From 87e326d976c73053f480c84fc4109eb7b56456df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Tronel?=
 <frederic.tronel@centralesupelec.fr>
Date: Sat, 29 Aug 2026 13:50:46 +0200
Subject: [PATCH] Remove function to discover if required tools are installed.

---
 src/tscut/tools/discovery.py | 51 ++++++++++++++++++++++++++++++++++++
 src/tscut/tscut.py           | 39 ---------------------------
 2 files changed, 51 insertions(+), 39 deletions(-)
 create mode 100644 src/tscut/tools/discovery.py

diff --git a/src/tscut/tools/discovery.py b/src/tscut/tools/discovery.py
new file mode 100644
index 0000000..94d28a5
--- /dev/null
+++ b/src/tscut/tools/discovery.py
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2026 Frédéric Tronel
+
+
+import logging
+from shutil import which
+
+from typeguard import typechecked
+
+
+class MissingToolError(Exception):
+    pass
+
+@typechecked
+def check_required_tools() -> tuple[bool,dict[str,str]]:
+    """
+    Checks if all required external tools are installed.
+
+    This function verifies the presence of required and optional external tools on the system.
+    It returns a tuple containing a boolean indicating whether all optional tools are installed,
+    along with a dictionary containing the paths to all tools.
+
+    Args:
+        None
+
+    Returns:
+        tuple[bool, dict[str, str]]: 
+            - bool: True if all optional tools are installed, False otherwise
+            - dict[str, str]: dictionary containing the paths to all tools
+    """
+    logger = logging.getLogger(__name__)
+    all_optional_tools = True
+    paths = {}
+    required = ['ffmpeg', 'ffprobe', 'mkvmerge', 'mkvinfo']
+    optional = ['mkvextract', 'vobsubocr','tesseract']
+    for tool in required:
+        path = which(tool)
+        if  path is None:
+            logger.error('Required tool: %s is missing.',tool)
+            raise MissingToolError(tool)
+        paths[tool] = path
+    for tool in optional:
+        path = which(tool)
+        if path is None:
+            logger.info('Optional tool: %s is missing.',tool)
+            all_optional_tools = False
+        else:
+            paths[tool] = path
+
+    return all_optional_tools, paths
diff --git a/src/tscut/tscut.py b/src/tscut/tscut.py
index 37b4621..7eada87 100755
--- a/src/tscut/tscut.py
+++ b/src/tscut/tscut.py
@@ -21,7 +21,6 @@ from os import (
     set_inheritable,
     write,
 )
-from shutil import which
 from subprocess import PIPE, Popen
 from sys import exit
 from typing import IO
@@ -82,44 +81,6 @@ from tscut.tools.timeframe import (
 # Then finally, change the Private Codec Data in the final MKV.
 
 
-@typechecked
-def check_required_tools() -> tuple[bool,dict[str,str]]:
-    """
-    Checks if all required external tools are installed.
-
-    This function verifies the presence of required and optional external tools on the system.
-    It returns a tuple containing a boolean indicating whether all optional tools are installed,
-    along with a dictionary containing the paths to all tools.
-
-    Args:
-        None
-
-    Returns:
-        tuple[bool, dict[str, str]]: 
-            - bool: True if all optional tools are installed, False otherwise
-            - dict[str, str]: dictionary containing the paths to all tools
-    """
-    logger = logging.getLogger(__name__)
-    all_optional_tools = True
-    paths = {}
-    required = ['ffmpeg', 'ffprobe', 'mkvmerge', 'mkvinfo']
-    optional = ['mkvextract', 'vobsubocr','tesseract']
-    for tool in required:
-        path = which(tool)
-        if  path is None:
-            logger.error('Required tool: %s is missing.',tool)
-            exit(-1)
-        else:
-            paths[tool] = path
-    for tool in optional:
-        path = which(tool)
-        if path is None:
-            logger.info('Optional tool: %s is missing.',tool)
-            all_optional_tools = False
-        else:
-            paths[tool] = path
-
-    return all_optional_tools, paths
 
 @typechecked
 def get_tesseract_supported_lang(tesseract_path:str) -> dict[Lang, str]|None: