import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
import { AudioService } from "./audioService";

// ── WaveSurfer mock ────────────────────────────────────────────────────────────

const mockLoad = vi.fn();
const mockOn = vi.fn();
const mockUnAll = vi.fn();
const mockDestroy = vi.fn();
const mockGetDuration = vi.fn(() => 180);
const mockSetOptions = vi.fn();
const mockCreate = vi.fn();

vi.mock("wavesurfer.js", () => ({
  default: {
    create: (opts: unknown) => {
      mockCreate(opts);
      return {
        load: mockLoad,
        on: mockOn,
        unAll: mockUnAll,
        destroy: mockDestroy,
        getDuration: mockGetDuration,
        setOptions: mockSetOptions,
        isPlaying: vi.fn(() => false),
      };
    },
  },
}));

// ── Zustand store mock ─────────────────────────────────────────────────────────

vi.mock("../stores/playerStore", () => ({
  usePlayerStore: {
    getState: vi.fn(() => ({
      isPlaying: false,
      currentTime: 0,
      duration: 0,
      currentSongId: null,
      currentBandId: null,
      batchUpdate: vi.fn(),
      setDuration: vi.fn(),
      setCurrentSong: vi.fn(),
    })),
    subscribe: vi.fn(),
  },
}));

// ── Helpers ────────────────────────────────────────────────────────────────────

function makeContainer(): HTMLDivElement {
  return document.createElement("div");
}

function triggerWaveSurferReady() {
  // WaveSurfer fires the "ready" event via ws.on("ready", cb)
  const readyCb = mockOn.mock.calls.find(([event]) => event === "ready")?.[1];
  readyCb?.();
}

// ── Tests ──────────────────────────────────────────────────────────────────────

describe("AudioService.initialize()", () => {
  let service: AudioService;

  beforeEach(() => {
    AudioService.resetInstance();
    service = AudioService.getInstance();
    vi.clearAllMocks();
    mockGetDuration.mockReturnValue(180);
  });

  afterEach(() => {
    AudioService.resetInstance();
  });

  it("calls ws.load(url) without peaks when no peaks provided", async () => {
    const container = makeContainer();
    const url = "http://localhost/audio/song.mp3";

    const initPromise = service.initialize(container, url);
    triggerWaveSurferReady();
    await initPromise;

    expect(mockLoad).toHaveBeenCalledOnce();
    const [calledUrl, calledPeaks] = mockLoad.mock.calls[0];
    expect(calledUrl).toBe(url);
    expect(calledPeaks).toBeUndefined();
  });

  it("calls ws.load(url, [Float32Array]) when peaks are provided", async () => {
    const container = makeContainer();
    const url = "http://localhost/audio/song.mp3";
    const peaks = Array.from({ length: 500 }, (_, i) => i / 500);

    const initPromise = service.initialize(container, url, peaks);
    triggerWaveSurferReady();
    await initPromise;

    expect(mockLoad).toHaveBeenCalledOnce();
    const [calledUrl, calledChannelData] = mockLoad.mock.calls[0];
    expect(calledUrl).toBe(url);
    expect(calledChannelData).toHaveLength(1);
    expect(calledChannelData[0]).toBeInstanceOf(Float32Array);
    expect(calledChannelData[0]).toHaveLength(500);
    expect(calledChannelData[0][0]).toBeCloseTo(0);
    expect(calledChannelData[0][499]).toBeCloseTo(499 / 500);
  });

  it("does not re-initialize for the same url and container", async () => {
    const container = makeContainer();
    const url = "http://localhost/audio/song.mp3";
    const peaks = [0.5, 0.5, 0.5];

    const p1 = service.initialize(container, url, peaks);
    triggerWaveSurferReady();
    await p1;

    vi.clearAllMocks();

    // Second call with same URL + container: should no-op
    await service.initialize(container, url, peaks);
    expect(mockLoad).not.toHaveBeenCalled();
  });
});