Remove function to discover if required tools are installed.

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