# pip install watchdog
# python3 rename.py <path>

import sys
import time
from watchdog.observers import Observer
from watchdog.events import FileSystemEventHandler
import datetime
import os


FILE_FORMAT = "%Y%m%d_%H%M%S%f"


class FileRenamer(FileSystemEventHandler):
    def on_created(self, event):
        path = event.src_path
        now = datetime.datetime.now().strftime(FILE_FORMAT)
        head, tail = os.path.split(path)
        _, ext = os.path.splitext(tail)
        new_path = os.path.join(head, f"{now}{ext}")
        print(f"Renaming {path} --> {new_path}")
        os.rename(path, new_path)


if __name__ == "__main__":
    path = sys.argv[1] if len(sys.argv) > 1 else '.'
    event_handler = FileRenamer()
    observer = Observer()
    observer.schedule(event_handler, path, recursive=True)
    observer.start()
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()
    observer.join()