/**
 * AKSRT Rehydrate System
 *
 * Centralized component initialization and re-initialization system.
 * Components register their init functions, and rehydrate() is called
 * to initialize or re-initialize them on a given root element.
 *
 * Usage:
 *   AksrtFrontend.register('name', initFn);  // Register a component
 *   AksrtFrontend.boot(document);            // One-time initial page load
 *   AksrtFrontend.rehydrate(root, 'ajax');    // Initialize dynamic content
 *
 * @package AKSRT
 * @since   5.0.0
 */
(function () {
  'use strict';

  var _registry = [];
  var _booted = false;
  var _bootRoot = null;

  function invoke(entry, root, reason) {
    try {
      entry.initFn(root, reason);
    } catch (err) {
      console.error('[AKSRT Rehydrate] Error initializing "' + entry.name + '":', err);
    }
  }

  function dispatch(root, reason, eventName) {
    try {
      root.dispatchEvent(new CustomEvent(eventName, {
        bubbles: true,
        detail: { reason: reason }
      }));
    } catch (e) { /* IE fallback */ }
  }

  window.AksrtFrontend = {

    /**
     * Register a component's init function.
     *
     * @param {string}   name     Unique component name
     * @param {Function} initFn   Function(root, reason) - root defaults to document
     */
    register: function (name, initFn) {
      if (typeof name !== 'string' || typeof initFn !== 'function') return;
      // Prevent duplicate registrations
      for (var i = 0; i < _registry.length; i++) {
        if (_registry[i].name === name) {
          _registry[i].initFn = initFn;
          if (_booted) invoke(_registry[i], _bootRoot || document, 'init');
          return;
        }
      }
      var entry = { name: name, initFn: initFn };
      _registry.push(entry);
      if (_booted) invoke(entry, _bootRoot || document, 'init');
    },

    /**
     * Run the one-time initial page boot.
     *
     * @param {Element|Document} root The document root to initialize
     */
    boot: function (root) {
      if (_booted) return;
      _booted = true;
      _bootRoot = root || document;
      this.rehydrate(_bootRoot, 'init');
      dispatch(_bootRoot, 'init', 'aksrt:ready');
    },

    /**
     * Initialize or re-initialize all registered components on a root element.
     *
     * @param {Element|Document} root      The root DOM element to search within
     * @param {string}           reason    Why rehydrate is called:
     *                                     'init' = initial page load
     *                                     'ajax' = after AJAX content injection
     *                                     'modal' = after modal content loads
     *                                     Custom string for other triggers
     */
    rehydrate: function (root, reason) {
      root = root || document;
      reason = reason || 'init';

      for (var i = 0; i < _registry.length; i++) {
        invoke(_registry[i], root, reason);
      }

      dispatch(root, reason, 'aksrt:rehydrated');
    },

    /**
     * Get the list of registered component names (for debugging).
     */
    getRegistered: function () {
      return _registry.map(function (r) { return r.name; });
    },

    isBooted: function () {
      return _booted;
    }
  };

})();