From e17c4b6dd663154d449628fc4c8db440be01f541 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nuno=20Cora=C3=A7=C3=A3o?= <nunocoracao@gmail.com>
Date: Sun, 10 Mar 2024 10:55:57 +0000
Subject: [PATCH] initial commit for improvements

---
 .../lib/lite-youtube-embed/lite-yt-embed.css  |  95 ++++++++
 .../lib/lite-youtube-embed/lite-yt-embed.js   | 225 ++++++++++++++++++
 exampleSite/content/_index.md                 |   1 +
 exampleSite/content/docs/shortcodes/index.md  |  38 +++
 layouts/partials/vendor.html                  |   8 +
 layouts/shortcodes/youtubeLite.html           |  12 +
 package-lock.json                             |   7 +
 package.json                                  |  11 +-
 8 files changed, 396 insertions(+), 1 deletion(-)
 create mode 100644 assets/lib/lite-youtube-embed/lite-yt-embed.css
 create mode 100644 assets/lib/lite-youtube-embed/lite-yt-embed.js
 create mode 100644 layouts/shortcodes/youtubeLite.html

diff --git a/assets/lib/lite-youtube-embed/lite-yt-embed.css b/assets/lib/lite-youtube-embed/lite-yt-embed.css
new file mode 100644
index 00000000..c96a4726
--- /dev/null
+++ b/assets/lib/lite-youtube-embed/lite-yt-embed.css
@@ -0,0 +1,95 @@
+lite-youtube {
+    background-color: #000;
+    position: relative;
+    display: block;
+    contain: content;
+    background-position: center center;
+    background-size: cover;
+    cursor: pointer;
+    max-width: 720px;
+}
+
+/* gradient */
+lite-youtube::before {
+    content: attr(data-title);
+    display: block;
+    position: absolute;
+    top: 0;
+    /* Pixel-perfect port of YT's gradient PNG, using https://github.com/bluesmoon/pngtocss plus optimizations */
+    background-image: linear-gradient(180deg, rgb(0 0 0 / 67%) 0%, rgb(0 0 0 / 54%) 14%, rgb(0 0 0 / 15%) 54%, rgb(0 0 0 / 5%) 72%, rgb(0 0 0 / 0%) 94%);
+    height: 99px;
+    width: 100%;
+    font-family: "YouTube Noto",Roboto,Arial,Helvetica,sans-serif;
+    color: hsl(0deg 0% 93.33%);
+    text-shadow: 0 0 2px rgba(0,0,0,.5);
+    font-size: 18px;
+    padding: 25px 20px;
+    overflow: hidden;
+    white-space: nowrap;
+    text-overflow: ellipsis;
+    box-sizing: border-box;
+}
+
+lite-youtube:hover::before {
+    color: white;
+}
+
+/* responsive iframe with a 16:9 aspect ratio
+    thanks https://css-tricks.com/responsive-iframes/
+*/
+lite-youtube::after {
+    content: "";
+    display: block;
+    padding-bottom: calc(100% / (16 / 9));
+}
+lite-youtube > iframe {
+    width: 100%;
+    height: 100%;
+    position: absolute;
+    top: 0;
+    left: 0;
+    border: 0;
+}
+
+/* play button */
+lite-youtube > .lty-playbtn {
+    display: block;
+    /* Make the button element cover the whole area for a large hover/click target… */
+    width: 100%;
+    height: 100%;
+    /* …but visually it's still the same size */
+    background: no-repeat center/68px 48px;
+    /* YT's actual play button svg */
+    background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 68 48"><path d="M66.52 7.74c-.78-2.93-2.49-5.41-5.42-6.19C55.79.13 34 0 34 0S12.21.13 6.9 1.55c-2.93.78-4.63 3.26-5.42 6.19C.06 13.05 0 24 0 24s.06 10.95 1.48 16.26c.78 2.93 2.49 5.41 5.42 6.19C12.21 47.87 34 48 34 48s21.79-.13 27.1-1.55c2.93-.78 4.64-3.26 5.42-6.19C67.94 34.95 68 24 68 24s-.06-10.95-1.48-16.26z" fill="red"/><path d="M45 24 27 14v20" fill="white"/></svg>');
+    position: absolute;
+    cursor: pointer;
+    z-index: 1;
+    filter: grayscale(100%);
+    transition: filter .1s cubic-bezier(0, 0, 0.2, 1);
+    border: 0;
+}
+
+lite-youtube:hover > .lty-playbtn,
+lite-youtube .lty-playbtn:focus {
+    filter: none;
+}
+
+/* Post-click styles */
+lite-youtube.lyt-activated {
+    cursor: unset;
+}
+lite-youtube.lyt-activated::before,
+lite-youtube.lyt-activated > .lty-playbtn {
+    opacity: 0;
+    pointer-events: none;
+}
+
+.lyt-visually-hidden {
+    clip: rect(0 0 0 0);
+    clip-path: inset(50%);
+    height: 1px;
+    overflow: hidden;
+    position: absolute;
+    white-space: nowrap;
+    width: 1px;
+  }
diff --git a/assets/lib/lite-youtube-embed/lite-yt-embed.js b/assets/lib/lite-youtube-embed/lite-yt-embed.js
new file mode 100644
index 00000000..49db80e2
--- /dev/null
+++ b/assets/lib/lite-youtube-embed/lite-yt-embed.js
@@ -0,0 +1,225 @@
+/**
+ * A lightweight youtube embed. Still should feel the same to the user, just MUCH faster to initialize and paint.
