/**
 * Conversion API Client 單元測試（Phase 0.8 F-T2）
 *
 * 覆蓋 5 個 endpoint：
 *   1. initConversion — XHR multipart upload + progress / abort / 409
 *   2. getActiveConversion — has_active true / false / 異常
 *   3. getConversion — 200 / 403 / 404
 *   4. promoteConversionToModels — 201 / 409 / parse 缺欄
 *   5. getConversionDownloadURL — 純函式輸入輸出
 */

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

import {
  ConversionAPIError,
  getActiveConversion,
  getConversion,
  getConversionDownloadURL,
  initConversion,
  promoteConversionToModels,
} from "./conversion";

/* -------------------------------------------------------------------------- */
/* XHR mock helper — 取代 jsdom 的 XMLHttpRequest                             */
/* -------------------------------------------------------------------------- */

interface MockXHRInstance {
  open: ReturnType<typeof vi.fn>;
  send: ReturnType<typeof vi.fn>;
  abort: ReturnType<typeof vi.fn>;
  setRequestHeader: ReturnType<typeof vi.fn>;
  getResponseHeader: ReturnType<typeof vi.fn>;
  upload: { onprogress: ((ev: ProgressEvent) => void) | null };
  withCredentials: boolean;
  status: number;
  responseText: string;
  onload: (() => void) | null;
  onerror: (() => void) | null;
  ontimeout: (() => void) | null;
  // 觸發測試輔助
  _fireLoad: (status: number, body: unknown, headers?: Record<string, string>) => void;
  _fireError: () => void;
  _fireProgress: (loaded: number, total: number) => void;
  _formDataSent: FormData | null;
}

function installMockXHR(): { instances: MockXHRInstance[] } {
  const instances: MockXHRInstance[] = [];

  // 必須是真 constructor function（不能用 vi.fn().mockImplementation — 那回的是 mock，不可 `new`）
  function MockXHR(this: MockXHRInstance) {
    const headers: Record<string, string> = {};
    // 直接賦值到 this，避免 this 別名被 lint 警示
    this.open = vi.fn();
    this.abort = vi.fn();
    this.setRequestHeader = vi.fn();
    this.getResponseHeader = vi.fn((k: string) => headers[k.toLowerCase()] ?? null);
    this.upload = { onprogress: null };
    this.withCredentials = false;
    this.status = 0;
    this.responseText = "";
    this.onload = null;
    this.onerror = null;
    this.ontimeout = null;
    this._formDataSent = null;
    // send / fire* 需要持有 instance 參考；用 instance push 後再裝上
    instances.push(this);
    const idx = instances.length - 1;
    this.send = vi.fn((body: unknown) => {
      instances[idx]._formDataSent = body instanceof FormData ? body : null;
    });
    this._fireLoad = (status, body, hdrs) => {
      const ref = instances[idx];
      ref.status = status;
      ref.responseText =
        typeof body === "string" ? body : body == null ? "" : JSON.stringify(body);
      if (hdrs) {
        for (const [k, v] of Object.entries(hdrs)) headers[k.toLowerCase()] = v;
      }
      ref.onload?.();
    };
    this._fireError = () => {
      instances[idx].onerror?.();
    };
    this._fireProgress = (loaded, total) => {
      instances[idx].upload.onprogress?.({
        lengthComputable: true,
        loaded,
        total,
      } as ProgressEvent);
    };
  }

  // 覆蓋 global XMLHttpRequest
  (globalThis as unknown as { XMLHttpRequest: unknown }).XMLHttpRequest = MockXHR;
  return { instances };
}

/* -------------------------------------------------------------------------- */
/* fetch mock helper — 給 4 個非 init 的 endpoint                             */
/* -------------------------------------------------------------------------- */

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. initConversion                                                           */
/* ========================================================================== */

describe("initConversion", () => {
  it("happy path：multipart 含 model + ref_images + platform，回 normalized Job", async () => {
    const { instances } = installMockXHR();
    const file = new File(["onnx-bytes"], "yolov5s.onnx", {
      type: "application/octet-stream",
    });
    const ref = new File(["img"], "ref.jpg", { type: "image/jpeg" });

    const promise = initConversion({
      file,
      refImages: [ref],
      targetChip: "KL720",
      taskName: "yolov5s_test",
    });

