// Web Audio API Synthesizer for Children's Storybook

class SoundEffectsManager {
  private ctx: AudioContext | null = null;
  public enabled: boolean = true;

  private initCtx() {
    if (!this.ctx && typeof window !== 'undefined') {
      const AudioCtx = window.AudioContext || (window as unknown as { webkitAudioContext: typeof AudioContext }).webkitAudioContext;
      if (AudioCtx) {
        this.ctx = new AudioCtx();
      }
    }
    if (this.ctx && this.ctx.state === 'suspended') {
      this.ctx.resume();
    }
  }

  // Soft cheerful pop
  playPop() {
    if (!this.enabled) return;
    this.initCtx();
    if (!this.ctx) return;

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

    osc.type = 'sine';
    const now = this.ctx.currentTime;
    osc.frequency.setValueAtTime(400, now);
    osc.frequency.exponentialRampToValueAtTime(800, now + 0.08);

    gain.gain.setValueAtTime(0.18, now);
    gain.gain.exponentialRampToValueAtTime(0.001, now + 0.09);

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

    osc.start(now);
    osc.stop(now + 0.1);
  }

  // Pentatonic magical chime
  playChime() {
    if (!this.enabled) return;
    this.initCtx();
    if (!this.ctx) return;

    const notes = [523.25, 659.25, 783.99, 1046.5]; // C5, E5, G5, C6
    notes.forEach((freq, idx) => {
      if (!this.ctx) return;
      const osc = this.ctx.createOscillator();
      const gain = this.ctx.createGain();

      osc.type = 'triangle';
      const now = this.ctx.currentTime + idx * 0.07;
      osc.frequency.setValueAtTime(freq, now);

      gain.gain.setValueAtTime(0.12, now);
      gain.gain.exponentialRampToValueAtTime(0.001, now + 0.35);

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

      osc.start(now);
      osc.stop(now + 0.4);
    });
  }

  // Soft gentle raindrop plop
  playRain() {
    if (!this.enabled) return;
    this.initCtx();
    if (!this.ctx) return;

    const drops = [700, 1100, 850];
    drops.forEach((freq, i) => {
      if (!this.ctx) return;
      const osc = this.ctx.createOscillator();
      const gain = this.ctx.createGain();

      const now = this.ctx.currentTime + i * 0.08;
      osc.type = 'sine';
      osc.frequency.setValueAtTime(freq, now);
      osc.frequency.exponentialRampToValueAtTime(freq * 0.5, now + 0.07);

      gain.gain.setValueAtTime(0.14, now);
      gain.gain.exponentialRampToValueAtTime(0.001, now + 0.12);

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

      osc.start(now);
      osc.stop(now + 0.15);
    });
  }

  // Harp strum
  playHarp() {
    if (!this.enabled) return;
    this.initCtx();
    if (!this.ctx) return;

    const notes = [392.00, 523.25, 659.25, 783.99, 1046.5]; // G4, C5, E5, G5, C6
    notes.forEach((freq, i) => {
      if (!this.ctx) return;
      const osc = this.ctx.createOscillator();
      const gain = this.ctx.createGain();

      const now = this.ctx.currentTime + i * 0.05;
      osc.type = 'sine';
      osc.frequency.setValueAtTime(freq, now);

      gain.gain.setValueAtTime(0.1, now);
      gain.gain.exponentialRampToValueAtTime(0.001, now + 0.6);

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

      osc.start(now);
      osc.stop(now + 0.65);
    });
  }

  // Flutter / whoosh
  playFlutter() {
    if (!this.enabled) return;
    this.initCtx();
    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(220, now);
    osc.frequency.linearRampToValueAtTime(440, now + 0.1);
    osc.frequency.linearRampToValueAtTime(260, now + 0.2);

    gain.gain.setValueAtTime(0.08, now);
    gain.gain.exponentialRampToValueAtTime(0.001, now + 0.22);

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

    osc.start(now);
    osc.stop(now + 0.25);
  }

  // Playful giggle / chirp
  playGiggle() {
    if (!this.enabled) return;
    this.initCtx();
    if (!this.ctx) return;

    const notes = [587.33, 739.99, 587.33, 880.00];
    notes.forEach((freq, i) => {
      if (!this.ctx) return;
      const osc = this.ctx.createOscillator();
      const gain = this.ctx.createGain();

      const now = this.ctx.currentTime + i * 0.06;
      osc.type = 'triangle';
      osc.frequency.setValueAtTime(freq, now);

      gain.gain.setValueAtTime(0.09, now);
      gain.gain.exponentialRampToValueAtTime(0.001, now + 0.1);

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

      osc.start(now);
      osc.stop(now + 0.12);
    });
  }

  // Page turn sound
  playPageTurn() {
    if (!this.enabled) return;
    this.initCtx();
    if (!this.ctx) return;

    const bufferSize = this.ctx.sampleRate * 0.15;
    const buffer = this.ctx.createBuffer(1, bufferSize, this.ctx.sampleRate);
    const data = buffer.getChannelData(0);

    for (let i = 0; i < bufferSize; i++) {
      data[i] = (Math.random() * 2 - 1) * Math.exp(-i / (bufferSize * 0.3));
    }

    const noise = this.ctx.createBufferSource();
    noise.buffer = buffer;

    const filter = this.ctx.createBiquadFilter();
    filter.type = 'lowpass';
    filter.frequency.value = 1200;

    const gain = this.ctx.createGain();
    const now = this.ctx.currentTime;
    gain.gain.setValueAtTime(0.12, now);
    gain.gain.exponentialRampToValueAtTime(0.001, now + 0.14);

    noise.connect(filter);
    filter.connect(gain);
    gain.connect(this.ctx.destination);

    noise.start(now);
  }

  // Star Celebration fanfare
  playStarCelebration() {
    if (!this.enabled) return;
    this.initCtx();
    if (!this.ctx) return;

    const notes = [523.25, 659.25, 783.99, 1046.50, 1318.51];
    notes.forEach((freq, i) => {
      if (!this.ctx) return;
      const osc = this.ctx.createOscillator();
      const gain = this.ctx.createGain();

      const now = this.ctx.currentTime + i * 0.08;
      osc.type = 'sine';
      osc.frequency.setValueAtTime(freq, now);

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

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

      osc.start(now);
      osc.stop(now + 0.5);
    });
  }

  playSound(type: 'pop' | 'chime' | 'rain' | 'harp' | 'flutter' | 'giggle') {
    switch (type) {
      case 'pop': this.playPop(); break;
      case 'chime': this.playChime(); break;
      case 'rain': this.playRain(); break;
      case 'harp': this.playHarp(); break;
      case 'flutter': this.playFlutter(); break;
      case 'giggle': this.playGiggle(); break;
      default: this.playPop();
    }
  }
}

export const soundManager = new SoundEffectsManager();