+ *
+ * Thx to these as the inspiration
+ *   https://storage.googleapis.com/amp-vs-non-amp/youtube-lazy.html
+ *   https://autoplay-youtube-player.glitch.me/
+ *
+ * Once built it, I also found these:
+ *   https://github.com/ampproject/amphtml/blob/master/extensions/amp-youtube (👍👍)
+ *   https://github.com/Daugilas/lazyYT
+ *   https://github.com/vb/lazyframe
+ */
+class LiteYTEmbed extends HTMLElement {
+    connectedCallback() {
+        this.videoId = this.getAttribute('videoid');
+
+        let playBtnEl = this.querySelector('.lty-playbtn');
+        // A label for the button takes priority over a [playlabel] attribute on the custom-element
+        this.playLabel = (playBtnEl && playBtnEl.textContent.trim()) || this.getAttribute('playlabel') || 'Play';
+
+        this.dataset.title = this.getAttribute('title') || "";
+
+        /**
+         * Lo, the youtube poster image!  (aka the thumbnail, image placeholder, etc)
+         *
+         * See https://github.com/paulirish/lite-youtube-embed/blob/master/youtube-thumbnail-urls.md
+         */
+        if (!this.style.backgroundImage) {
+          this.style.backgroundImage = `url("https://i.ytimg.com/vi/${this.videoId}/hqdefault.jpg")`;
+          this.upgradePosterImage();
+        }
+
+        // Set up play button, and its visually hidden label
+        if (!playBtnEl) {
+            playBtnEl = document.createElement('button');
+            playBtnEl.type = 'button';
+            playBtnEl.classList.add('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();
+
+        playBtnEl.removeAttribute('href');
+
+        // On hover (or tap), warm up the TCP connections we're (likely) about to use.
+        this.addEventListener('pointerover', LiteYTEmbed.warmConnections, {once: true});
+
+        // Once the user clicks, add the real iframe and drop our play button
+        // TODO: In the future we could be like amp-youtube and silently swap in the iframe during idle time
+        //   We'd want to only do this for in-viewport or near-viewport ones: https://github.com/ampproject/amphtml/pull/5003
+        this.addEventListener('click', this.activate);
+
+        // Chrome & Edge desktop have no problem with the basic YouTube Embed with ?autoplay=1
+        // However Safari desktop and most/all mobile browsers do not successfully track the user gesture of clicking through the creation/loading of the iframe,
+        // so they don't autoplay automatically. Instead we must load an additional 2 sequential JS files (1KB + 165KB) (un-br) for the YT Player API
+        // TODO: Try loading the the YT API in parallel with our iframe and then attaching/playing it. #82
+        this.needsYTApi = this.hasAttribute("js-api") || navigator.vendor.includes('Apple') || navigator.userAgent.includes('Mobi');
+    }
+
+    /**
+     * Add a <link rel={preload | preconnect} ...> to the head
+     */
+    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);
+    }
+
+    /**
+     * Begin pre-connecting to warm up the iframe load
+     * Since the embed's network requests load within its iframe,
+     *   preload/prefetch'ing them outside the iframe will only cause double-downloads.
+     * So, the best we can do is warm up a few connections to origins that are in the critical path.
+     *
+     * Maybe `<link rel=preload as=document>` would work, but it's unsupported: http://crbug.com/593267
+     * But TBH, I don't think it'll happen soon with Site Isolation and split caches adding serious complexity.