    // 確認 XHR 已建立並送 form
    expect(instances.length).toBe(1);
    const xhr = instances[0];
    expect(xhr.open).toHaveBeenCalledWith(
      "POST",
      expect.stringMatching(/\/api\/conversion\/init$/),
      true,
    );
    expect(xhr.withCredentials).toBe(true);

    const form = xhr._formDataSent;
    expect(form).toBeInstanceOf(FormData);
    // model 檔
    expect((form!.get("model") as File).name).toBe("yolov5s.onnx");
    // ref_images[]（多筆同 key）
    const refs = form!.getAll("ref_images[]");
    expect(refs.length).toBe(1);
    expect((refs[0] as File).name).toBe("ref.jpg");
    // text fields — backend 用 `model_id` 欄裝 taskName、`platform` 用 wire 數字格式
    expect(form!.get("model_id")).toBe("yolov5s_test");
    expect(form!.get("platform")).toBe("720");
    expect(form!.get("version")).toBe("v1.0.0");

    // 模擬後端 200 回 envelope
    xhr._fireLoad(200, {
      success: true,
      data: {
        job_id: "550e8400-e29b-41d4-a716-446655440000",
        status: "running",
        stage: "onnx",
        progress: 0,
        created_at: "2026-04-30T12:00:00Z",
        expires_at: "2026-05-07T12:00:00Z",
        source_filename: "yolov5s.onnx",
        target_chip: "720",
      },
    });

    const job = await promise;
    expect(job.job_id).toBe("550e8400-e29b-41d4-a716-446655440000");
    expect(job.status).toBe("running");
    expect(job.target_chip).toBe("KL720"); // wire 520→KL520 normalize
    expect(job.stage).toBe("onnx");
  });

  it("沒給 taskName 時用檔名當 model_id", async () => {
    const { instances } = installMockXHR();
    const file = new File(["x"], "model.onnx");
    const promise = initConversion({ file, targetChip: "KL520" });
    const xhr = instances[0];
    xhr._fireLoad(200, {
      success: true,
      data: {
        job_id: "j1",
        status: "running",
        stage: "onnx",
        created_at: "2026-04-30T12:00:00Z",
        expires_at: "2026-05-07T12:00:00Z",
        source_filename: "model.onnx",
        target_chip: "520",
      },
    });
    await promise;
    expect(xhr._formDataSent!.get("model_id")).toBe("model.onnx");
    expect(xhr._formDataSent!.get("platform")).toBe("520");
  });

  it("onUploadProgress 被呼叫", async () => {
    const { instances } = installMockXHR();
    const file = new File(["x".repeat(100)], "m.onnx");
    const onUploadProgress = vi.fn();

    const promise = initConversion({
      file,
      targetChip: "KL520",
      onUploadProgress,
    });

    const xhr = instances[0];
    xhr._fireProgress(50, 100);
    xhr._fireProgress(100, 100);
    xhr._fireLoad(200, {
      success: true,
      data: {
        job_id: "j2",
        status: "running",
        stage: "onnx",
        created_at: "2026-04-30T12:00:00Z",
        expires_at: "2026-05-07T12:00:00Z",
        source_filename: "m.onnx",
        target_chip: "520",
      },
    });

    await promise;
    expect(onUploadProgress).toHaveBeenCalledWith(50, 100);
    expect(onUploadProgress).toHaveBeenCalledWith(100, 100);
    expect(onUploadProgress).toHaveBeenCalledTimes(2);
  });

  it("409 active_job_exists → throw ConversionAPIError(409, 'active_job_exists', requestId)", async () => {
    const { instances } = installMockXHR();
    const file = new File(["x"], "m.onnx");
    const promise = initConversion({ file, targetChip: "KL520" });

    instances[0]._fireLoad(
      409,
      {
        success: false,
        error: {
          code: "active_job_exists",
          message: "你已有進行中任務",
        },
      },
      { "X-Request-Id": "req-abc" },
    );

