from re import match
from typing import List, Optional

from scrapthechan.fileinfo import FileInfo
from scrapthechan.parser import Parser

__all__ = ["DvachParser"]


class DvachParser(Parser):
	"""JSON parser for 2ch.hk image board."""

	__url_thread_json = "https://2ch.hk/{board}/res/{thread}.json"
	__url_file_link = "https://2ch.hk"

	def __init__(self, board: str, thread: str,
				 skip_posts: Optional[int] = None) -> None:
		posts = self._get_json(self.__url_thread_json.format(board=board, \
			thread=thread))['threads'][0]['posts']
		super(DvachParser, self).__init__(board, thread, posts, skip_posts)

	@property
	def imageboard(self) -> str:
		return "2ch.hk"

	@property
	def op(self) -> str:
		return f"{self._op_post['subject']}\n{self._op_post['comment']}"

	def _parse_post(self, post) -> Optional[List[FileInfo]]:
		if not 'files' in post: return None
		files = []
		for f in post['files']:
			if match(f['fullname'], r"^image\.\w+$") is None:
				fullname = f['fullname']
			else:
				fullname = f['name']
			# Here's same thing as 4chan. 2ch.hk also has md5 field, so it is
			# completely fine to hardcode `hash_algo`.
			files.append(FileInfo(fullname, f['size'],
				f"{self.__url_file_link}{f['path']}",
				f['md5'], 'md5'))
		return files