import { isHTMLElement } from './is.js';
/**
 * Get an element's ancestor which has a `data-portal` attribute.
 * This is used to handle nested portals/overlays/dialogs/popovers.
 */
function getPortalParent(node) {
    let parent = node.parentElement;
    while (isHTMLElement(parent) && !parent.hasAttribute('data-portal')) {
        parent = parent.parentElement;
    }
    return parent || 'body';
}
/**
 * Gets the destination for a portal given the node and a user-specified portal prop.
 * If a portal prop is not `undefined`, it is used as the destination.
 */
export function getPortalDestination(node, portalProp) {
    // user-specified portal prop, use it
    if (portalProp !== undefined)
        return portalProp;
    // find the closest portal parent, or the body if none is found
    const portalParent = getPortalParent(node);
    // if the portalParent is the body, we portal to the body
    // making it a "top-level" portal
    if (portalParent === 'body')
        return document.body;
    // if the portalParent is not the body, we have a portal parent
    // and shouldn't portal to anything so it remains within that parent
    // so we return `null`
    return null;
}