import { existsSync } from 'node:fs';
import { join } from 'node:path';

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

import {
  BARS,
  CHORD_ROOTS,
  eventsAtStep,
  midiToFrequency,
  STEPS_PER_BAR,
  TOTAL_STEPS,
} from '../../app/static/js/logic/marchPattern.js';
import { allSoundFiles, AUDIO_PATH, SOUND_FILES, SOUND_OPTIONS } from '../../app/static/js/systems/AudioAssets.js';
import { AudioManager } from '../../app/static/js/systems/AudioManager.js';
import { SafeStorage, Settings } from '../../app/static/js/systems/Settings.js';
import { SYNTH_RECIPES } from '../../app/static/js/systems/Synth.js';

const ASSET_DIR = join(import.meta.dirname, '..', '..', 'app', 'static', 'assets', AUDIO_PATH);

// ------------------------------------------------------------ minimaler AudioContext-Ersatz

class FakeParam {
  constructor(value = 1) {
    this.value = value;
  }
  setValueAtTime(v) {
    this.value = v;
    return this;
  }
  exponentialRampToValueAtTime() {
    return this;
  }
  setTargetAtTime(v) {
    this.value = v;
    return this;
  }
}

class FakeNode {
  constructor(ctx) {
    this.ctx = ctx;
  }
  connect(node) {
    return node;
  }
  disconnect() {}
}

class FakeContext {
  constructor() {
    this.state = 'running';
    this.currentTime = 0;
    this.sampleRate = 8000;
    this.destination = new FakeNode(this);
    this.created = { oscillator: 0, source: 0 };
    this.startedBuffers = [];
  }
  createGain() {
    return Object.assign(new FakeNode(this), { gain: new FakeParam(1) });
  }
  createOscillator() {
    this.created.oscillator += 1;
    return Object.assign(new FakeNode(this), { frequency: new FakeParam(440), type: 'sine', start() {}, stop() {} });
  }
  createBufferSource() {
    this.created.source += 1;
    const ctx = this;
    return Object.assign(new FakeNode(this), {
      playbackRate: new FakeParam(1),
      buffer: null,
      start() {
        ctx.startedBuffers.push(this.buffer);
      },
      stop() {},
    });
  }
  createBiquadFilter() {
    return Object.assign(new FakeNode(this), { frequency: new FakeParam(350), Q: new FakeParam(1), type: 'lowpass' });
  }
  createBuffer(_channels, length) {
    const data = new Float32Array(length);
    return { getChannelData: () => data };
  }
  decodeAudioData(bytes) {
    return Promise.resolve({ decodedFrom: bytes.byteLength });
  }
  resume() {
    this.state = 'running';
    return Promise.resolve();
  }
}

function memorySettings() {
  const data = new Map();
  return new Settings(new SafeStorage({ getItem: (k) => data.get(k) ?? null, setItem: (k, v) => data.set(k, v) }));
}

const flush = () => new Promise((resolve) => setTimeout(resolve, 0));

// ------------------------------------------------------------------------------ Tests

describe('AudioAssets', () => {
  it('verweist nur auf vorhandene Dateien', () => {
    const missing = allSoundFiles().filter((file) => !existsSync(join(ASSET_DIR, file)));
    expect(missing).toEqual([]);
  });

  it('hat für jeden Effekt einen synthetischen Ersatz (Spiel bleibt ohne Dateien hörbar)', () => {
    const withoutRecipe = Object.keys(SOUND_FILES).filter((name) => typeof SYNTH_RECIPES[name] !== 'function');
    expect(withoutRecipe).toEqual([]);
  });

  it('hat für jeden Effekt Abspieloptionen mit gültiger Lautstärke', () => {
    for (const name of Object.keys(SOUND_FILES)) {
      const volume = SOUND_OPTIONS[name]?.volume ?? 1;
      expect(volume, name).toBeGreaterThan(0);
      expect(volume, name).toBeLessThanOrEqual(1);
    }
  });
});

describe('AudioManager', () => {
  beforeEach(() => {
    vi.stubGlobal('AudioContext', FakeContext);
  });
  afterEach(() => {
    vi.unstubAllGlobals();
    vi.useRealTimers();
  });

  it('bleibt vor der ersten Nutzeraktion stumm, ohne Fehler', () => {
    const audio = new AudioManager(memorySettings(), { fetchImpl: vi.fn() });
    expect(() => audio.play('shot-carbine')).not.toThrow();
    expect(audio.context).toBeNull();
  });

  it('lädt Dateien vorab und spielt sie nach dem Entsperren ab', async () => {
    const fetchImpl = vi.fn(async () => ({ ok: true, arrayBuffer: async () => new ArrayBuffer(16) }));
    const audio = new AudioManager(memorySettings(), { staticBase: '/glory/static/', fetchImpl });
    audio.preload();
    expect(fetchImpl).toHaveBeenCalledWith(`/glory/static/assets/${AUDIO_PATH}laserSmall_000.ogg`);
    expect(fetchImpl).toHaveBeenCalledTimes(allSoundFiles().length);