    await expect(promise).rejects.toBeInstanceOf(ConversionAPIError);
    try {
      await promise;
    } catch (e) {
      const err = e as ConversionAPIError;
      expect(err.status).toBe(409);
      expect(err.code).toBe("active_job_exists");
      expect(err.message).toBe("你已有進行中任務");
      expect(err.requestId).toBe("req-abc");
    }
  });

  it("network error → throw ConversionAPIError(0, 'network_error')", async () => {
    const { instances } = installMockXHR();
    const file = new File(["x"], "m.onnx");
    const promise = initConversion({ file, targetChip: "KL520" });
    instances[0]._fireError();
    await expect(promise).rejects.toMatchObject({
      name: "ConversionAPIError",
      status: 0,
      code: "network_error",
    });
  });

  it("AbortSignal.abort → 呼叫 xhr.abort 並 reject ConversionAPIError(0, 'aborted')", async () => {
    const { instances } = installMockXHR();
    const file = new File(["x"], "m.onnx");
    const ctrl = new AbortController();

    const promise = initConversion({
      file,
      targetChip: "KL520",
      signal: ctrl.signal,
    });

    ctrl.abort();
    await expect(promise).rejects.toMatchObject({
      name: "ConversionAPIError",
      code: "aborted",
    });
    expect(instances[0].abort).toHaveBeenCalled();
  });

  it("已 abort 的 signal → 立刻 reject 不送 XHR", async () => {
    const { instances } = installMockXHR();
    const file = new File(["x"], "m.onnx");
    const ctrl = new AbortController();
    ctrl.abort();

    const promise = initConversion({
      file,
      targetChip: "KL520",
      signal: ctrl.signal,
    });

    await expect(promise).rejects.toMatchObject({ code: "aborted" });
    expect(instances[0].send).not.toHaveBeenCalled();
  });
});

/* ========================================================================== */
/* 2. getActiveConversion                                                      */
/* ========================================================================== */

describe("getActiveConversion", () => {
  it("has_active=true → 回 normalized Job", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse({
        success: true,
        data: {
          has_active: true,
          job: {
            job_id: "j-active",
            status: "running",
            stage: "bie",
            progress: 45,
            created_at: "2026-04-30T12:00:00Z",
            expires_at: "2026-05-07T12:00:00Z",
            source_filename: "yolov5s.onnx",
            target_chip: "720",
          },
        },
      }),
    );

    const job = await getActiveConversion();
    expect(job).not.toBeNull();
    expect(job!.job_id).toBe("j-active");
    expect(job!.target_chip).toBe("KL720");
    expect(job!.stage).toBe("bie");
    expect(job!.progress).toBe(45);
  });

  it("has_active=false → 回 null", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse({ success: true, data: { has_active: false, job: null } }),
    );
    const job = await getActiveConversion();
    expect(job).toBeNull();
  });

  it("backend 401 → throw ConversionAPIError(401, 'unauthorized')", async () => {
    // F-T2 review Major #1：code 統一全小寫，對齊 conversion.md §6 i18n key 命名
    fetchMock.mockResolvedValue(new Response("", { status: 401 }));
    await expect(getActiveConversion()).rejects.toMatchObject({
      name: "ConversionAPIError",
      status: 401,
      code: "unauthorized",
    });
  });
});

/* ========================================================================== */
/* 3. getConversion                                                            */
/* ========================================================================== */

describe("getConversion", () => {
  it("成功回 normalized Job（completed → succeeded）", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse({
        success: true,
        data: {
          job_id: "j-1",
          status: "completed",
          progress: 100,
          created_at: "2026-04-30T12:00:00Z",
          expires_at: "2026-05-07T12:00:00Z",
          source_filename: "m.onnx",
          target_chip: "520",
          error_code: null,
          error_message: null,
        },
      }),
    );

    const job = await getConversion("j-1");
    expect(job.status).toBe("succeeded"); // completed → succeeded
    expect(job.target_chip).toBe("KL520");
    expect(job.error).toBeUndefined();
  });

  it("failed 時 error_code/message 包成 error 物件", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse({
        success: true,
        data: {
          job_id: "j-2",
          status: "failed",
          progress: 30,
          created_at: "2026-04-30T12:00:00Z",
          expires_at: "2026-05-07T12:00:00Z",
          source_filename: "m.onnx",
          target_chip: "720",
          error_code: "QUANTIZATION_FAILED",
          error_message: "Custom op X not supported",
        },
      }),
    );

