/**
 * Unit tests for api: buildFetchOptions, fetchDuties (403 handling, AbortError).
 */

import { describe, it, expect, vi, beforeEach, afterEach, beforeAll } from "vitest";

beforeAll(() => {
  document.body.innerHTML =
    '<div id="calendar"></div><h2 id="monthTitle"></h2>' +
    '<div id="dutyList"></div><div id="loading"></div><div id="error"></div>' +
    '<div id="accessDenied"></div><div class="header"></div><div class="weekdays"></div>' +
    '<button id="prevMonth"></button><button id="nextMonth"></button>';
});

const mockGetInitData = vi.fn();
vi.mock("./auth.js", () => ({ getInitData: () => mockGetInitData() }));

import { buildFetchOptions, fetchDuties, apiGet, fetchCalendarEvents } from "./api.js";
import { state } from "./dom.js";

describe("buildFetchOptions", () => {
  beforeEach(() => {
    state.lang = "ru";
  });

  it("sets X-Telegram-Init-Data when initData provided", () => {
    const opts = buildFetchOptions("init-data-string");
    expect(opts.headers["X-Telegram-Init-Data"]).toBe("init-data-string");
    opts.cleanup();
  });

  it("omits X-Telegram-Init-Data when initData empty", () => {
    const opts = buildFetchOptions("");
    expect(opts.headers["X-Telegram-Init-Data"]).toBeUndefined();
    opts.cleanup();
  });

  it("sets Accept-Language from state.lang", () => {
    state.lang = "en";
    const opts = buildFetchOptions("");
    expect(opts.headers["Accept-Language"]).toBe("en");
    opts.cleanup();
  });

  it("returns signal and cleanup function", () => {
    const opts = buildFetchOptions("");
    expect(opts.signal).toBeDefined();
    expect(typeof opts.cleanup).toBe("function");
    opts.cleanup();
  });

  it("cleanup clears timeout and removes external abort listener", () => {
    const controller = new AbortController();
    const opts = buildFetchOptions("", controller.signal);
    opts.cleanup();
    controller.abort();
  });
});

describe("fetchDuties", () => {
  const originalFetch = globalThis.fetch;

  beforeEach(() => {
    mockGetInitData.mockReturnValue("test-init-data");
    state.lang = "ru";
  });

  afterEach(() => {
    globalThis.fetch = originalFetch;
  });

  it("returns JSON on 200", async () => {
    globalThis.fetch = vi.fn().mockResolvedValue({
      ok: true,
      status: 200,
      json: () => Promise.resolve([{ id: 1 }]),
    });
    const result = await fetchDuties("2025-02-01", "2025-02-28");
    expect(result).toEqual([{ id: 1 }]);
  });

  it("throws ACCESS_DENIED on 403 with server detail from body", async () => {
    globalThis.fetch = vi.fn().mockResolvedValue({
      ok: false,
      status: 403,
      json: () => Promise.resolve({ detail: "Custom access denied" }),
    });
    await expect(fetchDuties("2025-02-01", "2025-02-28")).rejects.toMatchObject({
      message: "ACCESS_DENIED",
      serverDetail: "Custom access denied",
    });
  });

  it("rethrows AbortError when request is aborted", async () => {
    const aborter = new AbortController();
    const abortError = new DOMException("aborted", "AbortError");
    globalThis.fetch = vi.fn().mockImplementation(() => {
      return Promise.reject(abortError);
    });
    await expect(
      fetchDuties("2025-02-01", "2025-02-28", aborter.signal)
    ).rejects.toMatchObject({ name: "AbortError" });
  });
});

describe("apiGet", () => {
  const originalFetch = globalThis.fetch;

  beforeEach(() => {
    mockGetInitData.mockReturnValue("init-data");
    state.lang = "en";
  });

  afterEach(() => {
    globalThis.fetch = originalFetch;
  });

  it("builds URL with path and query params and returns response", async () => {
    let capturedUrl = "";
    globalThis.fetch = vi.fn().mockImplementation((url) => {
      capturedUrl = url;
      return Promise.resolve({ ok: true, status: 200 });
    });
    await apiGet("/api/duties", { from: "2025-02-01", to: "2025-02-28" });
    expect(capturedUrl).toContain("/api/duties");
    expect(capturedUrl).toContain("from=2025-02-01");
    expect(capturedUrl).toContain("to=2025-02-28");
  });

  it("omits query string when params empty", async () => {
    let capturedUrl = "";
    globalThis.fetch = vi.fn().mockImplementation((url) => {
      capturedUrl = url;
      return Promise.resolve({ ok: true });
    });
    await apiGet("/api/health", {});
    expect(capturedUrl).toBe(window.location.origin + "/api/health");
  });

  it("passes X-Telegram-Init-Data and Accept-Language headers", async () => {
    let capturedOpts = null;
    globalThis.fetch = vi.fn().mockImplementation((url, opts) => {
      capturedOpts = opts;
      return Promise.resolve({ ok: true });
    });
    await apiGet("/api/duties", { from: "2025-01-01", to: "2025-01-31" });
    expect(capturedOpts?.headers["X-Telegram-Init-Data"]).toBe("init-data");
    expect(capturedOpts?.headers["Accept-Language"]).toBe("en");
  });

  it("passes an abort signal to fetch when options.signal provided", async () => {
    const controller = new AbortController();
    let capturedSignal = null;
    globalThis.fetch = vi.fn().mockImplementation((url, opts) => {
      capturedSignal = opts.signal;
      return Promise.resolve({ ok: true });
    });
    await apiGet("/api/duties", {}, { signal: controller.signal });
    expect(capturedSignal).toBeDefined();
    expect(capturedSignal).toBeInstanceOf(AbortSignal);
  });
});

describe("fetchCalendarEvents", () => {
  const originalFetch = globalThis.fetch;

  beforeEach(() => {
    mockGetInitData.mockReturnValue("init-data");
    state.lang = "ru";
  });

  afterEach(() => {
    globalThis.fetch = originalFetch;
  });

  it("returns JSON array on 200", async () => {
    globalThis.fetch = vi.fn().mockResolvedValue({
      ok: true,
      status: 200,
      json: () => Promise.resolve([{ date: "2025-02-25", summary: "Holiday" }]),
    });
    const result = await fetchCalendarEvents("2025-02-01", "2025-02-28");
    expect(result).toEqual([{ date: "2025-02-25", summary: "Holiday" }]);
  });

  it("returns empty array on non-OK response", async () => {
    globalThis.fetch = vi.fn().mockResolvedValue({
      ok: false,
      status: 500,
    });
    const result = await fetchCalendarEvents("2025-02-01", "2025-02-28");
    expect(result).toEqual([]);
  });

  it("returns empty array on 403 (does not throw)", async () => {
    globalThis.fetch = vi.fn().mockResolvedValue({
      ok: false,
      status: 403,
    });
    const result = await fetchCalendarEvents("2025-02-01", "2025-02-28");
    expect(result).toEqual([]);
  });

  it("rethrows AbortError when request is aborted", async () => {
    const aborter = new AbortController();
    const abortError = new DOMException("aborted", "AbortError");
    globalThis.fetch = vi.fn().mockImplementation(() => Promise.reject(abortError));
    await expect(
      fetchCalendarEvents("2025-02-01", "2025-02-28", aborter.signal)
    ).rejects.toMatchObject({ name: "AbortError" });
  });
});