quartiles/src/engine/audio.js

/**
 * Web Audio API synthesizer for tactile, Apple-grade acoustic feedback
 * Requires 0 external audio files, operates instantly with zero latency
 */
class SoundEngine {
  constructor() {
    this.ctx = null;
    this.muted = localStorage.getItem('quartiles_sound_muted') === 'true';
  }

  initContext() {
    if (!this.ctx) {
      const AudioCtx = window.AudioContext || window.webkitAudioContext;
      if (AudioCtx) {
        this.ctx = new AudioCtx();
      }
    }
    if (this.ctx && this.ctx.state === 'suspended') {
      this.ctx.resume();
    }
  }

  isMuted() {
    return this.muted;
  }

  setMuted(muted) {
    this.muted = !!muted;
    localStorage.setItem('quartiles_sound_muted', this.muted ? 'true' : 'false');
  }

  toggleMute() {
    this.setMuted(!this.muted);
    return this.muted;
  }

  // Soft tactile click for tile selection
  playTileClick() {
    if (this.muted) return;
    this.initContext();
    if (!this.ctx) return;

    const osc = this.ctx.createOscillator();
    const gain = this.ctx.createGain();
    const now = this.ctx.currentTime;

    osc.type = 'sine';
    osc.frequency.setValueAtTime(620, now);
    osc.frequency.exponentialRampToValueAtTime(380, now + 0.04);

    gain.gain.setValueAtTime(0.12, now);
    gain.gain.exponentialRampToValueAtTime(0.001, now + 0.04);

    osc.connect(gain);
    gain.connect(this.ctx.destination);

    osc.start(now);
    osc.stop(now + 0.045);
  }

  // Gentle acoustic pop when tile is removed
  playTileRemove() {
    if (this.muted) return;
    this.initContext();
    if (!this.ctx) return;

    const osc = this.ctx.createOscillator();
    const gain = this.ctx.createGain();
    const now = this.ctx.currentTime;

    osc.type = 'sine';
    osc.frequency.setValueAtTime(320, now);
    osc.frequency.exponentialRampToValueAtTime(540, now + 0.05);

    gain.gain.setValueAtTime(0.1, now);
    gain.gain.exponentialRampToValueAtTime(0.001, now + 0.05);

    osc.connect(gain);
    gain.connect(this.ctx.destination);

    osc.start(now);
    osc.stop(now + 0.055);
  }

  // Shuffle swoosh sound
  playShuffle() {
    if (this.muted) return;
    this.initContext();
    if (!this.ctx) return;

    const now = this.ctx.currentTime;
    for (let i = 0; i < 4; i++) {
      const osc = this.ctx.createOscillator();
      const gain = this.ctx.createGain();
      const delay = i * 0.025;

      osc.type = 'triangle';
      osc.frequency.setValueAtTime(280 + i * 70, now + delay);
      osc.frequency.exponentialRampToValueAtTime(160, now + delay + 0.06);

      gain.gain.setValueAtTime(0.06, now + delay);
      gain.gain.exponentialRampToValueAtTime(0.001, now + delay + 0.06);

      osc.connect(gain);
      gain.connect(this.ctx.destination);

      osc.start(now + delay);
      osc.stop(now + delay + 0.065);
    }
  }

  // Gentle double boop on invalid submission
  playError() {
    if (this.muted) return;
    this.initContext();
    if (!this.ctx) return;

    const now = this.ctx.currentTime;
    [0, 0.09].forEach(delay => {
      const osc = this.ctx.createOscillator();
      const gain = this.ctx.createGain();

      osc.type = 'sawtooth';
      osc.frequency.setValueAtTime(140, now + delay);
      osc.frequency.exponentialRampToValueAtTime(110, now + delay + 0.08);

      gain.gain.setValueAtTime(0.08, now + delay);
      gain.gain.exponentialRampToValueAtTime(0.001, now + delay + 0.08);

      osc.connect(gain);
      gain.connect(this.ctx.destination);

      osc.start(now + delay);
      osc.stop(now + delay + 0.085);
    });
  }

  // Cheerful chime on valid word
  playWordValid(tileCount) {
    if (this.muted) return;
    this.initContext();
    if (!this.ctx) return;

    const now = this.ctx.currentTime;
    const baseFreqs = {
      1: [523.25, 659.25], // C5, E5
      2: [523.25, 659.25, 783.99], // C5, E5, G5
      3: [587.33, 739.99, 880.00, 1046.50] // D5, F#5, A5, C6
    };

    const freqs = baseFreqs[tileCount] || baseFreqs[2];

    freqs.forEach((freq, idx) => {
      const osc = this.ctx.createOscillator();
      const gain = this.ctx.createGain();
      const delay = idx * 0.045;

      osc.type = 'sine';
      osc.frequency.setValueAtTime(freq, now + delay);

      gain.gain.setValueAtTime(0.12, now + delay);
      gain.gain.exponentialRampToValueAtTime(0.001, now + delay + 0.22);

