replace libtorrent with torf (#506)

torf is a python library which deals with torrents, magnets and more. It
is a python only library and has no C backend.

The main reason for replacing it is that libtorrent doesn't have
bindings for pyhton 3.14, which is now the default on arch (I use arch
btw.)

---

Since I don't have a torrent downloader, someone should verify that this
still works (:

Maybe one should add tests for it as well :D

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Chores**
* Replaced the torrent parsing library and updated project dependency
accordingly.
  * Updated container build to remove the now-unused OS package.

* **Bug Fixes**
* Improved reliability of torrent info extraction during magnet and
fallback handling.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Dockerfile

@@ -13,7 +13,7 @@ RUN env PUBLIC_VERSION=${VERSION} PUBLIC_API_URL=${BASE_PATH} BASE_PATH=${BASE_P
 FROM ghcr.io/astral-sh/uv:python3.13-trixie-slim AS base 
 
 RUN apt-get update && \
-    apt-get install -y ca-certificates bash libtorrent21 gcc bc locales postgresql media-types mailcap curl gzip unzip tar 7zip bzip2 unar gosu && \
+    apt-get install -y ca-certificates bash gcc bc locales postgresql media-types mailcap curl gzip unzip tar 7zip bzip2 unar gosu && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/*
 

media_manager/torrent/utils.py

@@ -6,9 +6,9 @@ import shutil
 from pathlib import Path, UnsupportedOperation
 
 import bencoder
-import libtorrent
 import patoolib
 import requests
+import torf
 from pathvalidate import sanitize_filename
 from requests.exceptions import InvalidSchema
 
@@ -142,7 +142,7 @@ def get_torrent_hash(torrent: IndexerQueryResult) -> str:
     if torrent.download_url.startswith("magnet:"):
         log.info(f"Parsing torrent with magnet URL: {torrent.title}")
         log.debug(f"Magnet URL: {torrent.download_url}")
-        torrent_hash = str(libtorrent.parse_magnet_uri(torrent.download_url).info_hash)
+        torrent_hash = torf.Magnet.from_string(torrent.download_url).infohash
     else:
         # downloading the torrent file
         log.info(f"Downloading .torrent file of torrent: {torrent.title}")
@@ -157,7 +157,7 @@ def get_torrent_hash(torrent: IndexerQueryResult) -> str:
                 session=requests.Session(),
                 timeout=MediaManagerConfig().indexers.prowlarr.timeout_seconds,
             )
-            return str(libtorrent.parse_magnet_uri(final_url).info_hash)
+            return torf.Magnet.from_string(final_url).infohash
         except Exception:
             log.exception("Failed to download torrent file")
             raise

pyproject.toml

@@ -34,9 +34,9 @@ dependencies = [
     "pillow>=11.3.0",
     "sabnzbd-api>=0.1.2",
     "transmission-rpc>=7.0.11",
-    "libtorrent>=2.0.11",
     "pathvalidate>=3.3.1",
     "asgi-correlation-id>=4.3.4",
+    "torf>=4.3.1",
 ]
 
 [dependency-groups]