const t = new Transport(mkCfg({ batchSize: 2 }));
    t.push({ event_id: "e1" });
    t.push({ event_id: "e2" });
    expect(fetchMock).toHaveBeenCalledTimes(1);

    await vi.advanceTimersByTimeAsync(2000); // 第 1 次退避 500*2^1*jitter ∈ [800,1200]
    expect(fetchMock).toHaveBeenCalledTimes(2);
    expect(fetchMock.mock.calls[1][1].body).toBe(fetchMock.mock.calls[0][1].body);
  });

  it("400 不重试（参数错，重试无意义），事件落 dropped 桶（四桶对账无幽灵丢失）", async () => {
    fetchMock.mockResolvedValueOnce(res(400));
    const t = new Transport(mkCfg({ batchSize: 1 }));
    t.push({ event_id: "e1" });
    await vi.advanceTimersByTimeAsync(10000);
    expect(fetchMock).toHaveBeenCalledTimes(1);
    expect(t.dropped).toBe(1); // M1：4xx 不重试但必须计丢弃
  });

  it("403 不重试（权限错，重试只会掩盖配置问题），事件落 dropped 桶", async () => {
    fetchMock.mockResolvedValueOnce(res(403));
    const t = new Transport(mkCfg({ batchSize: 1 }));
    t.push({ event_id: "e1" });
    await vi.advanceTimersByTimeAsync(10000);
    expect(fetchMock).toHaveBeenCalledTimes(1);
    expect(t.dropped).toBe(1);
  });

  it("429 要重试（限流是暂态）", async () => {
    fetchMock.mockResolvedValueOnce(res(429)).mockResolvedValueOnce(res(200));
    const t = new Transport(mkCfg({ batchSize: 1 }));
    t.push({ event_id: "e1" });
    await vi.advanceTimersByTimeAsync(2000);
    expect(fetchMock).toHaveBeenCalledTimes(2);
    expect(t.dropped).toBe(0);
  });

  it("重试耗尽按本批事件数计丢弃", async () => {
    fetchMock.mockResolvedValue(res(500)); // 恒 500
    const t = new Transport(mkCfg({ batchSize: 2, maxRetry: 1 }));
    t.push({ event_id: "e1" });
    t.push({ event_id: "e2" });
    expect(fetchMock).toHaveBeenCalledTimes(1);

    await vi.advanceTimersByTimeAsync(2000); // 第 1 次重试（∈[800,1200]）后再失败
    expect(fetchMock).toHaveBeenCalledTimes(2); // 初发 1 + 重试 1，共 2 次
    expect(t.dropped).toBe(2); // 按入批事件数计，而非按批计
  });

  it("queueMax 溢出丢最旧", () => {
    const t = new Transport(mkCfg({ batchSize: 100, queueMax: 3, flushMs: 60000 }));
    ["e1", "e2", "e3", "e4"].forEach((id) => t.push({ event_id: id }));
    expect(t.dropped).toBe(1);
    t.flush();
    expect(fetchMock).toHaveBeenCalledTimes(1);
    const body = JSON.parse(fetchMock.mock.calls[0][1].body);
    expect(body.events.map((e: { event_id: string }) => e.event_id)).toEqual([
      "e2",
      "e3",
      "e4",
    ]); // 留最新 3 条
  });

  it("flush(true) 走 sendBeacon（Blob/text/plain），不调 fetch", async () => {
    // happy-dom 的 sendBeacon 会发真实网络请求，必须 stubGlobal 替换 navigator（不能只 spy）
    const beacon = vi.fn().mockReturnValue(true);
    vi.stubGlobal("navigator", { sendBeacon: beacon });
    const t = new Transport(mkCfg({ batchSize: 10 }));
    t.push({ event_id: "e1" });
    t.flush(true);

    expect(fetchMock).not.toHaveBeenCalled();
    expect(beacon).toHaveBeenCalledTimes(1);
    const [url, blob] = beacon.mock.calls[0];
    expect(url).toBe("/api/v1/collect");
    expect(blob).toBeInstanceOf(Blob);
    expect(blob.type).toBe("text/plain");
    expect(JSON.parse(await blob.text()).events).toEqual([{ event_id: "e1" }]);
  });

