add new youtubedl dependency

downloader/vendor/github.com/kkdai/youtube/v2/video_id.go

@@ -0,0 +1,34 @@
+package youtube
+
+import (
+	"regexp"
+	"strings"
+)
+
+var videoRegexpList = []*regexp.Regexp{
+	regexp.MustCompile(`(?:v|embed|shorts|watch\?v)(?:=|/)([^"&?/=%]{11})`),
+	regexp.MustCompile(`(?:=|/)([^"&?/=%]{11})`),
+	regexp.MustCompile(`([^"&?/=%]{11})`),
+}
+
+// ExtractVideoID extracts the videoID from the given string
+func ExtractVideoID(videoID string) (string, error) {
+	if strings.Contains(videoID, "youtu") || strings.ContainsAny(videoID, "\"?&/<%=") {
+		for _, re := range videoRegexpList {
+			if isMatch := re.MatchString(videoID); isMatch {
+				subs := re.FindStringSubmatch(videoID)
+				videoID = subs[1]
+			}
+		}
+	}
+
+	if strings.ContainsAny(videoID, "?&/<%=") {
+		return "", ErrInvalidCharactersInVideoID
+	}
+
+	if len(videoID) < 10 {
+		return "", ErrVideoIDMinLength
+	}
+
+	return videoID, nil
+}