#!/usr/bin/env python
from pathlib import Path
from argparse import ArgumentParser
from collections import Counter, defaultdict

def with_files(path, args):
    if args.files:
        return True
    return path.is_dir()

if __name__ == '__main__':
    parser = ArgumentParser(
        description='rename folders with case-insensitive names')
    parser.add_argument('startfolder', help='where to start')
    parser.add_argument('--with_files', '-w', action='store_true',
                        help='rename files, too')
    args = parser.parse_args()

    # recursively get and sort paths by length
    folders = sorted([path for path in Path(args.startfolder).rglob('*')
                      if with_files(path, args)], key=lambda x: len(x.parts),
                     reverse=True)
    foldernames = {str(folder): str(folder).lower() for folder in folders}
    
    counter = Counter(foldernames.values())
    duplicate_folders = [item for item in counter if counter[item] > 1]
    
    count_folders = defaultdict(lambda: 1)  # counters / folder start with 1
    rename_folders = []
    for duplicate_folder in duplicate_folders:
        names = sorted([key for key, value in foldernames.items()
                        if value == duplicate_folder])[1:]
        for name in names:
            rename_folders.append(
                (name, (name, count_folders[duplicate_folder])))
            count_folders[duplicate_folder] += 1

    for old, new in rename_folders:
        old = Path(old)
        newname, newcounter = new
        while newpath := Path('%s_%04d'%(newname, newcounter)):
            if not newpath.exists():
                break
            newcounter += 1
        old.rename(newpath)