Add tweet embed and oEmbed API support

src/routes/embed.nim

@@ -1,18 +1,45 @@
 # SPDX-License-Identifier: AGPL-3.0-only
-import asyncdispatch, strutils, strformat, options
+import asyncdispatch, strutils, strformat, json
 import jester, karax/vdom
-import ".."/[types, api]
+import ".."/[types, api, formatters]
 import ../views/[embed, tweet, general]
+include "../views/oembed.nimf"
 import router_utils
 
 export api, embed, vdom, tweet, general, router_utils
 
+proc parseTweetUrl*(url: string): tuple[username, id: string] =
+  var path = url
+  if path.startsWith("https://"):
+    path = path[8..^1]
+  elif path.startsWith("http://"):
+    path = path[7..^1]
+
+  const prefixes = ["twitter.com/", "x.com/", "mobile.twitter.com/",
+                    "www.twitter.com/", "www.x.com/"]
+  for prefix in prefixes:
+    if path.startsWith(prefix):
+      path = path[prefix.len..^1]
+      let parts = path.split('/')
+      if parts.len >= 3 and parts[1] == "status":
+        let tweetId = parts[2].split('?')[0].split('#')[0]
+        if tweetId.len > 0 and tweetId.allCharsInSet(Digits):
+          return (parts[0], tweetId)
+      break
+  return ("", "")
+
 proc createEmbedRouter*(cfg: Config) =
   router embed:
     get "/i/videos/tweet/@id":
-      let tweet = await getGraphTweetResult(@"id")
-      if tweet == nil or not tweet.hasVideos:
-        resp Http404
+      let
+        tweet = await getGraphTweetResult(@"id")
+        prefs = requestPrefs()
+
+      if tweet == nil:
+        resp renderErrorEmbed("Tweet not found", prefs, cfg, request)
+
+      if not tweet.hasVideos:
+        resp renderErrorEmbed("No video in tweet", prefs, cfg, request)
 
       resp renderVideoEmbed(tweet, cfg, request)
 
@@ -23,7 +50,7 @@ proc createEmbedRouter*(cfg: Config) =
         path = getPath()
 
       if tweet == nil:
-        resp Http404
+        resp renderErrorEmbed("Tweet not found", prefs, cfg, request)
 
       resp renderTweetEmbed(tweet, path, prefs, cfg, request)
 
@@ -34,3 +61,35 @@ proc createEmbedRouter*(cfg: Config) =
         redirect(&"/i/status/{id}/embed")
       else:
         resp Http404
+
+    get "/api/oembed":
+      let url = @"url"
+      if url.len == 0:
+        resp Http400, "Missing url parameter"
+
+      let (username, tweetId) = parseTweetUrl(url)
+      if username.len == 0 or tweetId.len == 0:
+        resp Http400, "Invalid tweet URL"
+
+      let tweet = await getGraphTweetResult(tweetId)
+      if tweet == nil:
+        resp Http404
+
+      let
+        embedUrl = getUrlPrefix(cfg) & "/" & username & "/status/" & tweetId & "/embed"
+        authorUrl = getUrlPrefix(cfg) & "/" & tweet.user.username
+
+      responseHeaders().get.add(("Access-Control-Allow-Origin", "*"))
+      respJson %*{
+        "version": "1.0",
+        "type": "rich",
+        "provider_name": cfg.title,
+        "provider_url": getUrlPrefix(cfg),
+        "author_name": tweet.user.fullname,
+        "author_url": authorUrl,
+        "url": embedUrl,
+        "width": 550,
+        "height": nil,
+        "cache_age": "3153600000",
+        "html": renderOembedIframe(embedUrl)
+      }

src/routes/router_utils.nim

@@ -4,7 +4,7 @@ from jester import Request, cookies
 
 import ../views/general
 import ".."/[utils, prefs, types]
-export utils, prefs, types, uri
+export utils, prefs, types, uri, json
 
 template savePref*(pref, value: string; req: Request; expire=false) =
   if not expire or pref in cookies(req):