  it("fetch 同步抛异常不冒泡到 push 调用方", async () => {
    vi.stubGlobal(
      "fetch",
      vi.fn(() => {
        throw new Error("network gone");
      })
    );
    const t = new Transport(mkCfg({ batchSize: 1, maxRetry: 0 }));
    expect(() => t.push({ event_id: "e1" })).not.toThrow(); // try/catch 全包红线
    await vi.advanceTimersByTimeAsync(100);
    expect(t.dropped).toBe(1); // maxRetry=0 耗尽 → 按事件数丢弃
  });

  it("sendBeacon 返回 false（队列满/载荷超限）按本批事件数计 dropped", () => {
    vi.stubGlobal("navigator", { sendBeacon: vi.fn().mockReturnValue(false) });
    const t = new Transport(mkCfg({ batchSize: 10 }));
    t.push({ event_id: "e1" });
    t.push({ event_id: "e2" });
    t.flush(true);
    expect(t.dropped).toBe(2); // 信标被浏览器拒收（64KB 上限等）→ 整批丢
    expect(fetchMock).not.toHaveBeenCalled();
  });

  it("stringify 抛错（track 引入宿主可控对象）：已换出批次按事件数计 dropped", () => {
    const t = new Transport(mkCfg({ batchSize: 10, flushMs: 60000 }));
    const bad: { event_id: string; self?: unknown } = { event_id: "bad" };
    bad.self = bad; // 循环引用 → JSON.stringify 抛 TypeError
    t.push(bad);
    t.push({ event_id: "ok" });
    expect(() => t.flush()).not.toThrow();
    expect(t.dropped).toBe(2); // 换出的 2 条全部落丢，不能静默不计
    expect(fetchMock).not.toHaveBeenCalled();

    t.push({ event_id: "e3" }); // 队列已换出，后续事件照常
    t.flush();
    expect(fetchMock).toHaveBeenCalledTimes(1);
    expect(JSON.parse(fetchMock.mock.calls[0][1].body).events).toEqual([{ event_id: "e3" }]);
  });

  // ---- T8：快照信封 / 混合拆批 / beacon 预算 / 响应计数 ----

  it("flush 从队首事件快照取归属：信封 visitor/session=事件顶层字段，identity 零调用", () => {
    const t = new Transport(mkCfg({ batchSize: 10 }));
    t.push({ event_id: "e1", visitor_id: "v-snap", session_id: "s-snap", page_id: "p-snap" });
    t.push({ event_id: "e2", visitor_id: "v-snap", session_id: "s-snap", page_id: "p-snap" });
    t.flush();
    expect(fetchMock).toHaveBeenCalledTimes(1);
    expect(getSessionId).not.toHaveBeenCalled(); // 快照归属——flush 不再读身份（消灭 D02 传输侧）
    expect(getVisitorId).not.toHaveBeenCalled();
    const body = JSON.parse(fetchMock.mock.calls[0][1].body);
    expect(body.visitor_id).toBe("v-snap");
    expect(body.session_id).toBe("s-snap");
  });

  it("混合归属队列拆子批：两组 (visitor,session,page) → 两次独立请求各含正确信封（组内 FIFO）", () => {
    const t = new Transport(mkCfg({ batchSize: 10 }));
    t.push({ event_id: "a1", visitor_id: "v1", session_id: "s1", page_id: "p1" });
    t.push({ event_id: "b1", visitor_id: "v2", session_id: "s2", page_id: "p2" });
    t.push({ event_id: "a2", visitor_id: "v1", session_id: "s1", page_id: "p1" });
    t.flush();
    expect(fetchMock).toHaveBeenCalledTimes(2);
    const b1 = JSON.parse(fetchMock.mock.calls[0][1].body);
    const b2 = JSON.parse(fetchMock.mock.calls[1][1].body);
    expect(b1.visitor_id).toBe("v1"); // 信封归属=组 key（组首事件快照）
    expect(b1.session_id).toBe("s1");
    expect(b1.events.map((e: { event_id: string }) => e.event_id)).toEqual(["a1", "a2"]); // 组内 FIFO
    expect(b2.visitor_id).toBe("v2");
    expect(b2.session_id).toBe("s2");
    expect(b2.events.map((e: { event_id: string }) => e.event_id)).toEqual(["b1"]);
    expect(b1.batch_id).not.toBe(b2.batch_id); // 每子批独立 batch_id
  });

