import { obtainAllFocusableElements } from "../../utils/dom/aria.mjs";
import { EVENT_CODE } from "../../constants/aria.mjs";
import { getEventCode } from "../../utils/dom/event.mjs";
import { nextTick } from "vue";
const FOCUSABLE_CHILDREN = "_trap-focus-children";
const FOCUS_STACK = [];
const FOCUS_HANDLER = (e) => {
  if (FOCUS_STACK.length === 0) return;
  const code = getEventCode(e);
  const focusableElement = FOCUS_STACK[FOCUS_STACK.length - 1][FOCUSABLE_CHILDREN];
  if (focusableElement.length > 0 && code === 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] = obtainAllFocusableElements(el);
    FOCUS_STACK.push(el);
    if (FOCUS_STACK.length <= 1) document.addEventListener("keydown", FOCUS_HANDLER);
  },
  updated(el) {
    nextTick(() => {
      el[FOCUSABLE_CHILDREN] = obtainAllFocusableElements(el);
    });
  },
  unmounted() {
    FOCUS_STACK.shift();
    if (FOCUS_STACK.length === 0) document.removeEventListener("keydown", FOCUS_HANDLER);
  }
};
export {
  FOCUSABLE_CHILDREN,
  TrapFocus as default
};
