From 87ff66f8fe8c8f42980fbf758641e380282870c8 Mon Sep 17 00:00:00 2001
From: Andy <scene@scene.com>
Date: Sun, 9 Nov 2025 21:27:19 +0000
Subject: [PATCH] fix: ensure subtitles use requests downloader instead of
 n_m3u8dl_re if Descriptor.URL

PR #38 refactored n_m3u8dl_re track selection to support DASH/ISM subtitle tracks, but this broke some subtitle downloads. Services that use direct URL downloads (Descriptor.URL) for subtitles, which n_m3u8dl_re does not support.
---
 unshackle/core/downloaders/n_m3u8dl_re.py |  6 ++++++
 unshackle/core/tracks/track.py            | 26 +++++++++++++----------
 2 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/unshackle/core/downloaders/n_m3u8dl_re.py b/unshackle/core/downloaders/n_m3u8dl_re.py
index 52ea3be..7472c59 100644
--- a/unshackle/core/downloaders/n_m3u8dl_re.py
+++ b/unshackle/core/downloaders/n_m3u8dl_re.py
@@ -142,6 +142,12 @@ def get_track_selection_args(track: Any) -> list[str]:
                         parts.append(f"lang={lang}")
                 return _create_args("-ss", parts, "subtitle", extra_args=["--auto-subtitle-fix", "false"])
 
+        case "URL":
+            raise ValueError(
+                f"[N_m3u8DL-RE]: Direct URL downloads are not supported for {track_type} tracks. "
+                f"The track should use a different downloader (e.g., 'requests', 'aria2c')."
+            )
+
     raise ValueError(f"[N_m3u8DL-RE]: Unsupported manifest type: {descriptor}")
 
 
diff --git a/unshackle/core/tracks/track.py b/unshackle/core/tracks/track.py
index 6cf12c9..0b1a38f 100644
--- a/unshackle/core/tracks/track.py
+++ b/unshackle/core/tracks/track.py
@@ -211,17 +211,21 @@ class Track:
         save_path = config.directories.temp / f"{track_type}_{self.id}.mp4"
         if track_type == "Subtitle":
             save_path = save_path.with_suffix(f".{self.codec.extension}")
-            # n_m3u8dl_re doesn't support directly downloading subtitles
-            if self.downloader.__name__ == "n_m3u8dl_re" and get_extension(self.url) in {
-                ".srt",
-                ".vtt",
-                ".ttml",
-                ".ssa",
-                ".ass",
-                ".stpp",
-                ".wvtt",
-                ".xml",
-            }:
+            # n_m3u8dl_re doesn't support directly downloading subtitles from URLs
+            # or when the subtitle has a direct file extension
+            if self.downloader.__name__ == "n_m3u8dl_re" and (
+                self.descriptor == self.Descriptor.URL
+                or get_extension(self.url) in {
+                    ".srt",
+                    ".vtt",
+                    ".ttml",
+                    ".ssa",
+                    ".ass",
+                    ".stpp",
+                    ".wvtt",
+                    ".xml",
+                }
+            ):
                 self.downloader = requests
 
         if self.descriptor != self.Descriptor.URL: