'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

var vue = require('vue');
var aria = require('../../utils/dom/aria.js');
var aria$1 = require('../../constants/aria.js');

const FOCUSABLE_CHILDREN = "_trap-focus-children";
const TRAP_FOCUS_HANDLER = "_trap-focus-handler";
const FOCUS_STACK = [];
const FOCUS_HANDLER = (e) => {
  if (FOCUS_STACK.length === 0)
    return;
  const focusableElement = FOCUS_STACK[FOCUS_STACK.length - 1][FOCUSABLE_CHILDREN];
  if (focusableElement.length > 0 && e.code === aria$1.EVENT_CODE.tab) {
    if (focusableElement.length === 1) {
      e.preventDefault();
      if (document.activeElement !== focusableElement[0]) {
        focusableElement[0].focus();
      }
      return;
    }
    const goingBackward = e.shiftKey;
    const isFirst = e.target === focusableElement[0];
    const isLast = e.target === focusableElement[focusableElement.length - 1];
    if (isFirst && goingBackward) {
      e.preventDefault();
      focusableElement[focusableElement.length - 1].focus();
    }
    if (isLast && !goingBackward) {
      e.preventDefault();
      focusableElement[0].focus();
    }
  }
};
const TrapFocus = {
  beforeMount(el) {
    el[FOCUSABLE_CHILDREN] = aria.obtainAllFocusableElements(el);
    FOCUS_STACK.push(el);
    if (FOCUS_STACK.length <= 1) {
      document.addEventListener("keydown", FOCUS_HANDLER);
    }
  },
  updated(el) {
    vue.nextTick(() => {
      el[FOCUSABLE_CHILDREN] = aria.obtainAllFocusableElements(el);
    });
  },
  unmounted() {
    FOCUS_STACK.shift();
    if (FOCUS_STACK.length === 0) {
      document.removeEventListener("keydown", FOCUS_HANDLER);
    }
  }
};

exports.FOCUSABLE_CHILDREN = FOCUSABLE_CHILDREN;
exports.TRAP_FOCUS_HANDLER = TRAP_FOCUS_HANDLER;
exports["default"] = TrapFocus;
//# sourceMappingURL=index.js.map