  it("无归属字段的兼容事件（track 宿主对象）走兜底组：信封从 identity 读，不静默丢", () => {
    const t = new Transport(mkCfg({ batchSize: 10 }));
    t.push({ event_id: "t1" }); // track 命令原样对象——无归属字段
    t.push({ event_id: "a1", visitor_id: "v1", session_id: "s1", page_id: "p1" });
    t.flush();
    expect(fetchMock).toHaveBeenCalledTimes(2); // 归属组 + 兜底组
    const b1 = JSON.parse(fetchMock.mock.calls[0][1].body);
    const b2 = JSON.parse(fetchMock.mock.calls[1][1].body); // 兜底组排后
    expect(b1.visitor_id).toBe("v1");
    expect(b1.events).toEqual([{ event_id: "a1", visitor_id: "v1", session_id: "s1", page_id: "p1" }]);
    expect(b2.visitor_id).toMatch(UUID_RE); // getVisitorId() 旧路径构造信封
    expect(b2.session_id).toMatch(UUID_RE); // getSessionId() 旧路径
    expect(b2.events).toEqual([{ event_id: "t1" }]); // 公开 API 不能静默丢
    expect(getSessionId).toHaveBeenCalledTimes(1); // 惰性求值：仅兜底组读一次
  });

  it("子批独立重试：组A 500 失败重试，组B 200 不重试", async () => {
    const t = new Transport(mkCfg({ batchSize: 10 }));
    t.push({ event_id: "a1", visitor_id: "v1", session_id: "s1", page_id: "p1" });
    t.push({ event_id: "b1", visitor_id: "v2", session_id: "s2", page_id: "p2" });
    fetchMock
      .mockResolvedValueOnce(res(500)) // 组A 初发
      .mockResolvedValueOnce(res(200)) // 组B（成功不重试）
      .mockResolvedValueOnce(res(200)); // 组A 重试
    t.flush();
    expect(fetchMock).toHaveBeenCalledTimes(2); // 组间顺序：初发各一次
    await vi.advanceTimersByTimeAsync(2000); // 组A 退避 ∈[800,1200]
    expect(fetchMock).toHaveBeenCalledTimes(3); // 仅组A 重试
    expect(fetchMock.mock.calls[2][1].body).toBe(fetchMock.mock.calls[0][1].body); // 同 body 重放
    expect(t.dropped).toBe(0);
  });

  it("子批独立重试资格：组A 耗尽不清扫组B 的重试计数（组B 仍可自救）", async () => {
    // 抖动钳制：两组退避同为 1000ms——fake timer 同刻按调度序（A 先）触发，
    // 否则 Math.random 会让 A/B 重试顺序随机翻转（响应序列错绑到另一组）
    const rnd = vi.spyOn(Math, "random").mockReturnValue(0.5);
    const t = new Transport(mkCfg({ batchSize: 10, maxRetry: 1 }));
    t.push({ event_id: "a1", visitor_id: "v1", session_id: "s1", page_id: "p1" });
    t.push({ event_id: "a2", visitor_id: "v1", session_id: "s1", page_id: "p1" });
    t.push({ event_id: "b1", visitor_id: "v2", session_id: "s2", page_id: "p2" });
    fetchMock
      .mockResolvedValueOnce(res(500)) // A 初发
      .mockResolvedValueOnce(res(500)) // B 初发
      .mockResolvedValueOnce(res(500)) // A 重试 → 耗尽（dropped+=2）
      .mockResolvedValueOnce(res(200)); // B 重试 → 成功
    t.flush();
    await vi.advanceTimersByTimeAsync(2000); // 两组退避均已到期
    expect(fetchMock).toHaveBeenCalledTimes(4); // 共享计数器下 B 会错失自己的重试（仅 3 次）
    expect(t.dropped).toBe(2); // 仅组A 的 2 条落丢
    expect(JSON.parse(fetchMock.mock.calls[3][1].body).visitor_id).toBe("v2"); // B 的重试成功送达
    rnd.mockRestore();
  });

