import { describe, it, expect, beforeEach, vi, afterEach } from "vitest";
import { Test, TestingModule } from "@nestjs/testing";
import { ServiceUnavailableException } from "@nestjs/common";
import { LlmService } from "./llm.service";
import type { ChatRequestDto, EmbedRequestDto } from "./dto";
const mockList = vi.fn(); const mockChat = vi.fn(); const mockEmbed = vi.fn();
vi.mock("ollama", () => ({ Ollama: class { list = mockList; chat = mockChat; embed = mockEmbed; } }));
describe("LlmService", () => {
  let service: LlmService;
  const originalEnv = { ...process.env };
  beforeEach(async () => { process.env = { ...originalEnv, OLLAMA_HOST: "http://test:11434", OLLAMA_TIMEOUT: "60000" }; vi.clearAllMocks(); service = (await Test.createTestingModule({ providers: [LlmService] }).compile()).get(LlmService); });
  afterEach(() => { process.env = originalEnv; });
  it("should be defined", () => { expect(service).toBeDefined(); });
  describe("checkHealth", () => { it("should return healthy", async () => { mockList.mockResolvedValue({ models: [{ name: "llama3.2" }] }); const r = await service.checkHealth(); expect(r.healthy).toBe(true); }); it("should return unhealthy on error", async () => { mockList.mockRejectedValue(new Error("fail")); const r = await service.checkHealth(); expect(r.healthy).toBe(false); }); });
  describe("listModels", () => { it("should return models", async () => { mockList.mockResolvedValue({ models: [{ name: "llama3.2" }] }); expect(await service.listModels()).toEqual(["llama3.2"]); }); it("should throw on error", async () => { mockList.mockRejectedValue(new Error("fail")); await expect(service.listModels()).rejects.toThrow(ServiceUnavailableException); }); });
  describe("chat", () => { const req: ChatRequestDto = { model: "llama3.2", messages: [{ role: "user", content: "Hi" }] }; it("should return response", async () => { mockChat.mockResolvedValue({ model: "llama3.2", message: { role: "assistant", content: "Hello" }, done: true }); const r = await service.chat(req); expect(r.message.content).toBe("Hello"); }); it("should throw on error", async () => { mockChat.mockRejectedValue(new Error("fail")); await expect(service.chat(req)).rejects.toThrow(ServiceUnavailableException); }); });
  describe("chatStream", () => { it("should yield chunks", async () => { mockChat.mockResolvedValue((async function* () { yield { model: "m", message: { role: "a", content: "x" }, done: true }; })()); const chunks = []; for await (const c of service.chatStream({ model: "m", messages: [{ role: "user", content: "x" }], stream: true })) chunks.push(c); expect(chunks.length).toBe(1); }); });
  describe("embed", () => { it("should return embeddings", async () => { mockEmbed.mockResolvedValue({ model: "m", embeddings: [[0.1]] }); const r = await service.embed({ model: "m", input: ["x"] }); expect(r.embeddings).toEqual([[0.1]]); }); });
});