from dataclasses import dataclass
from collections.abc import Iterable, Iterator
from typing import Optional
import requests

@dataclass(frozen=True)
class ListFileEntry:
  entry: str
  comment: Optional[str]

class ListFileIterator(Iterator[ListFileEntry]):
  def __init__(self, entries: list[ListFileEntry]):
    self._entries = entries
    self.index = -1
  def __next__(self) -> ListFileEntry:
    if self.index == len(self._entries):
      raise StopIteration
    self.index += 1
    return self._entries[self.index]

@dataclass(frozen=True)
class ListFile(Iterable[ListFileEntry]):
  def __init__(self, contents: str):
    self._contents = contents
    acc = []
    comment_acc = ""
    for line in contents.splitlines():
      if line.startswith("#"):
        continue
      elif line.startswith("##"):
        comment_acc += line[2:].strip()
      else:
        acc.append(ListFileEntry(comment = comment_acc if comment_acc else None, entry = line))

    self._entries = acc

  def __iter__(self) -> ListFileIterator:
    return ListFileIterator(self._entries)

  def entries(self) -> list[ListFileEntry]:
    return self._entries

  @classmethod
  def from_url(cls, url: str):
    return cls(requests.get(url, stream = False).text)