From 2affed814fe32a96abc7d28e81be95d5183331c5 Mon Sep 17 00:00:00 2001
From: Austin Chen <akrolsmir@gmail.com>
Date: Thu, 11 Aug 2022 11:00:58 -0700
Subject: [PATCH] Clean up embed rewrite code

---
 web/components/editor/embed-modal.tsx | 92 +++++++++++----------------
 1 file changed, 38 insertions(+), 54 deletions(-)

diff --git a/web/components/editor/embed-modal.tsx b/web/components/editor/embed-modal.tsx
index 5baac757..bb826e9e 100644
--- a/web/components/editor/embed-modal.tsx
+++ b/web/components/editor/embed-modal.tsx
@@ -7,65 +7,49 @@ import { Modal } from '../layout/modal'
 import { Row } from '../layout/row'
 import { Spacer } from '../layout/spacer'
 
-function isValidIframe(text: string) {
-  return /^<iframe.*<\/iframe>$/.test(text)
+type EmbedPattern = {
+  // Regex should have a single capture group.
+  regex: RegExp
+  rewrite: (text: string) => string
 }
 
-// A valid tweet URL looks like 'https://twitter.com/username/status/123456789'
-// Return the tweetId if the URL is valid, otherwise return null.
-function getTweetId(text: string) {
-  const match = text.match(/^https?:\/\/twitter\.com\/.*\/status\/(\d+)/)
-  return match ? match[1] : null
-}
-
-// Manifold URL: https://manifold.markets/Austin/will-manifold-ever-be-worth-1b
-function getManifoldSlug(text: string) {
-  const match = text.match(/^https?:\/\/manifold\.markets\/([^\/]+\/[^\/]+)/)
-  return match ? match[1] : null
-}
-
-// Youtube URL: 'https://www.youtube.com/watch?v=ziq7FUKpCS8'
-function getYoutubeId(text: string) {
-  const match = text.match(/^https?:\/\/www\.youtube\.com\/watch\?v=([^&]+)/)
-  return match ? match[1] : null
-}
-
-// Metaculus URL: 'https://www.metaculus.com/questions/5320/chinese-annexation-of-half-of-taiwan-by-2050/'
-function getMetaculusId(text: string) {
-  const match = text.match(/^https?:\/\/www\.metaculus\.com\/questions\/(\d+)/)
-  return match ? match[1] : null
-}
-
-function isValidUrl(text: string) {
-  // Conjured by Codex
-  return /^(https?:\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w \.-]*)*\/?$/.test(
-    text
-  )
-}
+const embedPatterns: EmbedPattern[] = [
+  {
+    regex: /^(<iframe.*<\/iframe>)$/,
+    rewrite: (text: string) => text,
+  },
+  {
+    regex: /^https?:\/\/manifold\.markets\/([^\/]+\/[^\/]+)/,
+    rewrite: (slug) =>
+      `<iframe src="https://manifold.markets/embed/${slug}"></iframe>`,
+  },
+  {
+    regex: /^https?:\/\/twitter\.com\/.*\/status\/(\d+)/,
+    rewrite: (id) => `<tiptap-tweet tweetid="t${id}"></tiptap-tweet>`,
+  },
+  {
+    regex: /^https?:\/\/www\.youtube\.com\/watch\?v=([^&]+)/,
+    rewrite: (id) =>
+      `<iframe src="https://www.youtube.com/embed/${id}"></iframe>`,
+  },
+  {
+    regex: /^https?:\/\/www\.metaculus\.com\/questions\/(\d+)/,
+    rewrite: (id) =>
+      `<iframe src="https://www.metaculus.com/questions/embed/${id}"></iframe>`,
+  },
+  {
+    regex: /^(https?:\/\/.*)/,
+    rewrite: (url) => `<iframe src="${url}"></iframe>`,
+  },
+]
 
 function embedCode(text: string) {
-  if (isValidIframe(text)) {
-    return text
-  } else if (getTweetId(text)) {
-    // Append a leading 't', to prevent tweetId from being interpreted as a number.
-    // If it's a number, there may be numeric precision issues.
-    return `<tiptap-tweet tweetid="t${getTweetId(text)}"></tiptap-tweet>`
-  } else if (getManifoldSlug(text)) {
-    return `<iframe src="https://manifold.markets/embed/${getManifoldSlug(
-      text
-    )}"></iframe>`
-  } else if (getYoutubeId(text)) {
-    return `<iframe src="https://www.youtube.com/embed/${getYoutubeId(
-      text
-    )}"></iframe>`
-  } else if (getMetaculusId(text)) {
-    return `<iframe src="https://www.metaculus.com/questions/embed/${getMetaculusId(
-      text
-    )}"></iframe>`
-  } else if (isValidUrl(text)) {
-    return `<iframe src="${text}"></iframe>`
+  for (const pattern of embedPatterns) {
+    const match = text.match(pattern.regex)
+    if (match) {
+      return pattern.rewrite(match[1])
+    }
   }
-  // Return null if the text is not embeddable.
   return null
 }