/**
 * Model Download API Client 單元測試（Phase 0.9 / ADR-017 v1.3 — query-string token + redirect 導航）
 *
 * 覆蓋：
 *   1. getModelDownload — 200 正規化（download_url + expires_at）/ 404 / 403 / 501 / 502 / parse 缺欄
 *   2. triggerNavDownload — 建立 anchor、href = 傳入的 downloadUrl、有 download 屬性、click 後從 DOM 移除
 *   3. ModelDownloadError 形狀
 *
 * v1.3 移除（對齊 ADR §11.8）：
 *   - downloadModelFile（fetch + Bearer + blob，CORS 405 元兇）整段拔掉 → 不再測。
 *   - deriveDownloadFilename（redirect 跨 origin 檔名由 FAA Content-Disposition 決定、前端命名無效）→ 不再測。
 *   - triggerBlobDownload（blob object URL）→ 改為 triggerNavDownload（FAA 真實 URL，不需 createObjectURL）。
 */

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

import {
  getModelDownload,
  ModelDownloadError,
  triggerNavDownload,
} from "./model-download";

function jsonResponse(body: unknown, status = 200): Response {
  return new Response(JSON.stringify(body), {
    status,
    headers: { "Content-Type": "application/json" },
  });
}

let fetchMock: ReturnType<typeof vi.fn>;

beforeEach(() => {
  fetchMock = vi.fn();
  globalThis.fetch = fetchMock as unknown as typeof fetch;
});

afterEach(() => {
  vi.restoreAllMocks();
});

/* ========================================================================== */
/* 1. getModelDownload                                                         */
/* ========================================================================== */

describe("getModelDownload", () => {
  it("200 → 正規化 { downloadUrl, expiresAt }（snake_case；download_url 已含 ?access_token=）", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse({
        success: true,
        data: {
          download_url:
            "https://faa.example.com:5081/files/models/u1/j1.nef?access_token=fdt_abc123",
          token: "fdt_abc123", // 後端仍回（deprecated），前端不使用
          expires_at: "2026-06-07T12:02:00Z",
        },
      }),
    );

    const grant = await getModelDownload("m1");
    expect(grant.downloadUrl).toBe(
      "https://faa.example.com:5081/files/models/u1/j1.nef?access_token=fdt_abc123",
    );
    expect(grant.expiresAt).toBe("2026-06-07T12:02:00Z");
    // 前端不再讀 token 欄位（已移出 ModelDownloadGrant 型別）
    expect((grant as unknown as Record<string, unknown>).token).toBeUndefined();
  });

  it("camelCase 也吃（downloadUrl / expiresAt）", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse({
        success: true,
        data: {
          downloadUrl: "https://faa/x.nef?access_token=fdt_x",
          expiresAt: "2026-06-07T00:00:00Z",
        },
      }),
    );
    const grant = await getModelDownload("m1");
    expect(grant.downloadUrl).toBe("https://faa/x.nef?access_token=fdt_x");
    expect(grant.expiresAt).toBe("2026-06-07T00:00:00Z");
  });

  it("空 modelId → validation_failed（不打 API）", async () => {
    await expect(getModelDownload("")).rejects.toMatchObject({
      name: "ModelDownloadError",
      code: "validation_failed",
    });
    expect(fetchMock).not.toHaveBeenCalled();
  });

  it.each([
    [404, "model_not_found"],
    [403, "forbidden"],
    [501, "upload_not_supported"],
    [502, "sign_failed"],
  ])("backend %i → ModelDownloadError code=%s（小寫）", async (status, code) => {
    fetchMock.mockResolvedValue(
      jsonResponse({ success: false, error: { code, message: "x" } }, status),
    );
    await expect(getModelDownload("m1")).rejects.toMatchObject({
      name: "ModelDownloadError",
      status,
      code,
    });
  });

  it("200 但缺 download_url → parse_error", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse({
        success: true,
        data: { expires_at: "2026-06-07T12:02:00Z" },
      }),
    );
    await expect(getModelDownload("m1")).rejects.toMatchObject({
      code: "parse_error",
    });
  });
});

/* ========================================================================== */
/* 2. triggerNavDownload                                                       */
/* ========================================================================== */

describe("triggerNavDownload", () => {
  it("建立 anchor、href = 傳入的 downloadUrl、有 download 屬性、click 後從 DOM 移除", () => {
    const clickSpy = vi
      .spyOn(HTMLAnchorElement.prototype, "click")
      .mockImplementation(() => {});
    let capturedHref = "";
    let hasDownloadAttr = false;
    const appendSpy = vi
      .spyOn(document.body, "appendChild")
      .mockImplementation((node) => {
        const a = node as HTMLAnchorElement;
        capturedHref = a.href;
        hasDownloadAttr = a.hasAttribute("download");
        return node;
      });
    const removeSpy = vi
      .spyOn(document.body, "removeChild")
      .mockImplementation((node) => node);

    const url = "https://faa.example.com:5081/files/models/u1/j1.nef?access_token=fdt_abc";
    triggerNavDownload(url);

    expect(capturedHref).toBe(url);
    expect(hasDownloadAttr).toBe(true);
    expect(clickSpy).toHaveBeenCalledOnce();
    expect(appendSpy).toHaveBeenCalledOnce();
    expect(removeSpy).toHaveBeenCalledOnce();
  });

  it("不建立 blob object URL（不呼叫 createObjectURL）", () => {
    const createObjectURL = vi.fn();
    globalThis.URL.createObjectURL =
      createObjectURL as unknown as typeof URL.createObjectURL;
    vi.spyOn(HTMLAnchorElement.prototype, "click").mockImplementation(() => {});

    triggerNavDownload("https://faa/x.nef?access_token=fdt_x");

    expect(createObjectURL).not.toHaveBeenCalled();
  });

  it("空 downloadUrl → validation_failed（不建立 anchor）", () => {
    const clickSpy = vi
      .spyOn(HTMLAnchorElement.prototype, "click")
      .mockImplementation(() => {});
    expect(() => triggerNavDownload("")).toThrowError(
      expect.objectContaining({ code: "validation_failed" }),
    );
    expect(clickSpy).not.toHaveBeenCalled();
  });
});

/* ========================================================================== */
/* 3. ModelDownloadError 形狀                                                  */
/* ========================================================================== */

describe("ModelDownloadError", () => {
  it("保留 status / code / message / requestId", () => {
    const e = new ModelDownloadError(403, "forbidden", "no", "req-1");
    expect(e.name).toBe("ModelDownloadError");
    expect(e.status).toBe(403);
    expect(e.code).toBe("forbidden");
    expect(e.message).toBe("no");
    expect(e.requestId).toBe("req-1");
    expect(e).toBeInstanceOf(Error);
  });
});