import { isBrowser, isHTMLElement, styleToString } from '../index.js';
/**
 * Creates or gets an announcer element which is used to announce messages to screen readers.
 * Within the date components, we use this to announce when the values of the individual segments
 * change, as without it we get inconsistent behavior across screen readers.
 */
function initAnnouncer() {
    if (!isBrowser)
        return null;
    let el = document.querySelector('[data-melt-announcer]');
    if (!isHTMLElement(el)) {
        const div = document.createElement('div');
        div.style.cssText = styleToString({
            border: '0px',
            clip: 'rect(0px, 0px, 0px, 0px)',
            'clip-path': 'inset(50%)',
            height: '1px',
            margin: '-1px',
            overflow: 'hidden',
            padding: '0px',
            position: 'absolute',
            'white-space': 'nowrap',
            width: '1px',
        });
        div.setAttribute('data-melt-announcer', '');
        div.appendChild(createLog('assertive'));
        div.appendChild(createLog('polite'));
        el = div;
        document.body.insertBefore(el, document.body.firstChild);
    }
    /**
     * Creates a log element for assertive or polite announcements.
     */
    function createLog(kind) {
        const log = document.createElement('div');
        log.role = 'log';
        log.ariaLive = kind;
        log.setAttribute('aria-relevant', 'additions');
        return log;
    }
    /**
     * Retrieves the log element for assertive or polite announcements.
     */
    function getLog(kind) {
        if (!isHTMLElement(el))
            return null;
        const log = el.querySelector(`[aria-live="${kind}"]`);
        if (!isHTMLElement(log))
            return null;
        return log;
    }
    return {
        getLog,
    };
}
/**
 * Creates an announcer object that can be used to make `aria-live` announcements to screen readers.
 */
export function getAnnouncer() {
    const announcer = initAnnouncer();
    /**
     * Announces a message to screen readers using the specified kind of announcement.
     */
    function announce(value, kind = 'assertive', timeout = 7500) {
        if (!announcer || !isBrowser)
            return;
        const log = announcer.getLog(kind);
        const content = document.createElement('div');
        if (typeof value === 'number') {
            value = value.toString();
        }
        else if (value === null) {
            value = 'Empty';
        }
        else {
            value = value.trim();
        }
        content.innerText = value;
        if (kind === 'assertive') {
            log?.replaceChildren(content);
        }
        else {
            log?.appendChild(content);
        }
        return setTimeout(() => {
            content.remove();
        }, timeout);
    }
    return {
        announce,
    };
}