Only download videos not already downloaded

kalite/updates/api_views.py

@@ -30,7 +30,8 @@
 from kalite.i18n.base import lcode_to_ietf, delete_language, get_language_name
 from kalite.shared.decorators.auth import require_admin
 from kalite.topic_tools.settings import CHANNEL
-from kalite.topic_tools.content_models import get_topic_update_nodes, get_download_youtube_ids, annotate_content_models_by_youtube_id
+from kalite.topic_tools.content_models import get_topic_update_nodes, get_download_youtube_ids, \
+    annotate_content_models_by_youtube_id, get as get_content_item
 
 
 def process_log_from_request(handler):
@@ -129,10 +130,12 @@ def start_video_download(request):
     lang = json.loads(request.body or "{}").get("lang", "en")
 
     youtube_ids = get_download_youtube_ids(paths, language=lang)
-
+    ids_to_queue = {id_: title for (id_, title) in youtube_ids.iteritems()
+                    if not get_content_item({"youtube_id": id_}).available}
+
     queue = VideoQueue()
 
-    queue.add_files(youtube_ids, language=lang)
+    queue.add_files(ids_to_queue, language=lang)
 
     force_job("videodownload", _("Download Videos"), locale=lang)