build spotify-to-navidrome migrator with recovery flow

internal/spotify/playlist_url.go

@@ -0,0 +1,43 @@
+package spotify
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+func ParsePlaylistID(input string) (string, error) {
+	s := strings.TrimSpace(input)
+	if s == "" {
+		return "", fmt.Errorf("empty playlist input")
+	}
+
+	if strings.HasPrefix(s, "spotify:playlist:") {
+		id := strings.TrimSpace(strings.TrimPrefix(s, "spotify:playlist:"))
+		if id == "" {
+			return "", fmt.Errorf("invalid spotify URI")
+		}
+		return id, nil
+	}
+
+	if !strings.Contains(s, "://") {
+		return s, nil
+	}
+
+	u, err := url.Parse(s)
+	if err != nil {
+		return "", fmt.Errorf("invalid playlist URL")
+	}
+	parts := strings.Split(strings.Trim(u.Path, "/"), "/")
+	for i := 0; i < len(parts)-1; i++ {
+		if parts[i] == "playlist" {
+			id := strings.TrimSpace(parts[i+1])
+			if id == "" {
+				return "", fmt.Errorf("missing playlist id in URL")
+			}
+			return id, nil
+		}
+	}
+
+	return "", fmt.Errorf("could not find playlist id in URL")
+}