+     */
+    static warmConnections() {
+        if (LiteYTEmbed.preconnected) return;
+
+        // The iframe document and most of its subresources come right off youtube.com
+        LiteYTEmbed.addPrefetch('preconnect', 'https://www.youtube-nocookie.com');
+        // The botguard script is fetched off from google.com
+        LiteYTEmbed.addPrefetch('preconnect', 'https://www.google.com');
+
+        // Not certain if these ad related domains are in the critical path. Could verify with domain-specific throttling.
+        LiteYTEmbed.addPrefetch('preconnect', 'https://googleads.g.doubleclick.net');
+        LiteYTEmbed.addPrefetch('preconnect', 'https://static.doubleclick.net');
+
+        LiteYTEmbed.preconnected = true;
+    }
+
+    fetchYTPlayerApi() {
+        if (window.YT || (window.YT && window.YT.Player)) return;
+
+        this.ytApiPromise = new Promise((res, rej) => {
+            var el = document.createElement('script');
+            el.src = 'https://www.youtube.com/iframe_api';
+            el.async = true;
+            el.onload = _ => {
+                YT.ready(res);
+            };
+            el.onerror = rej;
+            this.append(el);
+        });
+    }
+
+    /** Return the YT Player API instance. (Public L-YT-E API) */
+    async getYTPlayer() {
+        if(!this.playerPromise) {
+            await this.activate();
+        }
+
+        return this.playerPromise;
+    }
+
+    async addYTPlayerIframe() {
+        this.fetchYTPlayerApi();
+        await this.ytApiPromise;
+
+        const videoPlaceholderEl = document.createElement('div')
+        this.append(videoPlaceholderEl);
+
+        const paramsObj = Object.fromEntries(this.getParams().entries());
+
+        this.playerPromise = new Promise(resolve => {
+            let player = new YT.Player(videoPlaceholderEl, {
+                width: '100%',
+                videoId: this.videoId,
+                playerVars: paramsObj,
+                events: {
+                    'onReady': event => {
+                        event.target.playVideo();
+                        resolve(player);
+                    }
+                }
+            });
+        });
+    }
+
+    // Add the iframe within <noscript> for indexability discoverability. See https://github.com/paulirish/lite-youtube-embed/issues/105
+    addNoscriptIframe() {
+        const iframeEl = this.createBasicIframe();
+        const noscriptEl = document.createElement('noscript');
+        // Appending into noscript isn't equivalant for mysterious reasons: https://html.spec.whatwg.org/multipage/scripting.html#the-noscript-element
+        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');
+
+        if (this.needsYTApi) {
+            return this.addYTPlayerIframe(this.getParams());
+        }
+
+        const iframeEl = this.createBasicIframe();
+        this.append(iframeEl);
+
+        // Set focus for a11y
+        iframeEl.focus();
+    }
+
+    createBasicIframe(){
+        const iframeEl = document.createElement('iframe');
+        iframeEl.width = 560;
+        iframeEl.height = 315;
+        // No encoding necessary as [title] is safe. https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html#:~:text=Safe%20HTML%20Attributes%20include
+        iframeEl.title = this.playLabel;
+        iframeEl.allow = 'accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture';
+        iframeEl.allowFullscreen = true;
+        // AFAIK, the encoding here isn't necessary for XSS, but we'll do it only because this is a URL
+        // https://stackoverflow.com/q/64959723/89484
+        iframeEl.src = `https://www.youtube-nocookie.com/embed/${encodeURIComponent(this.videoId)}?${this.getParams().toString()}`;
+        return iframeEl;
+    }
+
+    /**
+     * In the spirit of the `lowsrc` attribute and progressive JPEGs, we'll upgrade the reliable
+     * poster image to a higher resolution one, if it's available.
+     * Interestingly this sddefault webp is often smaller in filesize, but we will still attempt it second
+     * because getting _an_ image in front of the user if our first priority.
+     *
+     * See https://github.com/paulirish/lite-youtube-embed/blob/master/youtube-thumbnail-urls.md for more details
+     */
+    upgradePosterImage() {
+         // Defer to reduce network contention.
