import type { NoteInputEvent } from './webmidi.ts';

// Captures note input against the transport clock while recording. Times
// are seconds on the song timeline; the store converts to ticks when the
// take is committed.

export interface CapturedNote {
  startSec: number;
  endSec: number;
  pitch: number;
  velocity: number; // 1..127
}

export class Recorder {
  private active = false;
  private open = new Map<number, { startSec: number; velocity: number }>();
  private captured: CapturedNote[] = [];

  get isActive(): boolean { return this.active; }

  start(): void {
    this.active = true;
    this.open.clear();
    this.captured = [];
  }

  noteEvent(e: NoteInputEvent, songSec: number): void {
    if (!this.active) return;
    if (e.on) {
      this.open.set(e.pitch, { startSec: songSec, velocity: e.velocity });
    } else {
      const o = this.open.get(e.pitch);
      if (!o) return;
      this.open.delete(e.pitch);
      this.captured.push({ startSec: o.startSec, endSec: Math.max(o.startSec + 0.03, songSec), pitch: e.pitch, velocity: o.velocity });
    }
  }

  stop(atSongSec: number): CapturedNote[] {
    for (const [pitch, o] of this.open) {
      this.captured.push({ startSec: o.startSec, endSec: Math.max(o.startSec + 0.03, atSongSec), pitch, velocity: o.velocity });
    }
    this.open.clear();
    this.active = false;
    const out = this.captured.sort((a, b) => a.startSec - b.startSec);
    this.captured = [];
    return out;
  }
}