    audio.unlock();
    await flush();
    await flush();
    audio.play('shot-carbine');
    expect(audio.context.startedBuffers).toHaveLength(1);
    expect(audio.context.startedBuffers[0]).toEqual({ decodedFrom: 16 });
  });

  it('weicht auf den Synthesizer aus, wenn Dateien fehlen', async () => {
    const fetchImpl = vi.fn(async () => ({ ok: false }));
    const audio = new AudioManager(memorySettings(), { fetchImpl });
    audio.preload();
    audio.unlock();
    await flush();
    audio.play('explosion-big');
    // Gespielt wurde nur Rauschen aus dem Synthesizer, keine dekodierte Datei.
    expect(audio.context.startedBuffers.filter((b) => b && 'decodedFrom' in b)).toHaveLength(0);
    expect(audio.context.created.oscillator).toBeGreaterThan(0);
  });

  it('begrenzt schnelle Wiederholungen desselben Effekts', () => {
    const audio = new AudioManager(memorySettings(), { fetchImpl: vi.fn() });
    audio.unlock();
    const before = audio.context.created.oscillator;
    audio.play('combo-step');
    audio.play('combo-step');
    expect(audio.context.created.oscillator - before).toBe(1);
  });

  it('überträgt Lautstärkeänderungen sofort auf die Kanäle', () => {
    const settings = memorySettings();
    const audio = new AudioManager(settings, { fetchImpl: vi.fn() });
    audio.unlock();
    settings.setVolume('music', 0.2);
    settings.setVolume('master', 0.6);
    expect(audio.gains.music.gain.value).toBe(0.2);
    expect(audio.gains.master.gain.value).toBe(0.6);
  });

  it('startet vorgemerkte Musik erst nach dem Entsperren und stoppt sie wieder', () => {
    vi.useFakeTimers();
    const audio = new AudioManager(memorySettings(), { fetchImpl: vi.fn() });
    audio.startMusic();
    expect(audio.music).toBeNull();
    audio.unlock();
    expect(audio.music).not.toBeNull();
    vi.advanceTimersByTime(200);
    expect(audio.context.created.oscillator).toBeGreaterThan(0);
    audio.stopMusic();
    expect(audio.music).toBeNull();
    expect(audio.musicWanted).toBe(false);
  });

  it('senkt die Musik in der Pause ab', () => {
    const audio = new AudioManager(memorySettings(), { fetchImpl: vi.fn() });
    audio.unlock();
    audio.duck(true);
    expect(audio.gains.duck.gain.value).toBeLessThan(1);
    audio.duck(false);
    expect(audio.gains.duck.gain.value).toBe(1);
  });
});

describe('Marschmuster', () => {
  const all = Array.from({ length: TOTAL_STEPS }, (_, step) => eventsAtStep(step));
  const count = (instrument) => all.flat().filter((e) => e.instrument === instrument).length;

  it('hat 8 Takte à 16 Schritte', () => {
    expect(TOTAL_STEPS).toBe(BARS * STEPS_PER_BAR);
    expect(CHORD_ROOTS).toHaveLength(BARS);
  });

  it('schlägt die große Trommel auf 1 und 3 jedes Takts', () => {
    expect(count('kick')).toBe(BARS * 2);
    for (let bar = 0; bar < BARS; bar += 1) {
      expect(all[bar * STEPS_PER_BAR].some((e) => e.instrument === 'kick')).toBe(true);
      expect(all[bar * STEPS_PER_BAR + 8].some((e) => e.instrument === 'kick')).toBe(true);
    }
  });

  it('spielt die Melodie nur mit Tönen aus C-Dur', () => {
    const cMajor = new Set([0, 2, 4, 5, 7, 9, 11]);
    const melody = all.flat().filter((e) => e.instrument === 'lead');
    expect(melody.length).toBeGreaterThan(20);
    for (const event of melody) expect(cMajor.has(event.notes[0] % 12)).toBe(true);
  });

  it('wiederholt sich nahtlos', () => {
    expect(eventsAtStep(TOTAL_STEPS)).toEqual(eventsAtStep(0));
    expect(eventsAtStep(-1)).toEqual(eventsAtStep(TOTAL_STEPS - 1));
  });

  it('rechnet MIDI-Töne in Frequenzen um', () => {
    expect(midiToFrequency(69)).toBeCloseTo(440);
    expect(midiToFrequency(57)).toBeCloseTo(220);
    expect(midiToFrequency(60)).toBeCloseTo(261.63, 1);
  });
});