  it("beacon 载荷超 60KB 预算 → 降级 fetch keepalive；失败耗尽按事件数计 dropped", async () => {
    const beacon = vi.fn().mockReturnValue(true);
    vi.stubGlobal("navigator", { sendBeacon: beacon });
    fetchMock.mockResolvedValue(res(500)); // 降级后恒失败
    const t = new Transport(mkCfg({ batchSize: 10, maxRetry: 0 }));
    t.push({
      event_id: "big",
      visitor_id: "v1",
      session_id: "s1",
      page_id: "p1",
      // 须落在 (60_000, 64_000] 窗口：超信标预算触发降级，又不触发 fetch 64KB 裁剪守卫
      properties: { blob: "x".repeat(62_000) },
    });
    t.flush(true);
    expect(beacon).not.toHaveBeenCalled(); // 超预算不走信标
    expect(fetchMock).toHaveBeenCalledTimes(1);
    const init = fetchMock.mock.calls[0][1];
    expect(init.keepalive).toBe(true);
    await vi.advanceTimersByTimeAsync(100);
    expect(t.dropped).toBe(1); // fetch 亦失败（maxRetry=0 耗尽）按事件数计
  });

  it("响应解析：accepted/duplicated/rejected 累计进 counts，server_time 记录（T3 契约）", async () => {
    const t = new Transport(mkCfg({ batchSize: 1 }));
    fetchMock.mockResolvedValueOnce(
      res(200, {
        code: 200,
        data: {
          accepted: 2,
          duplicated: 1,
          rejected: [{ index: 0, event_id: "e1", reason: "invalid_field" }],
          request_id: "r1",
          server_time: "2026-09-18T10:00:00+00:00",
        },
        message: "ok",
      })
    );
    t.push({ event_id: "e1", visitor_id: "v1", session_id: "s1", page_id: "p1" });
    await vi.advanceTimersByTimeAsync(0); // 微任务冲刷（json promise）
    expect(t.accepted).toBe(2);
    expect(t.duplicated).toBe(1);
    expect(t.rejected).toBe(1); // rejected 明细数组长度累计
    expect(t.lastServerTime).toBe("2026-09-18T10:00:00+00:00"); // 供 offset 估计

    fetchMock.mockResolvedValueOnce(
      res(200, {
        code: 200,
        data: { accepted: 1, duplicated: 0, rejected: [], request_id: "r2", server_time: "2026-09-18T10:00:05+00:00" },
        message: "ok",
      })
    );
    t.push({ event_id: "e2", visitor_id: "v1", session_id: "s1", page_id: "p1" });
    await vi.advanceTimersByTimeAsync(0);
    expect(t.accepted).toBe(3); // 跨批累计
    expect(t.rejected).toBe(1);
    expect(t.lastServerTime).toBe("2026-09-18T10:00:05+00:00"); // 最新值
  });

  it("响应体非 JSON 不影响送达判定：不重试不丢弃，计数不动", async () => {
    fetchMock.mockResolvedValueOnce({
      ok: true,
      status: 200,
      json: () => Promise.reject(new Error("not json")),
    } as unknown as Response);
    const t = new Transport(mkCfg({ batchSize: 1 }));
    t.push({ event_id: "e1", visitor_id: "v1", session_id: "s1", page_id: "p1" });
    await vi.advanceTimersByTimeAsync(2000);
    expect(fetchMock).toHaveBeenCalledTimes(1); // 计数解析失败不触发重试（批已送达）
    expect(t.dropped).toBe(0);
    expect(t.accepted).toBe(0);
  });

