Add check for no-files-found

regain

@@ -22,16 +22,26 @@
 # SOFTWARE.
 
 import os
+import sys
 import subprocess
 import logging
 import argparse
 
 FORMATS = ["flac", "m4a", "aac", "alac", "mp3", "m3a", "ogg", "opus", "oga"]
 PATH_TO_REGAINER = "./regainer.py"
+DESCRIPTION = """
+regain - Calls regainer.py on any albums found in subdirectories.
+\n\n
+Run the regain command in a directory that contains albums and ReplayGain tags will be
+added to the files, including album tags.
+\n\n
+regain will walk through all subdirectories so can be run in your 'Music' folder, or
+individual artist/album folders and tag as many albums as neccessary.
+"""
 
 def parse_arguments():
-    parser = argparse.ArgumentParser(description='Call regainer.py on subdirectories containing music files')
-    parser.add_argument('--debug', action='store_true', help='Enable debug logging')
+    parser = argparse.ArgumentParser(description=DESCRIPTION)
+    parser.add_argument('--debug', action='store_true', help='Enable debug logging (including regainer output)')
     return parser.parse_args()
 
 def configureLogging(debug_mode = False):
@@ -64,7 +74,12 @@ if __name__ == "__main__":
     logging.debug("Debug logs enabled")
     file_lists = find_files_by_extension(workdir)
     logging.debug(f"File lists: {file_lists}")
-    logging.info(f"Files for processing: {countFiles(file_lists)}")
+    file_count = countFiles(file_lists)
+    if file_count == 0:
+        logging.error("No files to process")
+        print("You should run this command from the parent directory of any album folders")
+        sys.exit(1)
+    logging.info(f"Files for processing: {file_count}")
 
     cmd = ["python", PATH_TO_REGAINER, "-f"]
     for sublist in file_lists: