/**
 * XZBT Control Bus
 *
 * XZBTControlBus is a small registry of named, settable console targets
 * (ranges, toggles and triggers).  Anything that wants to drive the console
 * from outside the DOM — contract adapter, hotkeys, future transports —
 * talks to the bus rather than reaching into app.js internals.
 *
 * MIDI NOTE: Web MIDI control belonged to standalone SciFi-XZBT until
 * Step 3.5.  External MIDI integration will be handled by XZBT-NGN, which
 * will send canonical contract commands (set / invoke) to this exhibit.
 * The control bus itself is transport-agnostic and is intentionally kept here.
 */

class XZBTControlBus {
  constructor() {
    this.targets = new Map();
    this.listeners = new Set();
  }
  register(id, spec) {
    this.targets.set(id, { id, ...spec });
  }
  set(id, value, source = 'external') {
    const t = this.targets.get(id);
    if (!t) return false;
    let v = value;
    if (t.type === 'range') {
      v = Math.max(t.min, Math.min(t.max, Number(value)));
      if (t.step) v = Math.round(v / t.step) * t.step;
    }
    if (t.apply) t.apply(v, source);
    this.listeners.forEach(fn => fn({ id, value: v, source, target: t }));
    return true;
  }
  trigger(id, source = 'external') {
    const t = this.targets.get(id);
    if (!t) return false;
    if (t.apply) t.apply(true, source);
    this.listeners.forEach(fn => fn({ id, value: true, source, target: t }));
    return true;
  }
  list() {
    return [...this.targets.values()];
  }
}
window.XZBTControlBus = XZBTControlBus;