      osc.connect(gain);
      gain.connect(this.ctx.destination);

      osc.start(now + delay);
      osc.stop(now + delay + 0.23);
    });
  }

  // Sparkling golden fanfare for 4-tile Quartile
  playQuartileFound() {
    if (this.muted) return;
    this.initContext();
    if (!this.ctx) return;

    const now = this.ctx.currentTime;
    // Major 7th arpeggio: C5, E5, G5, B5, C6
    const notes = [523.25, 659.25, 783.99, 987.77, 1046.50];

    notes.forEach((freq, idx) => {
      const osc = this.ctx.createOscillator();
      const gain = this.ctx.createGain();
      const delay = idx * 0.055;

      osc.type = 'triangle';
      osc.frequency.setValueAtTime(freq, now + delay);

      gain.gain.setValueAtTime(0.15, now + delay);
      gain.gain.exponentialRampToValueAtTime(0.001, now + delay + 0.45);

      osc.connect(gain);
      gain.connect(this.ctx.destination);

      osc.start(now + delay);
      osc.stop(now + delay + 0.46);
    });
  }

  // Grand celebration fanfare when all 5 Quartiles are discovered (+40 pts bonus!)
  playBonusCelebration() {
    if (this.muted) return;
    this.initContext();
    if (!this.ctx) return;

    const now = this.ctx.currentTime;
    // Fanfare chord progression
    const chords = [
      { delay: 0.0, freqs: [523.25, 659.25, 783.99], dur: 0.2 },
      { delay: 0.2, freqs: [587.33, 739.99, 880.00], dur: 0.2 },
      { delay: 0.4, freqs: [659.25, 830.61, 987.77], dur: 0.25 },
      { delay: 0.7, freqs: [783.99, 987.77, 1174.66, 1567.98], dur: 0.8 }
    ];

    chords.forEach(chord => {
      chord.freqs.forEach(freq => {
        const osc = this.ctx.createOscillator();
        const gain = this.ctx.createGain();
        const startTime = now + chord.delay;

        osc.type = 'triangle';
        osc.frequency.setValueAtTime(freq, startTime);

        gain.gain.setValueAtTime(0.14, startTime);
        gain.gain.exponentialRampToValueAtTime(0.001, startTime + chord.dur);

        osc.connect(gain);
        gain.connect(this.ctx.destination);

        osc.start(startTime);
        osc.stop(startTime + chord.dur + 0.05);
      });
    });
  }

  // Uplifting chord for rank progression (e.g. hitting Expert)
  playRankUp() {
    if (this.muted) return;
    this.initContext();
    if (!this.ctx) return;

    const now = this.ctx.currentTime;
    const freqs = [440, 554.37, 659.25, 880];
    freqs.forEach((freq, idx) => {
      const osc = this.ctx.createOscillator();
      const gain = this.ctx.createGain();
      const delay = idx * 0.08;

      osc.type = 'sine';
      osc.frequency.setValueAtTime(freq, now + delay);

      gain.gain.setValueAtTime(0.13, now + delay);
      gain.gain.exponentialRampToValueAtTime(0.001, now + delay + 0.35);

      osc.connect(gain);
      gain.connect(this.ctx.destination);

      osc.start(now + delay);
      osc.stop(now + delay + 0.36);
    });
  }

  // Triumphant fanfare for a perfect board: rising arpeggio, big chord, sparkles
  playPerfect() {
    if (this.muted) return;
    this.initContext();
    if (!this.ctx) return;

    const now = this.ctx.currentTime;
    const tone = (freq, start, dur, type = 'triangle', vol = 0.12) => {
      const osc = this.ctx.createOscillator();
      const gain = this.ctx.createGain();
      osc.type = type;
      osc.frequency.setValueAtTime(freq, now + start);
      gain.gain.setValueAtTime(0.0001, now + start);
      gain.gain.exponentialRampToValueAtTime(vol, now + start + 0.02);
      gain.gain.exponentialRampToValueAtTime(0.001, now + start + dur);
      osc.connect(gain);
      gain.connect(this.ctx.destination);
      osc.start(now + start);
      osc.stop(now + start + dur + 0.05);
    };

    // C major arpeggio climbing two octaves
    [523.25, 659.25, 783.99, 1046.5, 1318.51, 1567.98].forEach((f, i) => tone(f, i * 0.09, 0.3));

    // Sustained final chord (C - E - G - C)
    [523.25, 659.25, 783.99, 1046.5].forEach(f => tone(f, 0.6, 1.6, 'triangle', 0.1));
    tone(261.63, 0.6, 1.6, 'sine', 0.12);

    // High sparkle shimmer
    [2093, 2637, 3136, 2637, 3520, 4186].forEach((f, i) => tone(f, 0.75 + i * 0.11, 0.25, 'sine', 0.04));
  }
}

export const sound = new SoundEngine();