  it("v2 信封形态：恒 schema_version=2 + sdk_version + build_id（sent_at 保留）", () => {
    const t = new Transport(mkCfg({ batchSize: 1 }));
    t.push({ event_id: "e1", visitor_id: "v1", session_id: "s1", page_id: "p1" });
    const body = JSON.parse(fetchMock.mock.calls[0][1].body);
    expect(body.schema_version).toBe(SCHEMA_VERSION); // types.ts 单一来源
    expect(body.schema_version).toBe(2); // v1 兼容形态不再产生
    expect(body.sdk_version).toBe(SDK_VERSION);
    expect(body.build_id).toBe(BUILD_ID); // vitest define 注入 "vitest"
    expect(body.sent_at).toMatch(/^\d{4}-\d{2}-\d{2}T/); // sent_at 已有保留
  });

  it("宿主对象归属字段 getter 抛错：不冒泡，兜底组落丢，归属组照发", () => {
    const t = new Transport(mkCfg({ batchSize: 10 }));
    const evil = { event_id: "evil" } as { event_id: string; visitor_id?: string };
    Object.defineProperty(evil, "visitor_id", {
      // 分组读取/stringify 都会触发——宿主可控对象红线（spec §4.5）
      get() {
        throw new Error("getter boom");
      },
      enumerable: true,
    });
    t.push(evil);
    t.push({ event_id: "ok" }); // 与 evil 同落兜底组（无归属字段）
    t.push({ event_id: "safe", visitor_id: "v1", session_id: "s1", page_id: "p1" });
    expect(() => t.flush()).not.toThrow(); // 红线：异常不得冒泡
    expect(t.dropped).toBe(2); // 兜底组（evil+ok）stringify 抛错按组内事件数计
    expect(fetchMock).toHaveBeenCalledTimes(1); // 归属组不受宿主坏对象波及
    expect(JSON.parse(fetchMock.mock.calls[0][1].body).events).toEqual([
      { event_id: "safe", visitor_id: "v1", session_id: "s1", page_id: "p1" },
    ]);
  });

  // ---- I1/M1：超预算组送达闭环 + 4xx 丢弃计数 ----

  it("超 64KB 组丢最旧闭环：裁剪至预算内送达，最旧事件计 dropped", () => {
    const t = new Transport(mkCfg({ batchSize: 10 }));
    const big = (id: string, n: number) => ({
      event_id: id,
      visitor_id: "v1",
      session_id: "s1",
      page_id: "p1",
      properties: { blob: "x".repeat(n) },
    });
    t.push(big("e1", 33_000));
    t.push(big("e2", 33_000));
    t.push(big("e3", 2_000));
    t.flush();
    expect(fetchMock).toHaveBeenCalledTimes(1);
    const body = JSON.parse(fetchMock.mock.calls[0][1].body);
    expect(body.events.map((e: { event_id: string }) => e.event_id)).toEqual(["e2", "e3"]); // e1(最旧)被裁
    expect(t.dropped).toBe(1); // 被裁的最旧事件逐条计 dropped
  });

  it("单事件超 64KB：整组裁空不发送不空转重试，全量计 dropped", async () => {
    fetchMock.mockResolvedValue(res(500)); // 若误发送会进入重试空转——用调用数守卫
    const t = new Transport(mkCfg({ batchSize: 10, maxRetry: 3 }));
    t.push({
      event_id: "huge",
      visitor_id: "v1",
      session_id: "s1",
      page_id: "p1",
      properties: { blob: "x".repeat(70_000) },
    });
    t.flush();
    expect(fetchMock).not.toHaveBeenCalled(); // keepalive 64KiB 硬限确定性失败——不空转
    await vi.advanceTimersByTimeAsync(60_000);
    expect(fetchMock).not.toHaveBeenCalled();
    expect(t.dropped).toBe(1); // 整组丢弃完毕
  });
});

describe("mergeConfig", () => {
  it("缺省填充默认值，显式项覆盖", () => {
    expect(mergeConfig({ siteId: "s", endpoint: "/e" })).toEqual({
      siteId: "s",
      endpoint: "/e",
      batchSize: 10,
      flushMs: 15000,
      maxRetry: 3,
      queueMax: 200,
    });
    expect(mergeConfig({ siteId: "s", endpoint: "/e", batchSize: 5, flushMs: 1000 })).toMatchObject(
      { batchSize: 5, flushMs: 1000, maxRetry: 3, queueMax: 200 }
    );
  });
});