feat(import): youtube csv playlist import

src/invidious/routes/preferences.cr

@@ -310,6 +310,8 @@ module Invidious::Routes::PreferencesRoute
               response: error_template(415, "Invalid subscription file uploaded")
             )
           end
+        when "import_youtube_playlist"
+          Invidious::User::Import.from_youtube_playlist(user, body)
         when "import_freetube"
           Invidious::User::Import.from_freetube(user, body)
         when "import_newpipe_subscriptions"

src/invidious/user/imports.cr

@@ -149,6 +149,43 @@ struct Invidious::User
       return true
     end
 
+    # -------------------
+    #  YouTube playlist
+    # -------------------
+
+    def from_youtube_playlist(user : User, body : String)
+      
+      csv = CSV.new(body, headers: true)
+      csv.next
+
+      playlist_title = csv[4]
+      playlist_description = csv[5]
+      playlist = create_playlist(playlist_title, PlaylistPrivacy::Private, user, playlist_description)
+      
+      # skip playlist data
+      csv.next
+
+      # skip the blank lines before the videos
+      until csv[0] != ""
+        csv.next
+      end
+      
+
+      while csv.next
+        # check if the string is a valid
+        #YouTube video ID
+        video_id = csv[0]
+        if /^[A-Za-z0-9_-]{11}$/ =~ video_id
+          begin
+            video = get_video(video_id)
+            playlist.add_new_video(video)
+          rescue ex : NotFoundException
+          rescue ex
+          end
+        end
+      end
+    end
+
     # -------------------
     #  Freetube
     # -------------------