Implement skipping videos that we've already seen

youtubeWatcher/main.go

@@ -74,9 +74,22 @@ func (w *RssWatcher) CheckFeed(videoUrls chan string) error {
 	}
 
 	for _, entry := range feed.Entry {
+		uploaded, err := time.Parse(time.RFC3339, entry.Published)
+		if err != nil {
+			return fmt.Errorf("[%s]: failed to parse published date: %w", w.Feed.Id, err)
+		}
+		if uploaded.Before(w.Feed.LastSeen) {
+			log.Printf("[%s]: Skipping video titled %q because it was uploaded before %s", w.Feed.Id, entry.Title, w.Feed.LastSeen.Format(time.RFC3339))
+			continue
+		}
 		log.Printf("[%s]: Found new video titled %q with url %q", w.Feed.Id, entry.Title, entry.Link.Href)
 		videoUrls <- entry.Link.Href
 	}
+	err = w.Feed.WriteLastSeen(time.Now())
+	if err != nil {
+		return fmt.Errorf("[%s]: failed to write last seen: %w", w.Feed.Id, err)
+	}
+	w.Feed.LastSeen = time.Now()
 
 	return nil
 }