#!python

import os
import sys
import datetime
from pathlib import Path

if len(sys.argv) < 2:
    print(
        """pysm_tag_filename

    Modify a filename to add a datestamp based on the last modification date
    e.g. `myfile.txt` becomes `myfile_2022.06.22.txt`"""
    )

for filename in sys.argv[1:]:
    filename = Path(filename)
    file_modification_date = datetime.datetime.fromtimestamp(
        os.path.getmtime(filename)
    ).strftime("%Y.%m.%d")
    new_filename = f"{filename.stem}_{file_modification_date}{filename.suffix}"
    print(filename, "=>", new_filename)
    filename.rename(new_filename)
