#!/usr/bin/python3

from glob import glob
from os import remove as os_remove
from os.path import isdir as path_isdir, isfile as path_isfile, abspath, \
    basename
from pathlib import Path
from re import sub as re_sub
from shutil import rmtree

DRY_RUN = False

remove_comments = lambda s: re_sub(r"(?<!\\)#.*$", "", s).replace(r"\#", "#")


def read_gitignore(path: str) -> str:
    with open(path, "r", encoding="utf-8-sig") as gitignore_file:
        res = gitignore_file.read().splitlines()
    return res


def delete(file_path: str) -> None:
    is_dir = path_isdir(file_path)
    is_file = path_isfile(file_path)

    if not (is_dir or is_file):
        return

    display_file_path = abspath(file_path)
    if DRY_RUN:
        if is_dir:
            print("Removing directory", display_file_path)
        elif is_file:
            print("Removing file", display_file_path)

    if DRY_RUN:
        return

    if is_dir:
        rmtree(file_path, ignore_errors=True)
    elif is_file:
        os_remove(file_path)


def extend_wildcards(patterns: list) -> list:
    res = []
    for pattern in patterns:
        processed_line = remove_comments(pattern).strip()

        if processed_line.startswith("!"):
            exception_pattern = processed_line[1:]
            exceptions = glob(exception_pattern, recursive=True)
            res = [path for path in res if path not in exceptions]
        else:
            res.extend(glob(processed_line, recursive=True))

    return res


def clean_gitignored_files(base_path: str = ".") -> None:
    for gitignore_path in list(Path(base_path).rglob("*.gitignore")):
        for file_path in extend_wildcards(read_gitignore(gitignore_path)):
            delete(file_path)


if __name__ == "__main__":
    from sys import argv

    if "-h" in argv or "--help" in argv:
        print("Usage:", basename(argv[0]), "[options]")
        print()
        print("[ ]: Optional arguments")
        print()
        print("Options:")
        print("    -h, --help: Display this help text")
        print("    -d, --dry-run: Only list files")
    else:
        if (argc := len(argv)) == 2 and argv[1] in ["-d", "--dry-run"]:
            DRY_RUN = True
        clean_gitignored_files()