    const job = await getConversion("j-2");
    expect(job.status).toBe("failed");
    expect(job.error).toEqual({
      code: "QUANTIZATION_FAILED",
      message: "Custom op X not supported",
    });
  });

  it("404 not_found → throw ConversionAPIError(404, 'not_found')", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse(
        { success: false, error: { code: "not_found", message: "任務不存在" } },
        404,
      ),
    );
    await expect(getConversion("missing")).rejects.toMatchObject({
      name: "ConversionAPIError",
      status: 404,
      code: "not_found",
    });
  });

  it("403 forbidden → throw ConversionAPIError(403, 'forbidden')", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse(
        { success: false, error: { code: "forbidden", message: "你無權存取此任務" } },
        403,
      ),
    );
    await expect(getConversion("other-user-job")).rejects.toMatchObject({
      status: 403,
      code: "forbidden",
    });
  });

  it("空 jobId → 立刻 throw ConversionAPIError 不打 fetch", async () => {
    await expect(getConversion("")).rejects.toMatchObject({
      code: "validation_failed",
    });
    expect(fetchMock).not.toHaveBeenCalled();
  });
});

/* ========================================================================== */
/* 4. promoteConversionToModels                                                */
/* ========================================================================== */

describe("promoteConversionToModels", () => {
  it("成功回 { model_id }", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse(
        {
          success: true,
          data: {
            model_id: "m-abc-123",
            source: "converted",
            source_job_id: "j-1",
            name: "yolov5s_kl720",
            target_chip: "kl720",
            file_size: 12345678,
            status: "ready",
            created_at: "2026-04-30T12:30:00Z",
          },
        },
        201,
      ),
    );

    const res = await promoteConversionToModels("j-1", { name: "yolov5s_kl720" });
    expect(res).toEqual({ model_id: "m-abc-123" });

    // 驗證 request body
    const [, init] = fetchMock.mock.calls[0] as [string, RequestInit];
    expect(init.method).toBe("POST");
    expect(init.body).toBe(JSON.stringify({ name: "yolov5s_kl720" }));
  });

  it("body 省略時送空物件", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse(
        { success: true, data: { model_id: "m-1" } },
        200,
      ),
    );
    await promoteConversionToModels("j-2");
    const [, init] = fetchMock.mock.calls[0] as [string, RequestInit];
    expect(init.body).toBe("{}");
  });

  it("409 job_not_completed → throw ConversionAPIError(409, 'job_not_completed')", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse(
        { success: false, error: { code: "job_not_completed", message: "尚未完成" } },
        409,
      ),
    );
    await expect(promoteConversionToModels("j-3")).rejects.toMatchObject({
      status: 409,
      code: "job_not_completed",
    });
  });

  it("response 缺 model_id → throw ConversionAPIError(500, 'parse_error')", async () => {
    fetchMock.mockResolvedValue(
      jsonResponse({ success: true, data: { source: "converted" } }, 201),
    );
    await expect(promoteConversionToModels("j-4")).rejects.toMatchObject({
      code: "parse_error",
      status: 500,
    });
  });

  it("空 jobId → 立刻 throw 不打 fetch", async () => {
    await expect(promoteConversionToModels("")).rejects.toMatchObject({
      code: "validation_failed",
    });
    expect(fetchMock).not.toHaveBeenCalled();
  });
});

/* ========================================================================== */
/* 5. getConversionDownloadURL                                                 */
/* ========================================================================== */

describe("getConversionDownloadURL", () => {
  it("組相對 URL（不含 base，給 anchor / location.href 用）", () => {
    expect(getConversionDownloadURL("550e8400-e29b-41d4-a716-446655440000")).toBe(
      "/api/conversion/550e8400-e29b-41d4-a716-446655440000/download",
    );
  });

  it("encodeURIComponent 防止 jobId 含特殊字元注入", () => {
    expect(getConversionDownloadURL("a/b?c=d")).toBe(
      "/api/conversion/a%2Fb%3Fc%3Dd/download",
    );
  });
});