Lofi_Generator/lib/audio/drumMachine.ts

import * as Tone from 'tone';
import { DrumPattern, DrumKit, Genre } from '@/types/audio';
import { getRandomPattern } from './patterns';

export class DrumMachine {
  private kick: Tone.MembraneSynth | null = null;
  private snare: Tone.NoiseSynth | null = null;
  private hihat: Tone.NoiseSynth | null = null;
  private openhat: Tone.NoiseSynth | null = null;
  private snareFilter: Tone.Filter | null = null;
  private hihatFilter: Tone.Filter | null = null;
  private openhatFilter: Tone.Filter | null = null;
  private sequence: Tone.Sequence | null = null;
  private pattern: DrumPattern;
  private output: Tone.Gain;
  private lowpass: Tone.Filter;
  private currentKit: DrumKit = 'acoustic';
  private genre: Genre = 'hiphop';

  constructor(destination: Tone.InputNode) {
    this.output = new Tone.Gain(0.8);
    this.lowpass = new Tone.Filter({
      frequency: 8000,
      type: 'lowpass',
      rolloff: -12,
    });

    this.lowpass.connect(this.output);
    this.output.connect(destination);

    this.pattern = getRandomPattern(this.genre);
    this.createKit('acoustic');
  }

  private createKit(kit: DrumKit): void {
    // Dispose existing instruments
    this.kick?.dispose();
    this.snare?.dispose();
    this.hihat?.dispose();
    this.openhat?.dispose();
    this.snareFilter?.dispose();
    this.hihatFilter?.dispose();
    this.openhatFilter?.dispose();

    const kitConfigs: Record<DrumKit, {
      kick: Partial<Tone.MembraneSynthOptions>;
      snareFilter: number;
      hihatFilter: number;
      snareDecay: number;
      hihatDecay: number;
    }> = {
      acoustic: {
        kick: { pitchDecay: 0.05, octaves: 6, envelope: { attack: 0.001, decay: 0.4, sustain: 0.01, release: 0.4 } },
        snareFilter: 5000,
        hihatFilter: 10000,
        snareDecay: 0.2,
        hihatDecay: 0.05,
      },
      electronic: {
        kick: { pitchDecay: 0.08, octaves: 8, envelope: { attack: 0.001, decay: 0.3, sustain: 0, release: 0.3 } },
        snareFilter: 4000,
        hihatFilter: 12000,
        snareDecay: 0.15,
        hihatDecay: 0.03,
      },
      '808': {
        kick: { pitchDecay: 0.15, octaves: 10, envelope: { attack: 0.001, decay: 0.8, sustain: 0.1, release: 0.6 } },
        snareFilter: 3000,
        hihatFilter: 8000,
        snareDecay: 0.25,
        hihatDecay: 0.04,
      },
      orchestral: {
        kick: { pitchDecay: 0.02, octaves: 4, envelope: { attack: 0.01, decay: 0.5, sustain: 0.05, release: 0.5 } },
        snareFilter: 6000,
        hihatFilter: 6000,
        snareDecay: 0.3,
        hihatDecay: 0.1,
      },
    };

    const config = kitConfigs[kit];

    // Kick drum
    this.kick = new Tone.MembraneSynth({
      ...config.kick,
      oscillator: { type: 'sine' },
    });
    this.kick.connect(this.lowpass);

    // Snare
    this.snareFilter = new Tone.Filter({
      frequency: config.snareFilter,
      type: 'bandpass',
      Q: 1,
    });
    this.snare = new Tone.NoiseSynth({
      noise: { type: 'white' },
      envelope: { attack: 0.001, decay: config.snareDecay, sustain: 0, release: 0.1 },
    });
    this.snare.connect(this.snareFilter);
    this.snareFilter.connect(this.lowpass);

    // Closed hi-hat
    this.hihatFilter = new Tone.Filter({
      frequency: config.hihatFilter,
      type: 'highpass',
    });
    this.hihat = new Tone.NoiseSynth({
      noise: { type: 'white' },
      envelope: { attack: 0.001, decay: config.hihatDecay, sustain: 0, release: 0.02 },
    });
    this.hihat.connect(this.hihatFilter);
    this.hihatFilter.connect(this.lowpass);

    // Open hi-hat
    this.openhatFilter = new Tone.Filter({
      frequency: config.hihatFilter - 2000,
      type: 'highpass',
    });
    this.openhat = new Tone.NoiseSynth({
      noise: { type: 'white' },
      envelope: { attack: 0.001, decay: 0.3, sustain: 0, release: 0.15 },
    });
    this.openhat.connect(this.openhatFilter);
    this.openhatFilter.connect(this.lowpass);

    this.currentKit = kit;
  }

  setInstrument(kit: DrumKit): void {
    this.createKit(kit);
  }

  setGenre(genre: Genre): void {
    this.genre = genre;
    this.pattern = getRandomPattern(genre);
  }

  createSequence(onStep?: (step: number) => void): void {
    if (this.sequence) {
      this.sequence.dispose();
    }

    const steps = Array.from({ length: 16 }, (_, i) => i);

    this.sequence = new Tone.Sequence(
      (time, step) => {
        if (this.pattern.kick[step] && this.kick) {
          this.kick.triggerAttackRelease('C1', '8n', time, 0.8);
        }
        if (this.pattern.snare[step] && this.snare) {
          this.snare.triggerAttackRelease('8n', time, 0.5);
        }
        if (this.pattern.hihat[step] && this.hihat) {
          this.hihat.triggerAttackRelease('32n', time, 0.3);
        }
        if (this.pattern.openhat[step] && this.openhat) {
          this.openhat.triggerAttackRelease('16n', time, 0.25);
        }

        if (onStep) {
          Tone.getDraw().schedule(() => {
            onStep(step);
          }, time);
        }
      },
      steps,
      '16n'
    );

    this.sequence.start(0);
  }

  setPattern(pattern: DrumPattern): void {
    this.pattern = pattern;
  }

  randomize(): DrumPattern {
    this.pattern = getRandomPattern(this.genre);
    return this.pattern;
  }

  setVolume(volume: number): void {
    this.output.gain.rampTo(volume, 0.1);
  }

  mute(muted: boolean): void {
    this.output.gain.rampTo(muted ? 0 : 0.8, 0.1);
  }

  getPattern(): DrumPattern {
    return this.pattern;
  }

  dispose(): void {
    this.sequence?.dispose();
    this.kick?.dispose();
    this.snare?.dispose();
    this.hihat?.dispose();
    this.openhat?.dispose();
    this.snareFilter?.dispose();
    this.hihatFilter?.dispose();
    this.openhatFilter?.dispose();
    this.lowpass.dispose();
    this.output.dispose();
  }
}