/**
 * The seam between the analysis half and the sound half. Everything above
 * this interface deals in NoteEvents (a time, a voice, a strength);
 * everything below turns them into audio. The synth renderer is the first
 * implementation; the instrawave renderer replaces a binding's preset with
 * an instrument file plus parameter values, groups events by bake key so
 * voices sharing a bake render in one pass, and mixes the traces.
 */
export interface NoteEvent {
  t: number;        // seconds from the start of the take
  voiceId: string;
  gain: number;     // linear, 0..1, from the hit's measured loudness
}

export type SynthPreset = 'kick' | 'snare' | 'hat' | 'tom';

export interface Renderer {
  render(events: NoteEvent[], preset: (voiceId: string) => SynthPreset, seconds: number): Promise<AudioBuffer>;
}

/** Map a hit's peak level to a note strength. Levels are taken relative to
 *  the loudest hit in the take and compressed (0.5 exponent over a 30 dB
 *  window), so soft hits stay audible while the ordering is preserved. */
export function gainFromPeakDb(peakDb: number, refDb: number): number {
  const rel = Math.max(-30, Math.min(0, peakDb - refDb));
  return Math.pow(10 ** (rel / 20), 0.5);
}