#!python
import os
import shutil
import argparse

def combine_split_files(base_dir, subdir_prefix="subdir_"):
    """
    Moves all files from subdirectories (whose names start with subdir_prefix)
    back to the base directory.

    Args:
        base_dir (str): Path to the base directory containing split subdirectories.
        subdir_prefix (str): Prefix used for subdirectories created during split.
                              Default is "subdir_".
    """
    # List items in the base directory
    items = os.listdir(base_dir)
    combined_count = 0

    for item in items:
        sub_dir_path = os.path.join(base_dir, item)
        # Process only directories with the given prefix
        if os.path.isdir(sub_dir_path) and item.startswith(subdir_prefix):
            print(f"Processing directory: {sub_dir_path}")
            for file_name in os.listdir(sub_dir_path):
                src_file = os.path.join(sub_dir_path, file_name)
                dst_file = os.path.join(base_dir, file_name)
                # If a file with the same name already exists, handle it (here we skip)
                if os.path.exists(dst_file):
                    print(f"Warning: {dst_file} already exists. Skipping {src_file}.")
                    continue
                try:
                    shutil.move(src_file, dst_file)
                    combined_count += 1
                except Exception as e:
                    print(f"Error moving {src_file} to {dst_file}: {e}")
            # After moving, attempt to remove the now-empty subdirectory
            try:
                os.rmdir(sub_dir_path)
                print(f"Removed directory: {sub_dir_path}")
            except Exception as e:
                print(f"Could not remove directory {sub_dir_path}: {e}")

    print(f"\nCombined {combined_count} files into {base_dir}.")

def main():
    parser = argparse.ArgumentParser(
        description="Rollback split files by moving files from split subdirectories back into the base directory."
    )
    parser.add_argument("base_dir", help="Base directory containing the split subdirectories")
    parser.add_argument(
        "--prefix",
        default="subdir_",
        help="Prefix of the split subdirectories (default: 'subdir_')"
    )
    args = parser.parse_args()

    # Validate the base directory exists
    if not os.path.isdir(args.base_dir):
        print(f"Error: {args.base_dir} is not a valid directory.")
        return

    combine_split_files(args.base_dir, args.prefix)

if __name__ == "__main__":
    main()