+        setTimeout(() => {
+            const webpUrl = `https://i.ytimg.com/vi_webp/${this.videoId}/sddefault.webp`;
+            const img = new Image();
+            img.fetchPriority = 'low'; // low priority to reduce network contention
+            img.referrerpolicy = 'origin'; // Not 100% sure it's needed, but https://github.com/ampproject/amphtml/pull/3940
+            img.src = webpUrl;
+            img.onload = e => {
+                // A pretty ugly hack since onerror won't fire on YouTube image 404. This is (probably) due to
+                // Youtube's style of returning data even with a 404 status. That data is a 120x90 placeholder image.
+                // … per "annoying yt 404 behavior" in the .md
+                const noAvailablePoster = e.target.naturalHeight == 90 && e.target.naturalWidth == 120;
+                if (noAvailablePoster) return;
+
+                this.style.backgroundImage = `url("${webpUrl}")`;
+            }
+        }, 100);
+    }
+}
+// Register custom element
+customElements.define('lite-youtube', LiteYTEmbed);
diff --git a/exampleSite/content/_index.md b/exampleSite/content/_index.md
index 476eaeee..b8c1ad74 100755
--- a/exampleSite/content/_index.md
+++ b/exampleSite/content/_index.md
@@ -11,6 +11,7 @@ npx blowfish-tools
 
 <iframe width="100%" height="350" src="https://www.youtube.com/embed/SgXhGb-7QbU?si=ce44baicuQ6zMeXz" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
 
+
 <!--You can also find the complete theme documentation in [docs]({{< ref "docs" >}}). Blowfish is highly customizable and can be configured to fit your needs: from a static website to a blog. Checkout some [examples](/examples) and what some of our [users](/users) have been building.
 
 Explore the [shortcode list]({{< ref "docs/shortcodes" >}}) and [sample pages]({{< ref "samples" >}}) to get a feel for what Blowfish can do. If you like what you see, check out the project on <a target="_blank" href="https://github.com/nunocoracao/blowfish">Github</a> or read the [Installation guide]({{< ref "docs/installation" >}}) to get started.-->
diff --git a/exampleSite/content/docs/shortcodes/index.md b/exampleSite/content/docs/shortcodes/index.md
index 8c9bba1e..e167e99c 100644
--- a/exampleSite/content/docs/shortcodes/index.md
+++ b/exampleSite/content/docs/shortcodes/index.md
@@ -729,3 +729,41 @@ consectetur adipiscing elit.
 "I'm gonna make him an offer he can't refuse." The Godfather (1972)
 "Toto, I've a feeling we're not in Kansas anymore." The Wizard of Oz (1939)
 {{< /typeit >}}
+
+
+<br/><br/><br/>
+
+## Youtube Lite
+
+tbd
+
+https://github.com/paulirish/lite-youtube-embed
+
+
+
+<!-- prettier-ignore-start -->
+| Parameter          | Description                                                                                                                                        |
+| ------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `tag`              | [String] `html` tag that will be used to render the strings.                                                                                       |
+| `classList`        | [String] List of `css` classes to apply to the `html` element.                                                                                     |
+| `initialString`    | [String] Initial string that will appear written and will be replaced.                                                                             |
+| `speed`            | [number] Typing speed, measured in milliseconds between each step.                                                                                 |
+| `lifeLike`         | [boolean] Makes the typing pace irregular, as if a real person is doing it.                                                                        |
+| `startDelay`       | [number] The amount of time before the plugin begins typing after being initialized.                                                               |
+| `breakLines`       | [boolean] Whether multiple strings are printed on top of each other (true), or if they're deleted and replaced by each other (false).              |
