API: make /api/v1/videos respect the 'local' parameter (#3567)

src/invidious/routes/api/v1/videos.cr

@@ -6,6 +6,7 @@ module Invidious::Routes::API::V1::Videos
 
     id = env.params.url["id"]
     region = env.params.query["region"]?
+    proxy = {"1", "true"}.any? &.== env.params.query["local"]?
 
     begin
       video = get_video(id, region: region)
@@ -15,7 +16,9 @@ module Invidious::Routes::API::V1::Videos
       return error_json(500, ex)
     end
 
-    video.to_json(locale, nil)
+    return JSON.build do |json|
+      Invidious::JSONify::APIv1.video(video, json, locale: locale, proxy: proxy)
+    end
   end
 
   def self.captions(env)

src/invidious/routes/video_playback.cr

@@ -101,14 +101,8 @@ module Invidious::Routes::VideoPlayback
           env.response.headers["Access-Control-Allow-Origin"] = "*"
 
           if location = resp.headers["Location"]?
-            location = URI.parse(location)
-            location = "#{location.request_target}&host=#{location.host}"
-
-            if region
-              location += "&region=#{region}"
-            end
-
-            return env.redirect location
+            url = Invidious::HttpServer::Utils.proxy_video_url(location, region: region)
+            return env.redirect url
           end
 
           IO.copy(resp.body_io, env.response)