// SonicForge Studio - DAW Command Dispatcher
// Command Pattern & Undo/Redo Engine (28_AI_PANEL.md §1 & §2)

const DAWCommandDispatcher = (function() {
  const MAX_HISTORY = 50;
  const history = [];
  let historyIndex = -1;

  function pushHistory(entry) {
    history.push(entry);
    if (history.length > MAX_HISTORY) history.shift();
    historyIndex = history.length - 1;
  }

  function undo() {
    if (historyIndex < 0) return null;
    const entry = history[historyIndex];
    historyIndex--;
    return entry;
  }

  function redo() {
    if (historyIndex >= history.length - 1) return null;
    historyIndex++;
    const entry = history[historyIndex];
    return entry;
  }

  function canUndo() { return historyIndex >= 0; }
  function canRedo() { return historyIndex < history.length - 1; }

  const registry = {};

  function register(name, handler) {
    registry[name] = handler;
  }

  function execute(name, args) {
    if (!registry[name]) {
      return { success: false, error: `Unknown command: ${name}` };
    }
    return registry[name](args);
  }

  return {
    register,
    execute,
    undo,
    redo,
    canUndo,
    canRedo,
    pushHistory,
    get history() { return history; },
    get historyIndex() { return historyIndex; }
  };
})();

window.DAWCommandDispatcher = DAWCommandDispatcher;