From 75182df441d705d790c04a3da8e61bd33dfd9712 Mon Sep 17 00:00:00 2001
From: Enrico Ros <enrico.ros@gmail.com>
Date: Sat, 11 Jan 2025 14:35:38 -0800
Subject: [PATCH] YouTube URLs - improve matching, incl regional, shortlinks,
 etc.

---
 src/modules/youtube/youtube.utils.ts | 72 ++++++++++++++++++++++++++--
 1 file changed, 68 insertions(+), 4 deletions(-)

diff --git a/src/modules/youtube/youtube.utils.ts b/src/modules/youtube/youtube.utils.ts
index f33307548..c43b25bbd 100644
--- a/src/modules/youtube/youtube.utils.ts
+++ b/src/modules/youtube/youtube.utils.ts
@@ -1,5 +1,69 @@
-export function extractYoutubeVideoIDFromURL(videoURL: string): string | null {
-  const regExp = /^(?:https?:\/\/)?(?:www\.)?(?:youtube\.com\/(?:watch\?v=|embed\/|v\/)|youtu\.be\/)([\w-]{11})(?:\S+)?$/;
-  const match = videoURL.match(regExp);
-  return match ? match[1] : null;
+export function extractYoutubeVideoIDFromURL(testYTUrl: string): string | null {
+
+  /* NOTE: We had this approach before, but changing to using the URL class for parsing.
+   * const regExpInitial = /^(?:https?:\/\/)?(?:www\.)?(?:youtube\.com\/(?:watch\?v=|embed\/|v\/)|youtu\.be\/)([\w-]{11})(?:\S+)?$/;
+   * const regExpProbOkay = /^(?:https?:\/\/)?(?:www\.|m\.)?(?:youtube\.com\/(?:watch\?v=|embed\/|v\/|shorts\/|live\/|clip\/)|youtu\.be\/)([\w-]{11})(?:\S+)?$/;
+   * const match = videoURL.match(regExp);
+   * return match ? match[1] : null;
+   */
+  try {
+    testYTUrl = testYTUrl.trim();
+    if (!testYTUrl)
+      return null;
+
+    // relax protocol
+    // noinspection HttpUrlsUsage
+    if (!testYTUrl.startsWith('http://') && !testYTUrl.startsWith('https://'))
+      testYTUrl = 'https://' + testYTUrl;
+
+    const url = new URL(testYTUrl);
+
+    // require a YouTube hostname
+    const youtubeDomainPatterns = [
+      /^(?:www\.)?youtube\.com$/,                    // Main domain
+      /^(?:.*\.)?youtube\.com$/,                     // Any subdomain
+      /^youtu\.be$/,                                 // Short links
+      /^youtube\.[a-z]{2,3}(?:\.[a-z]{2})?$/,        // Country-specific domains
+    ] as const;
+    const isYoutubeHostname = youtubeDomainPatterns.some(pattern => pattern.test(url.hostname));
+    if (!isYoutubeHostname)
+      return null;
+
+    // YouTube video ID validation pattern
+    const videoIdPattern = /^[\w-]{11}$/;
+
+    // SHORTLINK path match
+    if (url.hostname === 'youtu.be') {
+      const possibleID = url.pathname.slice(1).split('/')[0]; // Get first path segment
+      if (videoIdPattern.test(possibleID))
+        return possibleID;
+      console.log('[DEV]: Invalid youtu.be video ID:', possibleID);
+      return null;
+    }
+
+    // QUERY match - Check for video ID in query parameters - both 'v' and 'video_id'
+    const queryVideoId = url.searchParams.get('v') || url.searchParams.get('video_id');
+    if (queryVideoId && videoIdPattern.test(queryVideoId))
+      return queryVideoId;
+
+    // PATH match - Handle various YouTube path patterns
+    const validPaths = ['watch', 'embed', 'shorts', 'live', 'clip', 'v'];
+    const pathSegments = url.pathname.split('/').filter(Boolean);
+
+    // If the first segment is a known path type, look for ID in the next segment
+    if (pathSegments.length >= 2 && validPaths.includes(pathSegments[0])) {
+      const possibleID = pathSegments[1];
+      if (videoIdPattern.test(possibleID))
+        return possibleID;
+    }
+
+    // Check each path segment for a valid video ID
+    for (const segment of pathSegments)
+      if (videoIdPattern.test(segment))
+        return segment;
+
+    return null;
+  } catch (e) {
+    return null;
+  }
 }
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