+| `waitUntilVisible` | [boolean] Determines if the instance will begin when loaded or only when the target element becomes visible in the viewport. The default is `true` |
+| `loop`             | [boolean] Whether your strings will continuously loop after completing                                                                             |
+
+<!-- prettier-ignore-end -->
+
+**Example 1:**
+
+```md
+{{</* typeit */>}}
+Lorem ipsum dolor sit amet 
+{{</* /typeit */>}}
+
+SgXhGb-7QbU
+```
+
+{{< youtubeLite />}}
diff --git a/layouts/partials/vendor.html b/layouts/partials/vendor.html
index 94ffa3c4..d1e77f8b 100644
--- a/layouts/partials/vendor.html
+++ b/layouts/partials/vendor.html
@@ -64,4 +64,12 @@
 {{ if or (.Page.HasShortcode "carousel") (.Page.HasShortcode "timeline")}}
 {{ $twelementsLib := resources.Get "lib/tw-elements/index.min.js" }}
 <script defer src="{{ $twelementsLib.RelPermalink }}" integrity="{{ $twelementsLib.Data.Integrity }}"></script>
+{{ end }}
+
+{{/* youtubeLite */}}
+{{ if .Page.HasShortcode "youtubeLite" }}
+{{ $youtubeLiteJS := resources.Get "lib/lite-youtube-embed/lite-yt-embed.js" }}
+{{ $youtubeLiteCSS := resources.Get "lib/lite-youtube-embed/lite-yt-embed.css" }}
+<link rel="stylesheet" href="{{ $youtubeLiteCSS.RelPermalink }}" integrity="{{ $youtubeLiteCSS.Data.Integrity }}"/>
+<script src="{{ $youtubeLiteJS.RelPermalink }}" integrity="{{ $youtubeLiteJS.Data.Integrity }}"></script>
 {{ end }}
\ No newline at end of file
diff --git a/layouts/shortcodes/youtubeLite.html b/layouts/shortcodes/youtubeLite.html
new file mode 100644
index 00000000..8817dc67
--- /dev/null
+++ b/layouts/shortcodes/youtubeLite.html
@@ -0,0 +1,12 @@
+{{- $content := split .Inner "\n" -}}
+{{- $initialString := .Get "initialString" | default "" -}}
+{{- $speed := .Get "speed" | default 100 -}}
+{{- $lifeLike := .Get "lifeLike" | default false -}}
+{{- $startDelay := .Get "startDelay" | default 0 -}}
+{{- $breakLines := .Get "breakLines" | default true -}}
+{{- $waitUntilVisible := .Get "waitUntilVisible" | default true -}}
+{{- $loop := .Get "loop" | default false -}}                                                                    
+
+
+
+<lite-youtube videoid="ogfYd705cRs" playlabel="Play: Keynote (Google I/O '18)"></lite-youtube>
diff --git a/package-lock.json b/package-lock.json
index 55f86c93..ab004fa7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -21,6 +21,7 @@
         "fuse.js": "^7.0.0",
         "jquery": "^3.7.1",
         "katex": "^0.16.9",
+        "lite-youtube-embed": "^0.3.2",
         "mermaid": "^10.9.0",
         "packery": "^2.1.2",
         "prettier": "^3.2.5",
@@ -2209,6 +2210,12 @@
       "resolved": "https://registry.npmjs.org/lines-and-columns/-/lines-and-columns-1.2.4.tgz",
       "integrity": "sha512-7ylylesZQ/PV29jhEDl3Ufjo6ZX7gCqJr5F7PKrqc93v7fzSymt1BpwEU8nAUXs8qzzvqhbjhK5QZg6Mt/HkBg=="
     },
+    "node_modules/lite-youtube-embed": {
+      "version": "0.3.2",
+      "resolved": "https://registry.npmjs.org/lite-youtube-embed/-/lite-youtube-embed-0.3.2.tgz",
+      "integrity": "sha512-b1dgKyF4PHhinonmr3PB172Nj0qQgA/7DE9EmeIXHR1ksnFEC2olWjNJyJGdsN2cleKHRjjsmrziKlwXtPlmLQ==",
+      "dev": true
+    },
     "node_modules/lodash": {
       "version": "4.17.21",
       "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
diff --git a/package.json b/package.json
index 9ee7d09d..21d7bdb6 100644
--- a/package.json
+++ b/package.json
@@ -39,6 +39,7 @@
     "fuse.js": "^7.0.0",
     "jquery": "^3.7.1",
     "katex": "^0.16.9",
+    "lite-youtube-embed": "^0.3.2",
     "mermaid": "^10.9.0",
     "packery": "^2.1.2",
     "prettier": "^3.2.5",
@@ -96,6 +97,14 @@
     {
       "from": "node_modules/tw-elements/js/tw-elements.umd.min.js",
       "to": "assets/lib/tw-elements/index.min.js"
+    },
+    {
+      "from": "node_modules/lite-youtube-embed/src/lite-yt-embed.js",
+      "to": "assets/lib/lite-youtube-embed/lite-yt-embed.js"
+    },
+    {
+      "from": "node_modules/lite-youtube-embed/src/lite-yt-embed.css",
+      "to": "assets/lib/lite-youtube-embed/lite-yt-embed.css"
     }
   ],
   "dependencies": {
@@ -104,4 +113,4 @@
     "@tailwindcss/forms": "^0.5.7",
     "commander": "^12.0.0"
   }
-}
\ No newline at end of file
+}