from __future__ import annotations

import re
from dataclasses import dataclass


@dataclass
class File:
    name: str
    size: int

    def __equals__(self, other):
        return self.name == other.name and self.size == other.size


@dataclass
class Folder:
    name: str
    parent: Folder | None
    children: list[Folder | File]

    def __equals__(self, other):
        return self.name == other.name and self.parent == other.parent

    @property
    def full_name(self):
        if self.parent is None:
            return "/"
        else:
            return self.parent.full_name + f"/{self.name}"

    @property
    def size(self):
        return sum(map(lambda x: x.size, self.children))

    def __lt__(self, other):
        return self.size < other.size


def pretty_print(folder: Folder, depth: int = 0) -> None:
    print("".join([" " for i in range(depth + 1)]), end="- ")
    print(f"{folder.name} (dir)")
    for object in folder.children:
        if type(object) is Folder:
            pretty_print(object, depth + 1)
        else:
            print("".join([" " for i in range(depth + 2)]), end="- ")
            print(f"{object.name} (file, size={object.size})")


def parse(filename: str) -> Folder:
    filesystem = Folder(name="/", parent=None, children=[])
    with open(filename) as f:
        f.readline()
        current = filesystem
        while line := f.readline()[:-1]:
            if line[0] == "$":
                if match := re.match(r"\$ cd (.+)", line):
                    folder_name = match.group(1)
                    if folder_name != "..":
                        current = filter(lambda x: x.name == folder_name, current.children).__next__()
                    else:
                        current = current.parent
            else:
                if match := re.match(r"(\d+) ((?:\w|.)+)", line):
                    fichier = File(name=match.group(2), size=int(match.group(1)))
                    current.children.append(fichier)
                elif match := re.match(r"dir (\w+)", line):
                    folder = Folder(name=match.group(1), parent=current, children=[])
                    current.children.append(folder)
    return filesystem