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

const ORIGINAL_ENV = { ...process.env };

const mockSuccessResponse = {
  id: "chatcmpl-test",
  created: 1,
  model: "qwen3.5-plus",
  choices: [
    {
      index: 0,
      message: {
        role: "assistant",
        content: "你好，我是测试响应。",
      },
      finish_reason: "stop",
    },
  ],
};

describe("invokeLLM", () => {
  beforeEach(() => {
    vi.resetModules();
    vi.restoreAllMocks();
    process.env = { ...ORIGINAL_ENV };
  });

  afterEach(() => {
    process.env = { ...ORIGINAL_ENV };
    vi.unstubAllGlobals();
  });

  it("uses LLM_* environment variables for request config", async () => {
    process.env.LLM_API_URL = "https://one.hao.work/v1/chat/completions";
    process.env.LLM_API_KEY = "test-key";
    process.env.LLM_MODEL = "qwen3.5-plus";
    process.env.LLM_MAX_TOKENS = "4096";
    process.env.LLM_ENABLE_THINKING = "0";

    const fetchMock = vi.fn().mockResolvedValue({
      ok: true,
      json: async () => mockSuccessResponse,
    });
    vi.stubGlobal("fetch", fetchMock);

    const { invokeLLM } = await import("./llm");
    await invokeLLM({
      messages: [{ role: "user", content: "你好" }],
    });

    expect(fetchMock).toHaveBeenCalledTimes(1);
    expect(fetchMock).toHaveBeenCalledWith(
      "https://one.hao.work/v1/chat/completions",
      expect.objectContaining({
        method: "POST",
        headers: expect.objectContaining({
          authorization: "Bearer test-key",
        }),
      })
    );

    const [, request] = fetchMock.mock.calls[0] as [string, { body: string }];
    expect(JSON.parse(request.body)).toMatchObject({
      model: "qwen3.5-plus",
      max_tokens: 4096,
      messages: [{ role: "user", content: "你好" }],
    });
    expect(JSON.parse(request.body)).not.toHaveProperty("thinking");
  });

  it("allows overriding the model per request", async () => {
    process.env.LLM_API_URL = "https://one.hao.work/v1/chat/completions";
    process.env.LLM_API_KEY = "test-key";
    process.env.LLM_MODEL = "qwen3.5-plus";

    const fetchMock = vi.fn().mockResolvedValue({
      ok: true,
      json: async () => mockSuccessResponse,
    });
    vi.stubGlobal("fetch", fetchMock);

    const { invokeLLM } = await import("./llm");
    await invokeLLM({
      model: "qwen3-vl-235b-a22b",
      messages: [{ role: "user", content: "describe image" }],
    });

    const [, request] = fetchMock.mock.calls[0] as [string, { body: string }];
    expect(JSON.parse(request.body)).toMatchObject({
      model: "qwen3-vl-235b-a22b",
    });
  });

  it("falls back to legacy forge variables when LLM_* values are absent", async () => {
    delete process.env.LLM_API_URL;
    delete process.env.LLM_API_KEY;
    delete process.env.LLM_MODEL;
    delete process.env.LLM_MAX_TOKENS;
    delete process.env.LLM_ENABLE_THINKING;
    delete process.env.LLM_THINKING_BUDGET;
    process.env.BUILT_IN_FORGE_API_URL = "https://forge.example.com";
    process.env.BUILT_IN_FORGE_API_KEY = "legacy-key";

    const fetchMock = vi.fn().mockResolvedValue({
      ok: true,
      json: async () => mockSuccessResponse,
    });
    vi.stubGlobal("fetch", fetchMock);

    const { invokeLLM } = await import("./llm");
    await invokeLLM({
      messages: [{ role: "user", content: "legacy" }],
    });

    expect(fetchMock).toHaveBeenCalledWith(
      "https://forge.example.com/v1/chat/completions",
      expect.objectContaining({
        headers: expect.objectContaining({
          authorization: "Bearer legacy-key",
        }),
      })
    );

    const [, request] = fetchMock.mock.calls[0] as [string, { body: string }];
    expect(JSON.parse(request.body)).toMatchObject({
      model: "gemini-2.5-flash",
    });
  });
});