/*
 * Modified version of Lite YouTube Embed
 * Original source: https://github.com/paulirish/lite-youtube-embed
 * Original license: Apache 2.0
 */

// BELOW IS A DRAFT/MODIFIED VERSION OF THE UPSTREAM SCRIPT ABOVE!
// See https://eternodevir.com/palimpsests/logs/lazy-loading-youtube-embeds/ for more info.
class LiteYTEmbed extends HTMLElement {
    connectedCallback() {
        this.videoId = this.getAttribute('videoid');
        this.posterId = this.getAttribute('poster-id') || this.videoId;
        let playBtnEl = this.querySelector('.lyt-playbtn,.lty-playbtn');
        this.playLabel = (playBtnEl && playBtnEl.textContent.trim()) || this.getAttribute('playlabel') || 'Play';
        this.dataset.title = this.getAttribute('title') || "";

        if (!this.style.backgroundImage && this.posterId) {
            const quality = this.getAttribute('poster-quality') || 'hq';
            this.style.backgroundImage = `url("https://i.ytimg.com/vi/${this.posterId}/${quality}default.jpg")`;
        }

        if (!playBtnEl) {
            playBtnEl = document.createElement('button');
            playBtnEl.type = 'button';
            playBtnEl.classList.add('lyt-playbtn', 'lty-playbtn');
            this.append(playBtnEl);
        }
        if (!playBtnEl.textContent) {
            const playBtnLabelEl = document.createElement('span');
            playBtnLabelEl.className = 'lyt-visually-hidden';
            playBtnLabelEl.textContent = this.playLabel;
            playBtnEl.append(playBtnLabelEl);
        }

        this.addNoscriptIframe();

        if(playBtnEl.nodeName === 'A'){
            playBtnEl.removeAttribute('href');
            playBtnEl.setAttribute('tabindex', '0');
            playBtnEl.setAttribute('role', 'button');
            playBtnEl.addEventListener('keydown', e => {
                if( e.key === 'Enter' || e.key === ' ' ){
                    e.preventDefault();
                    this.activate();
                }
            });
        }

        this.addEventListener('pointerover', LiteYTEmbed.warmConnections, {once: true});
        this.addEventListener('focusin', LiteYTEmbed.warmConnections, {once: true});
        this.addEventListener('click', this.activate);
    }

    static addPrefetch(kind, url, as) {
        const linkEl = document.createElement('link');
        linkEl.rel = kind;
        linkEl.href = url;
        if (as) linkEl.as = as;
        document.head.append(linkEl);
    }

    static warmConnections() {
        if (LiteYTEmbed.preconnected) return;
        LiteYTEmbed.addPrefetch('preconnect', 'https://www.youtube-nocookie.com');
        LiteYTEmbed.addPrefetch('preconnect', 'https://www.google.com');
        LiteYTEmbed.addPrefetch('preconnect', 'https://googleads.g.doubleclick.net');
        LiteYTEmbed.addPrefetch('preconnect', 'https://static.doubleclick.net');
        LiteYTEmbed.preconnected = true;
    }

    addNoscriptIframe() {
        const iframeEl = this.createBasicIframe();
        const noscriptEl = document.createElement('noscript');
        noscriptEl.innerHTML = iframeEl.outerHTML;
        this.append(noscriptEl);
    }

    getParams() {
        const params = new URLSearchParams(this.getAttribute('params') || []);
        params.append('autoplay', '1');
        params.append('playsinline', '1');
        return params;
    }

    async activate(){
        if (this.classList.contains('lyt-activated')) return;
        this.classList.add('lyt-activated');
        this.append(this.createBasicIframe());
    }

    createBasicIframe(){
        const iframeEl = document.createElement('iframe');
        iframeEl.width = 560;
        iframeEl.height = 315;
        iframeEl.title = this.playLabel;
        iframeEl.allow = 'accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture';
        iframeEl.allowFullscreen = true;
        iframeEl.referrerPolicy = 'strict-origin-when-cross-origin';
        const embedTarget = this.videoId ? encodeURIComponent(this.videoId) : 'videoseries';
        iframeEl.src = `https://www.youtube-nocookie.com/embed/${embedTarget}?${this.getParams().toString()}`;
        return iframeEl;
    }
}
customElements.define('lite-youtube', LiteYTEmbed);